Abstract P5-14-14: Benefit of Metallic Marker for Tumor Localization in Breast Cancer Patients Treated with Breast Conservative Surgery after Neoadjuvant Treatment. Comparative Study of Tumor Localization Markers

Abstract

Abstract Background: One of the benefits of neoadjuvant chemotherapy (NAC) is its ability to convert patients ineligible for breast conservative treatment (BCT) to be candidates for this treatment. The key to surgical planning for BCT after NAC is tumor localization. Tumor marking prior to NAC can be performed using skin tattoo or metallic marker. The objective of this study is to compare both types of tumor localization and to assess which technique improve BCT in achieving a complete resection while preserving the cosmetic outcome in patients with breast cancer after NAC. Material and Methods: One hundred and forty nine patients with breast cancer treated with BCT after NAC between 1999 and 2009 were eligible for the study. The skin tattoo group (TG) included 118 patients. The size and position of the tumor mass was marked on the skin surface with a China ink tattoo. The metallic marker group (MG) included 31 patients. The metallic marker was implanted in the center of the tumor under mammogram, ultrasound or MRI guidance. Both markers were placed before starting NAC. After completion of NAC a multidisciplinary team evaluated the cases for BCT. Clinicopathological data, volume of tumor excised, volume of lumpectomy, and margins statuses were analyzed and comparisons made between patients in the TG and the MG. Results: Median age of the patients in the TG was 54 years (range, 36-84) and 55 years (range 34-82) in the MG. Clinical stage was similar between groups, patients in TG had 53,4 % stage IIA, 25,4 % stage IIB and 15,3 % stage IIIA and in the MG 29 % stage IIA, 32,3 % stage IIB, 25,8 % stage IIIA and 9,7 % stage IIIB. Mean tumor volume was 15,9 cm3 in the TG and 28 cm3 in the MG (p=0,051). After NAC treatment, 63 patients (53%) in TG and 14 patients (45 %) in MG had a complete clinical response (P>0,5); partial clinical response was found in 53 patients (44 %) in TG and in 17 patients (54 %) in the MG (P>0,5). Pathological response was complete in 33 patients (28%) in TG and in 10 patients (32 %) in MG (p=0,3); and partial in 72 patients (61 %) in TG and 20 patients (64 %) in MG (p=0,3). Mean pathological tumor volume was not statistically significant between groups (5 cm3 in TG and 15 cm3 in MG). Lumpectomy volume was bigger in the TG (370 cm3 vs. 330 cm3, P<0,004). There were no statistically significant differences when comparing margin status and frequency of second surgeries for positive margins. Discussion: Lumpectomy in patients with metallic marker in the tumor after NAC allows lower excision of breast tissue without compromising margins. Having similar pathologic complete and partial response between groups, skin tattoo in patients with BCT after NAC leads to excise larger volume of tissue adding no benefits to the surgery. With the increasing pathologic complete responses with neoadjuvant treatments, patients who are candidates for BCT after NAC will benefit from marking the tumor with metallic markers prior to NAC. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-14-14.