Many news sources have reported that a “major review” of the NHS breast screening programme is to take place. BBC News said “the evidence for breast cancer screening in the UK is being reviewed amid controversy about the measure’s effectiveness”.
The news of the review comes from Professor Sir Mike Richards, national cancer director at the Department of Health, who discusses it in an open letter in the BMJ. It follows criticism of the current screening programme by some doctors who believe that by throwing up some false results, screening may be doing more harm than good.
The majority of specialists in the field are thought to support the current breast screening programme. However, Richards said: “Should the independent review conclude that the balance of harms outweighs the benefits of breast screening, I will have no hesitation in referring the findings to the UK National Screening Committee and then ministers.”
What has prompted this review?
Professor Richards announced the review in response to debate among scientists over the effectiveness of breast screening. For example, a recent Cochrane Collaboration review of breast screening concluded that “it was not clear whether screening does more good than harm”.
The three highest-quality studies covered by the review showed that screening did not significantly reduce death from breast cancer after 13 years in comparison to women who weren’t screened. However, lower-quality studies showed a significant reduction in breast cancer death in those who were screened.
When the high- and lower-quality studies were combined, the overall effect showed screening did reduce the relative risk of breast cancer death by 13-26%. The authors highlighted that the lower-quality studies may be biased to favour screening, and estimated the true relative reduction in death from breast cancer due to screening to be in the region of 15%.
What are the pros and cons of breast screening?
There has always been debate about the pros and cons of screening, revolving around the complex balance of its benefits and harms.
The benefit of screening is in finding breast cancer at an early stage when there is a good chance of successful treatment and full recovery. The drawback, however, is that screening will also result in some women being over-diagnosed - receiving a diagnosis of cancer that would not have led to death or sickness. Currently, it is not possible to tell who these women are, and they are therefore likely to have breasts or lumps removed and to receive unnecessary radiotherapy. The investigations, such as a biopsy, needed to reach a firm diagnosis can also cause harm.
Different research studies and reviews have produced different figures for the relative number of women who benefit from screening versus those potentially harmed. Hence, it is difficult to establish exactly how accurate the current screening programme is.
What is the breast screening programme?
The NHS Breast Screening Programme screens around 1.6million women a year. Women aged 50 to 70 years of age, who are registered with a GP, are automatically invited for screening every three years. In 2012, an extension to the programme is being introduced by conducting a large trial where women aged between 47 and 73 will be invited to take part in the study.
Screening takes place at a special clinic or mobile breast screening unit where a mammogram (X-ray of the breast) is taken by a female health professional. This is then studied to look for any abnormalities. The aim is to find breast cancer at an early stage, when any changes in the breast would be too small to feel and when there is a good chance of successful treatment and full recovery.
The main treatments for breast cancer are surgery (removing a lump or the entire breast), radiotherapy, chemotherapy, hormone therapy and biological therapy. Patients may have one of these treatments or a combination.
How will the review be carried out?
The independent review will be led by Professor Richards and Harpal Kumar, chief executive at Cancer Research UK. Professor Richards says they are seeking independent advisers for the review who have never previously published on the topic of breast cancer screening. The letter did not give any indication of how long the review might take.
- Bewley S. The NHS breast screening programme needs independent review. BMJ 2011; 343:d6894
- Richards M. An independent review is under way. BMJ 2011; 343:d6843