Analysis of Clinical Characteristics, Treatment Patterns, and Outcome of Patients with Bilateral Testicular Germ Cell Tumors

Introduction: Bilateral testicular germ cell tumor (BGCT) is a rare disease that is considered to be more aggressive than unilateral germ cell tumors (GCT). Among BGCT, a synchronous disease is more aggressive than the metachronous presentation and results in lower CSS. Hence, our study aimed to perform a comparative analysis between unilateral testicular GCT, bilateral synchronous GCT, and bilateral metachronous GCT, aiming to verify the possibility that BGCT is a more aggressive disease form that may require more aggressive management. Material: and methods: In our multicenter retrospective study we reviewed medical records of 40 patients with BGCT (24 metachronous and 16 synchronous). Clinical characteristics, pathological features of the primary and secondary tumors, adjuvant treatments (chemotherapy and radiotherapy) and sperm quality were evaluated as well as cancer-specific survival and overall survival. A cohort of 40 patients with unilateral GCT were used to determine risk factors for developing BGCT. Results: Patients with BGCT were slightly younger compared to those with unilateral GCT and had more advanced disease. Despite similar T-stage distribution between the two groups, nodal involvement was nearly 2-fold more frequent in patients with bilateral disease (42% vs 22%, p=0.056). additionally, although similar histological subtypes distribution at presentation among the two groups, the synchronous disease was more aggressive. This biological difference was evident by a higher rate of local T-stage (OR=3.4), higher proportions of patients with elevated serum BHCG levels, and more frequent nodal involvement (OR=2.2). This more aggressive biology was later on translated into over 3-fold higher disease-specific mortality rate. The median time to develop contralateral GCT was 92 months. Pathological local T-stage (T2-T3) of the primary tumor predicted a shorter time interval to a diagnosis of a second GCT (HR 0.92, P<0.05). Conclusion: BGCT presents at a younger age and as a more aggressive disease. Synchronous BGCT is diagnosed at a more advanced stage and has higher disease-specific mortality. Metachronous tumors have a longer time interval for the development of a contralateral neoplasm. The main predictor of developing an early metachronous disease is a high primary T stage.