Ovarian cancer ranks as the eighth most frequently diagnosed
cancer and the eighth leading cause of cancer-related deaths in
women worldwide. An estimated 324,603 women were diag-
nosed with ovarian cancer in 2022 and 206,956 died of the
disease according to GLOBOCAN 2022 1. The global number
of ovarian cancer cases and deaths is projected to increase by
46.9% and 62.7%, respectively, reaching 476,912 cases and
336,637 deaths by 2050 2. Although there have been advances
in ovarian cancer screening, detection, and treatment meth-
ods over the past several decades, particularly targeted ther -
apy and immunotherapy 3, ovarian cancer remains largely
incurable with a 5-year net survival < 50% in most countries4.
The substantial disease burden underscores the public health
significance given the persistent challenges in treating ovar -
ian cancer. A structured search of PubMed, Web of Science,
and EMBASE (January 1990–May 2025) was performed using
terms related to ovarian cancer epidemiology, risk factors,
screening, and prevention. Peer-reviewed original studies,
pooled analyses, meta-analyses, and large population-based
investigations were included, while non-English publica-
tions, case reports, conference abstracts, and studies lacking
methodologic detail were excluded. Additional sources were
identified through manual reference screening. This review
presents the most recent and comprehensive evidence on the
epidemiology, risk factors, screening, and prevention of ovar-
ian cancer with the aim of enhancing global understanding
and informing public health strategies to reduce the burden
of disease.
*These authors contributed equally to this work.
Correspondence to: Bin Li and Hongmei Zeng
E-mail:
[email protected] and
[email protected]
ORCID ID: https://orcid.org/0000-0001-8660-6457 and https://orcid.
org/0000-0003-3999-3081
Received October 9, 2025; accepted December 24, 2025; published
online March 24, 2026.
Available at www.cancerbiomed.org
©2026 The Authors. Creative Commons Attribution-NonCommercial
4.0 International License (CC BY-NC 4.0).
2 Li et al. Global epidemiology of ovarian cancer
Pathologic classification of ovarian
cancer
Ovarian cancer encompasses a heterogeneous group that orig-
inates from epithelial and non-epithelial cells, resulting in two
major subtypes (epithelial and non-epithelial ovarian cancer).
Each subtype is characterized by distinct origins, pathologic
features, epidemiologic patterns, and risk factors.
Epithelial ovarian cancer is the most common form,
accounting for 90%–95% of all ovarian cancers 5,6. Epithelial
cancer is classified histologically into serous (52%), endome-
trioid (10%), mucinous (6%), clear cell (6%), and unspecified
subtypes (approximately 25%) 7. Low-grade serous carcino-
mas are thought to originate from fallopian tube epithelium
(endosalpingiosis) or serous ovarian borderline tumors,
whereas endometrioid and clear cell carcinomas originate
from endometrial tissue (endometriosis) 8. Most mucinous
carcinomas are believed to derive from transitional epithelium
at the tuboperitoneal junction9.
Epithelial ovarian cancer can be further grouped as type I or
II ovarian cancer according to clinicopathologic and molecular
characteristics9. Type I epithelial ovarian cancers are generally
low-grade and indolent, genetically stable, large, unilateral,
cystic tumors that are confined to the ovary and are believed
to develop from extraovarian benign lesions. Type II epithelial
ovarian cancers typically present in an advanced stage and are
high-grade bilateral types with aggressive behavior and lethal
survival. Type II epithelial ovarian cancers are thought to orig-
inate as fallopian tube fimbriae carcinomas that spread to the
ovaries and/or peritoneum9,10.
Non-epithelial ovarian cancer consists of sex cord-stromal
tumors (e.g., granulosa cell tumors and thecomas) and germ cell
tumors (e.g., teratomas and dysgerminomas). These subtypes are
relatively rare and occur more frequently in younger women.
The endometrioid subtype of localized and regional epi-
thelial ovarian cancer exhibits the most favorable prognosis,
followed by low-grade serous and mucinous ovarian cancer.
Ovarian carcinosarcoma is associated with the poorest prog-
nosis with a 5-year survival rate < 50%. However, distant-stage
ovarian cancer, which accounts for the majority of diagnoses,
presents a comparatively worse prognosis. Within these clas-
sifications, low-grade serous, endometrioid, and high-grade
serous ovarian cancer have the best prognosis, followed by
clear cell and mucinous subtypes. Ovarian carcinosarcoma has
the worst histology of ovarian cancer6.
Descriptive epidemiology and time
trend of the cancer burden
The global annual incident cases of ovarian cancer reached
324,603 in 2022 according to GLOBOCAN 1; the geographic
incidence variation differed worldwide. The highest age-ad-
justed incidence rates for ovarian cancer were in Eastern Europe
at 11.0/100,000, followed by Northern Europe (9.1/100,000),
Southern Europe (8.4/100,000), and South-East Asia (8.1/100,000).
The lowest age-adjusted incidence rates for ovarian cancer were
in Middle Africa (4.3/100,000), Southern Africa (4.9/100,000),
and the Caribbean (4.9/100,000). Detailed data for each region
are shown in Table 1.
