Treatment patterns and costs of metastatic triple negative breast cancer (mTNBC) in US women: A retrospective cohort study of first-line chemotherapy

Background: TNBC disproportionally affects younger women and is the leading cause of cancer-related deaths in women under 40. Treatment burden likely has a greater impact in younger women given employment and/or parental status. Little is known about treatment-related healthcare utilization, costs, or absenteeism or disability in women with mTNBC. This study describes real-world treatment patterns and the economic burden of mTNBC among patients treated with a first line (1L) chemotherapy. Methods: A retrospective cohort analysis of IBM MarketScan(R) Commercial and Medicare Supplemental Claims Databases was conducted. The analysis included adult female patients diagnosed with mTNBC who initiated 1L therapy from 1/1/2011 - 9/30/2017. Patients were continuously enrolled with medical and pharmacy benefits \u003e 6 months prior to mTNBC diagnosis date and the start of 1L chemotherapy (index date) and for 3 mos after the index date. End of 1L was defined by treatment change, discontinuation (\u003e60-day gap), or inpatient death or hospice. Patient follow-up was from the index date to the end of continuous enrollment or the end of the study period, 12/31/2017. Baseline demographic, clinical characteristics and per patient per month (PPPM) healthcare utilization and costs were analyzed descriptively. Indirect productivity burden of mTNBC using employed patient’s absenteeism (ABS), short-term disability (STD), and long-term disability (LTD) are reported. All costs are 2017 US dollars. Results: 1,027 patients with mTNBC meeting eligibility criteria were identified. Median age was 55 years; 69.5% of women were ages 45 - 64. Mean Charlson Comorbidity Index score was 8.8. Of the 27 1L treatments observed, the 3 most common were cyclophosphamide/doxorubicin (44.7%), cyclophosphamide/docetaxel (10.1%), and paclitaxel (7.7%). Median time to treatment post diagnosis was 27 days. Observed median follow-up time was 271 days; 13.2% of patients remained on 1L chemotherapy to end of follow-up. Mean duration of 1L treatment was 86 days (SD, 67 days); 69.2% of patients had a change in 1L treatment. For all-cause healthcare utilization during 1L, 11.6% patients had an inpatient admission, 16.9% had an ED visit, and 98.0% had an outpatient visit, of which 80.7%, 52.7%, and 98.8% were breast cancer-related, respectively. Mean all-cause total healthcare costs and outpatient prescription costs were $17,727 (SD $13,701) and $10,861 (SD $10,136) PPPM, respectively. Of breast cancer-related treatments, all patients received chemotherapy, 4.9% received radiation therapy, 1.2% underwent breast cancer surgery, and 96.5% received supportive care. The mean total breast cancer-related treatment cost was $10,322 (SD $9,512) PPPM. At 6 months post-index, 56 patients (5.5%) had either ABS, STD, or LTD data eligibility. Of this subset, 4 (7.1%) patients had an ABS claim and missed an average of 245 work-hours and had a mean productivity loss of $6,472. STD and LTD claims were available for 14 (25.0%) and 4 (7.1%) patients who experienced an average of 63 and 76 work-days lost and a mean loss of $9,265 and $11,192, respectively. Conclusion: Patients with mTNBC continue to experience significant treatment burden. Moreover, though many therapies were observed, limited long term treatment options are available suggesting a need for a durable treatment options that also minimize the burden for patients. Citation Format: Ashley Tabah, Ronda Copher, David Huggar, Marc Tian, Sarah S. Mougalian. Treatment patterns and costs of metastatic triple negative breast cancer (mTNBC) in US women: A retrospective cohort study of first-line chemotherapy [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-08-09.