Abstract P3-06-10: All-cause resource use among elderly breast cancer patients by receipt of human epidermal growth factor receptor 2-targeted therapy: An analysis of US national data 2006-2009

Abstract

Abstract BACKGROUND: There are few recent studies of all-cause resource use among elderly, newly diagnosed breast cancer (BC) patients by receipt of human epidermal growth factor receptor 2- (HER2-) targeted therapy. METHODS: Using linked Surveillance, Epidemiology, and End Results (SEER) and Medicare claims and enrollment data from 2006-2009, women aged 65+ years with an incident diagnosis of BC (index date) in 2007 and no prior history of any other cancer were identified and followed to evaluate all-cause resource use. Study patients were required to have continuous enrollment from 1 year before index (baseline period) through the end of the data window, disenrollment or death, whichever came first. Patients were classified as having received HER2-targeted therapy if they had any claim indicating trastuzumab or lapatinib following diagnosis. Demographics and all-cause resource use (hospitalizations, hospital days, outpatient visits, physician/provider services, prescription drug use, skilled nursing facility [SNF] care, home health care, hospice care, and durable medical equipment) were evaluated by receipt of HER2-targeted therapy (and by stage and age among those treated with HER2-targeted therapy). RESULTS: Among 11,238 female BC patients, 510 received HER2-targeted therapy (99.8% trastuzumab, 2.5% lapatinib) and 10,728 did not. Duration of follow-up was longer for the HER2- targeted therapy group (mean: 28.0 vs. 27.2 months, P = 0.06). Patients receiving HER2-targeted therapy were more likely to be hospitalized during follow-up (72.4% vs. 57.8%, P<0.01), though they had fewer mean per-patient-per-month (PPPM) hospital days (0.38 vs. 0.49, P<0.01). Almost all patients had an outpatient visit (100.0% and 97.3%, P<0.01) and a physician/provider visit (100.0% and 99.6%, P = 0.42) during follow-up, though patients receiving HER2-targeted therapy experienced greater PPPM service use (mean outpatient visits 1.08 vs. 0.69, P<0.01; mean physician/provider services 3.91 vs. 2.79, P<0.01). Similar proportions of patients had prescription drug (61.2% vs. 57.7%, P = 0.12), SNF care (14.3% vs. 14.5%, P = 0.95), and hospice care (both 8.2%, P = 1.00) use. Among patients treated with HER2-targeted therapy, those with later stage cancer were more likely to receive SNF (8.6% [Stage I], 11.8% [Stage II], 16.8% [Stage III], 27.8% [Stage IV]; P<0.01), home health (20.7%, 39.6%, 50.4%, 50.0%; P<0.01), and hospice care (0.0%, 0.5%, 15.1%, 31.5%; P<0.01), and had higher mean PPPM hospital days (0.23, 0.32, 0.47, 0.73; P<0.01). Patients treated with HER2-targeted therapy aged 75+ were more likely to be hospitalized (64.7% [65-69], 73.3% [70-74], 79.4% [75+]; P = 0.01) and to receive SNF (12.4%, 10.0%, 21.3%; P = 0.01), home health (31.2%, 35.6%, 51.9%; P<0.01), and hospice care (5.3%, 4.4%, 15.6%; P<0.01). CONCLUSIONS: Patients receiving HER2-targeted therapy were more likely to be hospitalized than those not receiving HER2-targeted therapy, although with fewer mean PPPM hospital days. Outpatient and physician visits also were more frequent in the HER2-targeted therapy group. Among those receiving HER2-targeted therapy, resource use was higher among those diagnosed at later stages and advanced ages. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-06-10.