doxorubicin + cyclophosphamide + carboplatin + paclitaxel + olaparib

This is a combination chemotherapy regimen consisting of five drugs used primarily in cancer treatment, especially breast and ovarian cancers. - **Doxorubicin** is an anthracycline antibiotic that works by intercalating DNA and inhibiting topoisomerase II, causing DNA damage at any point in the cell cycle, preventing cancer cell replication. - **Cyclophosphamide** is an alkylating agent that cross-links DNA strands during the resting phase of the cell cycle, inhibiting DNA synthesis and preventing cancer cell division. - **Carboplatin** is a platinum-based chemotherapy drug that causes DNA crosslinking leading to apoptosis. - **Paclitaxel** stabilizes microtubules and prevents their disassembly, disrupting mitosis and inducing apoptosis. - **Olaparib** is a small molecule PARP inhibitor targeting poly (ADP-ribose) polymerase enzymes involved in single-strand DNA break repair. It exploits homologous recombination deficiency (HRD), especially in BRCA-mutated cancers, leading to accumulation of double-strand breaks and cancer cell death. This combination leverages multiple mechanisms to target tumor cells through different pathways including direct DNA damage (doxorubicin, cyclophosphamide, carboplatin), mitotic inhibition (paclitaxel), and targeted synthetic lethality via PARP inhibition (olaparib). It has been studied for use particularly in breast cancer regimens combining AC-T with olaparib for enhanced efficacy against BRCA-mutated or HRD-positive tumors.