{"paper_id":"4e20728c-7fe0-4f44-a4d6-84d3bbaa4be6","body_text":"1 \nSix-Month Dienogest Therapy Reduced the Endometrioma Size, Pelvic Pain, And CA-125 1 \nLevels 2 \nSeyma Ozcan¹,2, a, Ozlem Karabay Akgul¹,2,b, and Hakan Guraslan¹,2,b 3 \n¹Department of Obstetrics and Gynecology, Istanbul Bagcılar Training and Research Hospital, Istanbul, Turkey. 4 \n² Department of Obstetrics and Gynecology, Health Sciences University, Istanbul, Turkey. 5 \na First author. 6 \nb Corresponding author. 7 \nKeywords: Endometriosis; Dienogest; Endometrioma; Pelvic pain; CA-125 8 \nABSTRACT 9 \nBackground: Endometriosis affects approximately 10% of women of reproductive age and is 10 \nassociated with pelvic pain, infertility, and reduced quality of life. Dienogest is widely used for 11 \nmedical management. This study evaluated the effects of dienogest on endometrioma size, serum 12 \nCA-125 levels, and pelvic pain. 13 \nMethods: In this retrospective study, medical records of 45 women aged 18 –49 years who 14 \nreceived oral dienogest (2 mg/day) for at least six months were reviewed. Endometrioma size was 15 \nassessed by ultrasound, pelvic pain using the Visual Analog Scale (VAS), and serum CA -125 16 \nlevels from laboratory records. Baseline and six-month values were compared using the Wilcoxon 17 \ntest and correlations were analyzed using Spearman’s test. 18 \nResults: After six months of treatment, significant reductions were observed in endometrioma size 19 \nand V AS scores (p<0.001) and CA-125 levels (p<0.001) compared with baseline.  No significant 20 \ncorrelation was found between endometrioma size and VAS scores or CA-125 levels either before 21 \nor after treatment (p>0.05). A significant negative correlation was identified between patient age 22 \nand post-treatment endometrioma size (r = −0.320, p<0.05). 23 \nConclusion: Six months of dienogest therapy was associated with significant improvements in 24 \nlesion size, pain, and biochemical markers. Dienogest may represent an effective medical 25 \nAll rights reserved. No reuse allowed without permission. \n(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. \nThe copyright holder for this preprintthis version posted March 24, 2026. ; https://doi.org/10.64898/2026.03.20.26348926doi: medRxiv preprint \nNOTE: This preprint reports new research that has not been certified by peer review and should not be used to guide clinical practice.\n\n 2 \ntreatment option for symptomatic patients, particularly for those seeking to avoid surgery and 26 \npreserve ovarian reserve. 27 \nINTRODUCTION 28 \nEndometriosis is a chronic, estrogen -dependent inflammatory disease characterized by the 29 \npresence of endometrial -like tissue outside the uterine cavity and affects approximately 10% of 30 \nwomen of reproductive age (Zondervan et al., 2018; Zondervan et al., 2020). It is a major cause of 31 \ndysmenorrhea, dyspareunia, chronic pelvic pain, and infertility, significantly impairing quality of 32 \nlife and work productivity (Zondervan et al., 2020; Giudice & Kao, 2004). Ovarian endometriomas 33 \nare among the most common manifestations of the disease and are frequently associated with 34 \npelvic pain, infertility, and reduced ovarian reserve (ESHRE Guideline, 2022; Dunselman et al., 35 \n2014). 36 \nManagement of endometriosis should be individualized based on symptom severity, disease 37 \nextent, age, and reproductive plans. Although surgery may be effective in selected cases, repeated 38 \nsurgical interventions may lead to adhesions and decreased ovarian reserve (Dunselman et al., 39 \n2014; ACOG, 2010). Therefore, long -term medical therapy aimed at symptom control and 40 \nsuppression of disease activity has become a cornerstone of management, particularly in patients 41 \nwho wish to preserve fertility. 