Reliability of Serum Tumor Marker Measurement to Diagnose Recurrence in Patients with Clinical Stage I Nonseminomatous Germ Cell Tumors Undergoing Active Surveillance: A Systematic Review.

Abstract

PURPOSE\nMen with nonseminomatous germ cell tumors (NSGCT) of the testicle without evidence of residual disease after radical orchiectomy (Clinical stage I; CS-I) are increasingly managed with active surveillance. The guideline-recommended cornerstones of surveillance are conventional serum tumor markers (STM) and computed tomography (CT) imaging. The reliability of STM as a tool to early diagnose recurrent NSGCT in CS-I patients is unclear. The objective was to conduct a systematic review of the currently available evidence assessing the reliability of STM as a test to diagnose a recurrence in CS-I NSGCT patients under active surveillance.\n\n\nMATERIALS AND METHODS\nA systematic review was conducted in accordance with PRISMA guidelines, with no language or date restriction. Studies were included that readily identified the tumor marker status of CS-I NSGCT patients who had a recurrence on active surveillance. The primary outcome was marker positivity at the time of recurrence. Risk of bias assessment was undertaken.\n\n\nRESULTS\n2,157 studies were identified and independently screened by two reviewers. 37 studies were ultimately included. A relatively high risk of bias was identified among the studies, with the vast majority being retrospective series. The total population for the included studies was 8,545 CS-I NSGCT patients managed with active surveillance, and 2,254 ultimately relapsed. STM were elevated in 28 - 75% of patients at the time of recurrence, and STM was the only indication of recurrence in 4 - 39%. The unavailability of patient-level data is the major limitation to the present findings.\n\n\nCONCLUSIONS\nIn patients with CS-I NSGCT managed with active surveillance, the use of STM cannot obviate the need for CT imaging. More reliable serum markers are needed in order to limit radiation exposure for these patients.