Breast cancer in elderly women: role of tumor characteristics in predicting axillary lymph node metastasis.

BACKGROUND The number of elderly women with breast cancer is increasing and will become a major health concern. Worldwide, nearly a third of breast cancer cases occurs in eldery women. Differences in the pathologic features of breast tumors in aging women have been described. Axillary lymph node metastasis (ALNM) is one of the most important prognostic factors in breast cancer patients. Some studies reported that tumor characteristics were related to axillary lymph node metastasis. AIM/OBJECTIVES The aim of this study was to identify tumor characteristics associated with axillary lymph node metastasis. METHODS This retrospective study concerned data of 96 cases of breast cancer in elderly women (≥75 years) collected from 2010 to 2013 at Salah Azaïz Institute of Tunisia. Patient's details including age at diagnosis, tumor size, lymph node status, tumor grade, hormonal receptor status and HER2 status were retrieved from the medical records. Patients were divided into 2 groups: ALNM-positive and ALNM-negative. RESULTS The median age of patients was 81 years (range, 75-96). The average tumor size was 3.59 cm (range, 1-11cm). The predominant histology was invasive ductal carcinoma (95%, n=96). The SBR grade II was the predominant histological grade (66.3%, n=67).The mean number of dissected lymph nodes was 15. 70.1% (n=47) of patients presented axillary lymph node metastasis. The distributions of molecular subtypes, tumor grade and lymphovascular invasion within the 2 groups were significantly different. Two variables were found to be significant in the univariate analysis. They included molecular subtypes and lymphovascular invasion. Molecular subtypes were highly associated with axillary nodal involvement and with an increasing risk of ALNM (p=0.001). Presence of lymphovascular invasion (p=0.02) was also a significant factor for axillary nodal disease. There was no significant difference between 2 groups with regard to age (p=0.480), histological type (p=0.543), tumor size (p=0.388), tumor grade (p=0.333), estrogen receptor (p=0.686), progesterone receptor (p=0.545), HER2 over expression (p=0.747) and Ki67 proliferation index (p=0.324). CONCLUSIONS Two independent predictors of ALNM were identified. lymphovascular invasion and molecular subtypes were the strongest predictors of ALNM. Further research should be conducted in order to help physicians in assessing axillary nodal condition in elderly women with breast cancer. [ABSTRACT FROM AUTHOR]