Ideal breast volume resection during wide local excision: Is it ∏ in the sky?

Abstract

91 Background: Despite advances in imaging and pre-operative work-up, there is significant variability in breast volume excision, margin positivity and re-excision rates in wide local excision (WLE) surgery. Suggested ideal resection volumes and benchmarks for maximal % breast volume excision have been suggested (Krekel N, Zonderhuis B, Muller S et al (2011). Excessive Resections in Breast Conserving Surgery A Retrospective Multicentre Study. The Breast Journal 17 (6): 602-609). This study assessed whether there was much difference between actual and expected breast specimen volumes, allowing for tumour size variation. Methods: A retrospective review was undertaken of symptomatic patients undergoing WLE in a single breast surgeon’s practice between May 2011 and May 2013 at a designated breast cancer centre. Patients with DCIS were not included. Modified Krekel optimal resection volumes (ORV) [4/3 π (r+1.0cm)3] were estimated to include 1.0cm, 1.5cm and 2.0cm macroscopic margins. Breast volume was calculated using Katariya and Kalbhen mammographic formulae. Excess resection was defined as the difference between total specimen and optimal specimen volume. Results: 50 consecutive patients, mean age 63 years (range 38-88), mean BMI 28.1 ±4.8, mean tumour size 24.0 ±11.5cm3 were studied. Of the 50 patients 44/50 (88%) had a palpable tumour. 52% had T2 tumours, 68% had associated DCIS and 32% were node positive. Mean specimen weight was 78.6g ±1. Mean optimal and actual breast resection volumes were 42.6 ±37.3 cm3and 160 ±102.4 cm3; 6/50 had positive margins leading to re-excision in 4. The mean breast and specimen resection volumes were 815 ±327.4cm3 and 225 ±153.8 cm3 resulting in a mean percentage breast volume excision of 19.3 ±99%. Potential excess resection in 48/50 patients with a mean excess resection volume of 182.7 ±145 cm3. Conclusions: This study identified the opportunity to improve consistency in the volume of breast resected. Determining ideal volume resection should be part of patient surgical oncological planning.