It is claimed that drug therapy can improve survival rates by up to 20 per cent. However, it’s been found that, after a certain time, the drugs will often stop working - and some prostate cancers don’t respond to hormones at all (Prostate Cancer Prostatic Dis, 2002; 5: 13-5).
As a recent study by Sweden’s Karolinska Institute admits, hormone therapy has turned out to be 'disappointing'. Indeed, the report concluded, 'No decisive breakthrough in the pharmacological treatment of prostate cancer has occurred in the last 60 years' (Lakartidningen, 2000; 97: 3466-9).
Because prostate chemotherapy destroys male hormones, it is sometimes referred to as ‘chemical castration’. Predictably, its main side-effect is to curtail sexual functioning. But it also causes osteoporosis, nausea and severe anaemia, and has even killed people through liver toxicity.
Because of the high cost of hormone-blocking drugs, doctors may recommend actual physical castration as a cheaper option; particularly in the UK, this is considered the ‘gold-standard’ treatment for advanced prostate cancer (Br J Hosp Med, 1993; 49: 710-1, 714-5).
However, since there have been no prospective randomised trials of the treatment options, there is little evidence that any medical intervention currently on offer actually prolongs life. As a statement from the US National Cancer Institute bluntly put it, 'It is not known if the potential benefits of prostate cancer screening outweigh the risks, if surgery is better than radiation, or if treatment is better than no treatment' (US National Cancer Institute Statement, October 2000).
This may explain why, besides surgery, radiation and drugs, there is a fourth treatment - do absolutely nothing. The official medical term is ‘watchful waiting’. There is evidence to show that this is often the best option.
In the biggest study to date, 60,000 Americans diagnosed with localised prostate cancer in the 1980s were followed for 10 years to compare the effects of different treatments.
For men with minor to medium-stage cancer, there were just as many men still alive after no treatment as after surgery. Radiation treatment appeared to actually increase death rates. Only in cases of initially serious cancers did there appear to be any (albeit slight) survival advantage of 'aggressive therapy' over watchful waiting (Lancet, 1997; 349: 906-10).
However, even these findings - which were effectively proving that having no treatment was as good as or better than any treatment - were soon attacked as 'exaggerating the benefits of treatment' (Lancet, 1997; 349: 1551-2).
Some experts are now beginning to concentrate on prevention - mainly by diet. Even such bastions of the cancer Establishment as the Sloan-Kettering Cancer Center in New York are contemplating dietary manipulation as a 'treatment strategy' (Semin Urol Oncol, 1999; 17: 154-63).
Despite the initial medical scepticism, evidence of a connection between diet and prostate cancer has been getting stronger year by year.
There is relatively good evidence of an association with a high-fat diet, although recent studies suggest that reducing fat intake does not have a marked preventative effect (Curr Opin Urol, 2001; 11: 457-61).
There appears to be a stronger connection with dairy foods. Studies in the US and Sweden have shown that a high consumption of dairy products can increase prostate cancer risk by 50 per cent. The culprit doesn’t appear to be the fat content of milk but - perhaps surprisingly - the calcium. One of calcium’s effects in the body is to reduce vitamin D levels, and vitamin D is one of the many micronutrients known to prevent prostate cancer (Cancer Causes Control, 1998; 9: 559-66).