The potential benefits do not outweigh the horrors of screening men found to have prostatic cancer
If breast cancer is what women are scared of, men fear prostate cancer. The widespread use or misuse of the prostate-specific antigen (PSA) and screening tests for prostatic cancer takes a multitude of men to physicians. The prostate gland surrounds the male urethra, through which urine passes. It is between 7 and 16 grams in weight and just below the urinary bladder. This is why it can be felt on rectal examination. It secretes a milky white fluid which constitutes 50 to 70 per cent of the semen volume. The alkalinity of this seminal secretion helps to neutralise the acidity in the vagina. It is possible for the male to achieve orgasm by stimulation of the prostatic gland through the rectum.
Not all prostate enlargements are cancerous and benign enlargement of the prostate is more common. The process of enlargement begins in the 30s and by 80, up to 85 per cent of men have benign prostatic enlargement. The enlargement of the gland may induce frequent urination, especially at night, a feeling of incomplete release or leakage after urination.
The severity of the symptoms is assessed on the basis of the American Urological Association symptom index. There is some literature to suggest that diets low in fat and red meat and high in protein and vegetables can protect against benign prostatic enlargement. Likewise, there is scant literature to show that alcohol consumed regularly may protect against benign enlargement of the prostate. It is important to remember that medication used particularly for asthma precipitates retention in prostatic enlargement. There are several treatment options that are beyond the scope of this article. It is also important to remember that prostatic size may not always correlate with symptoms.
In 2010, around 32,050 men died from prostate cancer in the US. Though it has been estimated that widespread use of PSA has helped detection of cancer, the benefits of screening procedures like these are as yet unclear. Prostate cancer remains the second-leading cause of cancer death in men. From one in five men diagnosed with this disease, only one in 30 will die from this disease.
You are at double the risk of being diagnosed with prostatic cancer if one first-degree relative is affected, and the risk is fourfold if two or more are affected. Afro-American males are at greater risk and this is associated with their higher levels of testosterone. There is therefore a genetic basis related to the SRDSA2 gene. It is also true that diet plays a role in this disease and high consumption of dairy fat increases the risk of prostate cancer.
There are protective factors against such a cancer and they include flavanoids found in legumes and cruciferous vegetables, lycophenes found in tomatoes, and inhibitors of cholesterol such as the statin group of drugs.
Over 60 per cent of patients with prostatic cancer are asymptomatic and the diagnosis is made on screening. Symptoms, when they appear, are indistinguishable from benign prostatic enlargement. The appearance of blood in urine should alert the physician to the possibility of prostatic cancer.
The PSA (Prostatic Specific Antigen) test is a screening test. It is true that it is prostate-specific but it is not cancer-specific. Elevated levels may also be seen from prostatitis (inflammation of prostate) and benign enlargement of the prostate. The levels are not markedly elevated after examining the prostate from the rectum, but are elevated after a prostate biopsy and continue to remain elevated for eight to 10 weeks. PSA testing was approved by the US FDA in 1974 and helps in diagnosis. The level of PSA in the blood is strongly associated with the risks and outcomes of prostate cancer. Despite this, the test has created great controversy and continues to do so. I find that in my practice it is a great cause of misery to patients. Various authorities have different recommendations.
The American Cancer Society recommends PSA and rectal examination for men over 50 who have an anticipated survival of more than 10 years. For Afro-Americans, the recommendation is to start testing at the age of 45. The American Urological Association recommends similarly, but continues that the risk and benefits of such tests are not properly defined. PSA levels may also fluctuate and therefore the value of a single reading becomes suspect. The United States Preventive Services task force doses not recommend PSA screening, noting that the test may cause over-diagnosis and treatment has risks, such as erectile dysfunction and incontinence.
While PSA testing may help 1:1000 to avoid death from prostatic cancer, they note that even four to five in 1,000 would die from prostate cancer after 10 years, despite screening. Simply put, the potential benefit does not outweigh the horrors of screening men found to have prostatic cancer; frequent over-diagnosis occurs because most prostatic cancer does not cause symptoms. Up to 90 per cent of such men opt to receive therapy, and for every 1,000 such men, 29 will become impotent from erectile dysfunction, 18 will suffer distressing urinary incontinence and will have cardiovascular events, one will suffer lung clots or clotting in the veins of the legs and one will have death during surgery. A small percentage of PSA in the blood is free and not bowed and it is sometimes necessary to measure (with levels of PSA between 4 and 10ng/ ml) to determine if a biopsy is necessary.
We now need a better parameter than PSA, one that is sensitive and specific, but that is also more sensible to use on the general public: one that will not scare the patient unnecessarily and confuse the physician. I am sure the day is not far away when we have a marker that can help diagnose which cancers are likely to spread or be problematic.