Abstract P1-09-07: Survival, Health Care Utilization and Cost after Recurrence among Patients with Triple Negative Breast Cancer in a U.S. Managed Care Setting

Abstract

Abstract Background: Triple negative breast cancer (TNBC) is characterized by the lack of expression of the genes for estrogen receptor, progesterone receptor or human epidermal growth factor recepter-2 and therefore it has a shorter recurrence-free interval. We compared the survival rates, health care costs and utilization of breast cancer recurrent patients who have triple negative versus no triple negative breast cancer. Methods: Analyses were conducted using Impact Intelligence Oncology Management (IIOM) (2002-2009) linked with United Health administrative claims. Patients were followed from the time of initial breast cancer diagnosis until death, disenrollment or end of the observation period. Continuous enrollment was required during the observation period. Staging and estrogen and progesterone receptors (ER/PR) and HER2 status were obtained at time of initial diagnosis. Patients’ age, region, cancer stage, and comorbid conditions were controlled for risk-adjusted comparison. A stratified log-rank test was used to determine the equality of survival functions. Cox regression was used for the risk-adjusted survival analysis. Health care resource use during the follow-up period after recurrence was modeled with negative binomial regression. Inverse probability weight adjusted generalized linear models were used to estimate risk-adjusted total health care costs. Results: The study included 289 recurrent breast cancer patients, out of which 87 (30%) had triple negative breast cancer. At time of recurrence, TNBC patients had similar age, plan, region, and cancer stage distribution relative to non-TNBC patients. During follow-up, TNBC patients had significantly lower survival rate (log-rank test P<0.001). After controlling for baseline differences, the overall mortality risk rates for TNBC recurrent patients were almost three times higher than non-TNBC recurrent patients (HR:2.84, p=0.056). The risk-adjusted annual number of hospitalizations was also higher for TNBC patients with a recurrent event (1.65 vs. 1.13, p=0.05). There were no differences in health care costs after recurrence between TNBC and non-TNBC patients. Conclusion: Although similar in health care costs, triple negative breast cancer is associated with higher mortality and number of hospitalizations after the recurrence of breast cancer. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-09-07.