LAUSR

BACKGROUND Controversy exists regarding the optimal management strategy for clinical stage IS seminomatous (SGCT) and nonseminomatous germ cell tumors (NSGCT) of the testis. OBJECTIVE To assess contemporary treatment patterns and outcomes for clinical stage IS testicular cancer. DESIGN, SETTING, AND PARTICIPANTS Using the National Cancer Data Base (2004-2012), we identified 1362 patients with clinical stage IS SGCT and NSGCT of the testis, treated with either adjuvant treatment (AT) or observation. OUTCOME MEASURES AND STATISTICAL ANALYSIS We calculated the annual percent change (APC) to assess treatment trends. Inverse probability of treatment weighting (IPTW)-adjusted Kaplan-Meier curves and Cox regression analyses were used to compare overall survival (OS) between AT and observation groups. Analyses were stratified by histologic type. RESULTS AND LIMITATIONS Overall, there were 581 (43%) and 781 (57%) men with SGCT and NSGCT, respectively. Among men with SGCT, the use of AT decreased over the study period (APC=-2.7, 95% confidence interval [CI]: -4.4, -1.1, p=0.001). The 5-yr IPTW-adjusted rates of OS were 99% and 97% in the AT and observation groups, respectively (hazard ratio = 0.36, 95% CI: 0.12, 1.14, p=0.08). Among men with NSGCT, the use of AT remained stable over the study period (APC = +0.8, 95% CI: -0.7, +2.2, p=0.29). The 5-yr IPTW-adjusted rates of OS were 97% and 95% in the AT and observation groups, respectively (HR=0.66, 95% CI: 0.27, 1.61, p=0.36). Limitations include the lack of full treatment details and cancer-specific survival information. CONCLUSIONS Trends in the use of AT significantly decreased over time for SGCT, while it remained stable for NSGCT. Nonetheless, we report 5-yr OS rates of ≥95% for both histologies without any significant benefit with the use of AT. Further studies are warranted to confirm these findings. PATIENT SUMMARY We evaluated treatment trends and outcomes for stage IS testicular cancer. We found that treatment changed over time for seminoma and remained stable for nonseminoma; there was no significant survival benefit in the use of adjuvant treatment versus observation for both seminomatous and nonseminomatous germ cell tumors.