Sentinel Lymph Node Metastasis in Invasive Lobular Carcinoma of the Breast

Abstract

ABSTRACTObjective: Invasive lobular carcinoma (ILC) of the breast makes up 5 to 15 percent of all invasive breast cancers. It has distinctive clinical andhistopathological features when compared to invasive ductal carcinoma (IDC). This study intends to describe factors influencing sentinel lymphnode (SLN) positivity in patients with “pure” ILC.Materials and Methods: Data of 105 patients, who were treated at a tertiary oncology center, with lobular carcinoma of the breast that weresubjected to SLN biopsy was probed retrospectively. Patients were categorized as ≤60 and >60 years of age, positive or negative for estrogen receptorand progesterone, tumor grade I, II and III, Ki67≤15% and >30%, lymphovascular invasion presence and the presence of multicentricity andmultifocality.Results: Mean age at the time of diagnosis was 52 (38-81). Mean tumor size was 2.7 cm (0.7-13cm). Univariate analyses revealed a significantrelationship between tumor size (≤2 cm vs >2cm) and metastasis in the SLN. This relation kept its significance in multivariate analyses. (p=0.013).Conclusion: With so many different characteristics from IDC, ILC is mostly a uniform tumor. In this study, tumor size was the only independentclinical parameter that was found related to SLN metastases.