BMI Associated With Adverse Tumor Pathology and Size in Prostate Cancer

By Patrick Daly - Last Updated: December 2, 2022

Researchers, led by Resa Magill, hypothesized that increased body mass index (BMI) was associated with transition zone (TZ) tumors and unfavorable pathology in patients with localized prostate cancer. They performed a retrospective analysis and determined that increasing BMI was associated with clinically aggressive prostate cancer.

Additionally, the investigators reported that increased BMI was not significantly associated with higher grade or stage TZ tumors, but it was associated with larger TZ tumor volume. Magill presented the study’s findings at the 23rd Annual Meeting of the Society of Urologic Oncology.

Obesity May Impact Localized Prostate Cancer Origin and Progression

The study included 636 patients with a median age of 62 years (interquartile range [IQR], 56-67 years) who underwent radical prostatectomy. Based on presurgery BMI, 101 (16%) patients were considered normal weight (BMI=18.5-24.9), 297 (47%) were overweight (BMI=25-29.9), 170 (27%) were obese (BMI=30-34.9), and 68 (11%) were severely obese (BMI ≥35). Across the cohort, 58 (9%) patients had dominant TZ tumors and 350 (55%) had dominant PZ tumors with Gleason Grade Group (GGG) 3 or pT3 disease.

The primary end point was detection of clinically aggressive disease, defined as GGG 3 or stage pT3 disease, in patients with TZ- or peripheral zone (PZ)-dominant tumors. The researchers used analysis of variance to evaluate relationships between TZ and PZ tumor size and BMI.

Notably, increased BMI was associated with the presence of PZ tumors (P=.02) with adverse pathological features but not with the presence of TZ tumors (P=.23). However, increasing BMI was associated with larger TZ tumor volume across BMI ranges (P=.02), with an average tumor volume of 0.67 ± 1.04 cc in the normal weight group and 1.79 ± 2.69 cc in the severely obese group. The authors added that PZ tumor volume increased alongside increasing BMI, though the correlation was not significant (P=.13).

Overall, the authors supported an association between increasing BMI and higher stage or grade prostate cancer in patients undergoing radical prostatectomy for localized disease. “These results suggest a relationship between tumor zonal origin and obesity and offer evidence to support findings that obesity may play a role in localized prostate cancer progression,” they concluded.