Neoadjuvant Chemotherapy in Patients With Locally Advanced Breast Cancer. Factors Related to Ipsilateral Breast Recurrence in Patients Submitted to Conservative Surgery

INTRODUCTION: In patients submitted to neoadjuvant chemotherapy (NC), the breast conservative surgery (BCS) rates vary from 37 to 82%, but it occurs in 1.7% to 28% of patients with locally advanced breast cancer (LABC), which constitutes a sub-group of patients. One way to assess the safety of the BCS after NC is by analyzing recurrence rate. The tumor margins, the form of tumor fragmentation after NC and tumor characteristics are the main factors related to Ipsilateral Breast Tumor Recurrence (IBTR). MATERIAL AND METHODS: A retrospective study approved by the Ethics committee (112/2007) evaluating patients with LABC who were seen in the period from 01/2006 10/2009, and submitted to NC based on 4 cycles of doxorubicin + cyclophosphamide followed by 4 cycles of Docetaxel. BCS was considered when breast or skin was preserved, so this group represents patients submitted to quadrantectomy or skin sparing mastectomy. We evaluated factors related to the IBTR in univariate analysis. RESULTS: A total of 321 patients undergoing chemotherapy, 78 underwent BCS. The age ranged between 21-73 years (median 45.1 years). The clinical tumor size ranged from 1.4 to 9.0 cm (median 5.5 cm). The main histological type was invasive ductal carcinoma (92.3%). There are 6.4% in clinical stage II, 60.3% IIIa, 28.2% IIIb and 5.1% IIIb. Concerning immunohistochemistry expression, 57.7% had estrogen receptor positive, 52.6% progesterone receptor positive and 82.1% HER-2 negative. of the total, 19.2% (15) underwent skin sparing mastectomy and 80.8% quadrantectomy. 2 affected margins (2.6%) were observed. All patients underwent adjuvant radiotherapy and 47.7% to hormonal therapy. Follow-up ranged from 4.5 to 38.4 months (median 19.3 months). At the end of the study 9.0% were alive with disease, 3.8% died from the disease, 2% had lost the follow up, and the others were alive and without disease. The IBTR rate was 9.0%. Local recurrences were more frequent in patients with estrogen receptor negative (p = 0.02), progesterone receptor negative (p = 0.02), EC IIIA (p = 0.50), pT3 (p = 0.73), submitted to quadrantectomy (p = 0.62). The margin (p=0.78) did not influence the recurrence rate. Discussion:Tumor margins and tumor characteristics are the main factors related to IBTR. IBTR occurs 12.7% in patients with clear margins, 15% when the margin is smaller than 15mm and 20.3% positive margins. Besides large tumors and limited follow up, our study was unable to find differences related to margin, because of its low presentation in those cases. IBTR occurs in 0,8% of tumors luminal A and 7,1% of tumors basal-like, but there is no study evaluating that fact in LACB and NC. We observed higher IBTR in the absence of expression of hormonal receptor fact that makes our findings of particular interest. CONCLUSION: The rate of IBTR was acceptable, which justifies this therapy in selected patients. More studies are necessary to evaluate the role of biological characteristics of the tumor and its role in the margin on the LABC.