Introduction. Estimations of sun exposure (but less so spot serum Vitamin D levels) correlate with risk of prostate cancer occurrence. This suggests that it is due to long term Vitamin D deficiency over 10-40 years as a possible explanation. This, via diminished macrophage function, could allow persistence of low grade pathogens to set up chronic inflammation that could lead to Proliferative Inflammatory Atrophy (PIA) of the prostate, now thought to be an important precursor of cancer. Despite multiple investigations of sexually transmitted infections, there has been no consistently associated organism. However recently infection with two low grade pathogenic organisms, teenage acne associated anaerobic bacterium Propionibacterium.acnes (PA) and protozoan Trichomonas vaginalis (TA), have shown a more consistent association with prostate cancer. This abstract reports the results of a systematic review of publications investigating the association of sun exposure and prostate cancer and of PA and T V with prostate cancer and considers how these observations could lead to improved specificity of PSA screening

Methods. Pubmed searches using terms prostate or prostatic, sunshine or UVB or Vitamin D and acne or PA or TA were performed and the abstracts reviewed and appropriate papers selected for review and data extraction

Results . Amongst 1134 abstracts investigating PC and Vitamin D were two systematic reviews that failed to produce a consistent association. In contrast four of four studies of an index of sun exposure involving 1568 patients (OR 0.75, 0.75, 0.59 & 0.89) and 6 of 7 geographic studies (0.32, 0.38, 0.44, 0.16, 0.52, 1.63 & 0.64) demonstrated an association of high UVB exposure with reduced PC risk. Four of five publications on PA and PC (1.7, 1.67, 2.17 & 0.67) and 2 of 3 publications on TV and PC (1.23, 1.43 & 0.83) from 205 papers reviewed showed consistent increase risk of PC associated with infection.

Conclusion. Lack of association with spot Vitamin D but clear association with index of sun exposure suggest that the association is due to reduced long term Vitamin D mediated non-specific macrophage surveillance that is involved against lowly pathogenic agents of which PA and TV could be lead organisms. Impact on PSA of elimination of these organisms could become an important strategy in future efforts of to improve the specificity of PSA screening and chemoprevention of PC

Citation Format: Tim R T D Oliver. The significance of Vitamin D deficiency and low grade pathogens in etiology of prostate cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2865. doi:10.1158/1538-7445.AM2013-2865