No ‘cure’ within 12 years of diagnosis amongst breast cancer patients who are diagnosed via mammographic screening: women diagnosed in the West Midlands region of England 1989-2011
Menée en Angleterre à partir de données portant sur 19 800 patientes âgées de 50 à 70 ans et atteintes d'un cancer du sein invasif non métastatique diagnostiqué entre 1989 et 2011 dans le cadre d'un dépistage par mammographie, cette étude évalue la survie et la part de la population "guérie" (durée de suivi : 12 ans)
Background : We have previously reported that there is little evidence of population ‘cure’ amongst two populations of women diagnosed with invasive breast cancer. ‘Cure’ has not yet been examined in the context of screen-detection.
Patients and methods : We examined cancer registry data on 19,800 women aged 50-70, diagnosed with a primary, invasive, non-metastatic breast cancer between 1 April 1989 and 31 March 2011 in the West Midlands region of England, linked to Hospital Episode Statistics (HES) and the National Breast Screening Service (NBSS). Follow-up was complete on all women up to 31 July 2012. Analyses were stratified by screening status, age, tumour stage, deprivation and ethnicity. We estimated net survival for the whole cohort and each subgroup. Population ‘cure’ was evaluated by fitting flexible parametric log-cumulative excess hazard regression models in which the excess hazard of breast cancer death was assumed to be equal to zero after a given follow-up time.
Results : There was an overall lack of evidence for ‘cure’. Across all subgroups examined the general pattern was that of a continuous decrease in net survival over time, with no obvious asymptotic tendency within 12 years of follow-up. Model-based analyses confirmed this observation.
Conclusions : Despite dramatic improvements in survival over past decades, diagnosis with breast cancer remains associated with a small but persistent increased risk of death for all groups of women, including those whose cancer is detected asymptomatically. These findings are unlikely to be due to methodological inadequacies. Communication of these long-term consequences of breast cancer amongst women recently diagnosed and to those considering undergoing screening should take due consideration of these patterns.
Annals of Oncology , résumé, 2016