{"paper_id":"0840d974-eb72-4074-99f6-4104248f84d4","body_text":"JCOG 2019;29(3):88-93 \n88 \nndometriosis ,whichispoorly understoodinapathophysiological \nsense,isa hormone -dependentinflammatory chronic gynecological \ndisease.Itisdescribedasthepresenceof ectopicendometrial glands \nandstroma outside the uterinecavityandisassociatedwithpelvicpain,dys -\nm enorrhea,andinfertility. 1 Retrograde menstruation, menstrualtissueim -\nplantation ,and impairedimmune response are the most commonly \nobserved conditions .Endometriosisisafairlycommon condition, prevalent \nin ~10% of the women ofreproductive age. An estimated176 million \nwomen areaffectedbythisdisease worldwide. 2 An increaseintheoverall \ncancerincidenceinpatientswithendometriosis hasbeen reportedbyvar -\niousstudies. However,littleisknown abouttheeffectofendometriosison \ncancersurvival. 3\nMost ofthepreviousinvestigations on theimpactofendometriosis on \ncancerhad focused on itsrelationto ovariancancer. Therefore,whilethe re -\nlationshipbetweenendometriosisandovariancancer iswellknown, itsas -\nDoesEndometriosisImpactthePrognosisof \nEndometrialCancer? \nAA BBSS  TT RR AA CCTT   OO bbjjeeccttiivvee::  Despite the well-known relationship between endometriosis and the risk \nand prognosis of ovarian cancer, studies on the association the two are rare. Moreover, the impact \nof endometriosis on the prognosis of endometrial cancer has not been described in the literature. \nIn this study, we attempted to investigate whether endometriosis had an effect on the prognosis of \nendometrial cancer. MM aatteerriiaall  aanndd  MM eetthhooddss::This retrospective study was carried out on data from \nendometrial cancer patients between January 1996 and February 2016 at the Gynecological On -\ncology Department of Çukurova University Balcalı Hospital in Adana, Turkey. The pathological \nreports of 920 cases, operated after the diagnosis of endometrial cancer, were screened. Among \nthese cases, 764 patients were found to be eligible for enrollment in this study. The patients were \ndistributed into two groups based on the presence or absence of endometriosis in the pathological \nmaterials. The prognosis of the groups was compared using the Kaplan-Meier method. \nRR eessuullttss::The \nendometriosis group was associated with younger age, less parity, more infertility, and a higher risk \nof simultaneous ovarian cancer. There were non-significant differences between the groups re -\ngarding pathological risk factors such as myometrial invasion, lymphovascular space involvement, \nlymph node positivity, and stage of progression. No recurrences or deaths were observed in the en -\ndometriosis group, although this observation was not statistically significant. \nCCoonncclluussiioonn::  It is sug -\ngested that endometriosis does not influence the prognosis of endometrial cancer. However, a \nconclusive assessment could not be made by this study alone and, therefore, further studies are \nneeded and researchers are encouraged to focus more on this subject. \nKK eeyywwoorrddss::  Endometrial cancer; endometriosis; endometriosis-associated cancers \nGhanim KHATIB a, \nİsa TEMUR b, \nÜmran KÜÇÜKGÖZ GÜLEÇ a, \nAhmet Barış GÜZEL a, \nMete SUCU a, \nEmine BAĞIR c,  \nDerya GÜMÜRDÜLÜ c, \nMehmet Ali VARDAR a\naDepartment of Obstetrics and Gynecology, \nÇukurova University Faculty of Medicine, \nAdana, TURKEY \nbClinic of Obstetrics and Gynecology, \nKahramanmaraş Necip Fazıl City Hospital, \nKahramanmaraş, TURKEY \ncDepartment of Pathology, \nDivision of Gynecologic Pathology, \nÇukurova University Faculty of Medicine, \nAdana, TURKEY \nRe ce i ved:  12 Jun 2019 \nReceived in revised form: 20 Jul 2019 \nAc cep ted: 22 Aug 2019 \nAvailable online :  22 Oct 2019 \nCor res pon den ce: \nGhanim KHATIB \nÇukurova University Faculty of Medicine, \nDepartment of Obstetrics and Gynecology, \nAdana, TURKEY \nghanim.khatib@gmail.com \nCop yright © 2019 by Tür ki ye Kli nik le ri \nDOI: 10.5336/jcog.2019-70088 ORIGINAL RESEARCH \n\n\nsociation with other malignancies remains contro -\nversial. Recently, clear cell endometrioid and sero- \nm ucinous ovarian carcinomas were accepted as \nendometriosis-associated ovarian cancers (EAOC). \nThe endometrioid subtype is known to be the m ost \ncommonly associated histopathologic type with si -\nm ultaneous endometrial and ovarian cancers. \nNearly 30% of the simultaneous cases were re -\nported to harbor endometriosis. 