Grant: Project Grant - PA: Health Economics/Health Services Research in Cancer Control

High grade serous ovarian cancer (HGSOC) is a common and aggressive type of ovarian cancer which can be associated with BRCA mutations. Advanced HGSOC (stage III-IV) is typically treated with a combination of surgery and platinum-based chemotherapy. However, most women will relapse and their cancer will become resistant to chemotherapy. The use of maintenance therapy with PARP inhibitors, such as olaparib and niraparib, after chemotherapy has been shown to delay recurrence/progression in clinical trials. However, studies have shown that these drugs are most effective in patients with BRCA mutations. Benefit in patients without BRCA or similar mutations was small, only delaying progression/recurrence by an average of 3 months. Further, treatments that lead to benefit in clinical trials do not always show the same improvements when they are used in the "real world", and sometimes lead to more or different side effects than those seen in studies. In addition, not all patients have equal access to new drugs due to reasons such as risk of side effects in certain patients, or lack of awareness of study results and available funding by their physicians. This research is being done to determine if patients receiving maintenance therapy with PARP inhibitors for ovarian cancer in Ontario are receiving equal and adequate access to these new drugs, and whether the risks and benefits are still important when used in patients not enrolled in clinical trials. To perform this research, we will use data from large Ontario databases which have collected data on patients receiving treatment ovarian cancer. This will be linked to BRCA status collected from pathology reports. We will analyze these data to examine the proportion and characteristics of patients who have received these drugs and determine whether their long-term outcomes are better than those of patients who did not receive maintenance therapy.