Shah, Harsh N.

Background and ObjectivesCurrent randomized controlled trials are investigating the outcomes of non‐surgical treatment for patients with ductal carcinoma in situ (DCIS). We sought to evaluate pre‐operative factors associated with no residual disease at definitive resection following a core needle biopsy (CNB) diagnosis of DCIS.MethodsEight hundred and thirty‐four operations for DCIS were performed at our institution between January 2004 and October 2014. We evaluated patient and biopsy tumor characteristics to determine pre‐operative factors associated with no residual disease at surgical resection using uni‐ and multivariable analyses.ResultsSixty‐nine patients (8%) had no residual disease on final pathology. On multivariable analysis, low‐ or intermediate‐grade lesions, <1 cm in size on mammography, and lesions where ≥90% of calcifications were removed correlated with finding no residual disease on final pathology, c‐statistic 0.84. Of the 14 patients with all three low‐risk factors, 36% had no residual disease on final pathology.ConclusionsAlthough our multivariable analysis performed well, its clinical utility would be limited as we were unable to identify a subset of patients with DCIS in whom the probability of finding no residual disease is low enough to consider routine use of non‐surgical management.