Survival of women with inflammatory breast cancer: A large population based study
A partir des données des registres américains des cancers portant sur 7 679 patientes atteintes d'un cancer inflammatoire du sein de stade III diagnostiqué entre 1990 et 2010, cette étude en population analyse l'évolution de la survie
Background : Our group has previously reported that women with inflammatory breast cancer (IBC) continue to have worse outcome compared to those with non-inflammatory breast cancer. We undertook this population based study to see if there have been improvements in survival among women with stage III IBC, over time. Patient and Methods : We searched the Surveillance, Epidemiology and End Results Registry to identify female patients diagnosed with stage III IBC between 1990 and 2010. Patients were divided into 4 groups according to year of diagnosis: 1990-1995, 1996-2000, 2001-2005 and 2006-2010. Breast cancer specific survival (BCSS) was estimated using the Kaplan-Meier method and compared across groups using the log rank test. Cox models were then fit to determine the association of year of diagnosis and BCSS after adjusting for patient and tumor characteristics. Results : 7,679 patients with IBC were identified of whom 1,084 patients (14.1%) were diagnosed between 1990-1995, 1,614 patients (21.0%) between 1996-2000, 2,683 patients (34.9%) between 2001-2005 and 2,298 patients (29.9%) between 2006-2010. The 2-year BCSS for the whole cohort was 71%. 2-year BCSS were 62%, 67%, 72%, and 76% for patients diagnosed between 1990-1995, 1996-2000, 2001-2005 and 2006-2010 respectively (p<0.0001). In the multivariable analysis, increasing year of diagnosis (modeled as a continuous variable) was associated with decreasing risks of death from breast cancer (HR=0.98, 95% CI: 0.97–0.99, p< 0.0001). Conclusion : There has been a significant improvement in survival of patients diagnosed with IBC over a two-decade time span in this large population based study. This suggests that therapeutic strategies researched and evolved in the context of non-inflammatory breast cancer have also had a positive impact in women with IBC.