Treatment, outcomes, and resource utilization among patients with metastatic breast and advanced epithelial ovarian cancer, by BRCA1/2 and HRD status.

BACKGROUND

Poly(adenosine diphosphate [ADP]-ribose) polymerase inhibitors (PARPis) are indicated for treatment of tumors with breast cancer susceptibility genes BRCA1/2 mutations and homologous recombination deficiency (HRD). Little is known about differences in care by BRCA1/2 and HRD status for breast and ovarian cancers.

METHODS

We investigated clinical characteristics, treatment, clinical outcomes, and health-care resource utilization by BRCA1/2 or HRD status among patients diagnosed between 2018-2020 with HER2-negative metastatic breast (mBC) and advanced epithelial ovarian cancer (aEOC) in the United States community healthcare setting.

RESULTS

The study included 314 patients with mBC and 465 with aEOC. Patients with mBC carrying a BRCA1/2 mutation were younger and had a higher proportion of triple negative cancer than non-carriers (50% vs 38%). Only 8% of eligible patients received a PARPi in first-line (1L) and 18% in second-line (2L) of treatment for mBC. In aEOC, patients with HRD were younger and a higher proportion received 1L maintenance treatment with a PARPi than patients with non-HRD tumors (95% vs 66%). In aEOC, patients without HRD had greater healthcare resource use. Patients with BRCA-mutated tumors had poorer overall survival (OS); there were no differences in OS by HRD status in aEOC.

CONCLUSION

This study demonstrated differences in treatment by BRCA1/2 and HRD status. There was low PARPi uptake among patients with BRCA-mutated mBC but not among patients with aEOC. In aEOC, the cost to "treat all" may outweigh benefits; identifying patients without HRD likely to benefit from PARPis is needed.