Prostate cancer

Prostate cancer is the most common form of cancer, excluding skin cancer, in men in the United States. It is primarily diagnosed in men over 65, although it may begin much earlier. Some cancers of the prostate are very slow growing, while others behave aggressively. Prostate cancer often metastasizes to other tissue, including the brain, lungs, lymph nodes, and bones. Early detection is critical in order to increase the chances for survival. The cancer can be felt upon digital rectal examination (DRE). These examinations are recommended routinely for all men over the age of 50 and high-risk men should commence at age 40.

The prostate is a walnut-sized gland in men that lies just below the bladder, surrounding the urethra. The function of the prostate is to enhance the movement of sperm cells by secreting a thin, lubricating fluid into the urethra.

Little is known about the causes of prostate cancer. Risk factors for prostate cancer include family history and black race. While most prostate cancers are found in the peripheral zone, they may occur anywhere in the prostate. Most pathologists use the Gleason grading system to assess the tumor progression. A score from 2 to 4 indicates a well-differentiated cancer; 5 to 6 correlates with a moderately differentiated cancer; and 7 to 10 indicates a poorly differentiated cancer. The poorer the differentiation of the cancer cells (the higher the score), the worse the prognosis. Well-differentiated tumors grow slowly, whereas poorly differentiated tumors grow rapidly and are associated with a poor prognosis.

A study published in the February 2007 edition of Journal of Clinical Nutrition examined the role of selenium in prostate cancer risk with tobacco use. This nest case-controlled study compared 724 cases of prostate cancer and 879 control subjects. These men were matched for the year of blood drawn, and were followed for up to 8 years. The results showed that selenium, overall, was not associated with prostate cancer risk. However, in men with higher intakes of vitamin E, selenium levels did show a lower risk. This was also seen in men who took multivitamins and in smokers. The authors concluded that, “Greater prediagnostic serum selenium concentrations were not associated with prostate cancer risk in this large cohort, although greater concentrations were associated with reduced prostate cancer risks in men who reported a high intake of vitamin E, in multivitamin users, and in smokers.

By Am J Clin Nutr. Peters U, et al. Serum selenium and risk of prostate cancer—a nested case-control study. Source: content.nhiondemand.com