Chemoprevention of prostate cancer: is there evidence from clinical trials?

Marcelo Langer Wroclawski, Cynthia Kuk, Antonio Finelli, Neil E Fleshner, Alexandre R Zlotta

Prostate cancer is the most common malignancy in men and the second leading cause of death from cancer in Western society. Due to the introduction of prostate-specific antigen screening, insignificant tumors are being over‑diagnosed and patients who may not benefit from curative procedures (i.e., surgery or radiotherapy) are being overtreated, and resultantly may suffer the consequences of these procedures, leading to decreased quality of life. Thus, prostate cancer prevention could result in saving lives and, even if this goal cannot be achieved, reduction of morbidity and economic gains are significant end points that may be reached. Many compounds have been hypothesized as possible chemoprevention agents in epidemiological or observational studies. However, there are few clinical trials available in the current literature. This article reviews the main clinical trials that have been published regarding prostate cancer chemoprevention. Pharmacological intervention is discussed through papers suggesting that 5a-reductase inhibitors, such as dutasteride and finasteride, may prevent prostate cancer. Toremifen and statins are also possible chemoprevention agents. Dietary supplementation with selenium, vitamins A, C, D and E, folic acid, green tea, soy and lycopene are also debated.