Jin‐Sung Yuk

Relationship between uterine fibroids and risk of cancers: Population‐based retrospective cohort study

Abstract Objective Numerous studies have assessed the relationship between estrogen and cancer, and an association between uterine fibroids and an increased risk of endometrial cancer and thyroid cancer has been found. However, previous studies are limited by small sample sizes and lack of information on patient characteristics. This population‐based retrospective cohort study aimed to confirm the association between uterine fibroids and cancer risk. Methods This population‐based retrospective cohort study used insurance information recorded in the Korea's Health Insurance Review and Assessment Service from January 1, 2009, to December 31, 2020. Patients with a diagnosis of uterine fibroids and uterine fibroid removal surgery code were included in the uterine fibroid group. Women who visited a clinic for a health checkup were included in the non‐uterine fibroid group. Results In total, 714 171 individuals were studied, 492 610 in the non‐uterine fibroids group and 221 561 in the uterine fibroids group. The all‐site cancer hazard ratio (HR) of the uterine fibroid group was higher than that of the non‐uterine fibroid group (all sites: HR, 1.399, confidence interval [CI]: 1.346–1.454), with HR for breast 1.263 (CI: 1.177–1.354), uterus 2.459 (CI: 2.009–3.010), ovary 1.349 (CI: 1.097–1.659), kidney 1.432 (CI: 1.014–2.022), thyroid 1.693 (CI: 1.591–1.800), and retroperitoneum and peritoneum 3.059 (CI: 1.263–7.414). Conclusion Surgically treated uterine fibroids are associated with increased cancer risk. They are associated with an increased risk of breast, uterine, ovarian, kidney, thyroid, peritoneal, and retroperitoneal cancers.

Endometrial cancer risk with menopausal hormone therapy: Health Insurance Database in South Korea‐based cohort study

AbstractObjectiveTo determine the risk of endometrial cancer according to the types of menopausal hormones used.MethodsThis retrospective cohort study recruited postmenopausal women older than 40 years from 2003 to 2011, utilizing data from the Korean national health insurance system from 2002 to 2019. The menopausal hormone therapy (MHT) group consisted of women who had been prescribed MHT for greater than 6 months between 2003 and 2011. The non‐MHT group consisted of women who had never used menopausal hormones between 2003 and 2011.ResultsA non‐MHT group of 1 000 550 women and a MHT group of 353 025 women were chosen. In comparison to never‐users, the risk of endometrial cancer was not higher in women who reported last using tibolone (adjusted hazard ratio [aHR] 1.08, 95% confidence interval [CI] 0.96–1.2), combined estrogen plus progestin by the manufacturer (aHR 0.83, 0.72–0.96), combined estrogen plus progestin by the physician (aHR 0.88, 0.7–1.12), and transdermal estrogen (aHR 1.13, 0.36–3.52).ConclusionsTibolone, combined estrogen plus progestin by the physician, and transdermal estrogen do not affect the risk of endometrial cancer. The combination of estrogen plus progestin by the manufacturer decreases the risk of endometrial cancer.

Incidence and risk of venous thromboembolism according to primary treatment in women with ovarian cancer: A retrospective cohort study

Objective This study aimed to investigate incidence and risk for venous thromboembolism (VTE) according to primary treatment in women with ovarian cancer. Methods We selected 26,863 women newly diagnosed with ovarian cancer between 2009 and 2018 from the Korean Health Insurance Review and Assessment Service databases. During the total follow-up period and the first six months after initiation of primary treatments, incidence and risk of VTE were evaluated according to primary treatment as no treatment, surgery, radiotherapy, or chemotherapy. Results The mean follow-up period was 1285.5±6 days. The VTE incidence was highest in women who underwent chemotherapy (306 per 10,000 women). Among women who underwent surgery, VTE was highest in surgery with neoadjuvant chemotherapy (536 per 10,000 women), followed by surgery with adjuvant chemotherapy (360 per 10,000 women) and surgery alone (132 per 10,000 women). During the first 12 months, monthly incidence of VTE decreased. Compared with women with no treatment, risk of VTE significantly increased in women undergoing chemotherapy (HR 1.297; 95% CI, 1.08–1.557; P = 0.005) during the total follow-up period and decreased in women undergoing surgery (HR 0.557; 95% CI, 0.401–0.775; P<0.001) and radiotherapy (HR 0.289; 95% CI, 0.119–0.701; P = 0.006) during the first six months. Among women who underwent surgery, VTE risk significantly increased in surgery with neoadjuvant chemotherapy (HR 4.848; 95% CI, 1.86–12.632; P = 0.001) followed by surgery with adjuvant chemotherapy (HR 2.807; 95% CI, 1.757–4.485; P<0.001) compared with surgery alone during the total follow-up period and in surgery with neoadjuvant chemotherapy (HR 4.223; 95% CI, 1.37–13.022; P = 0.012) during the first six months. Conclusions In this large Korean cohort study, incidence and risk of VTE were highest in women with ovarian cancer who underwent chemotherapy and surgery with neoadjuvant chemotherapy as a primary cancer treatment. Incidence of VTE decreased over time.