Long-term results in patients affected by testicular seminoma treated with radiotherapy: risk of second malignancies

To report clinical results in patients with testicular seminoma treated with postoperative radiotherapy with regard to survival, acute and late toxicity, and risk of second malignancy. 176 stage I-Il testicular seminoma patients treated with radiotherapy from 1964 to 1994 at the Radiotherapy Division of Pisa University, using 60Co or Linac, were analyzed retrospectively. The follow-up ranged from 0.13 to 32.37 years, with a median of 12.1 years. The observed numbers of second malignancies were compared with those expected, taking into account age, sex, and incidence rates from the Tuscany Tumor Registry. Overall and specific survival at 10-15 years were 89-82% and 93-92%, respectively. Multivariate analysis revealed a significantly better survival in patients younger than 50 years and in those treated with Linac. Severe late sequelae occurred in 8% of the patients. Sixteen second malignancies were observed (14 solid tumors and 2 leukemias); median latency was 13 years (range, 3-27) and the observed/expected ratio 1.4 (P not significant). Solid cancers were localized in the bladder (2), kidney (2), skin (2), stomach (1), prostate (1), lung (1), larynx (1), uvea (1) and contralateral testicle (1); 1 patient presented an intestinal carcinoid and 1 a metastasis from an unknown primary. The risk of a second malignancy was higher in the patient group receiving less than 4000 cGy (observed/expected, 2.8; P = 0.015). The study confirmed the high cure rate in stage I-II seminomas after postoperative radiotherapy. Incidence of a second malignancy was higher than expected, but the difference was not statistically significant.