Original Title: Cánceres de intervalo en el Programa de Detección Precoz del Cáncer de Mama

Authors' objectives: • Analyse the methodology used in early breast cancer detection programmes for the collection, classification, revision and analysis of interval cancers, in order to draw up proposals on this subject for the Early Breast Cancer Detection Programme of the Basque Autonomous Community. • Analyse the frequency and characteristics of interval cancers in the Early Breast Cancer Detection Programme of the Basque Autonomous Community. • Analyse the factors that could modify the reliability of the screening mammography and the effectiveness and potential utility of the different interventions proposed in order to reduce interval cancer rates in Early Breast Cancer Detection Programmes.

Authors' results and conclusions: In view of the data from the Basque Autonomous Community, we have concluded that the percentage of interval cancers in the Early Breast Cancer Detection Programme is within the desired levels proposed in the European Guidelines.

Authors' recommendations: It is not considered necessary to modify the current methodology of the Early Breast Cancer Detection Programme in the Basque Autonomous Community, neither with regard to the duration of the screening interval between two mammographies, nor to the introduction of a double reading, since in our context, these will provide little benefit and would mean an increase in the number of women without cancer being subjected to unnecessary tests. Recommendations:: 1) To use the classification proposed in the European Guideline for the valid classification of interval cancers. This is a valid classification in a large number of European countries as it enables comparisons to be made between different studies. 2) To make decisions regarding the mammography review methodology applicable to cases of interval cancer with the participation of the professionals who read the mammographies. 3) To introduce fields or variables in hospital and population Cancer Records in order to indicate whether the cancer has been diagnosed within the screening programme or whether it is an interval cancer. 4) To inform health service professionals that the use of oestrogen hormonal compounds during menopause and post-menopause may cause an increase in breast density leading to a reduction in the reliability of the mammograph, reducing its sensitivity and specificity; women themselves should be informed about this circumstance.

Authors' methods: • Analysis of the situation regarding interval cancers in the Basque Autonomous Community: interval cancers have been found in the Basque Autonomous Community among women screened by the Early Breast Cancer Detection Programme and a descriptive analysis has been made of these. The characteristics of interval cancers have been compared with cancers diagnosed by the Early Breast Cancer Detection Programme and with cases of cancer detected among the target population group in 1995, before the screening programme was instated. • The sensitivity of the screening tests of the Early Breast Cancer Detection Programme of the Basque Autonomous Community and the incidence rates of interval cancers have been estimated using the methodology proposed in the European Quality Guarantee Guides in Mammographic Screening. • Review of the bibliography.

Project Status: Completed

Year Published: 2007

URL for published report: https://www.euskadi.eus/contenidos/informacion/2007_osteba_publicacion/es_def/adjuntos/d_07-07_cancer_interval.pdf

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: Spain

Organisation Name: Basque Office for Health Technology Assessment

Contact Address: C/ Donostia – San Sebastián, 1 (Edificio Lakua II, 4ª planta) 01010 Vitoria - Gasteiz

Contact Name: Lorea Galnares-Cordero

Contact Email: lgalnares@bioef.eus

Copyright: <p>Basque Office for Health Technology Assessment, Health Department Basque Government (OSTEBA)</p>