Positive margins (R1) risk factors in breast cancer conservative surgery

Abstract

Background

The primary goal in conservative breast cancer surgery is the complete excision of the tumor, but at the same time attempting to obtain a satisfactory postoperative esthetic result. The notion of “No Ink on Tumor” that indicates exclusively the presence of tumor cells on the inked surface of the surgical specimen is now the gold standard; however, the problem of the free margin is still a fundamental topic of debate that has not yet found a definitive solution.

Methods

Our retrospective analysis takes into account 1440 patients undergoing breast conservative surgery, from October 2004 to November 2018, all treated at the breast unit of our institution.

Results

Positive margins (R1) rate was 10.2% (147 cases out of 1440). Overall survival was 95% at 5 years and 89% at 10 years. No differences in mortality and local recurrence rate between R0 and R1 patients were found. Half of the R1 patients underwent secondary surgery with enlargement of margins, while in the other half we performed direct mastectomy. Among the analyzed variables, age, histological size, histological type, grading, multifocality, lympho-vascular invasion and lymph node status were significantly correlated with the R1 status. The multivariate analysis shows  the association of age and surgical technique (oncoplastic) with R1 status.

Conclusion

Further studies will allow the creation of a statistical model, for better pre-operative prediction of patients with higher risk of R1 and better selection of patients to be candidates for conservative surgery.

Keywords:

• breast-conserving therapy
• margin status
• age
• oncoplastic surgery

Ethics and consent statement

The authors declare that this is a retrospective study and it does not require approval by the Ethics Committee, but rather, only required approval by the Breast Unit Core Team Institutional Review Board (Professor Claudio Amanti, breast surgery, Professor Mattia Falchetto Osti, radiation oncology, and Professor Patrizia Pellegrini, oncology). Patient consent to review their medical records was not required by the board because all patients included in the study signed, at admission, a standard form about privacy and processing of personal data.

Disclosure

The authors report no conflicts of interest in this work.