Though the causes of prostate cancer are still unknown it is noted to occur when a malignant tumor develops in these prostate glands. It is believed that prostate cancer develops following a sequence of genetic mutation. In the early stages mutations have been noted particularly as a result of a mutation in the p53 genes which are known to act as tumor suppressors. In approximately 64% of prostate cancer cases the abnormalities could have been traced to this specific genetic mutation. Another abnormality in the p21 gene also accounts for 55% cases.
The gene p73 also acts as a suppresant to tumours. The most commonly mutated gene responsible for suppressing the development of tumors is MMAC. The incidents of prostate cancer over the past decades or so has been on the increasing. One estimate says that one in six American men are likely to develop cancer. Figures for 1997 reveal that 209, 900 American males were diagnosed in that year alone, and that is not accounting for missing reports. The corresponding rates in the United Kingdom are that the rates have increased by more than three fold.
The clinical term used in reference to prostate cancer is usually adenocarcinoma of the prostate for a cancerous tumor on the prostate gland. As prostate cancer grows, it spreads to the interior of the gland, nearby tissues near, to sac-like structures attached to the prostate , and to distant parts of the body (e. g. , bones, liver, lungs). Prostate cancer confined to the gland often is treated successfully. Prevalence The worldwide rates of prostate cancer are highest in the U. S. and Sweden. In Canada the incidence is also comparatively high.
Prostate cancer is most noted among African American males and this group is believed to be at a 50 to 60% higher risk of developing prostate cancer than their white counterparts. Asian countries are noted to have the least cases of prostate cancer. Within Western societies prostate cancer is the second most diagnosed cancer for men and represents the fourth leading cause of male deaths in these populations. In the United States alone deaths from prostate cancer account for the second highest cause of death and this is second only to heart disease.
Risk factors As observed before the causes of prostate cancer have yet to be determined and Freeman et al does not believe that much breakthrough will be achieved in the very near future. Age, however, seems to be one of the greatest correlates of prostate cancer. Dimah and Dimah note that there is a large degree of “ageism” associated with the development of prostate cancer as older men dye more from the disease than younger men. Gronberg also observes that the disease is very rare among males less than 50 years of age and only an insignificant number (<0.
1%) of patients manifest prostate cancer before they reach 50. The average age of patients who develop prostate cancer is from 72 to 74 years and the majority of cases (85%) are diagnosed in men older than 65. Chinese, particularly those in Tianjin, are believed to be the least affected group with only about 1. 9 occurring per 100, 000 annually. North America and Scandinavia are at the opposite end of the spectrum with the highest rates. Besides age, one other significant correlate of prostate cancer is familial history of the disease.
Having a first degree relative with the disease increases the risk of developing prostate cancer by about two times among the black, white and Asian population in North America. The more first degree relatives have the disease the greater the chances become. Having two or more such relatives increases the risk by more than four in whites and Asians but by more than ten among black North Americans. Further, it is thought that the risk is even greater if the disease developed in the relative before the age of 65. However, generally all black men are at risk of developing prostate cancer.
Blacks have a notably higher risk of dying from prostate cancer according to Freeman et al. Other risk or preventative factors of developing prostate cancer include diet, obesity, environmental exposure, having a vasectomy and genetics. The diet rich in fat and low in fiber, evidenced in Western societies, has been blamed for the development of prostate and other cancers. The high soy intake among Asian men has been associated with the lower risk of prostate cancer. A diet rich in Vitamin E and selenium has been noted to act as protecting factors against the development of cancerous tumors.
Gallagher and Fleshner report on studies which found that an intake of about 200 mg of selenomethionine is useful in reducing the incidence of prostate cancer. Genetics and hormones are also linked to prostate cancer formation. It is believed that about 9% of all prostate cancers and 40% of those that develop in males less than 55 years of age may be linked to a genetic defect inherited from father to son. There is believed to be a link also with prostate cancer and the presence of the male sex hormone since eunuchs do not develop prostate cancer.