BRCA1 and ovarian carcinoma: Moreover, patients who cannot undergo BRCA gene testing may also benefit from olaparib therapy, e.g., patients in Japan, who cannot undergo BRCA1/2 somatic mutation testing or HRD testing under insurance coverage despite the fact that approximately 30% of all Japanese patients with recurrent ovarian cancer have BRCA1/2 mutations and that somatic BRCA1/2 mutations account for 5% of all patients with recurrent ovarian cancer overall.