Basal-like (BL) carcinoma, distinguished by the expression of keratins that are a characteristic of myoepithelial cells, is 1 of the 5 distinct subtypes of breast tumors identified by gene microarray technologies. BL cancers have been well described in women <40 years of age. However, little data exist about this carcinoma in older patients. Twenty-three BL breast cancer specimens from patients >40 years of age were evaluated. The study demonstrated that there is a subset of patients >40 years of age with breast cancers, manifesting features of BL carcinoma. There has been a significant increase in BL cancers among women >40 years of age having larger tumors and lymph node metastasis in comparison with younger women <40 years of age. This could be due to the tumor heterogeneity in BL cancers between the 2 age groups. BL cancer patients from all age groups require further investigation for BRCA-1, as well as gene microarray analysis to compare the gene expressions with those observed in the younger population.