Testicular cancer is the most common solid neoplasm of adult men between the ages of 20 and 40 years. Germ cell tumors account for 95% of all testicular tumors. The assessment of staging is essential to guide further management of patients with testicular cancer and to prognosticate cancer-related outcomes. Postradical orchiectomy treatment options, including adjuvant therapy and active surveillance, vary based on the anatomical extent of disease, serum tumor markers, pathologic diagnosis, and imaging. This review provides an update on the germ cell tumor staging system adopted by the 8th edition of the American Joint Commission on Cancer (AJCC) Staging Manual, treatment implications, risk factors, and predictors of outcomes.

Testicular cancer is the most common solid neoplasm of adult men between the ages of 20 and 40 years. Germ cell tumors account for 95% of all testicular tumors. The assessment of staging is essential to guide further management of patients with testicular cancer and to prognosticate cancer-related outcomes. Postradical orchiectomy treatment options, including adjuvant therapy and active surveillance, vary based on the anatomical extent of disease, serum tumor markers, pathologic diagnosis, and imaging. This review provides an update on the germ cell tumor staging system adopted by the 8th edition of the American Joint Commission on Cancer (AJCC) Staging Manual, treatment implications, risk factors, and predictors of outcomes.

Rete testis invasion (RTI) is an unfavourable prognostic factor for the risk of relapse in clinical stage I (CS I) seminoma patients. Notably, no evidence of difference in the proteome of RTI-positive vs. -negative CS I seminomas has been reported yet. Here, a quantitative proteomic approach was used to investigate RTI-associated proteins. 64 proteins were differentially expressed in RTI-positive compared to -negative CS I seminomas. Of them, 14-3-3γ, ezrin, filamin A, Parkinsonism-associated deglycase 7 (PARK7), vimentin and vinculin, were validated in CS I seminoma patient cohort. As shown by multivariate analysis controlling for clinical confounders, PARK7 and filamin A expression lowered the risk of RTI, while 14-3-3γ expression increased it. Therefore, we suggest that in real clinical biopsy specimens, the expression level of these proteins may reflect prognosis in CS I seminoma patients.

OBJECTIVE: The aim of this study was to assess a risk-adapted strategy for stage I seminoma guided by the presence of rete testis invasion.
METHODS: Between January 2013 and December 2015, a total of 135 consecutive patients with stage I seminoma from 18 Spanish tertiary hospitals were included in a prospective multicenter study. Median patient age was 38 years (range 22-60). Preoperative beta-human chorionic gonadotropin was elevated in 9.6% of patients. Rete testis invasion was present in 47.4% of patients. After orchiectomy, subjects with rete testis invasion were treated with 2 courses of adjuvant carboplatin (area under the curve of 7, with 21-day interval). Those without this risk factor were managed by surveillance. Disease-free survival (DFS) and overall survival (OS) were estimated with the Kaplan-Meier method.
RESULTS: After a median follow-up time of 33 months, only 6 relapses were recorded (5 on surveillance, 1 after carboplatin). These cases were rescued with BEP or EP chemotherapy, and all 135 patients are currently disease free without sequelae. Three-year DFS was 92.0 and 98.2% for patients on surveillance and after carboplatin, respectively. Three-year OS was 100%.
CONCLUSIONS: A risk-adapted approach based on rete testis invasion as a single risk factor is feasible and yielded an excellent outcome with a 3-year DFS of 94.9%.

To systematically evaluate evidence on prognostic factors for tumor recurrence in patients with clinical stage I seminoma undergoing surveillance.
Systematic literature search conducted of Medline, Web of Science, Cochrane Library, and the conference proceedings of the ASCO, AUA, and EAU meetings (last search: October 2016), according to our prospectively registered protocol (PROSPERO registration number CRD42014009434). Identified records were reviewed according to the Cochrane Method Group of Prognosis Reviews recommendations and the PRISMA reporting guideline. Study quality was appraised with the Quality in Prognosis Studies (QUIPS) tool.
Nineteen studies reporting on 26 potential prognostic factors were included in our analysis. Among the most frequently reported factors, tumor size (continuous or dichotomized) was significantly associated with relapse in 10/14 studies with a hazard ratio (HR) ranging from 1.33 (95% confidence interval [CI]: 1.14-1.56) to 3.17 (95% CI: 1.08-9.26). Rete testis invasion was significantly associated with relapse in only 4/13 studies with a HR ranging from 1.18 (95% CI: 0.92-1.51) to 1.36 (95% CI: 0.81-2.28). Lymphovascular invasion, young age, and preoperative HCG level had no association with relapse. Our findings are limited by heterogeneity of study designs, potential reporting bias, and moderate-to-poor study quality.
In stage I seminoma, tumor size is the most valuable prognostic factor on which to base relapse risk and to counsel patients about adjuvant treatment. Large tumor size was defined quite inhomogenously among the included studies, so no distinct cutoff value for tumor size can be recommended. Other potential prognostic factors including rete testis invasion play a minor role in stage I seminoma.