Stage I seminoma: adjuvant treatment is effective but is it necessary?

Over the past 40 years, the incidence of testicular cancer has increased in almost all populations worldwide, and it remains the most common solid malignancy in young men between the ages of 20 and 35 years. Primary germ cell tumors are the predominant histological type, with approximately 60% of germ cell tumors being pure seminoma, 30% being nonseminomatous germ cell tumors, and 10% being mixed tumors (1). In the United States, 8480 new diagnoses and 350 deaths from the disease have been projected for 2010 (2). Because 80%–85% of seminoma patients present with disease that is clinically confined to the testis, more than 50% of all patients with newly diagnosed testicular cancer have stage I seminoma. Post-orchiectomy management in stage I seminoma includes surveillance, with treatment reserved for those who relapse, or adjuvant treatment with either radiation therapy or chemotherapy. Regardless of the management strategy used, nearly 100% of patients are ultimately cured. In this issue of the Journal, Mead et al. (3) report on the mature results of three large randomized trials (TE10, TE18, and TE19) of adjuvant therapy in patients with stage I seminoma. Results from these trials indicate that 1) if adju-vant radiation therapy is given, that a dose of 20 Gy in 10 fractions is all that is necessary; 2) if the para-aortic lymph nodes alone are treated, that the pelvic relapse rate is low (approximately 2%); and 3) both adjuvant radiation therapy and one course of carboplatin give a relapse rate of approximately 5%. The trials also provide extensive information about relapse sites and timing of relapse. The Medical Research Council investigators are to be congratulated for this major contribution to our body of knowledge about the management of stage I seminoma. Although these trials address the relative merits of differing adjuvant therapy strategies, a key question is whether adjuvant therapy is necessary at all? Between 1950 and 1990, adjuvant radiation therapy was the standard treatment of stage I seminoma. However, during the past 20 years, mounting evidence has led to concern regarding the late effects of radiation therapy. The most important and worrisome late complication of radiation therapy is the risk of second nontesticular cancers. Since this increased risk is expressed more than 10–15 years after treatment, it is not apparent in most published series with shorter follow-up. Travis et al. (4) combined 14 population-based registries that included 10 534 patients with seminoma (all …