Utilization of Tumor Markers for Intraoperative Specimen Radiography Does Not Decrease the Rate of Margin Positivity in Breast Conservation Surgery (BCS).

IntroductionMargin status after lumpectomy is crucial in determining risk of local recurrence. Current guidelines recommend "no ink on tumor" as adequate negative margins for invasive breast carcinoma. Still, up to 20% of patients may have positive margins and need re-excision. This study explored the use of a commercially available tumor marking system during specimen radiography and its effect on re-excision rates in breast conservation surgery.MethodsWith IRRB approval, a review was conducted of a prospectively collected cohort of 105 study patients and a retrospectively collected cohort of 92 control patients with invasive breast carcinoma undergoing breast conservation surgery. In the study group, lumpectomy specimens were labeled with clips from a commercial tumor marking system, followed by two-view radiography to assess the need for shave margins. The surgeon interpreted the radiograph, and, at their discretion, excised additional margins. A control group was managed by the same surgeons without the tumor marking system. Categorical variables were compared using Chi-Squared or Fisher's exact tests and continuous variables were compared using t-tests or Wilcoxon Rank Sum tests depending on their distribution.ResultsA total of 197 patients were divided into a study group (n = 105) and a control group (n = 92). The types of margin excision rates differed significantly between groups (P ≤ 0.0105). In the study group, the rates of selective and complete margin excisions were 39% and 7%, respectively, while 53% had no margins excised, as determined using the tumor marking system. In the control group, rates of selective and complete margin excisions were 42% and 21%, respectively, and 37% had no margins excised. Final pathology showed positive margins in 24% (study) vs 21% (control), with no significant difference between the groups (P ≤ 0.0810).ConclusionsThe tumor marking system did not decrease the rate of margin positivity compared to the control group. However, the study group demonstrated a significant decrease in the number of patients requiring selective or complete margin excision.