ABSTRACT
This chapter discusses the biology of the breast cancer susceptible gene (BRCA) gene as it pertains to its role in cancer, the effects of mutations in BRCA genes, the role of polymerase (PARP) in DNA repair, as well as PARP inhibitors and their clinical development as anticancer agents. Cells undergo DNA damage during replication and from environmental exposures. Increasing evidence implicates defects in the DNA repair pathway in carcinogenesis, cancer progression, and response to therapy. The incidence of the BRCA germline mutations is low in the general population; however, some tumors have somatic mutations or epigenetic changes in the BRCA gene or other mutations that impair homologous recombination and lead to behavior similar to that of tumors with germline BRCA mutations. Immunotherapy using immune checkpoint inhibitors has revolutionized the landscape of cancer treatment. Traditional chemotherapy is designed to kill tumor cells by targeting them directly.