4-6 Both en -\ndometriosis and endometrial cancer have the same \norigin; they have an identical molecular profile and \netiological mechanisms such as chronic inflamma -\ntion and the estrogen effect. Therefore, it is possi -\nble that endometriosis might affect the risk and \nprognosis of endometrial cancer. 4,7-9 \nDespite these facts, due attention has not been \ngiven to the endometriosis-endometrial cancer as -\nsociation. T o the best of our knowledge, no study in \nthe literature has discussed the impact of en -\ndometriosis on the prognosis of endometrial can -\ncer. Hence, this paper investigates the possible \nimpact of endometriosis on the prognosis of en -\ndometrial cancer. For this purpose, we retrospec -\ntively analyzed the cases of endometrial cancer \nover the last 20 years at our center. In addition, the \nsubgroups for endometrioid and non-endometrioid \nendometrial cancer cases were compared .\nMAT ERIAL AND METH ODS \nT his study was carried out on patients of endome -\ntrial cancer that were operated at the Gynecologi -\ncal Oncology Department of a Tertiary University \nH ospital between January 1996 and February 2016 .\nThe study was conducted in accordance with the \nHelsinki Declaration. Ethical approval was not re -\nquired for this study because of its retrospective na -\nture. Written informed consent was obtained from \nall the participants of the study. The electronic and \narchival records were retrospectively reviewed and \n920 endometrial cancer patients that were operated \nat our clinic during this period were identified .\nAmon g them ,detailed pathology records of 764 \ncases were obtained and utilized for this study. \nT he demographic, clinicopathologic ,and fol -\nlow-up data of the patients were recorded . All \nthese cases were operated and pathologically eval -\nuated at the same center by expert gynecological \npathologists. The major surgical procedures in -\nvolved total hysterectomy with bilateral salpingo- \noophorectomy (via laparotomy or laparoscopy) and \npelvic-para-aortic lymphadenectom y (except those \nwith low risk). Omentectomy was performed in the \nnon-endometrioid histologies. FIGO 2009 gu ide -\nlines were used for staging. All the pathological re -\nports of the operated cases were reviewed to \nidentify the presence of endometriosis in the sur -\ngical specimens. The patients were then distributed \ninto two groups based on the presence or absence \nof endometriosis in the pathological materials. \nOnly the diagnosis of endometriosis that was \nproven using histopathology was taken into ac -\ncount. The patients were followed up every three \nmonths for the first two years after the operation ,\nevery six months for the next three years , and an -\nnually thereafter . The period in months between \nthe dates of histopathological diagnosis and recur -\nrence was considered as disease-free survival (DFS) ,\nand from diagnosis to the date of death as the over -\nall survival (OS). \nThe descriptive statistics used were mean \n±standard deviation, median ,and minimum-maxi -\nmum values. Categorical data were analyzed using \nChi-square or Fisher’s exact tests. Mann-W hitney \nU test was performed for analysis of the numerical \ndata. Kaplan-Meier method was followed to test \nthe effect of endometriosis on survival. The differ -\nences between survival curves were evaluated \nusing the log-rank test. The statistical software \nSPSS version 23.0 (IBM, Armonk, NY, USA) was \nused for all analyses .\nRESULT S \nDuring the study period, 92 0 endometrial cancer \npatients were operated at our clinic. Among them, \nthe detailed pathological records of 764 cases were \nobtained and endometriosis was reported in 17 \n(2.2%) of them. The average and median age of all \nthe patients was 57.2 ±10.5 years and 58 (27-91) \nyears, respectively. Median parity of the patients \nwas 3  (0-15). Mean ages of the endometriosis and \nnon-endometriosis groups were 50.59±8.3 and \n57.28 ±10.2, respectively. There was a significant \nG hanim KHA TIB et al. JCOG 2019;29(3):88-93 \n89 \n\nG hanim KHATIB et al. JCOG  2019;29(3):88-93 \n90 \ndifference in the mean age of both groups \n(p=0.007). The Body Mass Indices (BMI) of both \ngroups were similar (P=0.530). The clinicopatho -\nlogical characteristics of the patients are demon -\nstrated in Table 1 .