INCREASED FREQUENCY OF CHROMOSOMAL DAMAGE IN PERIPHERAL-BLOOD LYMPHOCYTES UP TO 9 YEARS FOLLOWING CURATIVE CHEMOTHERAPY OF PATIENTS WITH TESTICULAR-CARCINOMA

The presence of micronuclei (MN) in binucleated peripheral blood lymphocytes of 37 testicular carcinoma patients was studied 1.5 to 9.3 years following curative chemotherapy. All patients received cisplatinum, 35 patients also received bleomycin. In addition, most patients were treated with another cytotoxic drug, i.e., vinblastine (n = 23) and/or etoposide (n = 24). The mean time interval between cessation of chemotherapy and the micronucleus assay was 4.6 years. The median frequency of MN in binucleated cells in treated patients (0.059) was significantly higher than that in 12 untreated cancer patients (0.036; P = 0.003) or that in 26 healthy age-matched controls (0.034; P < 0.001). Frequencies of MN in the 12 untreated cancer patients (including 7 patients with disseminated testicular carcinoma) did not differ from those in the 26 healthy controls (P = 0.890), suggesting that chromosomal damage in lymphocytes of treated testicular cancer patients must be attributed to the chemotherapy. Results indicate that lymphocytes containing chemically induced chromosomal damage persist for up to 9.3 years following cessation of chemotherapy. The implications of these findings with regard to the increased risk for secondary tumors are discussed.