Enlarged prostate linked to lower risk of significant prostate cancer

In a recent study published in The Prostate, investigators from Beaumont Health, Royal Oak, Michigan, found that enlarged prostates show lower risk of significant prostate cancer.^1,2

The investigators evaluated 405 male patients who underwent magnetic resonance imaging (MRI) and biopsy and/or prostatectomy from January 2019 to January 2021 at Beaumont Health. The researchers quantitatively analyzed the MRIs to “look at the different anatomy of the prostate, specifically differentiating the central and outer aspects of the prostate gland, and also for underlying cancer,” Kiran Nandalur, MD, vice chief of diagnostic radiology and molecular imaging at Beaumont Hospital stated in a press release.

The purpose was to examine the relationship between various quantitative prostate compositional metrics, such as central gland (CG) volume, peripheral zone (PZ) volume, PZ mean thickness, and PZ mean apparent diffusion coefficient (ADC).

Using multivariable logistic regression, the results showed higher CG volumes associated with lower odds of Grade Group 2 prostate cancer (GG2) disease (n = 227) (OR: 0.97, 95% CI 0.96-0.98, P <.0001). For every 1 cc increase in CG volume, there was an approximately 3% decrease in odds of greater than or equal to GG2 disease.

For multifocal disease, the investigators noted similar results (n = 180) (OR: 0.97, 95% CI 0.96-0.98, P <.0001). In addition, ADC of the normal PZ did not have a significant association with CG volume (P = .21) and was also found not a predictor of disease (P = .49).

“Previous studies are unclear whether BPH increases, decreases, or has no effect on prostate cancer risk. Our findings should help reduce possible fears about significant prostate cancer when diagnosed with BPH, which is often misunderstood by the public,” stated Nandalur.

Given the significant anxiety that older male patients have when urinary symptoms arise, the findings of this study support further research into the association between BPH and prostate cancer. More research, specifically involving risk stratification and possible BPH therapy, will save patients from undergoing unnecessary treatments, tests, and fears. The takeaway from this research is that BPH could be a potential stabilizing factor of global tumor growth predicted by theoretical mechanobiological model, the investigators reported.

“According to the studied MRI data, patients with BPH appear to have a potential protective factor against prostate cancer. The results may also explain why previous data has shown commonly prescribed drugs used to treat BPH may result in higher grade prostate cancer. However, individualized management of a patient’s BPH is best determined after consultation with their physician,” Nandalur said.

References

1. Nandalur KR, Colvin R, Walker D, et al. Benign prostate hyperplasia as a potential protective factor against prostate cancer: Insights from a magnetic resonance imaging study of compositional characteristics. The Prostate. Published online August 10, 2021. Accessed August 25, 2021. doi:10.1002/pros.24207

2. Researchers: Enlarged prostate lowers odds of significant prostate cancer. News release. Beaumont Health. August 18, 2021. Accessed August 25, 2021. https://www.newswise.com/articles/researchers-enlarged-prostate-lowers-odds-of-significant-prostate-cancer?sc=sphr&xy=10016681