Countries with a very high human development index
(HDI) had the highest age-adjusted incidence rates for ovar -
ian cancer (8.2/100,000). Low HDI countries had the lowest
incidence rate for ovarian cancer (4.9/100,000). The global
age-standardized incidence rate for ovarian cancer declined
from 7.22/100,000 to 6.71/100,000 from 1990 to 2021 with
an estimated annual percentage change of −0.38 [95% con-
fidence interval (CI), −0.43 to −0.32] 1,11. Detailed data from
2005–2016 revealed a decreased incidence rate for ovarian
cancer in Australia, the USA, Denmark, Sweden, Germany,
France, Colombia, and Norway, which was due, at least in
part, to the increased use of oral contraceptive pills and the
decreased administration of menopausal estrogen-only hor -
mone therapy 7,12. In contrast, the incidence rates for ovar -
ian cancer in Eastern Europe and some regions of Asia have
been increasing, particularly in Belarus, Japan, Thailand,
and India 12,13. Of note, the lower use of oral contraceptive
pills and lower parity might partially explain the increas-
ing rates 14. Statistics in China showed the age-standardized
incidence rates for ovarian cancer were relatively stable from
2011–2018 15.
The global new deaths from ovarian cancer have reached
206,956 according to GLOBOCAN 2022. Regionally, the high-
est age-adjusted mortality rates for ovarian cancer were also
in Eastern Europe (6.1/100,000), followed by South-East Asia
(5.1/100,000), and Northern Europe (4.8/100,000). Eastern Asia
had the lowest age-adjusted mortality rate for ovarian cancer
(2.7/100,000). Countries with a medium HDI had the highest
age-adjusted mortality rate for ovarian cancer (4.5/100,000),
while the high HDI countries had the lowest mortality rate
(3.3/100,000). The global age-standardized mortality rate for
ovarian cancer declined from 1999–2021 by an estimated
annual percentage change of −0.62 (95% CI, −0.68 to −0.57) 11.
The mortality rate of ovarian cancer in the USA declined
between 1976 and 2015 by 33.0%7. However, the mortality rate
for ovarian cancer in China showed an upward trend with an
average annual percentage change of 4.4% from 2000–201815.
The age-standardized 5-year net ovarian cancer survival
rate in most countries was still < 50% for women diagnosed
from 2010–2014 according to the CONCORD-3 4. Survival
rates for ovarian cancer ranged from 40.0%–49.0% in
Canada, the USA, China, Japan, Korea, Singapore, Austria,
Finland, France, Germany, Iceland, Norway, Portugal,
Sweden, Switzerland, and Australia. Survival rates for ovar -
ian cancer were < 30% in Chile and < 20% in India. The
Cancer Biol Med Vol xx, No x Month 2026 3
survival trend for ovarian cancer has remained relatively
flat between 1995-1999 and 2010-2014 4,16. Improvements
in 5-year survival for ovarian cancer were reported across
17 countries, including the USA, Japan, Korea, Bulgaria,
the Czech Republic, Denmark, France, Ireland, Italy, the
Netherlands, Norway, Poland, Portugal, Spain, Switzerland,
the UK, and Australia. The most remarkable improvement
in survival for ovarian cancer was observed in Japan with
an increase of 11.1%; detailed data are shown in Figure 1 .
The updated age-standardized 5-year relative survival rate
for ovarian cancer in China between 2019 and 2021 was
39.6%; the rate was stable from 2008–2021 17. The 5-year rel-
ative ovarian cancer survival rate in the US increased from
44.6% to 52.8% between 2000 and 2017 with an average
absolute increase of 0.4% according to the SEER database of
21 registries 18.
Table 1 Age-standardized ovarian cancer incidence and mortality rates in 2022
World Incidence Mortality
Number ASR Crude rate Cumulative risk Number ASR Crude rate Cumulative risk
Region
Northern America 24,484 7.5 13.0 0.83 15,554 3.8 8.3 0.44
Central America 6175 6.0 6.6 0.64 4033 3.9 4.3 0.44
South America 16,447 5.6 7.4 0.62 10,866 3.5 4.9 0.41
Eastern Africa 7690 5.3 3.3 0.60 5518 4.2 2.3 0.50
Middle Africa 2458 4.3 2.6 0.45 1794 3.5 1.9 0.39
Northern Africa 7145 6.0 5.6 0.66 4687 4.0 3.7 0.48
Southern Africa 1677 4.9 4.8 0.55 1424 4.2 4.1 0.47
Western Africa 6790 5.1 3.2 0.54 4601 3.8 2.2 0.43
Caribbean 1450 4.9 6.5 0.53 1012 3.2 4.5 0.36
Eastern Asia 75,773 6.0 9.5 0.64 40,264 2.7 5.1 0.32
South-East Asia 32,113 8.1 9.4 0.85 20,514 5.1 6.0 0.58
South Central Asia 61,931 6.1 6.2 0.67 42,839 4.3 4.3 0.51
Western Asia 8406 6.1 6.1 0.66 5930 4.3 4.3 0.51
Eastern Europe 29,416 11.0 19.0 1.2 19,165 6.1 12.4 0.73
Northern Europe 9787 9.1 18.1 1.0 6586 4.8 12.2 0.56
Southern Europe 13,265 8.4 17.1 0.93 8398 4.1 10.8 0.48
Western Europe 17,004 7.1 17.0 0.81 12,083 4.1 12.1 0.48
Australia-New Zealand 2177 8.0 14.0 0.89 1384 4.0 8.9 0.46
Melanesia 359 7.5 6.4 0.77 262 5.8 4.6 0.64
Micronesia 22 7.3 7.9 0.91 19 6.4 6.9 0.83
Polynesia 34 9.0 10.0 1.1 23 6.0 6.7 0.76
HDI level
Very high HDI country 120,904 8.2 14.6 0.91 77,625 4.3 9.4 0.51
High HDI country 113,283 6.0 8.3 0.65 66,974 3.3 4.9 0.38
Medium HDI country 70,820 6.4 6.4 0.70 48,669 4.5 4.4 0.53
Low HDI country 19,477 4.9 3.2 0.53 13,590 3.7 2.3 0.43
ASR, age-adjusted rate, per 100,000 person-years; HDI, human development index.
