Aim: To determine whether the insertion of more than one localization wire for larger areas of malignant microcalcification reduces the need for re-excision.
Method: This is a retrospective study of 101 cases of malignant calcifications preoperatively marked by one or more wires. Surgical and histopathology data were obtained from hospital records. Mammograms and specimen radiographs were evaluated without knowledge of the eventual outcome, i.e., whether further surgery was required or not. All cases had a preoperative diagnosis of malignancy.
Result: In this study the group of patients in which two or more wires were inserted had mammographically larger lesions (p<0.000001) but did not have a greater chance of needing re-excision (p=0.822). Mammograms that demonstrated flecks of microcalcification outlying the main cluster were also more likely to require further surgery (p<0.01). Calcifications associated with high-grade ductal carcinoma in situ (DCIS) had three times the risk of requiring further surgery (p<0.01). However, as reported in other studies re-excision was not related to breast size (p=0.63) [Kollias J, Gill PG, Beamond B, Rossi H, Langlois S, Vernon-Roberts E. Clinical and radiological predictors of complete excision in breast-conserving surgery for primary breast cancer. Aust N Z J Surg 1998;68:702-6].
Conclusion: It was previously suggested that the risk of re-excision for DCIS is related to the size of the initial lesion [Cheng L, Al-Kaisi NK, Gordon NH, Liu AY, Gebrail F, Shenk RR. Relationship between the size and margins of ductal carcinoma in situ of the breast and residual disease. J Nat Cancer Inst 1997;89:1356-60]. However, in the present study larger clusters of microcalcification that have been 'bracketed' by two or more wires do not appear to have a greater requirement for re-excision. Grading of the malignant microcalcifications preoperatively may encourage the surgeon to take a wider margin. Careful examination of the mammograms at localization to include outlying flecks could help to reduce the need for further surgery.