Final answer:
Nitrosoureas are chemotherapy agents that alkylate DNA, leading to cancer cell death. They are used to treat various cancers, including brain tumors, but come with the risk of significant toxicities such as bone marrow suppression and secondary malignancies.
Step-by-step explanation:
Nitrosoureas are a group of alkylating agents used in chemotherapy that have broad-spectrum antitumor activity. They work by transferring alkyl groups to DNA, cross-linking DNA at the O6 position of guanine, leading to DNA damage and apoptosis in cancer cells. Nitrosoureas require biotransformation to become active alkylating agents, and this activation can sometimes take place preferentially in cancer cells, potentially leading to a more selective toxicity profile against malignant cells.
Clinical uses of nitrosoureas include the treatment of various types of cancers, such as brain tumors, multiple myeloma, and lymphomas. However, they are associated with potential toxicities, which can include bone marrow suppression, pulmonary fibrosis, renal toxicity, and even secondary malignancies due to their genotoxic potential. Examples of nitrosoureas include carmustine (BCNU) and lomustine (CCNU), which have been used either alone or in combination with other chemotherapeutic drugs, such as in the BEACOPP regimen (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone) for Hodgkin lymphoma. The decision to use these agents must balance the potential for therapeutic efficacy with the risks associated with toxicity.