Hormonal treatments are almost twice as effective as venlafaxine in reducing hot flushes related to prostate cancer treatment.

Hot flushes are a common and troublesome side effect of GnRH analogue therapy for prostate cancer. Treatment options for hot flushes can be divided into hormonal and non-hormonal. Hormonal treatments consist of cyproterone acetate, a steroidal anti-androgen which may also be used in the management of the cancer itself, or medroxyprogesterone (a progestogen). Non-hormonal therapy is most commonly with SSRIs such as venlafaxine.

This study from France was a double-blind, randomised trial comparing these three drugs in a group of 300 men with prostate cancer. Patients completed a daily hot flush diary, and the primary outcome measure was the change in hot flush scores at one month after randomisation.

Venlafaxine was found to decrease hot flush scores by 47.2%, cyproterone by 94.5% and medroxyprogesterone by 83.7%. All treatments therefore showed a statistically significant reduction in the incidence of hot flushes, but the two hormonal treatments were significantly better than venlafaxine - no significant difference between cyproterone and medroxyprogesterone was identified.

Androgen suppression using GnRH analogues is the most common form of treatment for advanced prostate cancer. While highly effective in the management of the disease, these drugs are associated with significant side effects due to androgen deprivation, most notably erectile dysfunction, loss of libido and hot flushes. Studies estimate the incidence of hot flushes in men on GnRH analogues as approximately 80%, with 27% reporting them as the most bothersome side effect of treatment.

The authors conclude that given that cyproterone acetate is a hormonal treatment for prostate cancer, its use for this indication could potentially interfere with prostate cancer treatment, and therefore recommend medroxyprogesterone as standard therapy for treatment-relatedhot flushes.

For GPs it is also useful to know, that given the common co-existence of significant depression in cancer patients, treatment with an SSRI may significantly improve hot flushes for prostate cancer patients. Initiation of the more effective hormonal treatments will, however, most likely be carried out by uro-oncologists rather than in a primary care setting.

Dr Jonathan Rees