4 Li et al. Global epidemiology of ovarian cancer
Disability-adjusted life years and
years lived with disability
Table 2 illustrates the disability-adjusted life years (DALYs)
and years lived with disability (YLDs) for ovarian can-
cer19. The global DALYs count reached 5,160,000/100,000
in 2021. The European region had the highest DALYs
count (1,260,000/100,000), followed by South-East Asia
(1,130,000/100,000) and the Western Pacific region
(1,120,000/100,000). The Eastern Mediterranean region
had the lowest DALYs count (320,000/100,000). The global
DALYs for ovarian cancer increased from 1990 to 2021
(Figure 2A).
The global YLDs count rose to 155,650/100,000 in 2021.
The regional distribution of ovarian cancer YLDs was compa-
rable to DALYs. The European region had the highest YLDs
count (38,100/100,000), followed by the Western Pacific region
(37,280/100,000) and South-East Asia (33,320/100,000). The
Eastern Mediterranean region had the lowest YLDs count
(8300/100,000). The global YLDs trend for ovarian cancer also
exhibited a similar increase from 1990–2021 (Figure 2B).
The age-specific DALYs counts in 2021 are shown in
Figure 3A. The DALYs counts increased with advancing age
at the time of diagnosis. Women > 70 years of age had the
highest DALYs count (1,130,000/100,000). The age-specific
YLDs counts in 2021 are shown in Figure 3B. The YLDs
increased with advancing age at the time of diagnosis.
However, it is worth noting that both DALYs and YLDs
counts declined in women who were diagnosed between 60
and 69 years of age, which may be attributed to the use of
oral contraceptives 12.
Risk factors for ovarian cancer
Several factors have been shown to be associated with the risk
of ovarian cancer, including reproductive, behavioral, dietary,
metabolic, medical, genetic, and environmental factors (Table
3, Figure 4). The risk estimates presented in Table 3 were
extracted from published meta-analyses or pooled studies,
each of which used a multivariable-adjusted analytical frame-
work as reported by the original authors. Because effect mod-
ifiers and confidence intervals were not uniformly available
across studies, these values should be interpreted as summa-
rized associations rather than harmonized effect sizes derived
from a single analytical model.
Reproductive factors
Studies have shown that childbirth has a protective effect on
epithelial ovarian cancer and the effect is subtype-depend-
ent. The risk of ovarian cancer decreased by 6% [relative risk
(RR), 0.94; 95% CI, 0.92–0.96] with each additional birth
among women who have had children in a prospective study
involving 1.1 million UK women with the greatest reduction
Kore
a
Singapor
e
Sw
eden
Norw
ay
FranceFinlan
d
USATurk
ey
Japan
Por
tugalChin
a
Austria
Sw
itzerlandGermanyIcelan
d
AustraliaCanada
Italy
Thailand
SpainBrazil
Netherlands
DenmarkKuwait
New ZealandCzech R
epublicRussi
a
PolandBulgariaColombia
UK
Irelan
d
ChileIndi
a
Country
Age-standardized 5-year net survival (%)
0
10
20
30
40
50
2000–2004 2005–2009 2010–2014
Figure 1 Age-standardized 5-year net ovarian cancer survival in different countries from 2000 to 2014. This figure illustrates the geographic
and temporal variations in ovarian cancer survival across select countries. A key box above the graph explains the colored lines representing
different time periods. The x-axis shows the countries sorted from highest-to-lowest average survival rate. The y-axis shows the age-stand -
ardized 5-year net survival rate expressed as a percentage (%).
Cancer Biol Med Vol xx, No x Month 2026 5
in the risk of clear cell carcinoma (RR, 0.75; 95% CI, 0.65–
0.85)20. However, in a Finnish cohort study involving 87,929
multiparous women, multiparity (> 5 births) did not provide
additional protection against ovarian cancer 37. In summary,
these findings indicated that while the number of pregnan-
cies is negatively correlated with the risk of ovarian cancer,
this protective effect does not follow a linear dose-response
relationship with the number of pregnancies. In fact, evidence
suggests that most of this protective effect is attributable to the
first three pregnancies38.
The current mainstream view is that the cessation of ovula-
tion during pregnancy and breastfeeding inhibits the division
and proliferation of ovarian epithelial cells, thereby reduc-
ing the chance of initiating or promoting carcinogenesis 39. A
pooled analysis of 13 case-control studies from the Ovarian
Cancer Association Consortium showed that breastfeeding
can reduce the risk of invasive ovarian cancer by 24% with
the greatest reduction observed in high-grade serous ovar -
ian cancer. The duration of breastfeeding can further reduce
the risk of ovarian cancer39. The risk of ovarian cancer can be
reduced by approximately 10% for every 12 months of breast-
feeding (RR, 0.89; 95% CI, 0.84–0.94)20.
Dietary and metabolic factors
Inflammation is a normal physiologic process but long-term,
persistent chronic inflammation may promote carcinogenesis
by damaging important cell components, activating tumor-
promoting signaling pathways, promoting abnormal prolifer-
ation, and inhibiting apoptosis40. Pro-inflammatory diets have
Table 2 Ovarian cancer DALYs and YLDs in the global burden of disease study 2021
Location DALYs per 100,000 YLDs per 100,000
Value Lower bound Upper bound Value Lower bound Upper bound
Africa 357,474.21 266,133.78 427,989.60 8,835.35 5,890.77 12,014.81
South-East Asia 1,132,285.22 966,868.25 1,372,584.52 33,318.56 23,436.52 44,561.70
Americas 944,236.63 889,096.85 990,123.33 28,354.09 20,965.35 36,478.54
Europe 1,263,327.45 1,177,992.02 1,332,170.16 38,099.13 28,070.04 48,972.54
Eastern Mediterranean 315,571.69 235,103.98 406,673.99 8,378.60 5,684.23 11,920.54
Western Pacific 1,120,217.11 896,904.74 1,364,393.88 37,279.62 25,724.54 51,643.26
Global 5,163,256.30 5,608,304.11 4,692,422.55 155,645.72 201,143.40 113,442.62
DALY, disability-adjusted life years; YLD, years lived with disability.
