The report, commissioned by Cancer Research UK and the UK Department of Health, reviews the benefits and harms of breast cancer screening. It concludes that breast screening in the UK reduces breast cancer mortality by about 20% in women invited for screening, based on 11 randomized controlled trials (RCTs) with 13 years of follow-up. However, this benefit must be balanced against the risk of overdiagnosis, which refers to cancers detected by screening that would not have become clinically apparent in a woman's lifetime without screening. The report estimates that about 11% of cancers diagnosed in women over their lifetime are overdiagnosed, and 19% of cancers diagnosed during the screening period. These figures are based on limited data and are subject to uncertainty. The report also notes that the absolute benefit of screening is significant, with one breast cancer death prevented for every 235 women invited to screening. However, the risk of overdiagnosis is higher, with about three overdiagnosed cases for each breast cancer death prevented. The report acknowledges that the benefits of screening and improvements in cancer treatment are independent, and that the benefits of screening remain relevant despite advances in treatment. The report concludes that breast screening in the UK provides significant benefits in reducing breast cancer mortality, but it also highlights the risks of overdiagnosis and unnecessary treatment. The panel recommends that women who choose to be screened should be aware of the potential benefits and harms, and that the decision to screen should be made with an understanding of these risks. The report also emphasizes the importance of clear communication of the benefits and harms of screening to women, and the need for further research to better understand the long-term effects of screening.The report, commissioned by Cancer Research UK and the UK Department of Health, reviews the benefits and harms of breast cancer screening. It concludes that breast screening in the UK reduces breast cancer mortality by about 20% in women invited for screening, based on 11 randomized controlled trials (RCTs) with 13 years of follow-up. However, this benefit must be balanced against the risk of overdiagnosis, which refers to cancers detected by screening that would not have become clinically apparent in a woman's lifetime without screening. The report estimates that about 11% of cancers diagnosed in women over their lifetime are overdiagnosed, and 19% of cancers diagnosed during the screening period. These figures are based on limited data and are subject to uncertainty. The report also notes that the absolute benefit of screening is significant, with one breast cancer death prevented for every 235 women invited to screening. However, the risk of overdiagnosis is higher, with about three overdiagnosed cases for each breast cancer death prevented. The report acknowledges that the benefits of screening and improvements in cancer treatment are independent, and that the benefits of screening remain relevant despite advances in treatment. The report concludes that breast screening in the UK provides significant benefits in reducing breast cancer mortality, but it also highlights the risks of overdiagnosis and unnecessary treatment. The panel recommends that women who choose to be screened should be aware of the potential benefits and harms, and that the decision to screen should be made with an understanding of these risks. The report also emphasizes the importance of clear communication of the benefits and harms of screening to women, and the need for further research to better understand the long-term effects of screening.