Anaerobes in prostate cancer: New approaches to treatment and prevention.

e13606 Background: The sun-sensitive microaerophylic bacterium C. acnes, is linked with prostate cancer (PC) in 9 studies 3 of which are cohort studies of 289,043 men followed for 30 years from puberty. That circumcision reduces PC risk further supports a role for anaerobes as they are reduced on the circumcised glans penis. A 1988 study linked anaerobes with PC but considered them opportunists. Reports that H. pylori, linked to stomach cancer, is also a microaerophilic bacterium led us to reinvestigate the association of PC and anaerobes. Methods: The MOLDI-TOF methodology for analysing anaerobes in 18 post rectal exam urine samples has been previously reported ( https://www.nature.com/articles/s41598-017-13782-6 ). This report analyses outcome after a further 21 patients were recruited and follow up was extended from 1 month to a median of 43 months. In total there were 21 diagnosed as PC and 18 BPH. Results: Of the 29 anaerobic isolates, 19 were Chlostridiales family, 2 Prevotella and 7 Actinomycoses (includes C.acnes) family. 12 cases had obligate anaerobes, 7 microaerophylic bacteria and 20 none of these. In 27 patients with PSA > 1.5, 56% had anaerobes, while in 12 with PSA = < 1.5 it was 17% (p < 0.037 Fisher’s exact test) In the 21 with prostate cancer, 7 (64%) of 11 without anaerobes and 2 of 10 (20% ) with anaerobes remain on Active Surveillance (p = 0.08 Fisher’s exact test) vs in 18 without cancer, 10/11 (91%) without and 5/7 (71%) with anaerobes remain without the need of TURP intervention. Conclusions: This is a small study and needs expanding. Given the rising incidence of antibiotic resistance more resources should be focused on the immune deficiency associated with chronic bacterial infection. Expansion of technology used to produce bacterial vaccines to treat women with recurrent cystitis could offer new approaches to prevention of PC and to treat patients with raised PSA and negative biopsy. Modern approaches to immunotherapy against these bacteria with checkpoint inhibitors could be used in combination with androgen suppression and chemotherapy.