Medical Research Council trial of 2 versus 5 CT scans in the surveillance of patients with stage I non-seminomatous germ cell tumours of the testis

Abstract

4519 Background: Surveillance is a standard management approach for stage 1 non seminomatous germ cell tumours (NSGCT), yet there is no agreement on the number of CT scans that are required to detect relapses. A randomised trial of 2 versus 5 CT scans was performed to determine whether the number of scans influenced the prognostic group (J Clin Oncol 15:594–603, 1997) at relapse. Methods: Patients with clinical stage 1 NSGCT opting for surveillance were randomised to chest and abdominal CT scans at either 3 and 12 or 3, 6, 9, 12, and 24 months, with all other investigations (clinical exams, markers, chest X-rays) carried out at equal frequency in the two arms. 3/5 patients were allocated to the 2 scan schedule. 400 patients were required to exclude a 3% increase in the proportion of patients relapsing with IGCCCG intermediate or poor prognosis disease with 90% power at the 5% significance level (1-sided). Results: 247 patients were allocated to 2 CT scans and 167 to 5 CT scans. With a median follow up of 40 months 37 (15%) relapses have occurred in the 2 scan arm and 33 (20%) in the 5 scan arm. No patients were poor prognosis at relapse but 2 (0.8%) of those relapsing in the 2 scan arm were intermediate prognosis compared to 1 (0.6%) in the 5 scan arm a difference of 0.2% (90% CI −1.2%, +1.6%). The mean diameter of abdominal mass at relapse was 2.1 cm in the two scan arm and 2.2 cm in the five scan arm. After chemotherapy a residual mass was present in 35% in the 2 scan and 36% in the 5 scan arm. No deaths have been reported. Conclusions: This study can exclude with 95% probability an increase in the proportion of patients relapsing with intermediate or poor prognosis disease of more than 1.6% if they have 2 rather than 5 CT scans as part of their surveillance protocol. CT scans at 3 and 12 months after orchidectomy should be considered as the new standard and will be associated with a reduction in radiation exposure. No significant financial relationships to disclose.