Phenotypic characteristics of basal-like breast cancer in rural Appalachia

A72

Introduction: “Basal-like” breast tumors are triple negative tumors with a high nuclear grade that are typically found in younger patients, African-American women, and in patients with the BRCA mutation. Because our population in West Virginia is mainly rural and Caucasian, we wanted to better define the phenotype of breast tumors among women in rural Appalachia.
 Methods: We performed a retrospective chart review of 96 women diagnosed with ER negative, PR negative, HER-2/neu negative, and high nuclear grade breast cancers from 2000 to 2005. The hospital’s tumor registry was reviewed to determine tumor size, stage, patient’s age, race, menopausal status, Body Mass Indexes (BMI) and BRCA 1/BRCA 2 state. Parameters of the “basal-like” group were then compared to all patients who were diagnosed with infiltrating ductal carcinoma from 1999-2004.
 Results: Ninety-six patients meet the criteria for “basal-like” breast cancer. The distribution of "basal-like" tumors for age was significant for the 40-59 year old group (p= 0.01). Most patients presented with T2 tumors (57%) and the majority had stage II disease (61%, p = 0.01). 67% of the population was postmenopausal. Those with "basal-like" tumors were more likely to be overweight or obese (73%, p = 0.03) as indicated by higher BMI. There was one African-American patient that met all criteria (2.8%). Of the 7 patients with "basal-like" tumors who received BRCA testing, four were BRCA1 positive. When comparing the “basal-like” subgroup with all patients with infiltrating ductal carcinoma regardless of receptor status, there were no differences due to patient age, stage, or BMI.
 Conclusion: In contrast to previous findings, triple negative tumors were found more frequently in middle aged, postmenopausal Caucasian women with higher than average BMI. They were also more likely to present with advanced Stage II disease. The potential risk factor of obesity observed in triple negative cancer subtypes may prompt further research into overall breast cancer survival in obese women from rural areas.