Body Mass Index and Outcomes in Germ-Cell Tumors

Abstract

Introduction: Obesity at the time of diagnosis has been associated with better outcomes in some metastatic cancers such as renal-cell cancer. The association between body mass index (BMI) and germ-cell tumor (GCT) outcomes has not been reported. We sought to assess the association between BMI and outcomes in men with GCT in a large hospital registry.

Patients and methods: Electronic medical records for 1161 GCT patients treated at Dana-Farber Cancer Institute between 1997 and 2012 were reviewed. Information regarding BMI, histology, stage, treatment, and patient characteristics was obtained. We separately evaluated patients with clinical stage 1 and metastatic disease. Using logistic regression analysis, we investigated the association between BMI and clinical features, such as International Germ Cell Consensus Classification (IGCCC) and stage at diagnosis. We used Cox proportional hazards regression to assess the association between BMI and risk of relapse and GCT-specific death.

Results: Among men diagnosed with clinical stage 1 GCT, BMI ≥ 25 kg/m² was not associated with an increased risk of relapse (hazard ratio = 0.83; 95% confidence interval, 0.53-1.30) compared to those with BMI < 25 kg/m². In the metastatic disease setting, men with BMI < 25 kg/m² were less likely to present with good-risk disease; however, BMI was not associated with risk of relapse (hazard ratio = 1.00; 95% confidence interval, 0.63-1.59, P = .99).

Conclusion: There was no evidence for an association between BMI and GCT outcomes. A lower BMI was associated with adverse prognostic variables at presentation per IGCCC risk groups for metastatic GCT, but this was not associated with relapse.

Keywords: Genitourinary oncology; Obesity; Obesity paradox; Outcomes research; Testicular Cancer.