42 \nDienogest, a fourth-generation oral progestin, exerts antiproliferative, anti-inflammatory, and anti-43 \nangiogenic effects on endometriotic lesions (Foster & Wilde, 1998; McCormack, 2010). Previous 44 \nstudies have demonstrated its effectiveness in reducing endometriosis-related pain and improving 45 \npatient-reported outcomes (Andres et al., 2015; Römer, 2018; Sağlık Gökmen et al., 2023). In 46 \naddition to symptomatic improvement, suppression of lesion activity may result in reductions in 47 \nendometrioma size and serum CA -125 levels, which may reflect disease activity in moderate to 48 \nsevere cases. 49 \nAlthough several studies have reported the clinical benefits of dienogest, real -world data 50 \nsimultaneously evaluating its effects on endometrioma size, pelvic pain severity, and CA -125 51 \nlevels remain limited. Assessment of these parameters together may provide a more 52 \ncomprehensive evaluation of treatment response in routine clinical practice. Therefore, the aim of 53 \nAll rights reserved. No reuse allowed without permission. \n(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. \nThe copyright holder for this preprintthis version posted March 24, 2026. ; https://doi.org/10.64898/2026.03.20.26348926doi: medRxiv preprint \n\n 3 \nthis study was to investigate the effects of six months of dienogest therapy on endometrioma size, 54 \npelvic pain assessed by the Visual Analog Scale (VAS), and serum CA-125 levels in patients with 55 \nendometriosis. 56 \nMETHODS 57 \nStudy design and setting 58 \nThis retrospective study was conducted in the Department of Obstetrics and Gynecology  at a 59 \ntertiary care training and research hospital in Istanbul, Turkey.  Medical records of patients 60 \nfollowed in the endometriosis and chronic pelvic pain outpatient clinic were reviewed. Clinical 61 \ndata at presentation were compared with findings obtained after treatment. 62 \nStudy population 63 \nPatients aged 18 –49 years with a diagnosis of endometriosis who had received regular oral 64 \ndienogest therapy (2 mg/day) for at least six months were eligible for inclusion. A total of 45 65 \npatients who met the predefined inclusion and exclusion criteria were included in the final analysis. 66 \nPatients were excluded if they were younger than 18 or older than 49 years, had known or 67 \nsuspected breast cancer, a history of venous thromboembolism, active smoking status, a history of 68 \nmalignancy, known liver disease, or diabetes mellitus with cardiovascular complications. Clinical 69 \nand laboratory data were retrospectively obtained from the hospital information system (HIS) and 70 \noutpatient clinic records. 71 \nUltrasound assessment 72 \nEndometrioma measurements were performed using transvaginal ultrasonography with a 5 -MHz 73 \nprobe (Esaote). In virgin patients, transabdominal ultrasonography was used. All measurements 74 \nwere performed by two experienced gynecologists with more than 10 years of experience in the 75 \nendometriosis unit. The largest diameter (mm) of the dominant endometrioma was recorded and 76 \nused for analysis. 77 \n 78 \nAll rights reserved. No reuse allowed without permission. \n(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. \nThe copyright holder for this preprintthis version posted March 24, 2026. ; https://doi.org/10.64898/2026.03.20.26348926doi: medRxiv preprint \n\n 4 \n 79 \nOutcome measures 80 \nPelvic pain assessment: Pelvic pain severity was evaluated using the Visual Analog Scale (VAS), 81 \nranging from 0 (no pain) to 10 (worst imaginable pain). VAS scores recorded at baseline and after 82 \nat least six months of treatment were compared. 83 \n 84 \n 85 \n 86 \n 87 \n 88 \n 89 \n 90 \nFigure 1: Visual analog scale with numeric pain rating scale  used in this study. Pain intensity was 91 \nassessed using a 0 –10 numeric rating, where 0 indicates  no pain, and 10 indicates the  worst imaginable 92 \npain. Participants were asked to select the number that best represented their perceived pain level at the 93 \ntime of assessment. This figure has been copied from Gift A.G., 1989. 