New hope for prostate cancer patients

Tamoxifen can alleviate the side effects of hormone therapies in patients with prostate cancer

The substance tamoxifen has been known for years as it is commonly used in the therapy of female breast cancer patients. Scientists from Friedrich-Alexander-Universität Erlangen-Nürnberg and the Deutsche Cochrane Zentrum (German Cochrane Centre, DCZ) have now published a systematic survey which proves that the substance might also be beneficial to male patients as it alleviates the side effects of hormone prostate treatment such as an enlarged mammary gland (gynecomastia). This effect might reduce the number of cases in which therapies are discontinued considerably. The latest research results will now be published in the journal ‘BMC Medicine’.

Prostate cancer is one of the most common forms of cancer in men; it usually responds very well to treatment. At an early stage, treatment suppressing male sexual hormones (androgens) can slow down the progression of an existing condition. However, patients often suffer mentally from the side effects since anti-androgen treatment can cause a sometimes painful enlargement of the mammary gland, which is one of the reasons why many men discontinue the therapy prematurely and thus endanger its success.

The group of researchers from Friedrich-Alexander-Universität Erlangen-Nürnberg and the Deutsche Cochrane Zentrum Freiburg have now proven that the substance tamoxifen, an anti-estrogen drug widely used in treating breast cancer, can suppress those side effects. Anti-androgens disrupt the growth of prostate cancer cells by preventing testosterone from docking to androgen receptors. In the process, however, receptors in the testicles are blocked as well. These in turn start to produce more and more testosterone, which is partly converted into estrogen stimulating the growth of breast tissue. Anti-estrogens can suppress this process.

In their survey study, Scientists from FAU and DCZ compared data from four independent clinical studies examining the effect of tamoxifen on the development of breast tissue in prostate cancer treatment. They discovered that administering tamoxifen significantly reduces patients suffering an enlargement of the mammary gland or having to endure breast pain. In general, the scientists found that tamoxifen treatment was more successful in suppressing breast enlargement than therapies with aromatase inhibitors or radiation.

At present, long-term data are not available yet but only few of the men treated with tamoxifen discontinued their cancer threrapy over the course of a year and there were no significantly adverse effects of tamoxifen.

For Dr. Frank Kunath who supervised the survey study at Universitätsklinikum Erlangen, this is a positive sign. ‘Of course, anti-androgen therapy does not result in an enlargement of the mammary gland in all patients with prostate cancer but when patients know that an effective cure for this side effect exists, they are more likely to consult their physician on first signs rather than discontinuing the treatment of their own accord. This means that we might also be able to prevent unnecessary deaths.’

Further information for the press:

uni | media service | research No. 37/2012 on 29.8.2012