Abstract P3-11-09: Body Mass Index (BMI) and Survival: A Retrospective Review of Women with Triple Negative Breast Cancer (An Update)

Abstract

Abstract Body Mass Index (BMI) has been reported as a risk factor for recurrence and decreased survival in women with breast cancer. At the Inter-American Breast Cancer Conference we presented data showing the effect BMI has on overall survival in women with triple negative breast cancer (TNBC). Here we present an update of this data which to our knowledge is the only study addressing the effect BMI has on outcomes in TNBC. We conducted a retrospective review of 170 patients with TNBC seen at the University of Miami Sylvester Comprehensive Cancer Center and Jackson Memorial Hospital between December of 1999 and April 2010. Charts were reviewed looking at BMI at the time of diagnosis and overall survival defined as date of last contact or date of death when known. 163 patients were included in the study. BMI was defined as normal (BMI 18.5-24.9) and overweight or obese (25 or greater). The average age at diagnosis was 50.96 years with a mean OS of 44.67 months. 21 patients (13%) had stage I disease, 61 (37.4%) had stage II disease, 81 (49.6%) had stage III disease. In patients with stage I disease 33% had a normal BMI with a mean OS of 51.7 months. 67% were overweight or obese with a mean OS of 60.2 months. In patients with stage II disease 33% had a normal BMI with a mean OS of 30.8 months. 67% were overweight or obese with a mean OS of 48.4 months. In patients with stage III disease 28% had a normal BMI with a mean OS of 37.2 months. 72% were overweight or obese with a mean OS of 43.1 months. Survival in patients with TNBC does not appear to be negatively impacted by the patients BMI at diagnosis. While not statistically significant (p=0.274) patients with stage I TNBC that were overweight or obese tended to have an increased OS compared to those with a normal BMI. In patients with stage II disease there was a statistically significant (p=0.010) increase in OS in overweight or obese patients compared to those with a normal BMI. In the patients with stage III disease there was no significant difference in the OS (p=0.458) between patients with a normal BMI and those that were overweight or obese. Our study shows that increased BMI at the time of diagnosis may have a positive impact on OS in patients with TNBC. Overweight and obese patients with stage I and II TNBC have an increased OS compared to those with a normal BMI. In those with stage II disease the difference was statistically significant. Although this study was limited by small sample size, if confirmed, it might suggest a relationship between obesity and survival in TNBC. Further studies are needed to evaluate these findings. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-11-09.