1990
2.6
2.8
3
3.2
3.4
3.6
3.8
4
4.2
4.4
4.6
4.8
5
5.2
5.4
5.6
60
80
100
120
140
160
180
200
1995 2000 2005
Year
AB
2010 2015 2020 1990 1995 2000 2005
Year
2010 2015 2020
Number of disability-adjusted life years
(millions)
Number of years lived with disability
(thousands)
Figure 2 Global trends in disability-adjusted life years (DALYs) and years lived with disability (YLDs) due to ovarian cancer (1990–2021). This
figure presents the global disease burden of ovarian cancer over three decades, as measured by DALYs (A) and YLDs (B). The global trends in
DALYs and YLDs from ovarian cancer showed an increasing trend from 1990 to 2021.
6 Li et al. Global epidemiology of ovarian cancer
1,200
1,000
800
600
400
200
0
35
30
25
20
5
15
10
0
<2020–2425–2930–3435–3940–4445–4950–5455–5960–6465–69 70+ <2020–2425–2930–3435–3940–4445–4950–5455–5960–6465–69 70+
Age at diagnosis Age at diagnosis
Number of disability-adjusted life
years (thousands)
Number of years lived with disability
(thousands)
AB
Figure 3 Age-specific disability-adjusted life years (DALYs) and years lived with disability (YLDs) for ovarian cancer in 2021. This figure depicts
the distribution of the ovarian cancer disease burden across different age groups in 2021. The x-axis represents the age groups at the time of
diagnosis. The y-axis represents the DALYs (A) or YLDs counts (B).
Table 3 Factors associated with the risk of ovarian cancer
Factors RR, OR, HR, SMR and 95% CI Reference
Reproductive factor
Childbirth Each of the first three pregnancies in ovarian cancer risk
[RR, 0.94; 95% CI, 0.92–0.96]
Each of the first three pregnancies in clear cell ovarian cancer risk
[RR, 0.75; 95% CI, 0.65–0.85]
20
Breastfeeding Every 12 months of breastfeeding
[RR, 0.89; 95% CI, 0.84–0.94]
Dietary factors
Vegetable intake Green leafy vegetables [RR, 0.91; 95% CI, 0.85–0.98]
Allium vegetables [RR, 0.79; 95% CI, 0.64–0.96]
21
Fiber intake Fiber [RR, 0.89; 95% CI, 0.81–0.98]
Fat intake Total fat [RR, 1.10; 95% CI, 1.02–1.18]
Saturated fat [RR, 1.11; 95% CI, 1.01–1.22]
Saturated fatty acid [RR, 1.19; 95% CI, 1.04–1.36]
Cholesterol [RR, 1.13; 95% CI, 1.04–1.22]
Tea intake Green tea [RR, 0.61; 95% CI, 0.49–0.76] 22
Pro-inflammatory diets Higher DII scores [OR, 1.42; 95% CI. 1.19–1.65]
Each increase in DII point [OR, 1.10; 95% CI, 1.06–1.14]
23
Metabolic factors
High BMI Serous borderline ovarian tumor [OR, 1.24; 95% CI, 1.18–1.30]
Endometrioid ovarian cancer [OR, 1.17; 95% CI, 1.11–1.23]
Mucinous ovarian cancer [OR, 1.19; 95% CI, 1.06–1.32]
24
Diabetes Diabetes [RR, 1.32; 95% CI, 1.14–1.52] 25
Cancer Biol Med Vol xx, No x Month 2026 7
been shown to be a risk factor for ovarian cancer in multiple
case-control studies41,42. Indeed, there was a positive correla-
tion between dietary inflammatory potential, as measured by
the dietary inflammatory index (DII), and the incidence of
ovarian cancer in a meta-analysis of six studies. Individuals
with higher DII scores had a 42% increased risk for ovarian
cancer [odds ratio (OR), 1.42; 95% CI, 1.19–1.65] 23. A mul-
ticenter case-control study from Italy involving 1031 ovarian
cancer cases and 2411 non-ovarian-cancer cases suggested that
a diabetes risk reduction diet reduces the risk of ovarian can-
cer43. A meta-analysis of 97 cohort studies showed that green
vegetable, fiber, and green tea intake reduced the risk of ovarian
cancer, while total fat, saturated fat, saturated fatty acids, cho-
lesterol, and retinol intake significantly increased the risk21,22.
Several studies have shown that overweight and obesity
increase the likelihood of developing ovarian cancer 44,45.
Cancer cells often exhibit altered metabolic pathways with
increased fatty acid oxidation, glycolysis, and glutaminolysis,
which contribute to ovarian cancer growth 46. Research indi-
cates that overweight or obesity can increase the risk of can-
cer through multiple pathways, including hyperinsulinemia/
insulin resistance and abnormalities in the insulin-like growth
factor-I (IGF-I) system and signaling, the biosynthesis and
action pathways of sex hormones, subclinical chronic low-
grade inflammation, and oxidative stress47. A Mendelian study
suggested a causal link between obesity and aggressive epi-
thelial ovarian cancer with body mass index (BMI) differen-
tially associated with histologic subtypes of ovarian cancer 48.
