Case Fatality in Breast Cancer: Relative Effect of Attendance at Breast Screening and Cancer Treatment

Abstract

ABSTRACT Aim: Invasive breast cancer is the second most common cause of cancer death among UK women. Although community breast screening has been shown to reduce breast cancer mortality, the relative effects of attendance at breast screening and improved treatment remain unclear.1 The aim of the study is to assess these relative effects on fatality from invasive primary breast cancer. Methods: A matched case-control study within the English National Breast Screening Programme was set up in the London region.2 Cases of invasive primary breast cancer death in 2008-09 were matched 1:1 to controls with breast cancer diagnosed within 6 months prior to the case diagnosis (age 47-89), known to be alive at the case death, and matched for date of birth and area of residence. All had been invited to breast screening at least once prior to first diagnosis. Cases and controls were compared with respect to screening attendance by conditional logistic regression adjusted for pathology, and treatment within 6 months of diagnosis. Results: The odds ratio (OR) for breast cancer fatality in women who attended at least one routine screen compared to never attenders was 0.41 (95% CI 0.30 - 0.55, p Conclusions: In women diagnosed with breast cancer, attendance at breast screening remained a significant protective factor for fatality from the disease after accounting for pathology and treatment; adjusting for treatment had little impact on the estimate. Potential biases remain to be investigated.