Corpora amylacea in prostatectomy tissue and associations with molecular, histological, and lifestyle factors

Abstract

Background: Corpora amylacea are amyloid bodies commonly found adjacent to damaged prostate epithelium. Little is known about their formation or function. The current study sought to characterize corpora amylacea in prostate tissue and to describe their relationship with clinical, histological, molecular and lifestyle factors, especially with chronic inflammation which is associated with aggressive disease. Methods: We studied a cohort of 355 men with prostate cancer and tissue specimens from the Health Professionals Follow-up Study. Pathologists examined H&E slides and undertook a standardized review for histologic data and inflammation. Trained observers counted corpora amylacea within the benign and predominately tumor areas. Immunohistochemistry biomarkers were available from tissue microarrays. We used multivariable logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI) to assess associations of chronic inflammation, clinical, histological, molecular and lifestyle factors with the presence of corpora amylacea. Results: Corpora amylacea were present in benign tissue area for 298 men (84%). Specimens with moderate to severe chronic inflammation were more likely to have corpora amylacea in benign regions (OR=5.4 95% CI 1.9, 15.6). Moreover, corpora amylacea were more common in men with higher body mass index (OR=1.13 95% CI 1.01, 1.26). In contrast, Gleason grade (OR=0.4 95% CI 0.2, 0.8), proliferation index (OR=0.6 95% CI 0.3, 1.2) and presence of the TMPRSS2:ERG fusion (OR=0.4 95% CI 0.2, 0.8) were inversely associated with corpora amylacea presence. TURP specimens were less likely to have corpora amylacea than prostatectomy specimens (OR=0.12 95% CI 0.03, 0.47). Age, PSA, stage, biomarkers of angiogenesis and PTEN, and vasectomy were not significantly associated with corpora amylacea. Conclusion: Corpora amylacea were common among men with prostate cancer and were associated with pro-inflammatory factors, some markers of less aggressive disease, and lack of the TMPRSS2:ERG fusion.

Corpora amylacea in benign prostatic acini are associated with concurrent, predominantly low‐grade cancer

“…Previously, there were few studies on CAM and their association with cancer and clinicopathologic factors. Our findings are concordant with previous studies showing an association of CAM with low Gleason grade 15,20 . Since prostatic calculi may arise from calcification of CAM, the studies on the association of prostatic calculi to cancer showed results ranging from no association, 23 to a positive association between large prostatic calcuIi and prostate cancer 24 .…”

“…In this study, 74.6% of all specimen types showed CAM in benign prostatic acini. Most prior studies included only cancer patients, were conducted in a specific type of specimens, 20 or did not study mainly CAM. Notably, cancer specimens had a higher incidence of CAM in benign acini compared to benign specimens.…”

“…Pathologists use CAM mainly as a marker for benign acini since CAM are rare in cancer. According to previous studies, CAM were found in 0% to 84% of benign acini of cancer patients, 0% to 55% of high‐grade prostatic intraepithelial neoplasia (HGPIN), 0% of atypical small acinar proliferation (ASAP) suspicious for cancer, and just 0.4% to 13% of cancer acini 14‐20 . CAM tend to be situated in proximity to cancer, 20 especially low‐grade cancer.…”

“…According to previous studies, CAM were found in 0% to 84% of benign acini of cancer patients, 0% to 55% of high‐grade prostatic intraepithelial neoplasia (HGPIN), 0% of atypical small acinar proliferation (ASAP) suspicious for cancer, and just 0.4% to 13% of cancer acini 14‐20 . CAM tend to be situated in proximity to cancer, 20 especially low‐grade cancer. A study from prostatectomies of cancer patients found an association between CAM and chronic inflammation, low Gleason grade, and higher body mass index (BMI) 20 …”

“…CAM tend to be situated in proximity to cancer, 20 especially low‐grade cancer. A study from prostatectomies of cancer patients found an association between CAM and chronic inflammation, low Gleason grade, and higher body mass index (BMI) 20 …”