94 \nSerum CA-125: Serum CA-125 levels were obtained from hospital laboratory records at baseline 95 \nand after treatment. Changes in CA -125 levels were used to assess the biochemical response to 96 \ntherapy.  97 \nEndometrioma size: Endometrioma size was evaluated using ultrasonography before treatment 98 \nand after at least six months of therapy. The maximum diameter of the largest endometrioma was 99 \nrecorded in millimeters. 100 \nStatistical analysis 101 \nAll rights reserved. No reuse allowed without permission. \n(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. \nThe copyright holder for this preprintthis version posted March 24, 2026. ; https://doi.org/10.64898/2026.03.20.26348926doi: medRxiv preprint \n\n 5 \nDescriptive statistics for continuous variables were presented as mean ± standard deviation, 102 \nmedian, minimum, and maximum values, while categorical variables were expressed as number s 103 \nand percentages. Normality of continuous data was assessed using the Shapiro–Wilk test. 104 \nComparisons between baseline and six -month values for VAS score, CA -125 level, and 105 \nendometrioma size were performed using the Wilcoxon signed -rank test. Z values represent the 106 \ntest statistics of the Wilcoxon analysis. V AS scores range from 0 (no pain) to 10 (worst imaginable 107 \npain). Endometrioma size is expressed in millimeters (mm) and CA -125 levels in units per 108 \nmilliliter (U/mL). A p-value < 0.05 was considered statistically significant.   109 \nCorrelations between endometrioma size, VAS score, and CA -125 levels were analyzed using 110 \nSpearman’s correlation coefficient.  Spearman’s correlation coefficients (r) were calculated to 111 \nassess the relationship between endometrioma size and V AS scores and serum CA -125 levels at 112 \nbaseline and post-treatment. A p-value < 0.05 was considered statistically. In addition, as indicated 113 \nabove, Spearman’s rank correlation analysis was performed to assess the association between 114 \npatient age and clinical parameters at baseline and after six months of treatment. Correlation 115 \ncoefficients (r) and corresponding p -values are presented. A p -value < 0.05 was considered 116 \nstatistically significant. 117 \nStatistical analyses were performed using IBM SPSS for Windows version 20.0 (SPSS Inc., 118 \nChicago, IL, USA). A p-value <0.05 was considered statistically significant. 119 \n 120 \nRESULTS 121 \nIn this study, 45 patients with endometrioma were evaluated. The mean age of the patients was 35 122 \nyears (range: 23–47 years). Chronic comorbidities were present in 4.4% of patients (n = 2). Among 123 \nthese, one patient had asthma, and the other had hyperprolactinemia. Medication use was reported 124 \nin 4.4% of patients (n = 2); one patient was using an inhaler , and the other was receiving 125 \ncabergoline (Dostinex). No personal or family history of malignancy was identified in the study 126 \npopulation. Baseline demographic and clinical characteristics are presented in Table 1, where age 127 \nAll rights reserved. No reuse allowed without permission. \n(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. \nThe copyright holder for this preprintthis version posted March 24, 2026. ; https://doi.org/10.64898/2026.03.20.26348926doi: medRxiv preprint \n\n 6 \nis expressed as mean ± standard deviation and median (range), and chronic disease and medication 128 \nuse are reported as numbers (n) and percentages (%) (Table 1). 129 \n 130 \nTable 1. Baseline characteristics of the study population.  