Risk of Endometriosis and Subsequent Ovary and Breast Cancers in Nurses: A Population-Based Cohort Study in Taiwan

Abstract

Background: Endometriosis has been associated with the subsequent development of ovarian and breast cancers. This study evaluated whether nurses were at increased risks of developing endometriosis and subsequent ovarian and breast cancers. Methods: From Taiwan National Health Insurance Research Database during 2000 to 2011, we established 3 study cohorts, consisting of 23,801 nurses, 11,973 other hospital employees, and 143,096 general women free of endometriosis and cancer. Women in all cohorts were followed to the end of 2011 to measure the occurrences of endometriosis and subsequent ovarian and breast cancers. The incident endometriosis cases and related hazard ratio (HR) and 95% confidence interval (CI) were calculated. The incident cases of ovarian cancer and breast cancer and related odds ratio were calculated. Results: The incidence of endometriosis was the highest in the nurse cohort (4.23 per 100, n = 966) followed by other health professionals (3.74 per 100, n = 427) and control cohort (3.06 per 100, n = 4193), with adjusted hazard ratios of 1.28 (95% CI = 1.20–1.38) and 1.13 (95% CI = 1.02–1.25), respectively, comparing to controls. Among those who developed endometriosis, nurses had higher subsequent ovarian cancer and lower breast cancer, but not significant. Conclusions: Nurses are at a higher risk of developing endometriosis. However, the link between endometriosis and subsequent cancers is weak.

The association between endometriosis and risk of endometrial cancer and breast cancer: a meta-analysis

“…All articles were published between 2011 and 2021. Studies were conducted in America [21,23,30,35,36,38], the UK [22,25], China [29,33,34,37,39,41], Korea [19], Denmark [20], Finland [31], Sweden [32], Germany [42], Puerto Rico [24], and Australia [40], with each of the latter seven countries having one study. Regarding the assessment of endometriosis, apart from studies including a clinical diagnosis made by the medical doctors during hospitalization or in the outpatient setting [19,20], the ICD code of the disease [21, 29, 32-34, 37, 41], medical records from the hospital database or relevant medical documents [39], laparoscopy or surgery [22,31,35], and selfreports [23,24,30,36,38,40,42], the remaining study included both patient-reported and clinically reported information [25].…”

Comparing Paclitaxel–Carboplatin with Paclitaxel–Cisplatin as the Front-Line Chemotherapy for Patients with FIGO IIIC Serous-Type Tubo-Ovarian Cancer

“…Epithelial tubo-ovarian cancer (ETOC) is the deadliest cancer among women, placing with fourth place of all the fetal diseases among women and ranking seventh of most common cancers in women's cancer and women's cancer-related deaths in Taiwan and globally in 2018 [1][2][3][4][5][6]. Serous-type is the most common subtype among EOCs in general; however, endometriosis-associated EOCs, such as clear cell type or endometrioid type are relatively common in certain populations, including Taiwan and Japan [7][8][9][10][11]. Clinically, the serous-type EOC and primary peritoneal serous carcinoma (PPSC) and primary Fallopian tube cancer (PFTC) are often considered the same group disease, based on the similar clinical behavior and possibly sharing the similar pathogenesis [12][13][14][15][16][17][18].…”

Further evidence that endometriosis is related to tubal and ovarian cancers: A study of 271,444 inpatient women

“…No association was found with mucinous or high-grade serous and borderline tumours [11,14]. However, in two large cohorts, the authors could not find any relationship between endometriosis and ovarian cancer [18,19]. The number of women with endometriosis in those studies may have been too low to reach the statistical power needed to demonstrate an association.…”