Summary
Research at Barts and the London School of Medicine and Dentistry showed that mammography which uses images from two instead of a single angle (view) were 24% better at detecting early stage breast cancer. As a result, an estimated 2,500-3,000 additional women per year in the UK will have breast cancer detected early. Two-view mammography is now national policy at by all breast cancer screening units. Researchers have also showed that radiotherapy following surgery for cancer of the milk ducts of the breasts reduces the risk of recurrence. Approximately 80% of breast cancer in post-menopausal women is hormone receptor positive, which was treated by tamoxifen, which had problems with recurrence and side effects. Researchers at the Barts and the London showed that tamoxifen could be replaced by the drug anastrozole which leads to lower risk of recurrence.
The science: better screening and treatment regimes for breast cancer
Breast cancer is the commonest female cancer in the UK with 50,000 new cases detected annually. Over 2 million women are screened in the UK annually. The National Breast Screening Program has been screening women aged 50-64 annually since 1988. A clinical trial conduced at Queen Mary University of London involving nine breast cancer screening units and 40,163 women compared breast cancer detection using one or two view mammography and found that 24% more women with breast cancer were detected using two view mammography as using a single view missed some cancers.
Cancer of the milk ducts of the breast is diagnosed in around 4.650 woman in the UK annually. Survival following treatment is 98% but risk of local recurrence is high. In another clinical trial Queen Mary researchers showed that radiotherapy after surgery reduced risk of developing invasive cancer by 70% and recurrence by 60%.
In a clinical trial in 381 centres in 21 countries involving 9,366 women over 45 years of age who had completed primary surgery and chemotherapy for invasive breast cancer a 24% reduction in recurrence was observed with anastrozole compared to tamoxifen. Additionally, anastrozole was better tolerated.
Putting research into action: impact on breast cancer screening and clinical guidelines
Two-view mammography is now routine practice in the UK. An audit of the NHS Breast Screening Program and Welsh National Breast Screening Programme (2000-2005) showed a 20% and 39% increase in cancer detection rates respectively. The use of two-view mammography in breast screening is now recommended by numerous professional bodies worldwide, including the World Health Organisation’s 2006 recommendation, which is still current. The US National Cancer Institute acknowledges the superiority of two- over one-view mammography. A review in 2012 of 25 national and regional programmes in Europe found that all used two-view mammography.
Clinical guidelines in the UK, US and Canada have changed to include the recommendation that radiotherapy should be offered to patients after surgery for cancer of the milk ducts in the breast with increasing numbers of clinicians taking up these recommendations. Additionally clinical guidelines worldwide including in the UK, USA and Australia have changed so that post-menopausal women with hormone receptive breast cancer are treated with anastrozole instead of tamoxifen. The clinical trial showed that 80% of patients taking anastrazole were cancer free over a 10 year period compared to 76% taking tamoxifen.