131 \nVariable Mean Value \nAge (years) 34.78 ± 7.61 \nMedian (range) 34 (23–47) \n \n \n \nChronic disease, n (%) n % \nNo 43  95.6 \nYes 2 4.4 \nMedication use, n (%)  \n \n \n \n \nNo 43 95.6) \nYes 2  4.4 \n 132 \nTable 2. Comparison of VAS scores, CA -125 levels, and endometrioma size at baseline and at six 133 \nmonths of treatment.  134 \n Before treatment \nBaseline \nPost Treatment  \n6 Months \n  \n Mean ± SD \nMedian (Min-Max) \nMean ± SD \nMedian (Min-Max) \nTest statistics        p  \nVAS 6.69±2.25 \n7 (0-10) \n3.64±2.55 \n3 (0-10) \nZ=-4.881 <0.001 d \nCA-125 (U/mL:) 61.85±58.25 \n41 (8-363) \n39.02±29.95 \n31 (8-146) \nZ=-3.058 0.002 d \nEndometrioma \nsize (mm) \n50.22±22.77 \n45 (18-118) \n38.24±20.43 \n35 (16-118) \nZ=-4.216 <0.001 b \nd: Wilcoxon test 135 \nAll rights reserved. No reuse allowed without permission. \n(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. \nThe copyright holder for this preprintthis version posted March 24, 2026. ; https://doi.org/10.64898/2026.03.20.26348926doi: medRxiv preprint \n\n 7 \nWe observed a significant reduction in pelvic pain, serum CA-125 levels, and endometrioma size 136 \nafter six months of dienogest therapy (Table 2).  After six months of dienogest therapy, significant 137 \ndecreases were observed in all evaluated clinical and radiological parameters (Table 2). A 138 \nsignificant difference was observed between baseline and six-month V AS scores (p < 0.001). V AS 139 \nscores at six months were significantly lower compared to pretreatment values (Table 2). Serum 140 \nCA-125 levels were also significantly reduced following six months of dienogest treatment. A 141 \nsignificant difference was observed between baseline and six -month CA-125 levels (p < 0.01) 142 \n(Table 2). Similarly, endometrioma size showed substantial reduction after treatment. The median 143 \nlesion size decreased from 45 mm to 35 mm. Endometrioma size at six months was significantly 144 \nsmaller compared to pretreatment measurements (Table 2). 145 \nWe then evaluated the relationship between endometrioma size and clinical parameters to 146 \ndetermine whether lesion size was associated with pain severity or serum CA -125 levels.  No 147 \nsignificant correlation was found between baseline endometrioma size and baseline V AS scores (p 148 \n> 0.05). Similarly, no significant correlation was observed between baseline endometrioma size 149 \nand baseline CA-125 levels (p > 0.05) (Table 3). Likewise, no significant correlation was identified 150 \nbetween post -treatment endometrioma size and post -treatment V AS scores (p > 0.05). No 151 \nsignificant association was observed between post -treatment endometrioma size and post -152 \ntreatment CA-125 levels (p > 0.05) (Table 3). 153 \nTable 3. Correlation between endometrioma size and clinical parameters at baseline and after six 154 \nmonths of treatment. 155 \n Endometrioma size before treatment \n r* p \nPre-treatment VAS 0.010 0.949 \nPost-treatment CA-125 0.152 0.319 \n Endometrioma size after treatment \n r* p \nPre-treatment VAS 0.283 0.073 \nPost-treatment CA-125 0.216 0.175 \n  *Spearman’ s Correlation Coefficient 156 \nAll rights reserved. No reuse allowed without permission. \n(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. \nThe copyright holder for this preprintthis version posted March 24, 2026. ; https://doi.org/10.64898/2026.03.20.26348926doi: medRxiv preprint \n\n 8 \nAfterwards, we examined whether patient age was associated with baseline and post -treatment 157 \nclinical parameters. No significant correlation was found between patient age and baseline 158 \nendometrioma size, VAS scores, or CA -125 levels (p>0.05). Similarly, no significant correlation 159 \nwas observed between patient age and post -treatment VAS scores or CA -125 levels (p>0.05). 