Accuracy of preoperative imaging estimates: Opportunities to de-escalate surgery for early invasive breast cancer.

BACKGROUND:There is current concern for overtreatment of breast cancer and rising mastectomy rates. This study compared preoperative imaging size (PIS) to postoperative pathology sizes (PPS) with a view to identifying opportunities to de-escalate surgery. METHODS:Patients having surgery from 2013 to 2017 for first invasive breast cancers were identified and PIS was compared to PPS looking at correlation and concordance. Associated clinical features were evaluated by regression models stratified by clinical T stage. RESULTS:We identified 1512 tumors among 1502 patients. Ultrasound, mammogram, and MRI correlated to PPS with increasing discordance with increasing PIS. Ultrasound underestimated T1 and T2 tumors, and mammogram underestimated T1 tumors and overestimated T3 tumors. For T1 and T2 tumors ultrasound had the highest concordance with PPS. CONCLUSION:Patients can be reassured that imaging size can be used dependably by surgeons to plan lumpectomy for clinical T1 tumors. For larger tumors, overestimation by PIS should be considered in surgical planning.