Effectiveness of Carbon Localization for Invasive Breast Cancer: An Institutional Experience.

Introduction: The final oncological and aesthetic results of breast-conserving surgery (BCS) are influenced by the precise localization of breast cancer (BC) tumors and by the quality of the intraoperative margin assessment technique. This study aimed to assess the effectiveness of the carbon localization (CL) technique by determining the success rate of BC identification and the proportion of adequate complete resection of BC lesions. Methods: We conducted a cross-sectional retrospective study of patients treated with primary BCS for invasive BC who underwent CL of their BC lesion at the Jules Bordet Institute between January 2015 and December 2017. Descriptive statistics with categorical and continuous variables were used. The success rate of tumor identification and the rate of adequate excision were calculated using the test of percentages for independent dichotomous data. Results: This study included 542 patients with 564 nonpalpable BC lesions. The median pathological tumor size was 12 mm. Of these, 460 were invasive ductal carcinomas. Most of the tumors were of the luminal subtype. CL was performed using ultrasound guidance in 98.5% of cases. The median delay between CL and surgery was 5 days, with 46% of the patients having CL one day before surgery. The lumpectomy weighed 38 g on average, with a median diameter of the surgical sample at 6 cm and a median volume of 44 cm3 (6-369). One-stage complete resection was successfully performed in 93.4% of cases. In 36% of cases, an intraoperative re-excision was performed, based on intraoperative macroscopic pathological margin evaluation. The tumor was identified in 98.9% of cases in the breast surgical specimen. Conclusion: This study demonstrated high success rates for BC tumor identification (99%) and one-stage complete resection (93.4%) after BCS and CL. These results show that CL is an effective, simple, and inexpensive localization technique for successful excision of BC lesions during BCS.

The impact of breast MRI workup on tumor size assessment and surgical planning in patients with early breast cancer.

BACKGROUND: The size and focality of the primary tumor in breast cancer (BC) influence therapeutic decision making. The purpose of this study was to evaluate whether preoperative breast magnetic resonance imaging (MRI) is helpful for the assessment of tumor size and surgical planning in early BC. METHODS: We performed a retrospective review of a prospectively collected database of 174 patients treated at a single institution for invasive BC who had complete documentation of the tumor size from mammography (MMG), ultrasonography (US), and MRI. RESULTS: A total of 186 breast tumors were analyzed. Mean tumor size varied by imaging method: 14.7 mm by MMG, 13.8 mm by US, and 17.9 mm by MRI. The concordance between breast imaging techniques (BIT) and final pathology with a cutoff ≤ 2 mm was 34.8% for MRI, 32.1% for US, and 27.2% for MMG. US and MMG underestimated while MRI and MMG overestimated the real tumor size. Concordance was the same in premenopausal women for MRI and US at 35%, while concordance was higher in postmenopausal women for MRI. Correlations between size determined by BIT and histopathological size were best with MRI (0.59), compared to US (0.56) or MMG (0.42). Intrinsic subtypes of BC had different concordances according to imaging method, but no significant associations were found. MRI examination revealed additional lesions in 13.8% of patients, 69% of these lesions were malignant. MRI changed the surgical plan in 15 patients (8.6%), and the rate of mastectomy increased by 6.9%. CONCLUSIONS: MRI estimates BC tumor size more accurately than US or MMG, but a significant overestimation exists. Complementary MRI examination improved the concordance for tumor size between BIT and final pathology in 16.7%. MRI did not alter surgical planning for most patients and allowed more appropriate treatment for 8% of them.