Performance characteristics of specimen radiography for margin assessment for ductal carcinoma in situ: a systematic review

Abstract

Background: Reducing positive margin rate (PMR) and reoperation rate in breast-conserving operations remains a challenge, mainly regarding ductal carcinoma in situ (DCIS). Intra-operative margin assessment tools have emerged to reduce PMR over the last decades, including specimen radiography (SR). No consensus has been reached on the reliability and efficacy of SR in DCIS.

Objective: We performed a systematic literature review to assess the performance characteristics of SR for margin assessment of breast lesions with pure DCIS and invasive cancers with DCIS components.

Methods: A literature search was conducted for diagnostic studies up to April 2017 concerning SR for intra-operative margin assessment of breast lesions with pure DCIS or with DCIS components. Studies reporting sensitivity and specificity calculated using final pathology report as reference test were included. Due to improved imaging technology, studies published more than 15 years ago were excluded. Methodological quality was assessed using quality assessment of diagnostic accuracy studies-2 checklist. Due to clinical and methodological diversity, meta-analysis was considered not useful.

Results: Of 235 citations identified, 9 met predefined inclusion criteria and documented diagnostic efficacy data. Sensitivity ranged from 22 to 77% and specificity ranged from 51 to 100%. Positive predictive value and negative predictive value ranged from 53 to 100% and 32 to 95%, respectively. High or unclear risk of bias was found in reference standard in 5 of 9 studies. High concerns regarding applicability of index test were found in 6 of 9 studies.

Conclusions: The present results do not support the routine use of intra-operative specimen radiography to reduce the rate of positive margins in patients undergoing breast-conserving surgery for pure DCIS or the DCIS component in invasive cancer. Future studies need to differentiate between initial and final specimen margin involvement. This could provide surgeons with a number needed to treat for a more applicable outcome.

Keywords: Breast cancer; Breast-conserving therapy; Ductal carcinoma in situ; Specimen radiography; Surgical margin.