UPmémoires

English

Impact of the French organised breast cancer screening programme on early diagnosis and survival: A population based study from a cancer registry

Introduction: Breast cancer is the leading cause of cancer deaths in women worldwide. Organised screening has been implemented to improve this situation with an earlier detection of these tumours. However, the effectiveness of screening programmes is regularly challenged with controversies. The aim of this study was to evaluate the impact of organised breast cancer screening on early diagnosis and on survival in France, using a cancer registry-based population.

Methods: Women aged 50 to 74 years, with breast cancer diagnosed between 2008 and 2009 from the Poitou-Charentes cancer registry were included in this study. The individual data regarding organised screening were obtained from the screening facilities. Patient vital status was obtained until 31 December, 2013. Patient characteristics were compared between patients detected by organised screening with those who were not, using a chi-square or Fisher's exact test. Survival probabilities were estimated using the Kaplan–Meier method. Hazard ratios and their 95% confidence intervals were estimated using Cox proportional hazard models.

Results: This study included 1,891 patients. Patients detected by organised screening had lower tumour stage (p<0.001) and lower tumour grade (p=0.001) than patients detected by other means. Significant heterogeneity of detection means was found with the patient's place of residence (p=0.020). A better survival was found in patients with tumours detected by organised screening (HR: 0.28; 95% CI: 0.18–0.41). Tumour stage was the main variable impacting on survival in the univariate and multivariate analyses.

Conclusion: The important benefit of organised breast cancer screening on 5-years survival demonstrates the importance of promoting this French programme, especially in geographic areas with low participation rate.

Keywords : breast neoplasms, survival, mass screening, cancer registry.