A pooled analysis of 15 case-control studies in the Ovarian
Cancer Association Consortium, including 13,548 cases and
17,913 controls, suggested that high BMI increases the risk
of serous borderline ovarian tumor (OR, 1.24; 95% CI, 1.18–
1.30), invasive endometrioid ovarian cancer (OR, 1.17; 95%
CI, 1.11–1.23), and invasive mucinous ovarian cancer (OR,
1.19; 95% CI, 1.06–1.32) but not high-grade invasive serous
cancer24.
Factors RR, OR, HR, SMR and 95% CI Reference
Behavioral factor
Prolonged sitting time 10–19 h/week sitting [HR, 1.25; 95% CI, 1.04–1.51]
≥ 20 h/week sitting [HR, 1.40; 95% CI, 1.14–1.71]
26
Psychosocial stress HR, 1.71; 95% CI, 1.16–2.52 27
Medical factors
Oral contraceptives Ever vs. never [OR, 0.73; 95% CI, 0.70–0.76]
Each 5 years of use decreased risk by 20% (95% CI, 18–23%)
28
Hormone replacement
therapy
Serous ovarian cancer [RR, 1.53; 95% CI, 1.40–1.66]
Endometrioid ovarian cancer [RR, 1.42; 95% CI, 1.20–1.67]
29
Endometriosis Clear cell ovarian cancer [OR, 3.05; 95% CI, 2.43–3.84]
Endometrioid ovarian cancer [OR, 2.04; 95% CI, 1.67–2.48]
30
Pelvic inflammatory disease Borderline ovarian tumor [OR, 1.50; 95% CI, 1.08–2.08] 31
Serous borderline ovarian tumor [OR, 1.76; 95% CI, 1.36–2.29] 32
Salpingectomy Unilateral or bilateral salpingectomy [HR, 0.65; 95% CI, 0.52–0.81]
Unilateral salpingectomy [HR, 0.71; 95% CI, 0.56–0.91]
Bilateral salpingectomy [HR, 0.35; 95% CI, 0.17–0.73]
33
Genetic factors
BRCA mutations BRCA1 carriers (by 70 years of age): 59% (95% CI, 43–76%)
BRCA2 carriers (by 70 years of age): 16.5% (95% CI, 7.5–34%)
34
Lynch syndrome Lifetime risk of 6.7% (95% CI, 5.3–9.1%) 35
Environmental factors
Occupational asbestos
exposure
Standardized mortality ratio, 1.77; 95% CI, 1.3–72.28 36
RR, relative risk; 95% CI, 95% confidence interval; HR, hazard ratio; DII, dietary inflammatory index; OR, odds ratio. The risk factors listed
above were associated with overall ovarian cancer when no specific histologic type was specified.
Table 3 Continued
8 Li et al. Global epidemiology of ovarian cancer
Diabetes may also increase the risk of ovarian cancer. Cancer
cells rely on aerobic Warburg metabolism to meet the energy
needs. Cancer cells also synthesize fatty acids, proteins, and
nucleotides. Therefore, cancer cells continuously require an
increased supply of glucose and diabetes-related hyperglyce-
mia may fuel this demand47. A meta-analysis of 9 case-control
and 27 cohort studies suggested that patients with diabetes had
a relatively increased risk of ovarian cancer (RR, 1.32; 95% CI,
1.14–1.52)25 and the association between diabetes and ovarian
cancer is more significant in Asian populations49.
Lifestyle and psychological factors
Prolonged sitting time may increase the risk of ovarian can-
cer50. In a cohort study involving 173,688 participants, women
who sat for 10–19 h/week [hazard ratio (HR), 1.25; 95% CI,
1.04–1.51] and women who sat for ≥ 20 h/week (HR, 1.40;
95% CI, 1.14–1.71) had an increased risk compared to women
who sat for < 5 h/week26. Another meta-analysis involving 26
studies showed that women who engaged in regular recrea-
tional physical activity had a 30%–60% lower risk of ovarian
cancer51.
Chronic stress is linked to increased ovarian cancer risk.
Stress can lead to increased concentrations of adrenaline and
norepinephrine, activate β-adrenergic signaling, then partici-
pate in the regulation of various cellular processes involved in
the occurrence and development of cancer, such as promoting
tumor angiogenesis, inducing DNA damage, inhibiting DNA
repair, and reducing tumor cell apoptosis 52. In a study that
included 115,694 participants with > 21 years of follow-up,
women who experienced ≥ 3 distress-related psychosocial fac-
tors had a > 70% increased risk of ovarian cancer compared
Environmental
Asbestos
exposure
Childbirth
Breast
feeding
Sedentariness
Stress
Vegetable,
fiber, and
tea intake
Fat intake
Overweight
Obese
Risk factor
Protective factor
DiabetesOral
contraceptives
Endometriosis
PID
HRT
Salpingectomy
BRCA mutation
Lynch syndrome
Reproductive
Behavioral
Dietary
Metabolic
Medical
Genetic
Factors associated with
risk of ovarian cancer
Figure 4 Summary of risk factors for ovarian cancer. This schematic summarizes and categorizes a spectrum of factors linked to ovarian
cancer risk, distinguishing between factors that increase risk and factors that confer protection. The factors are organized into seven intercon-
nected categories for systematic understanding, including genetic, reproductive, behavioral, dietary, metabolic, medical, and environmental
factors.
Cancer Biol Med Vol xx, No x Month 2026 9
to women who had < 3 distress-related psychosocial factors
(HR, 1.71; 95% CI, 1.16–2.52). Notably, when post-traumatic
stress disorder was included, the association between distress-
related factors and ovarian cancer was strengthened27.
Medical history
Oral contraceptives have long been known to reduce the inci-
dence of ovarian cancer by inhibiting the ovulation process.
