Abstract P1-15-08: Comparison of Core Needle Biopsy and Surgical Specimens To Investigate the Percentage of Pre-Operative Ductal Carcinoma In Situ Diagnosis Who Were Found To Have Invasive Breast Cancer after Surgery at University Hospitals of Leicester (UHL)
Authors: T Mehta, Q Syed, I De Silva, K Lambert, S. Shokuhi
Journal: Cancer Research (2010)

Abstract Introduction: Ductal carcinoma in situ (DCIS) accounts for 25% of all breast cancer diagnosis. This study was carried out to investigate the percentage of patients at UHL who are diagnosed to have DCIS on core needle biopsy but found to have invasive cancer from the surgical specimen. In addition, we analysed how many of these patient went on to have further surgery for removal of residual invasive cancer and axillary staging. Method: Data of all patients who presented between 2008 and 2010 was retrospectively analysed. Clinical presentation, histology pre-and post-procedure, cancer grade, treatment methods, axillary node involvement and calcification were recorded. Results: A total of 177 patients with DCIS were recorded. The mean age was 61.1 years (range 31 — 102). The most common site of cancer was upper outer quadrant (28.2%). Majority of patients were identified through the screening programme (67.2%) as opposed to symptomatic presentation (32.8%). The most common procedure was Wide Local Excision (59.3%) followed by Mastectomy (31.7%). 9% of patients who had positive histology did not have any surgery. Post-procedure histology proved that the mean size of DCIS was 25.4mm and 62.7% was high grade. Most patients had no axillary node involvement and no malignant calcification (91.5% and 74.6% respectively). In 54 of 177 (30.5%) patients who were histopathologically diagnosed as DCIS by core needle biopsy, final diagnosis was changed to invasive carcinoma in surgical specimens The mean size of the invasive tumour in these patients was 13.4 mm and majority of the patients had grade 2 invasion (46.2%). Out of these 54 patients with new invasion, core biopsy results showed 31 patients (57.4%) had high grade DCIS, 10 patients (18.5%) had intermediate grade DCIS, 5 patients (9.2%) had low grade DCIS and 8 patients (14.8%) had unknown DCIS grade. Nineteen out of 54 patients (35.2%) went on to have further surgery after invasion was detected. Conclusion: The most common site was upper outer quadrant and majority of patients have been identified through the screening programme. Wide local excision was the most common surgical intervention. Our study showed almost 1/3 patients who were originally diagnosed with DCIS were found to have invasion post surgery at UHL and majority had high grade DCIS on core needle biopsy. This value is in keeping with the findings from previous studies[1]. However, only a small percentage of these patients went on to have further surgery. [1] Predictors of invasive disease in breast cancer when core biopsy demonstrates DCIS only. Dillon MF, McDermott EW, Quinn CM, O'Doherty A, O'Higgins N, Hill AD. Department of Surgery, St Vincent's University Hospital, Dublin, Ireland. J Surg Oncol. 2006 Jun 1;93(7):559- 63. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-15-08.