Background: Epithelial ovarian cancer (EOC) is a leading cause of gynecological cancer death. Most cases are diagnosed with advanced stage disease and have a poor prognosis. Limited information is available on EOC mortality risk in Australia. We investigated associations between demographic factors and risk of mortality for women in New South Wales (NSW) diagnosed with EOC.
Methods: Data from the NSW Cancer Registry and Cause of Death Unit Record File was analysed, obtained through the Enduring Cancer Data Linkage program, diagnosed EOC between 2000 to 2019. Cox proportional hazards regression analysis was used to calculate hazard ratios (HR) and 95% confidence intervals (95% CI) for the risk of all-cause mortality in EOC patients. Exposures that were assessed included country of birth, remoteness of residence, and socioeconomic status. Multivariable models were adjusted for age at diagnosis, year of diagnosis, disease histology, and degree of spread.
Results: A total of 8,178 individuals diagnosed with invasive EOC (ovarian, primary peritoneal, and fallopian tube cancers) were included in the study. During the follow-up time (mean: 4.72 years, SD:4.71) a total of 5,065 (61.9%) individuals died. Compared to cases who were born in Australia, EOC patients who were born in South-East and North-East Asia, and the Americas had a lower risk of mortality [HRs (95% CIs) were 0.83 (0.70-0.99), 0.73 (0.60-0.88), and 0.69 (0.53-0.91) respectively]. For EOC patients who were born in other areas, (Northern/Western Europe, Southern/Eastern Europe, Sub-Saharan Africa, North Africa/Middle East, and Oceania except for Australia) there was no difference in EOC mortality risk compared with patients born in Australia. Regarding remoteness of residence in Australia, there was no difference in mortality risk for EOC patients who resided in rural versus urban areas. Compared to EOC patients who were classified in socioeconomic status (SES) quintile 1 (most disadvantaged), patients in quintiles 3-5 had a slightly lower risk of mortality [e.g., SES quintile 5 (least disadvantaged) versus quintile 1, HR=0.83, 95% CI=0.77-0.91].
Conclusions: We observed that EOC patients with the most disadvantaged SES had a higher risk of mortality. Patients who were born in certain regions of Asia and the Americas, compared to Australian-born, had a lower risk of mortality. Further research using datasets that include additional socio-demographic and health characteristics is needed to confirm these findings.