The biggest risk factor for prostate cancer is age. Over 85% of all cases are diagnosed above the age of 60. Most prostate cancers are slow and have an indolent course and therefore may not alter life expectancy. If younger men are diagnosed with prostate cancer it is important to treat them early, as in this situation life expectancy may decrease. A family history of prostate cancer is also a risk factor and there is some discussion of certain environmental and lifestyle factors increasing the risk, however no conclusive evidence is available.
In terms of early detection of prostate cancer, there is currently no beneficial evidence for mass screening. The rationale behind this is that many prostate cancers will not actually progress sufficiently to cause a man harm in his lifetime. For this reason prostate cancer detection should be done on individualised basis, taking into account each patients risk factors. Men above the age of 60, or those with a strong family history may choose to be screened by their general practitioner under this circumstance.
Screening for Prostate Cancer
There are two main forms of screening for prostate cancer. These tests are not 100% accurate and therefore it is important to be aware of this.
Digital Rectal Exam (DRE)
The first test a doctor may do is a digital rectal exam (DRE). With the DRE, the doctors gloved finger is inserted through the anus and feels through the wall of the rectum for any abnormalities in size, shape or texture of the prostate. While these irregularities may not be indicative of cancer, they give the doctor a general guide of the prostate. It should be noted however that some cancers may not be within reach of the finger.
Prostate Specific Antigen Test (PSA)
The next screening test for prostate cancer is the prostate specific antigen test (PSA). PSA is a protein produced by the prostate, and the levels of this protein tend to rise when the prostate enlarges.
Therefore again, if PSA levels are high, this does not necessarily indicate cancer as other conditions can cause this (e.g. benign enlargement of the prostate, urinary tract infections). Similarly, a low PSA does not necessarily mean that cancer does not exist.
Many organisations, including the Urological Society of Australasia, recommend that all men between the ages of 50-70 should have a DRE and/or their PSA tested annually. If there is a strong family history of prostate cancer, testing may start from as early as 40 years old.
Transrectal Ultrasound and Needle Biopsy
If a man’s PSA or DRE is abnormal he is then generally sent for a transrectal ultrasound (TRUS). This involves a probe being inserted into the rectum to take ultrasound images of the prostate. At the same time a needle biopsy can be taken to sample prostate tissue for cancer cells – this is generally the most reliable way to confirm the presence of prostate cancer, but obviously this can not be done on every man.
The early detection of prostate cancer can be important is some cases, but in others prostate cancer may not affect a man due to its slow growth patterns. If a man is concerned about prostate cancer it is important for him to consult with his doctor who can the assess him on an individualised basis.