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, occasionally considered to be more aggressive than unilateral germ cell tumors (GCT) in some reports. Among BGCT, a synchronous disease might be diagnosed at a higher stage than a metachronous disease, resulting in lower cancer-specific survival. 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 diagnosed with a higher stage and 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 one-to-one matched 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 twofold more frequent in patients with BGCT disease (42% vs 22%, p = 0.056). Additionally, although similar histological subtypes distribution at presentation among the two groups, the synchronous disease was diagnosed with a higher local T-stage (OR = 3.4), higher proportions of patients with elevated serum BHCG levels, and more frequent nodal involvement (OR = 2.2). This was later translated into an 18% higher disease-specific mortality rate. The median time to develop a contralateral tumor was 92 months. Pathological local T-stage (T2-T3) of the primary tumor predicted a shorter time interval to a diagnosis of a second contralateral tumor (HR 0.92, P < 0.05). Conclusion BGCT presents at a younger age and potentially with more advanced disease. Synchronous BGCT is diagnosed at a later stage compared to metachronous BGCT and has higher disease-specific mortality. Metachronous tumors might have a long time interval for the development of a contralateral neoplasm. The main predictor of developing an early metachronous disease is a high primary T stage.