Abstract.A positive resection margin is one of the most significant risk factors for local breast cancer recurrence following breast-conserving surgery (BCS). Intraoperative specimen mammography (SMMG) is routinely used to evaluate the surgical margin at our institution. The aim of the present study was to assess the adequacy of SMMG for margin assessment. The patient cohort included 174 women who underwent BCS in 2006. The sensitivity and specificity of SMMG were assessed by comparing the margins assessed by histological and radiological methods. It was also examined whether the rate of positive histological margins was decreased by re-excision following SMMG evaluation. A total of 23 false-negatives and 6 false-positives were determined by SMMG. The sensitivity and specificity of SMMG margin assessment for patients with primary breast cancer were 20.6 and 94.6%, respectively. The positive predictive value was 50% and the negative predictive value was 82.2%. A subgroup analysis revealed that the sensitivity and specificity of SMMG in cases with ductal carcinoma in situ (DCIS) were higher compared with those in invasive ductal carcinoma. Furthermore, the positive histological margin rate was not affected by re-excision. Although the general usefulness of intraoperative SMMG was not proven, this procedure may be useful in specific cases, particularly those with DCIS and those diagnosed by stereotactic biopsy. A prospective study with exact criteria and a standard procedure is required.
IntroductionThe standard surgical treatments for breast cancer are breast-conserving surgery (BCS) and mastectomy. The essential purpose of BCS is to completely remove the cancer while maintaining the cosmetic appearance of the breast, which is important to the patients. Previous studies have reported that BCS followed by radiation had a similar outcome to that of mastectomy in terms of mortality rate (1-5). However, a positive margin and young age (<53-55) are significant risk factors for ipsilateral breast tumor recurrence (IBTR) (6-8). Moreover, a meta-analysis by the Early Breast Cancer Trialists' Collaborative Group showed that local recurrence affected survival rate (9). Recently, Moran et al (10) reported that the American Society of Radiation Oncology consensus guideline uses the results of a meta-analysis of margin width and IBTR. This guideline also indicated the optimal criteria for determining margin width in BCS. However, despite numerous previous studies, the criteria for intraoperative margin assessment in BCS have yet to be established. At our institution, intraoperative specimen digital mammography (SMMG) is used to assess the resection margins in all cases of BCS. The aim of the present study was to evaluate the usefulness of SMMG for achieving margin-free resection of breast tumors.
Patients and methods
Patients.A retrospective study of the medical records, pathological diagnosis and re-evaluation by SMMG of 426 breast cancer patients who underwent BCS at the Aichi Cancer Center Hospital (Nagoya, Japan) between J...