The Diagnosis of Prostate Cancer
Diagnosis of Prostate Cancer
If you are concerned about prostate cancer, then you should visit your doctor.
It is a multi-step process to investigate the symptoms of prostate cancer: • Initially your doctor may take a small sample of blood which will undergo the prostate specific antigen (PSA) test . PSA is a protein produced by the prostate. If the prostate is active as a result of being enlarged, infected, or because cancer is present, the amount of PSA produced will increase. This can be measured from your blood sample. (Your doctor may want to carry out some tests to rule out a urine infection before proceeding with the PSA test). • You may also be offered a digital rectal examination (DRE), where the doctor inserts a gloved finger into the back passage (rectum) to feel the prostate: the prostate gland may feel abnormal if it is enlarged, or if cancer is present; but a benign enlargement of the prostate will often feel smooth, while a prostate which has developed cancer may feel more hard and/or lumpy. • If you have a lumpy and/or hard prostate, and a raised PSA level, your doctor may refer you to a specialist for a prostate biopsy . During a biopsy a probe is inserted into the rectum, and the prostate is examined using ultrasound waves . Small tissue samples are also taken from the whole of the prostate using a specially designed needle. The procedure may be uncomfortable, but it should not hurt. There will probably be a small amount of bleeding in the urine and faeces for two to three days afterwards. You may be prescribed antibiotics to decrease your chance of developing an infection. • If prostate cancer is diagnosed, then further tests are required to determine whether the cancer has spread, and what would be the most appropriate treatment.
The PSA Debate
Use of the PSA test to screen for prostate cancer has caused a large amount of controversy within the Scientific Community.
It is thought that use of the PSA test can lead to an earlier diagnosis of prostate cancer, before men have started to show clinical symptoms. Many believe that this will help to reduce the number of deaths which occur from prostate cancer because, by catching the cancer at an earlier stage, while it is still contained within the prostate, a patient can undergo treatment for his cancer with the aim to cure as opposed to prolong life.
It has not, however, been proven that PSA screening can reduce the number of deaths from prostate cancer, and there are also substantial arguments against using the PSA test to screen for prostate cancer in the general population.
Many researchers worry that the PSA test results in over-diagnosis of prostate cancer because, for a large proportion of men diagnosed with the disease, the cancer progresses so slowly that it will not actually affect their quality of life or reduce their life-span. It is believed that many men who are not destined to experience aggressive development of the disease are subjected to unnecessary radical treatment as a result of PSA screening. When you consider that the side-effects of radical treatment are often severe, and can include impotence , urinary incontinence , skin damage, and bowel problems, it is clear that over-diagnosis should be avoided.
Two major research trials which are currently underway – The European Randomized Study of Screening for Prostate Cancer (ERSPC) and the US National Cancer Institute sponsored Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial - are attempting to weigh the benefits of routine screening for prostate cancer in the general population, against the potential disadvantages. Results from these trials are not expected until 2008.
In the USA, it is currently advised that all men of 45 years and over with a family history of prostate cancer undergo a PSA test. Across the European Community prostate cancer screening policies vary, because it has not been proved that such programmes lead to a reduction in the number of deaths from the disease. The results of the ERSPC and PLCO trials may result in a change of EC Health Policy.
There is also much research being conducted into potential new markers which could be used to screen for prostate cancer (instead of blood PSA levels). It is hoped that new markers will be found which can distinguish between latent forms of prostate cancer (where men never actually develop clinical symptoms), and aggressive (fast-growing) forms of the disease.
The IMPACT-study and Prostate Cancer Screening
IMPACT is a ground-breaking new study which is looking at whether PSA screening can be targeted at men who have inherited a gene alteration which may predispose them to developing an aggressive (fast-growing) form of prostate cancer. This study will also investigate potential new markers for the disease. If you are interested in learning more about this study, please take a look at the about IMPACT study section of this site.