e11629 Introduction: Ireland offers a socialized national breast cancer screening program (Breastcheck) to women between 50 and 65 years of age with the aim of reducing breast cancer mortality. Historical axillary staging for screen detected breast cancer has shown nodal positivity in 25% of cases. This study examines axillary nodal disease from the Irish national breast cancer screening program in the era of sentinel lymph node biopsy (SLNB). Methods: Patients with clinically and radiologically early stage screen detected breast cancer and negative axillae are offered therapeutic surgery with SLNB. We examined prospective Breastcheck data collected from 2006 and 2007. Results: 136,527 women attended for routine screening and from these 574 invasive breast cancers were detected. 55 (9.6%) were clinically/radiologically axillary node positive at diagnosis. 519 clinically node negative patients proceeded to therapeutic surgery with SLNB, 113 (22%) were found to have a positive SLNB. Overall nodal positivity was 29.3% in this asymptomatic population. We examined tumour characteristics, hormone profile and HER-2 status from the SLNB group and tumor size was the only factor significantly associated with a positive SLNB (20.1mm vs. 14.3mm, p, 0.01). Conclusions: SLNB accurately detects axillary nodal disease from a purely screen detected population. Based on historic data, SLNB is superior to axillary sampling in this population. No significant financial relationships to disclose.
Cost-effectiveness of abbreviated-protocol MRI screening for women with mammographically dense breasts in a national breast cancer screening program
