Secondary neoplasms following treatment of malignant germ cell tumors.

Abstract

PURPOSE The current study investigates the frequency and outcome of secondary malignancies in patients treated for testicular cancer at Hannover University Medical School between 1970 and 1990. PATIENTS AND METHODS One thousand twenty-five patients with a median follow-up duration of 61 months (range, 12 to 240) were included in the analysis. Follow-up was complete in 1,018 patients (99%). Histology was seminoma in 324 patients (38.7%) and nonseminomatous germ cell tumor in 624 patients (61.3%). At the time of median follow-up, 814 patients (79.9%) were alive. RESULTS Fourteen patients developed a secondary neoplasm (cumulative incidence, 1.38%; 95% confidence interval [CI], 0.75 to 2.30); 13 patients had solid tumors and one had secondary lymphoblastic leukemia with a t(4; 11) translocation including band 11q23. None of 224 patients on surveillance strategy (with or without retroperitoneal lymph node dissection [RPLND]) developed a second neoplasm, compared with four of 413 patients (0.97%; 95% CI, 0 to 1.9) after cisplatin-based chemotherapy (not significant) and nine of 332 patients (2.7%; 95% CI, 0.9 to 4.5) after radiotherapy (P = .02). The cumulative incidence of a secondary neoplasia of 1.76% (95% CI, 0.97 to 2.94) in patients treated by radiotherapy and/or chemotherapy was significantly higher compared with patients on surveillance protocols (P = .03). Chemotherapy containing standard-dose etoposide did not increase the risk of occurrence of secondary neoplasms. A significantly elevated relative risk of 7.53 (range, 3.4 to 14.3) compared with the male German population was only found for patients treated by radiotherapy. CONCLUSION Compared with patients who have other curable malignant tumors, an incidence of 1.38 of secondary neoplasms after a median follow-up duration of 61 months is low. The highest risk for secondary neoplasia after treatment of testicular cancer is associated with the use of radiotherapy. Following chemotherapy, no significantly elevated risk was observed. In conclusion, the benefits of curative treatment far outweigh the risk of secondary cancer in patients with malignant germ cell tumors.