Method of primary breast cancer detection and the disease-free interval, adjusting for lead time
Menée à partir de données du registre néerlandais des cancers portant sur 21 391 femmes atteintes d'un cancer du sein diagnostiqué en 2005 ou entre 2006 et 2008 (âge : de 50 à 76 ans), cette étude évalue l'association entre la méthode de détection du cancer du sein (détection lors d'un examen de dépistage, détection clinique) et l'intervalle sans maladie (absence de récidive locorégionale, de métastase distante ou de cancer controlatéral) en prenant en compte le délai entre la date de détection du cancer détecté par examen de dépistage et la date à laquelle il aurait été diagnostiqué sans examen de dépistage
Background : Little is known about the impact of screen-detected breast cancer compared with clinically-detected breast cancer on the disease-free interval (i.e. free from locoregional recurrences, distant metastasis, contralateral breast cancer). Moreover, it is thought that most studies overestimate the beneficial effect of screening, as they do not adjust for lead time. We investigated the association between method of breast cancer detection and disease-free interval, taking lead time into account.
Method : Women, 50-76 years old, diagnosed with breast cancer between 2005-2008 were selected from the Netherlands Cancer Registry. Women diagnosed in 2005 were divided into screen-detected and clinically-detected cancer and had a follow-up of ten-years (2005 cohort). Women diagnosed in 2006-2008 were divided into screen-detected, interval, and non-screen-related cancer, and had a follow-up of five years (2006-2008 cohort). A previously published method was used to adjust for lead time. Analyses were repeated correcting for confounding variables instead of lead time.
Results : The 2005 cohort included 6,215 women. Women with screen-detected cancer had an improved disease-free interval compared to women with clinically-detected cancer (HR: 0.77, 95% CI: 0.68 to 0.87). The 2006-2008 cohort included 15,176 women. Women with screen-detected or interval cancer had an improved disease-free interval compared to women with non-screen-related cancer (HR: 0.76, 95% CI: 0.66 to 0.88; HR: 0.88, 95% CI: 0.78 to 0.99, respectively). Correcting for confounders instead of lead-time did not change associations.
Conclusion : Women with screen-detected cancer had an improved disease-free interval compared to women with a non-screen-related or clinically-detected cancer, after correction for lead time.
Journal of the National Cancer Institute , article en libre accès, 2022