Ovulation causes repeated microtrauma to the ovarian epithe-
lial surface, which increases the risk of malignant transforma-
tion. This process may explain why oral contraceptives reduce
the risk of ovarian cancer 45, especially in women with endo-
metriosis53. A Meta-analysis involving 23,257 women with
ovarian cancer and 87,303 women without ovarian cancer
from 45 studies in 21 countries showed that oral contracep-
tives can prevent ovarian cancer in the long term (RR, 0.73;
95% CI, 0.70–0.76); the duration of oral contraceptive usage
and the reduction in risk displayed a dose-response relation-
ship28. However, the protective effect of oral contraceptives
may decrease with age or after discontinuation.
Hormone replacement therapy (HRT), which has been
widely used to treat menopausal symptoms in women, is
associated with an increased risk of ovarian cancer. The main
HRT regimens include estrogen alone [estrogen replace-
ment therapy (ERT)] or an estrogen and progestin combi-
nation [estrogen-progestin replacement therapy (EPRT)].
The relationship between HRT and the risk of ovarian can-
cer has not been consistent across studies. A meta-analysis of
52 epidemiologic studies conducted since 1970 showed that
for every 1000 women who received hormone therapy for 5
years starting at approximately 50 years of age, 1 additional
ovarian cancer patient would be diagnosed. The increase was
most pronounced for serous (RR, 1.53; 95% CI, 1.40–1.66) and
endometrioid ovarian cancer (RR, 1.42; 95% CI, 1.20–1.67) 29.
Studies have shown a significant correlation between the use
of ERT and the incidence of ovarian cancer, while the use of
EPRT alone did not increase the risk 54. This finding may be
explained by the fact that most ovarian tumors are estrogen
receptor-positive and progesterone may counteract the pro-
liferative effect of estrogen by promoting ovarian cell apop-
tosis45. A meta-analysis of 21 cohort studies showed that the
use of HRT increased the risk of ovarian cancer. However,
when the research time frame was limited to the past decade,
the associated risk was minimal, indicating that the impact of
HRT on the incidence of ovarian cancer is not durable55.
Endometriosis is a recognized risk for ovarian cancer that
shares overlapping genetic susceptibility with endometrioid
and clear cell subtypes 56. A large international case-control
study including 13,226 controls and 7911 invasive ovarian can-
cer cases showed that endometriosis was most strongly asso-
ciated with clear cell carcinoma (OR, 3.05; 95% CI, 2.43–3.84)
and endometrioid carcinoma (OR, 2.04; 95% CI, 1.67–2.48)30.
In like manner, a cohort study involving 450,906 women
(78,476 with endometriosis and 372,430 without) showed that
women with endometriosis had a higher risk of type I ovarian
cancer than women without endometriosis, especially patients
with deep infiltrating endometriosis or ovarian endometriotic
cysts53.
Inflammation has been linked to ovarian cancer. In a popu-
lation-based case-control study including 554 Danish women
with invasive ovarian cancer, pelvic inflammatory disease
(PID) was associated with increased risk of borderline ovarian
tumor (OR, 1.50; 95% CI, 1.08–2.08)31. A Swedish case-control
study, including 4782 cases and 45,167 controls also reported
an elevated risk of serous borderline ovarian tumor among
women with a history of PID (OR, 1.76; 95% CI, 1.36–2.29)32.
Current evidence suggests that high-grade serous ovar -
ian cancer originates from the distal fallopian tube epithe-
lium, forming serous tubal intraepithelial carcinoma that
can shed and implant on the ovarian surface 57. Women who
underwent unilateral or bilateral salpingectomy in a popula-
tion-based cohort study spanning from 1973–2009 in Sweden
(n = 34,433) had a significantly lower risk of ovarian cancer
compared to women who had not undergone unilateral or
bilateral salpingectomy [n = 5,449,119] (HR, 0.65; 95% CI,
0.52–0.81). The reduction in ovarian cancer risk was greater
with bilateral salpingectomy than with unilateral33. Given the
long study period, potential variations in diagnostic criteria,
surgical practices, and classification systems should be consid-
ered. For example, changes in Swedish surgical coding after
1997 prevented distinction between unilateral and bilateral
salpingectomy, which limited stratified analyses. Nevertheless,
because meaningful risk reduction typically emerges >10 years
after salpingectomy, the extended follow-up and large sample
size still lend substantial strength to these findings. Evidence
linking hysterectomy to the risk of ovarian cancer remains
inconsistent. Several studies have found no significant associa-
tion between hysterectomy for benign gynecologic conditions
and ovarian cancer incidence58,59, whereas other studies have
reported a modest reduction in risk60.
Genetic factors
Hereditary breast-ovarian cancer syndrome is a major genetic
predisposition to ovarian cancer. Hereditary breast-ovarian
cancer syndrome results primarily from pathogenic variants
(mutations) in the BRCA1 or BRCA2 genes, which have key
roles in DNA damage repair61. BRCA1 and BRCA2 gene muta-
tions are associated with a high lifetime risk of ovarian cancer.
It is estimated that by 70 years of age, the average cumulative
risk of ovarian cancer for BRCA1 mutation carriers is 41% and
15% for BRCA2 mutation carriers62.
Lynch syndrome also contributes to hereditary ovarian
cancer. Lynch syndrome is an autosomal dominant disorder
caused by germline pathogenic variants in DNA mismatch
10 Li et al. Global epidemiology of ovarian cancer
repair (MMR) genes. Women with a family history of Lynch
syndrome have a 6.7% lifetime risk of ovarian cancer 35. The
increased risk of ovarian cancer in Lynch syndrome is not
histology-specific. In contrast, high-grade serous carcinoma
is nearly the only histologic type of hereditary ovarian can-
cer in hereditary breast-ovarian cancer syndrome with BRCA
mutations, suggesting that hereditary breast-ovarian cancer
may have a different nature from ovarian cancer in Lynch
syndrome63.