160 \nHowever, a significant negative correlation was identified between patient age and post-treatment 161 \nendometrioma size (r = −0.320, p<0.05), indicating that endometrioma size decreased with 162 \nincreasing age. 163 \nTable 4: Correlation between patient age and baseline and post-treatment endometrioma size, VAS 164 \nscores, and CA-125 levels.  165 \n Age \n r* p \nBaseline VAS -0.072 0.638 \nBaseline CA-125 0.008 0.959 \nBaseline Endometrioma Size -0.143 0.347 \nPost-treatment VAS -0.147 0.336 \nPost-treatment CA-125 -0.249 0.099 \nPost-treatment Endometrioma Size -0.320 0.041 \n  *Spearman’ s Correlation Coefficient 166 \nDISCUSSION 167 \nIn this study, six months of treatment with 2 mg/day oral dienogest in 45 patients with 168 \nendometrioma resulted in significant reductions in endometrioma size, pelvic pain severity (VAS 169 \nscore), and serum CA-125 levels. However, no correlation was observed between endometrioma 170 \nsize and VAS score or CA -125 levels. These findings suggest that while dienogest effectively 171 \nreduces disease activity and symptom burden, lesion size alone may not directly reflect symptom 172 \nseverity or biochemical markers. 173 \nSymptom control remains the primary goal in the management of endometriosis  (Ferrero et al., 174 \n2018). Current guidelines from the American Society for Reproductive Medicine recommend 175 \nmedical therapy as the first -line approach for patients with superficial or persistent disease, 176 \nreserving surgical treatment for those with large endometriomas or disease refractory to medical 177 \nAll rights reserved. No reuse allowed without permission. \n(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. \nThe copyright holder for this preprintthis version posted March 24, 2026. ; https://doi.org/10.64898/2026.03.20.26348926doi: medRxiv preprint \n\n 9 \nmanagement (ASRM, 2014). Effective medical therapies that reduce symptoms and suppress 178 \nlesion activity are therefore essential, particularly for patients who wish to avoid surgery and 179 \npreserve ovarian reserve. 180 \nPrevious studies have not clearly demonstrated superiority between estrogen –progestin 181 \ncombinations and progestin -only therapies in terms of efficacy, safety, tolerability, or cost 182 \n(Vercellini et al., 2016). Some patients using combined oral contraceptives may experience pain 183 \nduring hormone-free intervals due to withdrawal bleeding; in such cases, continuous rather than 184 \ncyclic use is recommended (Zorbas et al., 2015; Vercellini et al., 2018). Because endometriosis is 185 \na chronic disease requiring long-term treatment, progestins may be preferred as first -line therapy 186 \nin patients who cannot tolerate or have contraindications to combined oral contraceptives 187 \n(Vercellini et al., 2016). 188 \nDienogest is a selective progestin that suppresses local estrogen production and inhibits the 189 \nproliferation of endometrial cells. It also partially suppresses hypothalamic GnRH secretion, 190 \nleading to decreased LH and FSH levels and reduced ovarian estrogen production. These 191 \nmechanisms create a hypoestrogenic environment that limits the growth and activity of ectopic 192 \nendometrial tissue. Dienogest has no androgenic, glucocorticoid, or mineralocorticoid activity and 193 \nis characterized by high oral bioavailability and a pharmacokinetic profile suitable for once -daily 194 \nadministration (McCormack et al., 2010). 195 \nThe effectiveness of dienogest in reducing endometriosis -associated pain has been demonstrated 196 \nin several clinical studies. Römer et al. (2018) reported significant long-term reductions in pelvic 197 \npain scores in women receiving 2 mg/day dienogest, both after surgery and as primary treatment.  198 \nSimilarly, Sağlık Gökmen et al. (2023) evaluated 64 patients treated with dienogest and reported 199 \nsignificant reductions in both endometrioma size and pain scores. In our study, mean 200 \nendometrioma size decreased from 50.2 mm to 38.2 mm, and the mean VAS score decreased from 201 \n6.69 to 3.64, supporting the lesion-suppressive and symptom-relieving effects of therapy. 