\nTh e percentages of premenopausal patients in \nthe endometriosis and non-endometriosis groups \nwere 35.3% and 20.3% , respectively . The propor -\ntions of premenopausal patients were statistically \nsimilar (p=0.132). The percentage of infertility -\nlinked cases in the endometriosis and non-en -\ndometriosis groups were 35.3% and 14.5%, respec -\ntively, showing a significant difference between \ngroups (p=0.017). In the endometriosis group, there \nwere three (17.6% ) cases of simultaneous ovarian \ncancer, whereas 35 (4.8%) cases were recorded in \nthe non-endometriosis group. This difference was \nfound to be statistically significant (p=0.018). \nBoth the groups had similar rates of en -\ndometrioid (70.6% versus 76.5%) and non-en -\nVariable Endometriosis N (%) Non-endometriosis N (%) P\nAge Mean±SD 50.59±8.3 57.28±10.3 0.007 \nBody mass index Mean±SD 33.88±5.4 35.53±7.4 0.652 \nParity Median (min.-max.) 1 (0-9) 3 (0-15) 0.002 \nMenopausal status Premenopause 6 (35.3) 151 (20.3) 0.132 \nPostmenopause 11 (64.7) 592 (79.7) \nInfertility No 11 (64.7) 632 (85.5) 0.017 \nYes 6  (35.3) 107 (14.5) \nSynchronous ovarian tumor No 14 (82.4) 690 (95.2) 0.018 \nYes 3 (17.6) 35 (4.8) \nHistology Endometrioid 12 (70.6) 566 (76.5) 0.571 \nNon-endometrioid 5 (29.4) 174 (23.5) \nStage Stage 1-2 12 (70.6) 617 (84.2) 0.132 \nStage 3-4 5 (29.4) 116 (15.8) \nGrade 1 10 (66.7) 345 (54.0) 0.375 \n2 3 (20.0) 238 (37.2) \n3 2 (13.3) 56 (8.8) \nMyometrial invasion <50 12 (75.0) 485 (66.4) 0.473 \n≥50 4 (25.0) 245 (33.6) \nLymphovascular space invasion No 12 (70.6) 471 (63.9) 0.570 \nYes 5 (29.4) 266 (36.1) \nCytology Negative 3 (17.6) 117 (16.2) 0.809 \nPositive 0  (0.0) 17 (2.4) \nWasn't taken 14 (82.4) 587 (81.4) \nLymph node involvement Negative 14 (82.4) 658 (89.6) 0.333 \nPositive 3 (17.6) 76 (10.4) \nOmental metastasis No 3 (17.6) 184 (25.0) 0.303 \nYes 2 (11.8) 32 (4.3) \nNo omentectomy 12 (70.6) 521 (70.7) \nAdjuvant treatment No 9 (52.9) 436 (58.9) 0.621 \nYes 8 (47.1) 304 (41.1) \nRecurrence No 17 (100) 726 (97.8) 0.541 \nYes 0  (0.0) 16 (2.2) \nLife status Alive 17 (100) 579 (86.5) 0.105 \nEx 0  (0.0) 90 (13.5) \nTABLE 1: Demographic and clinical characteristics of patients. \n\ndometrioid (29.4% versus 23.5%) histology \n(p=0.571). The tumor was confined to the uterus \n(stage 1-2 ) in 70.6% and 84.2% of the endometrio -\nsis and non-endometriosis groups ,respectively, and \nthe difference was not statistically significant . The \ndistribution of tumor grade between the groups \nwas also not significant (p=0.375). Myometrial in -\nvasion of ≥50% was observed in 25% of the en -\ndometriosis and 33.6% of the non-endometriosis \ngroup, which was not significantly different \n(p=0.473). Lymphovascular space invasion (LVS I) \nwas reported in 29.4% and 36.1% of the en -\ndometriosis and non-endometriosis groups, respec -\ntively (p=0.570). The occurrence of positive \ncytology between groups (0% versus 2.4%) was sta -\ntistically similar . Lymph node (LN) involvement \nwas reported in 17.6% of the endometriosis and \n10.4% of the non-endometriosis groups, and these \nrates were not significantly different. Omental \nmetastases were observed in 11.8% and 4.3% of the \nendometriosis and non-endometriosis groups , re -\nspectively, which were not significantly different \n(p=0.303). Statistically similar rates of adjuvant \ntreatments were applied to both the groups (47.1% \nversus 41.1%). No recurrence in the endometriosis \ngroup and 2.2% recurrence in the non-en -\ndometriosis group were recorded, but this differ -\nence was statistically nonsignificant. While 13.5% \nof the non-endometriosis group patients died, no \ndeath was reported among those in the en -\ndometriosis group. However, this observation was \nnot statistically