Apart from non-melanoma skin cancer, cancer of the prostate is the most commonly diagnosed cancer among South Australian males. Primarily a disease of older men, prostate cancer is rarely found in men under 50 years of age. In South Australia there were 947 cases diagnosed in 1999. There were 987 cases diagnosed in 1998. Prostate cancer is the second most common cause of cancer deaths in South Australian men.
STRUCTURE AND FUNCTION OF THE
CAUSES AND PREVENTION OF PROSTATE CANCER
Prostate cancer has been associated with Western style high fat diets, alcohol, smoking, occupational exposure to cadmium and rubber, urban residence and a positive family history of the disease.
WHAT IS PROSTATE CANCER AND HOW DOES
In contrast, malignant or cancerous growths compress, invade, and destroy normal tissues. Over 95 percent of prostatic cancers are adenocarcinomas - cancer cells that arise from the lining or inner surface of this gland. The cancer cells may break away and spread through the blood and lymphatic systems to other parts of the body where they form secondary cancer deposits. Microscopically, the cancer cells of these secondary tumours are usually identical to those of the primary cancer. When prostatic cancer spreads, it most commonly travels to the lymph nodes and bone - especially the pelvis and lower spine.WHEN DO YOU SUSPECT CANCER OF THE PROSTATE?
This is difficult because the early symptoms associated with prostate cancer are identical to those produced by benign enlargements of the prostate. Also, in the very early stages when the tumour is small, there are no symptoms.
· Difficulty in passing urine.
can be present without
HOW IS PROSTATE CANCER DIAGNOSED?
It is virtually impossible on the basis of symptoms to say whether someone has benign enlargement of the prostate or cancer. As part of the assessment of men with urinary symptoms, the doctor will examine the prostate gland and if a cancer is present the gland will feel hard and irregular.
In the early stages of prostate cancer, it is often not possible to feel the cancer. It is possible to perform a blood test to measure the level of a substance produced by the prostate called Prostate Specific Antigen, usually referred to as a PSA test. If the blood level of this substance is elevated this suggests that prostate cancer may be present or at least that further investigations are required.
It is important to stress an abnormal level of PSA only suggests that a cancer may be present, it is not diagnostic and many conditions, such as a bladder infection, can cause elevated levels. Whilst both the clinical examination of the prostate and the blood test may suggest the presence of a cancer, the only way that the diagnosis can be confirmed is by biopsy of the prostate. This is usually done by inserting an ultrasound probe through the anal canal into the rectum to guide a biopsy needle to remove a series of small pieces of prostatic tissue. This tissue will then be examined by a pathologist who will be able to determine histologically whether a cancer is present.WHAT HAPPENS ONCE THE DIAGNOSIS OF CANCER HAS BEEN MADE?
The greatest influence on the treatment options will be determined by the extent of cancer at the time of diagnosis.
HOW IS THE DEGREE OF SPREAD
WHAT IS THE TREATMENT FOR PROSTATE
If there is a high probability that the cancer is localized to the prostate, then the two treatment options at present are:
i) the complete removal by surgery; or
ii) a course of radiotherapy to the prostate.
There are advantages and disadvantages for each of these types of treatment and the urologist who is caring for the patient will discuss these in detail.
If the cancer is not localized to the prostate, then surgery or radiotherapy is no longer the most appropriate treatment, as it is necessary to try to influence the cancer cells which have spread to other sites in the body. Prostate cancer, like the normal prostate, basically responds to male hormones (androgens). Therefore, the usual treatment is to reduce the level of male hormones which will slow down the growth which in turn can control but not eradicate the cancer. The testes are the main source of male hormones. The reduction in male hormones is achieved either by:i) the removal of the testes, bilateral orchidectomy; or
ii) the injection of a drug that blocks the release of male hormones from the testes, which is equivalent to bilateral orchidectomy.
Other hormone blocking agents are sometimes added and in certain cancers they will help keep the cancer under control for longer periods. Apart from the hormone treatments, drugs such as those used for chemotherapy at present do not seem to have a routine place in the treatment of prostate cancer.
If a low grade small volume cancer is detected the best form of treatment may be nothing more than a wait and see approach.RECOMMENDATIONS
The Anti-Cancer Foundation and the Australian Cancer Society at this stage, cannot recommend any one test for prostate cancer, but continuing research is being undertaken in this area. If a man presents with prostatic symptoms or wishes to have his prostate reviewed for malignancy, then a PSA test and rectal examination are the best initial investigations. However, it is important that the patient is aware of the risks and benefits that may follow from having a PSA test. Information is available from the ACF or your GP about the risks and benefits of having a PSA.
If a cancer is suspected then biopsy is necessary to make the diagnosis. If cancer is localized, surgery or radiotherapy can eradicate the disease. Unfortunately cancer is not always localized and clinical trials are still underway to establish how effective both surgery and radiotherapy are in these cancers.
If cancer is found to have spread, hormonal therapy has a good chance of significantly prolonging and improving quality of life.
The diagnosis and treatment of prostate cancer may necessitate both emotional support as well as the provision of more detailed information. The AntiCancer Foundation's Cancer Help Line
will provide both information and support in such situations. Professional staff are available to discuss the emotional and sexual issues that can arise with the management of this disease. Our staff can arrange referrals to other services that would be helpful to meet the specific needs of an individual or his family.
The 'Mr Phip' series of resources provides information appropriate to the five stages in the development of prostate cancer, beginning with the decision whether or not to take a PSA test. The information has been widely used by Urologists, Oncologists, community health centres, hospitals and prostate cancer support groups. It is also available from the Anti-Cancer Foundation.REFERENCES
These articles represent the opinions of the authors and may not always be in accordance with the policy of the Anti-Cancer Foundation.1. Marc B Gamick. The dilemmas of prostate cancer. Scientific American, April 1994.
i) P Dennis et al. Causes for concern in the use of PSA assays.ii) S Loh et al. The prostatic imperative.
5. Prostate Cancer Screening. Australian Health Technology Advisory Committee Report 1996.
Lions Australian Prostate Cancer Website:
This information sheet was prepared by the Anti-Cancer
Foundation and reviewed by a Consultant Urologist.