202 \nChen et al. (2024) also demonstrated significant reductions in pain scores, endometrioma size, and 203 \nCA-125 levels after six months of dienogest treatment. In their study, endometrioma size decreased 204 \nby approximately 35% after six months, and CA -125 levels showed marked improvement. Our 205 \nAll rights reserved. No reuse allowed without permission. \n(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. \nThe copyright holder for this preprintthis version posted March 24, 2026. ; https://doi.org/10.64898/2026.03.20.26348926doi: medRxiv preprint \n\n 10 \nfindings of reduced CA-125 levels and decreased lesion size are consistent with these observations. 206 \nThese effects may be attributed to dienogest-induced stromal atrophy within endometriotic lesions, 207 \ndecreased cellular proliferation, and a consequent reduction in active ectopic endometrial tissue. 208 \nFurthermore, as endometriosis is associated with peritoneal irritation and inflammation, the anti -209 \ninflammatory effects of dienogest may contribute to the observed decline in serum CA-125 levels. 210 \nThe strength of the present study is the simultaneous evaluation of clinical, radiological, and 211 \nbiochemical treatment outcomes in a real -world clinical setting. Assessing endometrioma size, 212 \npain severity, and CA-125 levels together provides a more comprehensive assessment of treatment 213 \nresponse. 214 \nHowever, several limitations should be acknowledged. The retrospective design, relatively small 215 \nsample size, and absence of a control group limit the generalizability of the findings. In addition, 216 \nthe follow -up period was limited to six months, and long -term outcomes were not evaluated. 217 \nLarger prospective studies with longer follow-up are needed to confirm these results. 218 \nOverall, our findings suggest that dienogest is an effective medical treatment option for patients 219 \nwith endometriosis, providing significant improvements in symptoms and disease -related 220 \nparameters while potentially reducing the need for surgical intervention. 221 \n 222 \nCONCLUSION 223 \nIn this study, six months of dienogest therapy was associated with significant reductions in 224 \nendometrioma size, pelvic pain severity, and serum CA-125 levels. These findings support the use 225 \nof dienogest as an effective and well-tolerated treatment option that may delay the need for surgical 226 \nintervention, particularly in patients who wish to preserve fertility. 227 \nLIMITATION OF STUDY 228 \nThe relatively small sample size, retrospective design, and short follow -up period limit the 229 \ngeneralizability of these findings.  Future prospective, randomized studies with larger patient 230 \nAll rights reserved. No reuse allowed without permission. \n(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. \nThe copyright holder for this preprintthis version posted March 24, 2026. ; https://doi.org/10.64898/2026.03.20.26348926doi: medRxiv preprint \n\n 11 \npopulations and longer follow -up are needed to confirm the long -term efficacy and safety of 231 \ndienogest therapy. 232 \nREFERENCES 233 \n1) Zondervan KT, Becker CM, Missmer SA. Endometriosis.  N Engl J Med . 234 \n2020;382(13):1244–1256. 235 \n2) Zondervan KT, Becker CM, Koga K, Missmer SA, Taylor RN, Viganò P. 236 \nEndometriosis. Nat Rev Dis Primers. 2018;4:9. 237 \n3) Giudice LC, Kao LC. Endometriosis. Lancet. 2004;364(9447):1789–1799. 238 \n4) European Society of Human Reproduction and Embryology (ESHRE). ESHRE guideline: 239 \nEndometriosis. 2022. 240 \n5) Dunselman GAJ, Vermeulen N, Becker C, et al. ESHRE guideline: management of women 241 \nwith endometriosis. Hum Reprod. 2014;29(3):400–412. 