Evaluation of a prognostic model for risk of relapse in stage I seminoma surveillance

Abstract

A prognostic model for relapse risk in stage I seminoma managed by surveillance after orchiectomy has been developed but has not been independently validated. Individual data on 685 stage I seminoma surveillance patients managed between 1998 and 2005 at three cancer centers were retrospectively analyzed. Variables including age and pathology of the primary tumor: small vessel invasion, tumor size, and invasion of rete testis were analyzed. Specifically median tumor size and rete testis invasion was tested to evaluate the performance of the published model. Median follow-up was 3.85 years (0.1–10.29), 88 patients relapsed and 5-year relapse-free rate was 85%. In univariate analysis, median tumor size (<3 cm vs. ≥3 cm) was associated with increased risk of relapse but rete testis invasion was not, nor was age and small vessel invasion. In multivariable analysis, tumor size above median (cutpoint of 3 cm) was a predictor for relapse, HR 1.87 (95% CI 1.15, 3.06), whereas rete testis invasion HR 1.36, (95% CI 0.81, 2.28) was not statistically significant. The 3-year relapse risk based on the primary tumor size alone increased from 9% for 1 cm primary tumor to 26% for 8 cm tumor. A clinically useful, highly discriminating prognostic model remains elusive in stage I seminoma surveillance as we were unable to validate the previously developed model. However, primary tumor size retained prognostic importance and a scale of relapse risk based on the unit increment of tumor size was developed to help guide patients and clinicians in decision making.

A Risk-Adapted Approach to Patients with Stage I Seminoma according to the Status of Rete Testis: The Fourth Spanish Germ Cell Cancer Group Study

“…In 2002, Warde et al [4] published the results of a retrospective multicenter pooled study and found that tumor diameter > 4 cm and stromal infiltration of the rete testis (rete testis invasion; RTI) were associated with tumor recurrence. The same group, however, was unable to validate these 2 risk factors in a prospective study [5]. Furthermore, recent studies on tumor diameter and RTI revealed conflicting results [6, 7].…”

The association between institution at orchiectomy and outcomes on active surveillance for clinical stage I germ cell tumours

“…While a referral bias may have been present for NSGCT, this did not seem to occur in seminoma, as there were no clinical or pathological differences, including tumour size, which is a known risk factor for progression, [15][16][17] in patients undergoing orchiectomy at a specialized vs. non-specialized institutions. This may be related to the overall lower risk of progression in CSI seminoma compared to NSGCT and, therefore, reflective of the relative comfort that clinicians outside specialized institutions have in managing CSI seminoma patients.…”

“…Pathology-specific covariates were chosen based on prior studies demonstrating their independent association with progression on AS. [14][15][16][17][18] To avoid collinearity, lymphovascular invasion was not included in the models for NSGCT, as this information is captured in the overall stage at presentation (i.e., IA vs. IB). The proportional hazards assumption was examined by evaluating cumulative score statistics.…”

Testicular Germ Cell Tumors

“…There is contradictory data with regard to prognostic value of rete testis invasion, tumor size, and invasion into the tunica albuginea in stage I seminoma [122][123][124][125][126].…”