Environmental and occupational exposures
Some occupational and environmental exposures may
increase ovarian cancer risk. A meta-analysis of 18 cohort
studies involving women with occupational asbestos expo-
sure showed that asbestos exposure was associated with an
increased risk of ovarian cancer (standardized mortality
ratio, 1.77; 95% CI, 1.37–2.28) 36. Talc, which is structurally
similar to asbestos, was among the first environmental risk
factors identified for ovarian cancer. Earlier studies suggested
that talc use increases the risk of ovarian tumors, especially
serous subtypes 64. However, recent evidence remains incon-
sistent. Case-control studies often report a weak positive
association, whereas cohort studies consistently showed null
results, with the discrepancy likely due to recall bias or resid-
ual confounding65-67.
Racial and ethnic disparities
Ovarian cancer risk and outcomes differ across racial and
ethnic groups and are influenced by underlying social deter -
minants, such as socioeconomic status (SES) and access to
healthcare. Data from the US Centers for Disease Control
and Prevention indicated that ovarian cancer rates are the
highest among non-Hispanic American Indian, native
Alaskan, and non-Hispanic White women, while the rates
are low among Hispanic, non-Hispanic Asian and Pacific
Islander, and non-Hispanic Black women. The higher rates
among non-Hispanic White women may be due to the
higher incidence of hereditary breast and ovarian cancer
mutations in the Ashkenazi Jewish population 68. SES can
influence the risk and prognosis of ovarian cancer through
multiple pathways. Women from lower-SES backgrounds
are more likely to experience adverse lifestyle and meta-
bolic factors, such as obesity and chronic inflammation, and
to have lower utilization of preventive healthcare services,
all of which may increase ovarian cancer risk 69. Limited
access to gynecologic care, delay in diagnosis, and decreased
adherence to guideline- recommended treatment have also
been associated with a higher likelihood of presenting
with advanced-stage ovarian cancer and poorer survival
outcomes70. Furthermore, a meta-analysis demonstrated
marked disparities in treatment adherence and mortality
across racial and socioeconomic groups. Black patients had
a 25% lower rate of adherence to ovarian cancer treatment
(RR, 0.75; 95% CI, 0.66–0.84) and an 18% higher risk of
mortality (RR, 1.18; 95% CI, 1.11–1.26) compared to White
patients. Patients in the lowest SES category had a 15% lower
adherence rate compared to patients in the highest SES
group (RR, 0.85; 95% CI, 0.77–0.94) and individuals with
fewer hospital visits showed a 30% lower adherence rate
compared to patients with more frequent healthcare contact
(RR, 0.70; 95% CI, 0.58–0.85) 71.
Screening of ovarian cancer
In ovarian cancer screening women are divided into average-
and high-risk populations. Women with a family history of
cancer or carrying BRCA1, BRCA2, or other pathogenic var -
iants have an increased ≥ 10% lifetime risk of ovarian cancer
compared to women with an average risk72,73. Because patients
with early-stage ovarian cancer frequently lack symptoms,
screening and early detection remain challenging.
Clinical trials, such as SCSOCS (82,487 participants with
a mean follow-up of 9.2 years) and PLCO (78,216 partici-
pants with a mean follow-up of 12.4 years), demonstrated
that screening strategies using serum CA-125 combined with
transvaginal ultrasound did not result in downstaging or a
reduction in ovarian cancer mortality for women at average
risk74. The UKCTOCS trial, which involved 202,638 partici-
pants with a median follow-up of 16.3 years, reported that
a multimodal screening strategy consisting of longitudinal
serum CA-125 levels interpreted by the risk of ovarian cancer
algorithm (ROCA) calculation combined with transvaginal
ultrasound findings, down-staged ovarian cancer but did not
reduce ovarian cancer mortality75. Therefore, screening is not
recommended for average-risk individuals according to the
international guidelines from the National Comprehensive
Cancer Network, the European Society of Medical Oncology,
and the Society of Gynaecological Oncology and Ovarian
Cancer Alliance76,77.
A GOG trial involving 3692 high-risk women with a strong
family history of BRCA1/2 pathogenic variants and a median
follow-up of 6 years showed that ROCA-based multimodal
screening every 3 months had better sensitivity and high spec-
ificity for early-stage ovarian cancer 23. The UKFOCSS trial
recruited 4348 high-risk women (≥ 10% lifetime risk) and per-
formed ROCA-based multimodal screening every 4 months.
This strategy resulted in downstaging of ovarian cancer after a
median follow-up of 4.8 years. However, the impact on mor -
tality could not be evaluated 42. A serum CA-125 level and
transvaginal ultrasound screening findings remain an option
with uncertain benefit for high-risk women who wish to delay
or decline risk-reducing surgery76,77.
Cancer Biol Med Vol xx, No x Month 2026 11
Artificial intelligence (AI)-enabled screening has recently
emerged as a potential approach for early detection of ovarian
cancer. Research involving 10,992 individuals (1 internal val-
idation set of 3007 individuals and 2 external validation sets
of 7985 individuals) from China used an AI model to inter -
pret laboratory tests, achieved an area under the receiver-op-
erating characteristic curve (AUC) of 0.949 in the internal
validation set and an AUC of 0.88 in the external validation
sets78. Another deep learning model using 17,119 ultrasound
images from 3652 patients across 20 centers in 8 countries also
reported promising diagnostic accuracy in detecting ovarian
cancer79. The integration of AI into ovarian cancer screening
offers a promising approach for improving early detection by
uncovering complex, non-linear relationships within mul-
ti-modal datasets that may elude traditional analysis. However,
this potential is limited by significant challenges, including the
“black-box” nature of many algorithms, which can obscure
the reasoning underlying decisions. Rigorous external val-
idation and prospective clinical trials are also necessary to
demonstrate a tangible impact on patient outcomes, such as
down-staging or reduced ovarian cancer mortality.
