Stratifying the risk of ovarian cancer incidence by histologic subtypes in the Korean Epithelial Ovarian Cancer Study (Ko‐EVE)

• Published in: Cancer medicine (Malden, MA) Vol. 12; no. 7; pp. 8742 - 8753
• Main Authors: Sung, Soseul, Hong, Youjin, Kim, Byoung‐Gie, Choi, Ji‐Yeob, Kim, Jae Weon, Park, Sang‐Yoon, Kim, Jae‐Hoon, Kim, Yong‐man, Lee, Jong‐Min, Kim, Tae Jin, Park, Sue K.
• Format: Journal Article
• Language: English
• Published: United States John Wiley & Sons, Inc 01.04.2023; John Wiley and Sons Inc; Wiley
• Subjects: Alcohol; Asian people; Breast cancer; Carcinogens; Carcinoma, Endometrioid - complications; Carcinoma, Ovarian Epithelial - complications; Carcinoma, Ovarian Epithelial - epidemiology; Case-Control Studies; Electrocardiography; Enrollments; epidemiology; Estrogens; Ethnicity; Family medical history; Female; Hormone replacement therapy; Hospitals; Humans; Hysterectomy; Incidence; Laboratories; Medical screening; Menarche; Oral contraceptives; Ovarian cancer; ovarian neoplasms; Ovarian Neoplasms - epidemiology; Ovarian Neoplasms - etiology; Ovarian Neoplasms - pathology; Ovariectomy; pathology; Pregnancy; Questionnaires; Regression analysis; Republic of Korea - epidemiology; Risk Factors; Smoking; Republic of Korea; epidemiology; ovarian neoplasms; risk factors; pathology
• ISSN: 2045-7634; 2045-7634
• DOI: 10.1002/cam4.5612

Introduction This study aimed to verify the association between ovarian cancer (OC) and reproductive‐ and lifestyle‐related risk factors stratified by the subtype of OC. Methods In this matched case–control study derived from the Korean epithelial ovarian cancer study (Ko‐EVE), we calculated the risk of OC subtypes using odds ratios (ORs) and 95% confidence intervals (95% CIs) in a logistic regression model. Results As a result of matching, 531 cases and 2,124 controls were selected. Smoking had positive association with high‐grade serous (HGS) OC (OR = 2.69, 95% CI = 1.15–6.30), whereas alcohol consumption had positive association with mucinous type (MUC) (OR = 3.63, 95% CI = 1.39–9.49). Obesity (≥30 kg/m2) was associated with clear cell type (CLC) (OR = 4.57, 95% CI = 1.06–19.77). Spontaneous abortion was negatively associated with CLC (OR = 0.34, 95% CI = 0.13–0.90), in contrast to HGS (OR = 1.43, 95% CI = 0.96–2.15). Tubal ligation, hysterectomy, and oophorectomy were associated with decreased risk of HGS (OR = 0.14, 95% CI = 0.05–0.39; OR = 0.23, 95% CI = 0.07–0.73; OR = 0.28, 95% CI = 0.08–0.97, respectively). Early menarche was strongly associated with increased risk of CLC, but not MUC (OR = 6.11, 95% CI = 1.53–24.42; OR = 3.23, 95% CI = 0.98–10.86). Further, childbirth (≥2 times) was negatively associated with endometrioid type OC and CLC (OR = 0.11, 95% CI = 0.04–0.35; OR = 0.12, 95% CI = 0.02–0.37, respectively). Oral contraceptives and hormone replacement therapy were negatively associated with OC (OR = 0.61, 95% CI = 0.40–0.93; OR = 0.51, 95% CI = 0.32–0.80, respectively), and similar negative associations were also observed in HGS (OR = 0.69; OR = 0.60, respectively). Associations between family history of breast cancer and OC, regular exercise (≥5/week), and artificial abortion and OC were similar across all subtypes (OR = 3.92; OR = 0.41; OR = 0.72, respectively). Conclusion A heterogeneous association between some risk factors and the incidence of each subtype of epithelial OC was observed, suggesting that the carcinogenic mechanisms of each subtype may be partly different. SCLC patients with TGRmax > −34.3%/m had worse PFS and OS in first‐line immunotherapy plus platin‐based chemotherapy.