HORMONE THERAPY FOR CANCER
Although chemotherapy now dominates cancer drug therapy, it was a hormone-based drug therapy that was the first successful medicinal cancer treatment. Hormone therapy for cancer dates back to the 1940s following observations made by Charles Huggins, an American urologist, on patients with advanced prostate cancer.
The pioneers of hormone therapy reasoned that if the ‘parent’ tissue needed normal hormone levels, then the abnormal tumour derived from the tissue may retain this dependence. Trials of castration in advanced prostate cancer produced dramatic results, with rapid and substantial improvements in symptoms such as pain from cancer deposits in bone. Following this, administration of female hormones, which of course suppress male characteristics, was attempted, again with dramatic results. Sadly, these endocrine effects, while substantial, would last for only 1 or 2 years, the disease then recurring. Similar effects were observed in pre-menopausal women with breast cancer following removal of the ovaries. The subsequent decades have seen the development of a whole range of hormone-based medications for both prostate cancer and breast cancer in particular. One of these drugs, the oestrogen blocker tamoxifen, is probably responsible for saving more lives than any other anticancer drug. More than half a century on, new drugs targeting the hormone pathways, are still appearing in the clinic.