Can it be prevented?

taken from Small Gland, Big Problem 4th Edition
by Professor Roger Kirby, Health Press 2011

Clearly you cannot change your age, ancestry or race (these are ‘non-modifiable risk factors’). However, several other risk factors for prostate cancer have been identified over which you can have some influence – lifestyle factors, such as diet and exercise (see pages 6–8). In addition, various dietary supplements, such as lycopenes, may offer some protection (see pages 7 and 8).

Geographically, prostate cancer tends to become more common as you move away from the equator: Norway and Sweden have the highest death rates from the disease worldwide. This fact points us to two further possible modifiable risk factors – low vitamin D and low exposure to sunlight, which itself helps the body to produce vitamin D. This evidence provides a good excuse for regular winter holidays in the sun! Alternatively you can take a daily vitamin D supplement.

As already mentioned, prostate cancer is characterized by an abnormal overgrowth of prostate cells. As scientists unravel the steps involved in the development of this abnormal cell overgrowth, it is possible, and indeed probable, that we will one day be able to intervene to reverse the earliest phases of the disease. A number of compounds that have this potential are currently being investigated for effectiveness and safety. One of the problems is that it is considerably more difficult (and expensive) to demonstrate that a given drug or vitamin is capable of preventing a disease than it is to show that it can cure a specific problem once it has developed. Because we are never sure exactly who will develop a disease such as prostate cancer, very large numbers of individuals have to be studied for many years (5, 10 or even 15) before we can be certain that a drug can safely and effectively prevent the disease from occurring.

The drug Proscar (finasteride) has been evaluated for its preventative activity. A report has revealed that 25% fewer cases of prostate cancer occurred in the men treated with Proscar at a dose of 5 mg/day. Surprisingly though, those cancers that did occur appeared to be more aggressive in nature than those that occurred in the men not treated with Proscar. For this reason, Proscar has not been approved for use as a preventative agent. Another large study, known as REDUCE, looked at a medication that acts in a similar fashion to Proscar, namely Avodart (dutasteride). It found that the likelihood of getting prostate cancer was 23% lower in the men taking dutasteride for 4 years compared with men taking a placebo (dummy medication). Once again, though, there were concerns about a very slight increase in the number of more aggressive cancers in the group receiving dutasteride. For this reason, neither Proscar or Avodart has been licensed for the prevention of prostate cancer. Recently, reports have begun to appear suggesting that the cholesterol-lowering drugs known as statins, such as Lipitor (atorvastatin), may offer some protection against prostate cancer as well as heart disease. This is intriguing, but needs to be verified.

Other so-called chemopreventative agents will doubtless emerge as more research is undertaken.

Case study

Kenneth, a moderately overweight 64-year-old university lecturer, requested a PSA check from his GP after reading about prostate cancer in the newspaper. The result came back a little raised at 5.6 ng/mL. He was referred to his local urologist who rechecked the PSA and examined his prostate, which was found to be enlarged but soft with no nodules. A biopsy was performed under antibiotic cover and local anaesthesia, which did produce some blood in the semen but no other side effects.

The biopsy revealed the presence of prostatic intraepithelial neoplasia (PIN), a condition regarded as pre-cancerous, in two out of eight cores and some inflammation in several of the remaining cores. No cancer was detected. Ken was advised to initiate lifestyle changes, with an improved diet and more exercise, and to take vitamin D and lycopene supplements and/or lycopenerich foods, such as tomatoes, on a regular basis. He will be followed up and a rebiopsy considered if the PSA rises or if the consistency of the prostate begins to feel suspicious