Long-term Relapse and Survival in Clinical Stage I Testicular Teratoma

Background and objective: Studies in metastatic nonseminomatous germ-cell tumor (NSGCT) suggest that the presence of teratomatous elements in the primary tumor is a risk factor for poor survival. Many guidelines have extrapolated this observation and recommend adjuvant retroperitoneal lymph-node dissection (RPLND) even for clinical stage I (CSI) teratoma confined to the testicle. Our objective was to assess relapse-free survival (RFS), cancer-specific survival (CSS), overall survival (OS) among patients with CSI pure teratoma in comparison to CSI NSGCT.

Methods: Patients with CSI NSGCT managed with surveillance between 1980 and 2023 were identified in the prospectively maintained Princess Margaret Cancer Centre database. We compared cases with pure teratoma with or without somatic transformation in the primary tumor to all other nonteratomatous NSGCTs.

Key findings and limitations: A total of 774 patients with CSI NSGCT were identified, including 63 (8.1%) with pure teratoma and/or somatic transformation in the primary tumor. Median follow-up was 61 mo. The pure teratoma group had superior RFS at 6 yr (85.2% vs 67.9%; p = 0.008). There were no significant differences in 6-yr CSS (100% vs 99.1%; p = 0.92) or OS (97.4% vs 98.1%; p = 0.33). Limitations include the single-center setting and the limited follow-up (median 61 mo), hindering the ability to detect late relapses.

Conclusions and clinical implications: CSI pure teratoma managed with surveillance is associated with a low risk of relapse overall and significantly lower risk of relapse in comparison to other CSI NSGCTs. No patients with CSI teratoma in the study population died of testicular cancer. Guidelines should be revised to include surveillance as a preferred approach for CSI teratoma.

Patient summary: We compared survival rates after testicle removal in clinical stage I testicular cancer for two different tumor types. We found that cancer-specific and overall survival rates were similar for pure teratoma tumors and nonseminoma tumors, and that the recurrence rate was lower for pure teratoma tumors. Our results support surveillance as a suitable option after surgery for patients with clinical stage I testicular teratoma.