Recommendations for breast cancer screening – Author's reply

Abstract

László Tabár and Peter Dean, Martin Yaffe and colleagues, and Daniel B Kopans have used my commentary 1 Miller AB Final results of the UK Age trial on breast cancer screening age. Lancet Oncol. 2020; 21: 1125-1126 Summary Full Text Full Text PDF PubMed Scopus (7) Google Scholar on the UK Age trial as a means to comment adversely on the Canadian National Breast Screening Study. Tabár and Dean rely on the International Agency for Research on Cancer 2016 evaluation of breast screening 2 International Agency for Research on Cancer Working Group on the Evaluation of Cancer Preventive StrategiesBreast Cancer Screening IARC Handbooks of Cancer Prevention. Volume 15. International Agency for Research on Cancer, Lyon2016: 254 Google Scholar to support their arguments, yet that evaluation did not consider the Canadian National Breast Screening Study. Yaffe and colleagues were impressed with the 25% reduction in breast cancer mortality at 10 years of follow-up in the UK Age trial (relative rate 0·75 [95% CI 0·58–0·97]), but acknowledge that this was attenuated on longer follow-up (0·98 [0·79–1·22]). They dismiss our determination of overdiagnosis in the Canadian National Breast Screening Study, casting doubt on the efficiency of our follow-up, which was in fact based on record linkage with the Canadian cancer and death registries. Only Kopans refers to the UK Age trial 3 Duffy SW Vulkan D Cuckle H et al. Effect of mammographic screening from age 40 years on breast cancer mortality (UK Age trial): final results of a randomised, controlled trial. Lancet Oncol. 2020; 21: 1165-1172 Summary Full Text Full Text PDF PubMed Scopus (26) Google Scholar and suggests that the absence of a benefit from initiating mammography screening at age 40–41 years could be because single-view mammography was used in the trial. This suggestion is ironic, as single-view mammography was used in Tabár and colleagues' Two-County Swedish trial, 4 Tabár L Vitak B Chen TH et al. Swedish Two-County trial: impact of mammographic screening on breast cancer mortality during 3 decades. Radiology. 2011; 260: 658-663 Crossref PubMed Scopus (490) Google Scholar where a benefit of mammography screening in women from age 40 years was reported. Final results of the UK Age trial on breast cancer screening ageIn The Lancet Oncology, the findings from a 23-year follow-up of the UK Age trial are presented by Stephen Duffy and colleagues.1 No difference in mortality from breast cancer was found between the group that began yearly mammography screening at age 39–41 years until they entered the National Health Service (NHS) Breast Screening Programme at age 50–52 years, and a group that did not begin mammography screening until they entered the NHS Breast Screening Programme (126 deaths vs 255 deaths occurring after more than 10 years of follow-up; relative rate 0·98 [95% CI 0·79–1·22]; p=0·86). Full-Text PDF Open AccessRecommendations for breast cancer screeningDespite evidence confirming the benefits of detecting breast cancer before it becomes palpable, in his Comment, Anthony Miller1 advocates that women should not have mammography screening, but instead could wait until their breast cancers have grown large enough to become palpable. Contrary to his closing statement, Miller's argument against earlier diagnosis of breast cancer through mammography screening is not supported by the WHO recommendations, which review various methodologies available to bring care to patients as early as possible. Full-Text PDF Recommendations for breast cancer screeningIn his Comment on the UK Age trial, Anthony Miller1 stated that it could be argued that breast cancer screening with mammography should not be initiated at any age. We disagree with this assertion, given the overwhelming evidence from multiple randomised trials and observational studies showing the lifesaving benefits of mammography screening—benefits that have been acknowledged by guideline-setting bodies in several countries.2 Furthermore, recent publications have shown a reduced need for mastectomy, chemotherapy, and axillary dissection when breast cancers are detected by mammography screening. Full-Text PDF Recommendations for breast cancer screeningIn his Comment, Anthony Miller1 asserted that his trials showed “comparability of the study groups”. Although Miller states that women were randomly assigned in the Canadian National Breast Screening Studies, he did not mention that all women had a clinical breast examination before allocation and study coordinators with this information could assign women out of random order. Significantly more women with palpable, advanced cancers were allocated to the screening group than to the control group of the Canadian National Breast Screening Study-1. Full-Text PDF