Description
Prostate cancer is a relatively common type of cancer affecting the small walnut-shaped prostate gland located near the base of the bladder and found only in men. The gland surrounds the upper part of the urethra, the tube that leads from the bladder to the penis. In more advanced stages of the disease the tumour may spread and eventually be carried (metastasise) to other areas of the body.
Prostate cancer is the commonest cause of cancer in men in the UK, accounting for a quarter of all new cases of cancer in males. In the UK there are about 40,000 new cases of prostate cancer each year. It is rare in men under 45 and quite common in men over 80. However, in older men the cancer is often small, restricted to the prostate and without symptom.
Often, the first symptom of prostate cancer is difficulty in urination, as the growing tumour constricts the urethra. Frequent urination (especially at night); a weak or interrupted urine stream; pain or burning upon urination or ejaculation; pus or blood in urine or semen; and discomfort in the lower back, pelvis, or upper thighs, are also symptoms of the disease. Other conditions, such as urinary-tract infections, benign enlargement of the prostate (benign prostatic hypertrophy or BPH), a serious infection of the prostate gland (acute prostatitis)and sexually transmitted diseases can also cause some of these symptoms.
Doctors must determine whether a man's symptoms are due to prostate cancer, BPH, or to another non-cancer-related condition. They must also determine whether the prostate cancer they have detected is clinically significant. If a prostate cancer is small, localised, and slow-growing, it may never cause significant health problems to the individual. In these cases, the treatments may sometimes be worse than the cancer as they can cause side effects such as erectile dysfunction and incontinence.
Some prostate cancers, however, do grow and spread aggressively into the pelvic region and then throughout the body; and some slow-growing cancers are eventually large enough and troublesome enough that they require intervention. The challenge for the doctor is detecting prostate cancer, evaluating its growth rate and spread, and then deciding, along with the affected person, which treatment courses to follow and when.
The tests most commonly used tests to investigate men with symptoms suggestive of prostate cancer are rectal examination and the Prostate-Specific Antigen (PSA) blood test. To perform a rectal examination, the doctor inserts a gloved, lubricated finger into the rectum (back passage) and feels the prostate gland with his or her finger for localised hardness or nodules. For the PSA test, blood is taken and sent to a clinical laboratory. There the blood is examined for an increased level of the blood marker which is associated with prostate inflammation or cancer.
Whilst the PSA level is raised in up to eighty percent of prostate cancers, an abnormal result does not necessarily mean a diagnosis of cancer. In fact, two-thirds of men with a raised serum PSA level do not have prostate cancer, although other abnormalities requiring treatment may be the cause of a raised PSA results. Rectal examination and PSA measurement can also assist in the early detection of benign prostatic hypertrophy (BPH). The current UK NHS policy about the use of PSA to screen men without symptoms for prostate cancer is explained under Screening/Adults 50+.
Should you have symptoms of prostate disease, be sure to let your GP know. If your PSA and/or rectal examination have normal results, your doctor can recommend when re-testing is appropriate. If your results are abnormal, your doctor may recommend further tests, such as a transrectal ultrasound-guided biopsy. This procedure allows a doctor to take a sample from the prostate for further study. It may be necessary to stop taking certain medicines up to ten days before the test. Ultrasound examination helps the doctor to assess the size of the prostate gland. A few weeks after the time of the biopsy you may also be asked to have an examination of your urinary flow rate and assessment of how much urine is retained in the bladder after urination. If your PSA level is only mildly elevated then your doctor may recommend re-testing after a certain period of time e.g. six months to a year.
Once a diagnosis of prostate cancer is made, doctors may use a variety of tests to monitor the cancer, determine treatment options, and evaluate the effectiveness of a chosen course of treatment. In addition to using rectal examination and PSA for this purpose, tests using X-ray, ultrasound, magnetic resonance imaging (MRI) and tissue sampling may be used.
Treatments for prostate cancer differ and are influenced by how much the tumour has spread outside the prostate (the "stage" of the cancer) and by how aggressive or fast growing the tumour is found to be in a tissue sample (the "grade" of the tumour). A doctor may use one or more of the tests discussed earlier to find out the stage of the tumour.
The decision to pursue one or a combination of treatments depends not only on the stage and grade of the tumour, but also on other factors such as the age of the patient and the patient's individual preferences.
Prostate cancer is typically treated using one or more of the following methods: "watchful waiting", surgery, radiation therapy and hormone treatment. Chemotherapy is rarely used for prostate cancer, but may be used in advanced cases that are unresponsive to hormone therapy.
Watchful waiting, surgery, and radiation are most often used when the tumour is contained and has not spread to other areas. As many prostate tumours grow slowly, a programme of watchful waiting may result in an unaffected life span that is largely symptom-free and uncompromised by side effects. This programme will be likely to include regular PSA testing and rectal examination.
Surgery can remove the entire tumour in early cases, and may be used to ease urination in more advanced cases. Cryosurgery, a relatively new surgical option, freezes and kills the affected tissue with liquid nitrogen. Radiation may be delivered as targeted rays from outside the body, or by inserting tiny radioactive seeds in the prostate, or by injection. Radiation can also be coupled with hormone treatment to provide pain relief in patients with prostate cancer that has spread to the bones.
Hormone therapy is most commonly used to treat prostate cancer that has metastasized to other areas of the body. While it is not a cure at this stage, the treatment can shrink tumours, relieve symptoms and extend the life of the patient. Hormone therapy is also used to treat less advanced stages of prostate cancer - either in conjunction with radiation therapy or to shrink a tumour prior to surgery. Men with decreased testosterone levels due to hormone treatment for prostate cancer are at an increased risk for developing osteoporosis. Your doctor can tell you whether you should have tests for a loss in bone density, or whether measures or treatments to prevent osteoporosis should be considered.
The side effects of different prostate cancer treatments can range from none to tiredness, hair loss, incontinence and the inability to have an erection. Your doctor can make treatment recommendations based upon your test results and particular circumstances.