significant (p=0.105). \nT he average follow-up period of the cohort \nwas 51 months. T he mean survival period for all \nthe endometrial cancer cases was 191.2 ±10.5 \nmonths (95% CI= 17 0.7-211.8). No deaths were ob -\nserved in the endometriosis group during the fol -\nlow-up period. The 5-year and 10-year survival \nrates in the non-endometriosis group were 86% \nand 74% ,respectively. The period and rate of sur -\nvival between endometriosis and non-endometrio -\nsis groups were not statistically significant \n(p=0.171) (Figure 1 ). \nT he survival rates of the endometrioid and \nnon-endometrioid endometrial cancer subgroups \nwere also compared and were found to be statisti -\ncally similar . Th e p-values for the endometrioid \nand non-endometrioid subgroups were 0.315 and \n0.341, respectively .\nDIS CUSSION \nDespite the association of endometriosis with ovar -\nian cancer being widely investigated, that with en -\ndometrial cancer has been rarely studied and with \nconflicting results. 4,10,11 While some studies have re -\nported an increased risk of endometrial cancer as -\nsociated with endometriosis, others have reported \ncontradictory findings .4,7,10-18 Moreover, two studies \nreported a non-significant decrease, while one \nstudy reported a significant decrease in the risk of \nendometrial cancer associated with endometrio -\nsis .18-20 \nTh ree large case -control studies from Taiwan \n(n=15,488) , A ustralia (n=1 ,399), and Denmark \n(n=1 ,398) reported an increased risk of endometrial \ncancer in the cases of endometriosis. 4,14,15 How ever, \nthis risk reflected a higher chance of detecting en -\ndometrial cancer among women with endometrio -\nsis more than the actual risk.s reported in a recent, \nlarge-volume prospective cohort (n=97,109) from \nthe USA. 7\nKok et al . published a population-based study \non the relation between endometriosis and the risk \nof developing several cancers ,including endome -\ntrial cancer. 21 They observed a significantly \nincreased risk of endometrial cancer among women \nG hanim KHA TIB et al. JCOG 2019;29(3):88-93 \n9 1 \nFIGURE 1: S urvival curves of the groups. \n\nwith endometriosis and/or adenomyosis. However, \nit was evident that histopathology was not the \nmain diagnostic tool in this study, especially in the \nadenomyosis patients, thus making the starting \npoint of the study and its results questionable. \nMunksgaard and Blaakaer reviewed seven \npopulation-based cohorts that investigated the as -\nsociation between the risk of endometrial cancer \nand endometriosis and reported that no clear asso -\nciation was observed in these studies. 13 Although \nsome studies did point to a possible association, \nthey concluded that the relatively small sample \nsizes precluded any definitive interpretation about \nthe possible association. \nOur study was different in its nature and de -\nsign from the above-mentioned studies. The cases \nof endometrial cancer that were operated at our \ncenter were retrospectively reviewed , and those \nwith histopathological diagnosis of endometriosis \n(17 patients) were compared with the non-en -\ndometriosis patients . T o the best of our knowledge, \nno previous studies in the literature had focused on \nthe association between endometriosis and en -\ndometrial cancer prognosis. It was observed that \nthe patients in the endometriosis group were sig -\nnificantly younger than the non-endometriosis pa -\ntients. The median value of parity in the \nendometriosis group was lesser, possibly due to the \nclose relationship between endometriosis and in -\nfertility. \nAbout 75% of the cases in each group showed \nendometrioid histology. The tumor histology of \nboth groups was similar . The patients in the en -\ndometriosis group demonstrated a higher but sta -\ntistically insignificant extra-uterine spread of the \ntumor (stage 3 -4, 29.4% versus 14.8%). In addition, \nthe tumor grade distribution was similar in both \ngroups (p=0.375) . Frequencies of myometrial inva -\nsion of at least 50% and LVSI were observed to be \nlesser by 8.6% and 6.7% in the endometriosis \ngroup, although this difference was not statistically \nsignificant . LN involvement was higher by 7.3% in \nthe endometriosis group than the non-en -\ndometriosis group, although this difference was sta -\ntistically nonsignificant . It is possible that the \nhigher LN positivity and the occurrence of extra- \nuterine disease in the endometriosis group make \nthe adjuvant treatments more suitable for this \ngroup (47.1% versus 41.1%). Despite these nega -\ntive factors, no recurrences or deaths were ob -\nserved in the endometriosis patients , when \ncompared to the 2.2% rate of recurrence and 13.5% \nrate of death in the non-endometriosis group. Nev -\nertheless, the rates of recurrence or survival status \nwere not significantly different between the \ngroups. The average follow-up period of the cohort \nwas 51 months. The mean survival period for all \nthe cases of endometrial cancer was 191.2 ±10.5 \nmonths (170.7 -2 11.8; 95% CI). As no deaths were \nobserved in the endometriosis group during the fol -\nlow-up period, survival rates could not be calcu -\nlated for this group. On the other hand , 5-year and \n10 -year survival rates in the non-endometriosis \ngroup were 86% and 74%, respectively. However, \nsurvival in both groups was statistically similar \n(p=0.171). In addition, when a subgroup analysis \nwas made for the endometrioid and non-en -\ndometrioid endometrial cancer histology, no sig -\nnificant difference in survival was observed \nbetween the endometriosis and non-endometriosis \npatients. \nAs expected, the endometriosis group showed \na significant association with infertility and syn -\nchronous ovarian cancer. Both these conditions \nwere significantly higher in the endometriosis \ngroup compared to the non-endometriosis group .\nThe strengths of this study were the fairly \nlarge number of endometrial cancer cases , as well \nas the length of the study period at the same cen -\nter with the same surgical procedures and pathol -\nogy team . These factors increased the consistency \nand reliability of the results of this study. However, \nthe retrospective nature of this study and the rela -\ntively small size of the endometriosis group were \nthe main weaknesses of this study. \nCONCLU SION \nIn this study, it was observed that the prognosis of \nendometrial cancer patients was neither positively \nnor negatively affected by endometriosis. How -\nG hanim KHATIB et al. JCOG  2019;29(3):88-93 \n92 \n\nG hanim KHA TIB et al. JCOG 2019;29(3):88-93 \n9 3 \never, the relatively small sample size in the en -\ndometriosis group precludes making any definitive \nconclusions. Therefore, further studies should be \nencouraged in this field. \nSSoouurrccee  ooff  FFiinnaannccee\nDuring this study, no financial or spiritual support was received \nneither from any pharmaceutical company that has a direct \nconnection with the research subject, nor from a company that \nprovides or produces medical instruments and materials which \nmay negatively affect the evaluation process of this study. \nCCoonnfflliicctt  ooff  IInntteerreesstt\nNo conflicts of interest between the authors and / or family \nmembers of the scientific and medical committee members or \nmembers of the potential conflicts of interest, counseling, ex -\npertise, working conditions, share holding and similar situa -\ntions in any firm. \nAA uutthhoorrsshhiipp  CCoonnttrriibbuuttiioonnss\nIIddeeaa//CCoonncceepptt::  Ghanim Khatib, Derya Gümürdülü, Mehmet Ali \nVardar; DDeessiiggnn::  G hanim Khatib, Ümran Küçükgöz Güleç; CCoonn--\nttrrooll//SSuuppeerrvviissiioonn::  M ehmet Ali Vardar, Ahmet Barış Güzel; DDaattaa\nCCoolllleeccttiioonn  aanndd//oorr  PP rroocceessssiinngg::  Ghanim Khatib, İsa Temur, Mete \nSucu, Emine Bağır; AA nnaallyyssiiss  aanndd//oorr  IInntteerrpprreettaattiioonn::  Ghanim \nKhatib, Emine Bağır, Ümran Küçükgöz Güleç; LLiitteerraattuurree  RR ee--\nvviieeww::  Ghanim Khatib, İsa Temur; WW rriittiinngg  tthhee  AA rrttiiccllee::  Ghanim \nKhatib; CCrriittiiccaall  RR eevviieeww::  Üm ran Küçükgöz Güleç, Ahmet Barış \nGüzel, Mehmet Ali Vardar; RR eeffeerreenncceess  aanndd  FFuunnddiinnggss::  Ghanim \nKhatib, İsa Temur, Mete Sucu, Emine Bağır. \n1. 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