242 \n6) American College of Obstetricians and Gynecologists (ACOG). Management of 243 \nendometriosis. ACOG Practice Bulletin No. 114. Obstet Gynecol. 2010;116(1):223–236. 244 \n7) American Society for Reproductive Medicine (ASRM). Treatment of pelvic pain 245 \nassociated with endometriosis: a committee opinion. Fertil Steril. 2014;101(4):927–935. 246 \n8) Foster RH, Wilde MI. Dienogest. Drugs. 1998;56(5):825–833. 247 \n9) McCormack PL. Dienogest: a review of its use in the treatment of endometriosis.  Drugs. 248 \n2010;70(16):2073–2088. 249 \n10) Andres MP, Borrelli GM, Abrão MS. Dienogest in the treatment of endometriosis: 250 \nsystematic review. Arch Gynecol Obstet. 2015;292(3):523–529. 251 \n11) Römer T. Long -term treatment of endometriosis with dienogest: a real -world 252 \nstudy. Gynecol Endocrinol. 2018;34(6):513–516. 253 \n12) Sağlık Gökmen N, et al. Effects of dienogest treatment on endometrioma size and pain 254 \nsymptoms. J Obstet Gynaecol Res. 2023;49(3 255 \n13) Chen X, et al. Clinical outcomes of dienogest treatment in women with endometriosis: a 256 \nretrospective study. Eur J Obstet Gynecol Reprod Biol. 2024 257 \n14) Vercellini P, et al. Medical treatment of endometriosis-related pain. Hum Reprod Update. 258 \n2016;22(3):314–335. 259 \nAll rights reserved. No reuse allowed without permission. \n(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. \nThe copyright holder for this preprintthis version posted March 24, 2026. ; https://doi.org/10.64898/2026.03.20.26348926doi: medRxiv preprint \n\n 12 \n15) Vercellini P, et al. Continuous use of oral contraceptives for endometriosis -associated 260 \npain. Fertil Steril. 2018;109(3) 261 \n16) Zorbas KA, et al. Continuous versus cyclic oral contraceptives in endometriosis.  Gynecol 262 \nEndocrinol. 2015;31(6):473–476. 263 \n17) Luciano DE, et al. Management of endometriosis: individualized treatment strategies. Clin 264 \nObstet Gynecol. 2011;54(4):485–496. 265 \n18) Gift, A. G. (1989). Visual analogue scales: Measurement of subjective 266 \nphenomena. Nursing Research, 38(5), 286–288.   267 \nFIGURES/TABLES 268 \nTable 1. Baseline characteristics of the study population (n = 45).  269 \nTable 2. Comparison of V AS scores, CA-125 levels, and endometrioma size at baseline and at six 270 \nmonths of treatment. 271 \nTable 3. Correlation between endometrioma size and clinical parameters at baseline and after six 272 \nmonths of treatment. 273 \nTable 4: Correlation between patient age and baseline and post-treatment endometrioma size, 274 \nVAS scores, and CA-125 levels. 275 \nACKNOWLEDGMENTS 276 \nWe would like to thank the staff of the Endometriosis and Chronic Pelvic Pain Clinic at Bagcılar 277 \nTraining and Research Hospital for their support in patient follow-up and data management. 278 \nFUNDING 279 \nThe authors received no specific funding. 280 \nCONFLICT OF INTEREST 281 \nThe authors declare no competing interests. 282 \nAll rights reserved. No reuse allowed without permission. \n(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. \nThe copyright holder for this preprintthis version posted March 24, 2026. ; https://doi.org/10.64898/2026.03.20.26348926doi: medRxiv preprint \n\n 13 \nETHICS/IRB STATEMENT 283 \nThe study was approved by the Clinical Research Ethics Committee of the University of Health 284 \nSciences Ba gcılar Training and Research Hospital. Due to the retrospective design, informed 285 \nconsent was waived. 286 \nDATA AVAILABILITY STATEMENT 287 \nData are available from the corresponding author upon reasonable request. 288 \nAll rights reserved. No reuse allowed without permission. \n(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. \nThe copyright holder for this preprintthis version posted March 24, 2026. ; https://doi.org/10.64898/2026.03.20.26348926doi: medRxiv preprint","source_license":"CC0","license_restricted":false}