Tamoxifen, or not tamoxifen? The issues surrounding chemoprevention
Dr Richard Roope, RCGP Clinical Champion for Cancer
Cancer incidence continues to rise in the U.K., as across the world. Between 2013 and 2030, cancer cases are predicted to rise by 30% in the U.K. and up to 70% in developing countries. On this backdrop, and in the light of financial pressures across all health systems, prevention is becoming a higher priority. Addressing lifestyle has become a major focus of attention of both the NHS and Government. Taxation policy (smoking, alcohol, and more recently sugary drinks) is one such strategy. Another prevention option is the use of medication to reduce risk. Previous research has shown that aspirin can reduce the incidence of a number of cancers. Current research streams are looking at the benefit : risk balance of aspirin use in this context.
Breast cancer, the commonest cancer in the U.K. with 55,222 new cases per year,, claiming 11,433 lives per year and a lifetime risk in women of 1 in 8, has specifically come under the chemoprevention spotlight, with the focus on those with an increased familial risk. NICE published guidance in 2004, 2011 and an update of the latter in 2013.
Cancer Research UK funded research to assess current attitudes and practice of using chemoprevention amongst GPs. They also explored what support GPs would want to implement the guidance. The findings showed, that of the 1,000 surveyed, only 24% knew that NICE recommends use of tamoxifen for women with an increased familial risk of breast cancer. GPs were more willing to prescribe tamoxifen when told of the benefits, however many wanted more support in doing so. GPs(63%) were happier to prescribe, when the treatment had been initiated in Secondary care.
These findings are not hugely surprising. We are inundated with paper and electronic correspondence, guidance, requests, results and information on a daily basis, more than even the fastest reader could read, let alone put into practice. The NICE Clinical Update for Guidelines 14 and 41 (“Classification and care of people at risk of familial breast cancer and management of breast cancer and related risks in people with a family history of breast cancer”) runs to 265 pages, so is not surprising that this has had low penetration into GP practice. Further to this, tamoxifen does not have a licence for this use and can cause significant unpleasant side effects(e.g. menopausal symptoms and thromboembolic events), making any discussion with the patient more involved, and to do this properly requires more time, which is at a particular premium with the current pressures prevalent in the consulting room.
However, tamoxifen has the potential to reduce cancer cases by 32% in those at high familial risk, and this research identifies that GPs need more information if we are to maximise the prevention potential in reducing breast cancer incidence in this group of patients. NICE is due to publish a patient decision support tool within the next few weeks, and the RCGP is looking to develop recommendations based on NICE’s publications soon after. These will include an update on breast cancer prevention in general, with 27% c of cases (14,900 per year) preventable.