Secondary Malignancies & Cancer Chemotherapy

SECONDARY MALIGNANCIES & CANCER CHEMOTHERAPY

The development of secondary malignancies is a late complication of the alkylating agents and the epipodophyllotoxin etoposide. The most frequent secondary malignancy is acute myelogenous leukemia (AML). In general, AML develops in up to 15% of patients with Hodgkin’s lymphoma who have received radiother-apy plus MOPP chemotherapy and in patients with multiple myeloma, ovarian carcinoma, or breast carcinoma treated with melphalan. The increased risk of AML is observed as early as 2–4 years after the initiation of chemotherapy and typically peaks at 5 and 9 years. With improvements in the clinical efficacy of various combination chemotherapy regimens resulting in prolonged sur-vival and in some cases actual cure of cancer, the issue of how second cancers may affect long-term survival assumes greater importance. There is already evidence that certain alkylating agents (eg, cyclophosphamide) may be less carcinogenic than oth-ers (eg, melphalan). In addition to AML, other secondary malig-nancies have been well-described, including non-Hodgkin’s lymphoma and bladder cancer, the latter most typically associated with cyclophosphamide therapy.