Effect of Interval Cancer and Screening Process on Survival and Disease-free Period in Breast Cancer

This is a multicenter retrospective cohort of women participating in breast cancer screening programs in Spain between 2000 and 2009, with a cancer diagnosed during the screening or between the screening interval (interval cancer), specifically true interval cancers and false negatives. The investigators obtained woman-related information (including breast density), tumor-related information (including tumor phenotype), and follow-up information (including relapses, second neoplasms and vital status at the end of follow up (June 2014)). The objective is to evaluate the survival and disease-free period of women participating in screening programs for breast cancer with a cancer diagnosed during the screening or an interval cancer, specifically true interval cancers and false negatives. This study is part of a broader project (CAMISS study), which also includes one prospective cohort (CAMISS Prospective cohort - Identifier in ClinicalTrials.gov: NCT02439554).