Rates of genetic consultation in high‐grade serous ovarian cancer patients in the era of PARP inhibitor therapy: A population‐based study

OBJECTIVE: The American Society of Clinical Oncology recommends all patients with high-grade serous ovarian carcinoma (HGSC) undergo germline genetic testing. Genetic consultation rates in Ontario, Canada, only reached 13.3% in 2011. In 2016, PARP inhibitor maintenance therapy became available in Ontario for BRCA-positive HGSC patients. Given expanding treatment options, we re-examined genetic consultation rates among HGSC patients. METHODS: This retrospective cohort study identified patients diagnosed with HGSC between 2012 and 2019 using population-based administrative data from Ontario. Genetics consultations were identified using Ontario Health Insurance Plan billing codes. Consultation rates over time were analyzed using Cochran-Armitage trend test and segmental regression analysis. Multivariable analysis identified factors associated with attending genetics consultation. RESULTS: This study included 4645 HGSC patients. The mean age was 64.2 years (±SD 12.3); 56.3% had stage 3-4 disease. Overall, approximately 35% attended genetics consultations. The genetic consultation rate per year increased significantly from 21.6% to 42.6% (P < 0.001). Shorter times between diagnosis and genetics consult were observed after PARP inhibitors became available (68.1 vs 34.1 weeks, P < 0.001). Patients treated at designated cancer centers (odds ratio [OR] 2.11, P < 0.001), diagnosed in later years (OR 1.33, P < 0.001), and from higher income groups (P < 0.05) were more likely to attend genetics consultation; older patients were less likely (OR 0.98, P < 0.001). After PARP inhibitors became available, consultation rates plateaued (P < 0.001). CONCLUSIONS: Between 2012 and 2019, genetic consultation rates improved significantly among HGSC patients; however, a large proportion of patients never attended consultation. Further exploration of barriers to care is warranted to improve consultation rates and ensure equitable access to care.