Long-term Surveillance of Patients with Complete Response Following Chemotherapy for Metastatic Nonseminomatous Germ Cell Tumor

Abstract Background There is controversy regarding the management of patients with normal markers and residual masses (≤1 cm) after chemotherapy for nonseminomatous germ cell tumors (NSGCTs). Objective To determine long-term outcomes of a surveillance strategy in such patients. Design, setting, and participants A retrospective review of our multidisciplinary testicular cancer database was performed. All patients who underwent primary chemotherapy for metastatic NSGCTs were identified between 1981 and 2016. A complete response (CR) was defined as normalization of serum tumor markers and a ≤1 cm residual mass in the largest axial dimension following chemotherapy. All such patients were surveilled. Outcome measurements and statistical analysis Outcome variables of interest were time to death, time to cancer-specific survival, and time to relapse. Overall survival and relapse-free survival were calculated using the Kaplan-Meier method, and the cumulative incidence of cause-specific survival rates was calculated using competing risk analysis. The impact of risk group and chemotherapy regimen on relapse-free survival was assessed using log-rank test. Results and limitations During the study period, 1429 metastatic germ cell tumor patients were treated with primary chemotherapy. CR was achieved in 191 (18.5%) NSGCT patients. The median age at diagnosis was 27.4 yr, with a median follow-up of 81.1 mo. The majority had American Joint Committee on Cancer stage II at diagnosis (I: 23.8%; II: 49.2%; III: 27%) and International Germ Cell Cancer Collaborative Group good-risk disease (good: 78%; intermediate: 17.8%; poor: 4.2%). Of the 191 patients with a CR, 175 (91.6%) never relapsed and remain disease free. Sixteen (8.4%) patients relapsed after a median of 11.3 mo (range 1–332 mo), with over half (nine patients; 4.7%) relapsing in the retroperitoneum only and salvaged successfully with postchemotherapy retroperitoneal lymph node dissection (PC-RPLND) alone. Of these nine patients, only two (1%) had viable disease in the PC-RPLND specimen. The remaining seven patients had relapses outside the retroperitoneum and received salvage chemotherapy ± postchemotherapy resection. Overall, nine (4.7%) patients have died, but only four (2.1%) from testis cancer. Conclusions Our data, the largest series to date, confirm that surveillance is safe and effective for men who achieve a CR following chemotherapy for metastatic NSGCTs. Patient summary Surveillance is a safe strategy for patients who achieve a complete response following chemotherapy for metastatic testis cancer.