Risk of recurrence and economic burden of early-stage, triple-negative breast cancer in a U.S.-managed care setting.

e11563 Background: Triple-negative breast cancer (TNBC), characterized by absence of ER and PR expression and lack of HER2 overexpression, is a high-grade BC with an aggressive clinical course. Evidence of differences in recurrence and associated economic burden between TNBC and non-TNBC is lacking. Objective: To compare recurrence rate, healthcare utilization, cost between early-stage TNBC and non-TNBC. Methods: This retrospective study used the Impact Intelligence Oncology Management system linked with 1999-2009 managed care administrative claims and social security administration mortality data. Staging, ER, PR, and HER2 status were obtained at diagnosis; local/distant recurrence was identified from medical claims. Stage I-III TNBC and non-TNBC patients were followed from diagnosis to recurrence, disenrollment, or end of observation period. Risk-adjusted recurrence rate, healthcare utilization, and costs during the follow-up period were compared. Results: 1967 patients with stage I-III BC (403 with TNBC) were included. During the follow-up period, 289 (14.7%) had local/distant recurrence. TNBC patients were younger (54 vs 56 years, P<0.0001) and more likely to experience recurrence (21.6% vs 12.9%, P<0.0001; adjusted HR=2.11, P<0.0001) vs non-TNBC. In terms of adjusted annual healthcare utilization and costs, patients with TNBC had significantly higher numbers of hospitalizations (all-cause: 1.20 vs 0.90, P=0.001; cancer-related: 0.62 vs 0.47, P=0.004), hospitalization days (all-cause: 8.8 vs 4.97, P<0.0001; cancer-related: 4.2 vs 2.6, P=0.004), emergency room visits (all-cause: 1.45 vs 0.95, P=0.009; cancer-related: 0.62 vs 0.39, P=0.026). TNBC patients had significantly higher inpatient costs (all-cause: $9,154 vs $5,501; cancer-related: $5,632 vs $2,869; P<0.0001 for both), emergency room costs (all-cause: $303 vs $182, P=0.003; cancer-related: $240 vs $138, P=0.012), inpatient costs to payers (all-cause: $7,347 vs $4,241; cancer-related: $4,471 vs $2,438, P<0.0001 for both). Conclusions: Using actual patient records, this real-world study demonstrates that TNBC is associated with a higher recurrence rate, increased healthcare utilization and costs vs non-TNBC.