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The incidence of prostate cancer increases with age with a diagnosis rarer before the age of 40 and greater in males of age 60 and above. The median age of diagnosis for prostate cancer is the mid sixties.
Though not all cases of prostate cancer are aggressive with metastases to distant organs or local spread, the health and human life cost of this silent disease is huge as it the second leading killer cancer among males after lung cancer.
What Causes Prostate Cancer ?
Like other types of cancers, several factors come into play in the development of prostate cancer. Most of these factors act to modulate the process leading to development of cancerous conditions in the prostate gland. That which is of note however, is that the critical step is the damage of genetic material which causes normal prostate cells to loose the ability to regulate their life cycle leading to cancerous change.
Who is at Risk Of Developing Prostate Cancer?
Unlike breast cancer which affects both sexes but with a lion share of cases afflicting women, prostate cancer is an exclusively male disease for obvious anatomical reasons. The following factors are important modulating factors for prostate cancer:
Age:: As alluded to above, increasing age is an important factor in developing prostate cancer. This relationship between prostate cancer and age is so intricate that in a sizable number of cases, the cause of death is advanced age rather than complications arising from prostate cancer. This is especially so in cases where the sufferer has slow progressing type of prostate cancer or is responsive to initiated treatment measures.
Race:: In America, African American males have the highest chance of developing prostate cancer- 60% more likely than white males. This disparity has been explained to be due to genetic, environmental and socioeconomic factors like access to health care. However, this lower incidence in white males is not uniform since a higher number of prostate cancer cases are reported in European countries further up in the northern hemisphere. Asian males residing in Asia have the lowest risk although the risk has been shown to be higher among Asian males who have adopted western lifestyles.
Environmental and Geographical factors:: The disparity in the number of cases among the races has been attributed to matters of geography. Even within the same continent, distance away from the sun bathed lower latitudes has been linked with higher chances of prostate cancer. Males residing in areas north of the 40 degrees latitudes are at a higher risk due to low exposure to sunlight during winter which reduces levels of Vitamin D.
The Role of genetics/ Family History In prostate cancer:: Just like breast cancer, individuals who have relatives who have suffered from the disease are at a higher risk of developing prostate cancer.
The exact molecular mechanisms involved in this familial link are still under investigation. Among the associations noted include a higher risk of prostate cancer among males with a first degree relative such as a father or brother who has been diagnosed with prostate cancer.
The risk is higher if the diagnosis was made in a brother as opposed to the father and decreases if it was a second degree relative like a cousin or uncle. Just as breast cancer where diagnosis before attainment of menopause is an ominous sign, a higher incidence and more aggressive forms of prostate cancer were noted in males whose relatives were diagnosed at a young age (55yrs and below).
Prostate cancer was also found to be higher among males whose female relatives had been diagnosed with breast cancer. The reverse is also true as females with male relatives who have suffered from prostate cancer are also at a higher risk of developing breast cancer.
It has also been observed that there is a relationship between prostate cancer and other types of cancer that run in families such as colon cancer and bladder cancer. This unholy alliance is attributed to the fact that the defective genes implicated in these familial cancers are similar [eg mutations in the tumor suppression genesBRCA 1, BRCA 2 and p53].
Testosterone Hormone:: The casual relationship between high levels of the male hormone testosterone and development of prostate cancer is yet to be supported by any clinical observations, but it has been demonstrated that castrated individuals with low testosterone levels have a lower incidence of prostate cancer. Castration is also used as a stop gap palliative measure in some settings to retard the spread of prostate cancer in extremely advanced cases.
Since the metabolism of estrogen and androgen like testosterone are closely linked, the level of both endogenous hormones is of importance to researchers seeking to understand this disease more. In some instances, genetic conditions that derange the metabolism of both hormones have been implicated in the development of prostate cancer.
Factors Responsible For More aggressive Forms Of Prostate Cancer
- Smoking is implicated in causing more aggressive forms as opposed to low grade disease.
- Diet : lack of vegetables
- Obesity/ High Body Mass Index : Some literature suggest that this is because of the role of fat in metabolism of endogenous hormones such as estrogen.
- Sedentary Lifestyles Devoid of Exercise commonly associated with individuals of a higher social economic status