Compared with survivors, the deceased patients were older, had a higher BMI and greater menopausal status at diagnosis, were more likely to have reported tubal ligation prior to diagnosis, and had higher parity and ever breastfeeding. A higher proportion of deceased patients was diagnosed at an advanced stage, with ascites and poorly differentiated histopathological grade, and chemotherapy after surgery. There were no significant differences in age at menarche, hysterectomy, hormone replacement therapy, oral contraceptive use, and family history of ovarian cancer between the living and deceased patients. The survival curves in the ovarian

cancer patients according to tubal ligation status were distinctly different visually (see Fig. 1) and, based on the log-rank test for equality of survival distributions, the difference was not a chance occurrence PD-1 antibody (P < 0.001). Only 21 (38.9%) of 54 patients who had tubal ligation survived to the time of interview, in contrast to 95 women (67.4%) still alive among the 141 women without tubal ligation. Table 3 shows the crude and AZD1152-HQPA adjusted mortality hazard ratios and 95% CI for epithelial ovarian cancer according to selected factors. Compared with patients in FIGO stage I, the adjusted HR were 12.25 (95% CI 2.47–60.78; P < 0.001) and 24.54 (4.50–133.8; P < 0.001) for those who were diagnosed at FIGO stage III and IV. An insignificant

increased HR was observed for ascites 1.27 (95% CI 1.00–1.60; P = 0.05). There was no significant association between cancer survival and age, BMI, World Health Organization (WHO) grade of differentiation, and chemotherapy status. Adjusted HR and 95% CI for reproductive, gynecological and hormone factors are shown in Table 4. HR significantly increased with tubal ligation prior to diagnosis. Compared to patients without tubal ligation, the adjusted HR was 1.62 (95% CI 1.01–2.59; P = 0.04) for patients who had tubal ligation. There was no significant association found with age at menarche, menopausal status, parity, breastfeeding, hormone replacement therapy, oral contraceptive use, and

hysterectomy. The study found that tubal ligation prior to diagnosis had an independently adverse influence on epithelial ovarian cancer survival in Chinese women. The study had a relatively small sample Phosphoglycerate kinase size and exposures to some factors were uncommon (e.g. only four cases were exposed to estrogens). There was no relationship found between other reproductive, gynecological, and hormone factors and survival of ovarian cancer, in contrast to substantial effects of these factors on the incidence of the disease reported elsewhere.2–9 In addition to the evidence presented here, previous tubal ligation or hysterectomy, multiparity, oral contraceptive use and breastfeeding have been reported as protective factors against ovarian cancer incidence in several others studies.