Fabiola Giudici1,2, Marina Bortul3,4, Elena Clagnan5, Stefania Del Zotto6, Antonella Franzo7, Livia Giordano8, Michele Gobbato6, Donella Puliti9, Diego Serraino6, Antonella Zucchetto6, Loris Zanier5, Fabrizio Zanconati3,10, Lauro Bucchi11. 1. Unità di biostatistica, epidemiologia e sanità pubblica, Università di Padova. 2. Unità di biostatistica, Dipartimento di scienze mediche, Università degli Studi di Trieste. 3. Dipartimento di scienze mediche, Università degli Studi di Trieste. 4. Dipartimento di chirurgia generale, Azienda sanitaria universitaria integrata di Trieste. 5. Servizio epidemiologico e flussi informativi, Azienda regionale di coordinamento per la salute, Regione autonoma Friuli Venezia Giulia, Udine. 6. Registro tumori del Friuli Venezia Giulia, Struttura operativa complessa (SOC) di epidemiologia oncologica, Centro di riferimento oncologico di Aviano (CRO) IRCCS, Aviano. 7. Area promozione della salute e prevenzione, Direzione centrale salute, politiche sociali e disabilità, Regione autonoma Friuli Venezia Giulia, Udine. 8. Unità di epidemiologia dei tumori, Centro di riferimento per l'epidemiologia e la prevenzione oncologica in Piemonte, Torino. 9. Unità di epidemiologia clinica, Istituto per lo studio, la prevenzione e la rete oncologica (ISPRO), Firenze. 10. Anatomia e istologia patologica, Azienda sanitaria universitaria integrata di Trieste. 11. Registro tumori della Romagna, Istituto scientifico romagnolo per lo studio e la cura dei tumori (IRST) IRCCS, Meldola, Forlì; lauro.bucchi@irst.emr.it.
Abstract
OBJECTIVES: to evaluate the incidence of advanced-stage breast cancer (BC) - an early surrogate indicator of effectiveness of mammography screening - among women who attended the Friuli Venezia Giulia (FVG) Region (Northern Italy) screening programme compared to women who did not attend. DESIGN: retrospective cohort study. Women invited to the first screening round (2006-2007) were identified from the database of the programme. The cohort was record-linked to the archive of women invited to the second round (2008-2009). The definition of attendance to screening was based on attendance to at least one of the two rounds. The incidence of BC was assessed through record linkage with the FVG cancer registry using an anonymous univocal identifier (end of follow-up: 31st December 2013). Three distinct definitions of advanced stage were used: pT2 or greater (pT2+), positive lymph nodes (pN+), and TNM stage II or greater (stage II+). SETTING AND PARTICIPANTS: organized mammography screening programme for women aged 50-69 years in the five regional healthcare districts. MAIN OUTCOME MEASURES: incidence rate ratio (IRR) between attenders and non-attenders, adjusted for age and deprivation index, with 95% confidence interval (95%CI). RESULTS: the cohort included 104,488 attenders and 49,839 non-attenders. During follow-up (median duration 84 months), 2,717 invasive BCs were diagnosed among attenders and 1,149 among non-attenders. Total incidence rate was 13% higher among attenders (IRR 1.13; 95%CI 1.05-1.21). These, conversely, had a 36% lower rate of pT2+ BC (IRR 0.64; 95%CI 0.56-0.72), a 13% lower rate of pN+ BC (IRR 0.87; 95%CI 0.78-0.98), a 22% lower rate of stage II+ BC (IRR 0.78; 95%CI 0.70-0.87), and a 32% lower rate of mastectomy (IRR 0.68; 95%CI 0.60-0.78). CONCLUSIONS: attenders had lower incidence rates of advanced-stage BC. This early effect is suggestive of a future impact of the screening programme on BC mortality.
OBJECTIVES: to evaluate the incidence of advanced-stage breast cancer (BC) - an early surrogate indicator of effectiveness of mammography screening - among women who attended the Friuli Venezia Giulia (FVG) Region (Northern Italy) screening programme compared to women who did not attend. DESIGN: retrospective cohort study. Women invited to the first screening round (2006-2007) were identified from the database of the programme. The cohort was record-linked to the archive of women invited to the second round (2008-2009). The definition of attendance to screening was based on attendance to at least one of the two rounds. The incidence of BC was assessed through record linkage with the FVG cancer registry using an anonymous univocal identifier (end of follow-up: 31st December 2013). Three distinct definitions of advanced stage were used: pT2 or greater (pT2+), positive lymph nodes (pN+), and TNM stage II or greater (stage II+). SETTING AND PARTICIPANTS: organized mammography screening programme for women aged 50-69 years in the five regional healthcare districts. MAIN OUTCOME MEASURES: incidence rate ratio (IRR) between attenders and non-attenders, adjusted for age and deprivation index, with 95% confidence interval (95%CI). RESULTS: the cohort included 104,488 attenders and 49,839 non-attenders. During follow-up (median duration 84 months), 2,717 invasive BCs were diagnosed among attenders and 1,149 among non-attenders. Total incidence rate was 13% higher among attenders (IRR 1.13; 95%CI 1.05-1.21). These, conversely, had a 36% lower rate of pT2+ BC (IRR 0.64; 95%CI 0.56-0.72), a 13% lower rate of pN+ BC (IRR 0.87; 95%CI 0.78-0.98), a 22% lower rate of stage II+ BC (IRR 0.78; 95%CI 0.70-0.87), and a 32% lower rate of mastectomy (IRR 0.68; 95%CI 0.60-0.78). CONCLUSIONS: attenders had lower incidence rates of advanced-stage BC. This early effect is suggestive of a future impact of the screening programme on BC mortality.
Entities:
Keywords:
breast cancer; screening; mammography; cohort study; tumour stage.