Poster Presentation NSW State Cancer Conference 2023

Ovarian cancer survival by racial and ethnic group: an analysis from the Ovarian Cancer Association Consortium (#177)

Nicola S Meagher 1 , Kami K White 2 , Lynne R Wilkens 2 , Penelope M Webb 3 , Anna H Wu 4 , Lauren C Peres 5 , Melissa A Merritt 1
  1. The Daffodil Centre, The University of Sydney, a joint venture with Cancer Council NSW, Sydney, NSW, Australia
  2. Cancer Epidemiology Program, University of Hawaii Cancer Center, Honolulu, HI, USA
  3. Population Health Program, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
  4. Department of Population and Public Health Sciences, University of Southern California Keck School of Medicine, Los Angeles, CA, USA
  5. Department of Cancer Epidemiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA

Background: Less than 50% of patients with epithelial ovarian cancer (EOC) survive beyond five years, however little is known about disparities in outcome by racial and ethnic group. Through the Ovarian Cancer Association Consortium (OCAC), we analysed associations with survival by racial and ethnic group across Asian, Hispanic, Native Hawaiian/Pacific Islander and Non-Hispanic White participants.

Methods: Participants came from 15 studies conducted in Australia, Canada, England, and the USA with a diagnosis of invasive EOC and available data on race and ethnicity, clinical and epidemiological factors, and vital status. Invasive EOC cases for survival analysis (n=12,849) were comprised of Asian (n=641); Hispanic (n=490); Native Hawaiian/Pacific Islander (n=98); and White non-Hispanic (n=11,420) women. Cox proportional hazards regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI) of overall survival between racial and ethnic groups. Additional analyses were restricted to women with high-grade serous carcinoma (HGSC) alone (n=7,538) as well as EOC cases with advanced stage (regional/distant) disease at diagnosis (n=9,923). The minimally adjusted model included strata variables for study site, age at diagnosis (10-year groups) and tumour stage and was adjusted for age (continuous) and histological subtype. Additional comprehensive multivariable models were adjusted for factors that are associated with EOC survival in the literature and could plausibly vary across racial and ethnic groups (body mass index, smoking, oestrogen-only menopausal hormone use).

Results: The mean follow-up after a diagnosis of EOC was 6.1 years (standard deviation = 4.8). Compared to White women, Native Hawaiian/Pacific Islander women with EOC had an increased risk of mortality (minimally adjusted model HR = 1.60, 95% CI = 1.17 - 2.17), and this association was strongest for HGSC (HR = 1.96, 95% CI = 1.33 - 2.89), and was also observed in analysis restricted to patients with advanced stage disease, HR = 1.73, 95% CI = 1.25 - 2.39). Risk of mortality was lower for Asian women with EOC (compared to White women, HR= 0.91, 95% CI = 0.79-1.04), although not statistically significant, and risk was similar for Hispanic women (HR = 1.07, 95% CI = 0.94 - 1.21). All results were similar, but the hazard ratios were slightly attenuated in the comprehensive multivariable adjusted models.

Conclusions: Native Hawaiian/Pacific Islander women with EOC have a higher risk of mortality compared with White women. More work is needed to understand factors contributing to this disparity to improve outcomes for this group.