Preventive medicine for breast cancer
The idea of drug treatment to prevent cardiovascular disease is well-established. Not so with cancer. Now a panel of cancer experts, writing in Lancet Oncology have suggested that drugs such as tamoxifen could reduce the chances of developing breast cancer. You can read more about the story here.
Tamoxifen is a powerful medicine and the researchers make clear that it is not without side-effects. So women would need to think carefully before deciding whether they wanted to take the treatment long-term.
As with all medicines it comes down to an assessment of risks versus benefits, but that is especially important when healthy individuals take a treatment.
Professor Jack Cuzick, an epidemiologist at Queen Mary, University of London put the risk-benefit analysis this way: "For every 1,000 women on tamoxifen for 10 years, we estimate there would be 20 fewer breast cancers. But there would be three more womb cancers and six more deep vein thromboses."
So a key factor will be identifying women who are at increased risk of breast cancer. Among measures already taken into account are family history and increasing age. The researchers say increased breast density - visible on mammograms - could also be a useful assessment tool.
There are other factors which affect a woman's lifetime risk such as reproductive history and issues such as bodyweight, physical activity and alcohol intake. The Cancer Research UK website has a huge amount of information.
Tamoxifen is not licensed as a preventive therapy, and is off-patent. Professor Cuzick suggested this meant there was no great financial motive for the pharmaceutical industry to push for it to be licensed for prevention. He hopes current trials might eventually persuade NICE, the health watchdog, to back it as a preventive treatment.