Our results suggest that GCSs may be found not infrequently in HBOC families and assimilate the analyzed CSs to BRCA1-related breast/ovarian carcinomas, where the above findings are frequently observed.
In contrast to carcinomas, BRCA1-deficient mouse carcinosarcomas resembling MBC show intrinsic resistance to olaparib caused by increased P-glycoprotein (Pgp) drug efflux transporter expression.