OUTLINE: An extra tube of blood is collected before, every 4 weeks during, and every 3 months after radiotherapy and/or chemotherapy. DNA is isolated from the blood sample and the GSTM1, GSTT1, and various cytochrome P (CYP) 450 genotypes are determined by polymerase chain reaction (PCR). Mononuclear leukocytes are analyzed for chromosome aberrations on chromosome numbers 3, 11, and 21. Pretreatment karyotype and frequency of translocations are determined for each patient. Peripheral blood lymphocyte DNA is also examined for t(14;18) gene rearrangements.