Variations in Ovarian Cancer Survival Rates: Investigating Equity and Prognostic Factors Throughout Nova Scotia
Introduction
There is large inter- and intra-country variability in ovarian cancer outcomes. Individuals diagnosed with advanced stage cancer in Nova Scotia have a 3-year net survival of 31.9%, the lowest in the country. This study aimed to identify factors impacting survival, and to investigate evidence of inequities in survival from the point of diagnosis moving forward.
Methods
This population-based retrospective study included all women diagnosed with ovarian cancer in Nova Scotia from Jan 1, 2007, to Dec 31, 2016. Administrative health data were linked to gather individual, tumor, and health system characteristics. Both prognostic and equity factors potentially contributing to variations and inequities in survival were assessed using descriptive and time to event techniques.
Results
This study found no regional differences in survival across Nova Scotia. It revealed that disparities in equity factors do not appear to be significantly associated with survival at the time of diagnosis moving forward. Instead, survival variations were attributed to legitimate prognostic factors, such as cancer stage, subtype, comorbidities, and frailty. However, notable inequities were identified between socioeconomic status and prognostic factors that may contribute to poor survival upstream, rather than at the time of diagnosis.
Conclusion
Though inequities do not appear to directly contribute to differences in ovarian cancer survival at the time of diagnosis, they may influence outcomes by increasing the development of prognostic factors that lead to poorer survival. Future research should capture equity factors not found in administrative data and begin making comparisons between other jurisdictions to determine why survival rates vary worldwide.