Purpose: Clinical stage 1 (CS1) testicular seminoma involves an almost 100 % disease-specific survival in controlled clinical trials. We aimed to find out whether these results can be matched in patients managed on the routine care level.
Patients, methods: In total, 725 patients with seminoma CS1 were prospectively enrolled from 130 institutions. Adjuvant management as decided by local physicians involved surveillance (n = 256), radiotherapy (41), 1× Carboplatin (362), and 2× Carboplatin (66). We registered type of management, age, duration of follow-up (F/U), relapse, rete testis invasion (RTI), and tumor size. Actuarial relapse-free survival curves were calculated for treatment modalities and stratified for tumor sizes and RTI. A Cox regression model was calculated to explore for factors influencing relapses.
Results: Disease-specific survival was 100 %. Crude relapse rates were 8.2, 2.4, 5.0, and 1.5 % for surveillance, radiotherapy, 1× Carboplatin, and 2× Carboplatin after a median F/U of 30 months. RTI and tumor size were not associated with progression in surveillance patients. One course Carboplatin caused relapses in 6.8 % in tumor sizes >4 cm and 9.3 % (actuarial 13 %) in sizes >5 cm. The Cox model revealed the association of tumor size with recurrence in the entire seminoma population (Hazard ratio 1.17; 95 % confidence intervals 1.03-1.33).
Conclusions: The overall outcome of CS1 seminoma managed on the routine care level mirrors that of controlled trials. Unexpectedly, the risk factors in surveillance patients were not confirmed, but tumor size proved to be a risk indicator in the entire group of seminoma. Importantly, one course Carboplatin involved low efficacy to control the disease in large tumors.
Keywords: Carboplatin; Radiotherapy; Rete testis; Surveillance; Testicular seminoma.