The evidence for breast cancer screening in the UK is being reviewed amid controversy about the measure\'s effectiveness. The NHS says screening saves lives, but other researchers have argued that it may cause more harm than good. The national cancer director for England, Prof Mike Richards, announced in the British Medical Journal that he will lead a review. He said he was taking the \"current controversy very seriously\". When it comes to cancer treatment, earlier is better. Screening programmes for a range of cancers help doctors make a diagnosis sooner. But they also run the risk of false positives, diagnosing someone with cancer when they are healthy. Screening was introduced for breast cancer in 1988 in the UK and now offers tests to women, over the age of 50, every three years. In 2002, the World Health Organization\'s International Agency for Research on Cancer estimated that screening reduced deaths from breast cancer by about 35%. The NHS says 1,400 lives are saved through screening in England alone. However, the evidence has been questioned. A review of clinical trials involving a total of 600,000 women concluded it was \"not clear whether screening does more good than harm\". It said that for every 2,000 women screened in a 10-year period: one life would be saved, 10 healthy women would have unnecessary treatment and at least 200 women would face psychological distress for many months because of false positive results. The authors of that research labelled the NHS Breast Screening Programme\'s advice \"seriously misleading\". Professor of complex obstetrics at King\'s College London, Susan Bewley, has turned down screening. In a letter to Prof Richards last month, she said: \"The distress of overdiagnosis and decision making when finding lesions that might, or might not, be cancer that might, or might not, require mutilating surgery is increasingly being exposed.\" In response, Prof Richards said research suggested that up to two and a half lives were saved for every over-diagnosed case. He added that he would lead a review of the evidence to settle the ongoing controversy. \"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. \"I am fully committed to the public being given information in a format... that enables them to make truly informed choices.\" Prof Julietta Patnick, director of the NHS Cancer Screening Programmes, welcomed the review: \"The NHS Breast Screening Programme has always been based on the best and latest evidence. \"Where new information has suggested them, a number of changes have been made to the Programme, for example extending the screening age range and using digital mammography.\" The review will be led jointly by Prof Richards and Cancer Research UK. The director of health information at the charity, Sara Hiom, said: \"Women need more accurate, evidence-based and clear information to be able to make an informed choice about breast screening. \"The decision whether to be screened is a personal one, but that decision should be made with all of the potential harms and benefits fully explained.\" Breakthrough Breast Cancer\'s chief executive Chris Askew said: \"Breast screening is vital as it can detect breast cancer at the earliest possible stages when no other symptoms are obvious. \"The earlier breast cancer is picked up the better for the one in eight women who are diagnosed every year with this disease, as treatment options are more likely to be less aggressive and have successful outcomes.\"