Several novel biomarkers and screening strategies are
under investigation, including DNA methylation biomark-
ers80, circulating tumor (ct) DNA 81, glycosylated CA-125 82,
and other candidate biomarkers, such as Osteopontin, Human
Epididymis Protein 4, and so on 83. Targeted cell-free DNA
methylation analysis had sensitivities for ovarian cancer of
83.1% (95% CI, 72.2–90.3%) across all stages and 50% (95%
CI, 23.7–76.3%) in stage I based on the Circulating Cell-free
Genome Atlas (CCGA) study84. Whether these new methods
can achieve down-staging or reduce ovarian cancer mortality
requires further investigation.
Prevention of ovarian cancer
Although ovarian cancer screening has limited efficacy, both
non-surgical and surgical options are available to reduce ovar-
ian cancer risk.
Non-surgical prevention is primarily achieved through use
of oral contraceptives 12. Oral contraceptive use is associated
with a 40%–50% reduction in lifetime ovarian cancer risk
among women at average risk 85. Women carrying BRCA1 or
BRCA2 mutations are also advised to consider oral contracep-
tive use for prevention86. A longer duration of oral contracep-
tive use provides greater protection for average- and high-risk
populations, although the potential risk of thrombosis should
be considered 87,88. The levonorgestrel intrauterine device
(LNG-IUD) has also been shown to reduce ovarian cancer risk
in women at average risk for ovarian cancer89,90.
Risk-reducing salpingo-oophorectomy (RRSO) can reduce
ovarian cancer risk by 80%–97% in BRCA carriers and reduce
the mortality rate. Therefore, for high-risk individuals who
have completed childbearing, bilateral RRSO is recommended
for pre-menopausal women with a ≥ 4% lifetime risk of ovar -
ian cancer and post-menopausal women with a ≥ 5% life-
time risk of ovarian cancer 72,91. BRCA1 mutation carriers are
advised to undergo RRSO between 35 and 40 years of age,
BRCA2 carriers between 40 and 45 years of age, and RAD51C,
RAD51D, PALB2, and BRIP1 carriers ≥ 45 years of age 92. The
timing of RRSO may be individualized based on family history
and personal choices86. HRT is recommended for pre-meno-
pausal women following RRSO if they do not have a personal
history of breast cancer93,94.
Risk-reducing salpingectomy with or without delayed oopho-
rectomy (RRSDO) represents an alternative for premenopausal
women who wish to retain ovarian function72,86. The multicenter
non-randomized controlled TUBA study recruited 577 women
with a BRCA1/2 pathogenic variant from the Netherlands
and showed that women undergoing RRSDO reported a bet-
ter menopause-related quality of life than women who under-
went RRSO95. The USWISP study used a similar design in 190
women and reported that the RRSO group exhibited worsen-
ing menopausal symptoms and greater decision regret 96. The
long-term safety and prophylactic effect of RRSDO are under
evaluation. The ongoing TUBA-WISP II trial aims to determine
whether delayed oophorectomy after salpingectomy is non-in-
ferior to immediate RRSO in reducing tubo-ovarian cancer risk.
However, follow-up remains too short for conclusions 97. To
date, RRSO remains the gold standard for risk reduction98.
RRSO should not be undertaken for ovarian cancer pre-
vention in women at average risk. Opportunistic bilateral
salpingectomy (OBS) may be offered at the time of benign
gynecologic surgery, after childbearing, and following coun-
selling on benefits and risks with informed consent72,91.
Endometriosis management should also be considered with
respect to endometriosis-associated ovarian cancer. Medical
or surgical treatment should be individualized according to
age, reproductive plans, and disease characteristics99.
Therapeutic landscape
Although each subtype of ovarian cancer has various clin-
ical features, molecular characteristics, and different prog-
noses, the subtypes share a similar principle of treatment.
Complete cytoreduction (R0 resection) remains the corner -
stone of ovarian cancer treatment across disease stages and
settings, including primary, interval, and secondary cytore-
ductive surgery 100,101. Platinum-based combination chemo-
therapy remains the standard first-line regimen for most
histologic subtypes of ovarian cancer. The introduction of
targeted therapy has transformed management paradigms.
Bevacizumab, a monoclonal antibody targeting VEGF , is rec-
ommended in combination with cytotoxic chemotherapy for
stage II–IV disease, followed by maintenance therapy (ICON7
12 Li et al. Global epidemiology of ovarian cancer
and GOG-218)102,103. However, neither trial showed a signifi-
cant overall survival benefit in the entire population. Further
analysis in ICON-7 demonstrated that the high-risk subgroup,
defined by stage IV ovarian cancer, inoperable stage III dis-
ease, or sub-optimally debulked (> 1 cm) stage III disease,
received a significant overall survival benefit from bevaci-
zumab administration with an HR of 0.78 (0.63–0.97). The
analysis suggested that residual tumor burden, presumably
producing VEGF , is necessary to enable bevacizumab to exert
an effect on the tumor microenvironment.
Poly (ADP-ribose) polymerase (PARP) inhibitors repre-
sent a major therapeutic advance. Maintenance therapy with
olaparib or niraparib, with or without bevacizumab, sub-
stantially prolongs progression-free and overall survival in
patients with germline BRCA1/2 mutations or homologous
recombination deficiency (HRD) 104-106. In contrast, benefits
in non-BRCA and HRD-proficient patients remain limited.