Stage I non-seminomatous germ-cell tumours of the testis: identification of a subgroup of patients with a very low risk of relapse.

There is no consensus about a reproducible prognostic model capable of distinguishing between clinical stage I non-seminomatous germ cell tumour (NSGCT) carrying a high and low risk of relapse. The aim of this study was to assess the prognostic value of histological parameters in patients with stage I NSGCT undergoing surveillance after orchiectomy. We retrospectively evaluated tumour specimens from 88 consecutive stage I NSGCT patients undergoing surveillance in our institution between 1984 and 1996. 24 patients relapsed (27%). Multivariate analysis singled out vessel invasion (VI) (relative risk (RR)=3.8; 95% confidence interval (CI) 1.4-10.4) and the presence of mature teratoma (RR= 0.2; 95% CI 0.1-0.6) as independently correlated with relapse-free survival (RFS). Patients can be classified accordingly into three prognostic groups with a low (27 patients with mature teratoma but without VI), intermediate (34 patients with both VI and mature teratoma or with neither VI or mature teratoma) and a high risk (23 patients with VI, but without mature teratoma) of relapse. Relapse rates in these three groups were 0%, 29% (95% CI: 23-35%) and 61% (95% CI: 55-67%), respectively. This prognostic index, based on two standard pathological parameters, identified a subgroup with a very low risk of relapse that represents approximately one third of stage I patients. Patients who belong to this subgroup should be managed by surveillance only, instead of retroperitoneal lymph node dissection (RPLND) or adjuvant chemotherapy.