Differential Tumor Gene Expression Profiling of Patients With Prostate Adenocarcinoma on the Basis of BMI

An increased BMI is linked to increased prostate adenocarcinoma incidence and mortality. Baseline tumor gene expression profiling (GEP) can provide a comprehensive picture of the biological processes related to treatment response and disease progression. We interrogate and validate the underlying differences in tumor GEP on the basis of BMI in patients with prostate adenocarcinoma.

The inclusion criteria consisted of histologically confirmed prostate adenocarcinoma and the availability of RNA sequencing data obtained from treatment-naïve primary prostate tissue. RNA sequencing was performed by a Clinical Laboratory Improvement Amendments-certified laboratory (Tempus or Caris Life Sciences). The Tempus cohort was used for interrogation and the Caris cohort for validation. Patients were stratified on the basis of BMI at the time of prostate cancer diagnosis: BMI-high (BMI_H; BMI ≥30) and BMI-low (BMI_L; BMI <30). Differential gene expression analysis between the two cohorts was conducted using the DEseq2 pipeline. The resulting GEPs were further analyzed using Gene Set Enrichment software to identify pathways that exhibited enrichment in each cohort.

Overall, 102 patients were eligible, with 60 patients in the Tempus cohort (BMI_L = 38, BMI_H = 22) and 42 patients in the Caris cohort (BMI_L = 24, BMI_H = 18). Tumor tissues obtained from patients in the BMI_L group exhibited higher expression of genes associated with inflammation pathways. BMI_H displayed increased expression of genes involved in pathways such as heme metabolism and androgen response.

Our study shows the upregulation of distinct genomic pathways in BMI_L compared with BMI_H patients with prostate cancer. These hypothesis-generating data could explain different survival outcomes in both groups and guide personalized therapy for men with prostate cancer.