Outcomes of active surveillance of clinical stage I non-seminomatous germ cell tumors: sub-analysis of the multi-institutional nationwide case series of the Japanese Urological Association.

Objective: To evaluate the survival rate and risk factors of distant metastasis in stage I non-seminomatous germ cell tumor (NSGCT) cases without adjuvant treatments.

Methods: A national testicular cancer survey of cases newly diagnosed in 2005 and 2008 was conducted by the Japanese Urological Association in 2011. In 159 stage I NSGCT cases, 132 were followed by active surveillance after high orchiectomy. Their recurrence-free survival rate (RFS) was compared with 27 cases that received adjuvant treatments, and clinical and pathological parameters were explored to identify significant risk factors of recurrence.

Results: Within a median follow-up period of 30.3 months (range: 0.3-65.6 months), 16 (12.1%) of the 132 surveillance cases relapsed at 2.8-51.2 months after high orchiectomy (median: 8.35 months). The 2-year RFS rate was 90%. Eleven (68.8%) cases relapsed within 1 year, and five (31.3%) cases relapsed in 3 years or more. Half (50%) of the recurrences were detected by imaging studies alone, 37.5% by imaging combined with tumor markers, and 12.5% by tumor marker elevation alone. The only significant risk factor of recurrence was the existence of embryonal carcinoma elements in the primary testicular tumor (P = 0.0068). There was no significant difference in RFS between cases with active surveillance and adjuvant treatments.

Conclusions: The present report is the first large scale study of clinical stage I NSGCTs in Japan. Active surveillance appears to be an effective treatment option for patients with clinical stage I NSGCTs.