Article Figures & Data
Tables
- Table 1.
Comparison of the Prostate Cancer Prevention (PCPT), Reduction of Dutasteride of Prostate Cancer Events (REDUCE), and Selenium and Vitamin E Cancer Prevention (SELECT) Trials
Patients (n) Age (years) PSA (ng/L) Follow-Up (years) Relative Risk of Prostate Cancer* Absolute Risk of Prostate Cancer* Absolute Risk of High-Grade Prostate Cancer* Risk of Diabetes PCPT 18,883 >55 ≤3 7 ↓25% ↓6% ↑0.6% n/a REDUCE 8,231 55–75 2.5–10 4 ↓23% ↓5% 0% to ↑0.5%† n/a SELECT 35,533 >50 ≤4 5.4 ↑Trend with vitamin E ↑Trend with vitamin E No known effect ↑Trend with selenium ↵* Compared with placebo.
↵† Original publication did not demonstrate increased risk of high-grade cancer; however, the Food and Drug Administration mandated re-analysis of biopsy specimen based on modified Gleason score suggesting a 0.5% increase of high-grade prostate cancer in the dutasteride arm.
PSA, prostate-specific antigen.
- Table 2.
A Summary of Proposed Agents for the Prevention of Prostate Cancer, Mechanisms, Demonstrated Benefits, Potential Harm and Quality of Evidence
Agents Proposed Mechanism* Demonstrated Benefit Potential Harm Quality of Evidence† Finasteride Inhibits 5-alpha reductase, lowers DHT Decreased incidence/diagnosis of prostate cancer, improved urinary symptoms Increased sexual side effects, may increase risk of high-grade prostate cancer Level 1 Dutasteride Inhibits 5-alpha reductase, lowers DHT Decreased incidence/diagnosis of prostate cancer, improved urinary symptoms Increased sexual side effects, may increase risk of high-grade prostate cancer Level 1 Selenium Inhibits clonal expansion of prostate cancer cells No effect May increase type II diabetes mellitus Level 1 Vitamin E Cell membrane antioxidant No effect May increase prostate cancer incidence, all cause mortality, and hemorrhagic stroke Level 1 Vitamin C Antioxidant No effect No effect Level 2 Beta-carotene Antioxidant No effect Increased risk of lung and gastric cancers Level 2 Multivitamins Various mechanisms No effect May increase rate of prostate specific death Level 2 Lycopene Antioxidant Possible effect but conflicting evidence Unknown Level 2 NSAIDs Reduces prostaglandin 2 and arachidonic acid Unclear effect on prostate cancer incidence Increased risk GI bleed Level 3 Aspirin Inhibit cell migration May decrease risk of prostate cancer Increased risk GI bleed Level 3 Cox 2 inhibitors Pro-apoptotic agent No effect Risk of cardiovascular events at high dose Level 3 Statins Multiple potential cholesterol and non-cholesterol-dependent mechanisms May lower incidence of advanced prostate cancer Myalgia, hepatic dysfunction Level 3 Toremifene Selective estrogen receptor modulator May decrease incidence of prostate cancer Hot flashes, nausea, hepatic dysfunction Level 3 Soy Weak estrogen Increased intake may decrease prostate caner risk Unknown Level 3 Protein/meat intake Unknown; may be related to fat intake Lowering meat intake has not been shown lower cancer risk Increased red meat intake may have increased risk of prostate cancer Level 3 Fat intake Fat increases circulating androgen Conflicting evidence for lowering fat intake on prostate cancer, but documented benefit to cardiovascular health High-fat diets are associated with higher incidence and more advanced prostate cancer Level 3 Fish consumption Via modifying omega 3:omega 6 fatty acid ratio Increased fish intake may decrease prostate cancer death Unknown Level 3 ↵* There are no clearly identified causal mechanisms for prostate cancer prevention; commonly accepted mechanisms with some evidence from preclinical investigations are presented.
↵† Levels of evidence employ the strength of recommendation taxonomy (SORT) as described in Ebell MH, Siwek J, Weiss BD, et al. Strength of recommendation taxonomy (SORT): a patient-centered approach to grading evidence in the medical literature. J Am Board Fam Pract 2004;17:59–67.
DHT, dihydrotestosterone; GI, gastrointestinal; NSAIDs, nonsteroidal anti-inflammatory drugs.
