Longitudinal treatment patterns and adverse events (AEs) in younger patients (Pts) with metastatic triple-negative breast cancer (mTNBC): A real-world landscape analysis.
Kuderer, NM; Varghese, D; Hill, K; Lyman, GH; Botteman, M
Published in: Journal of Clinical Oncology
e12562 Background: While no uniform standard of care exists for mTNBC, conventional chemotherapy remains the treatment mainstay. This retrospective analysis of U.S. commercial claims data was conducted to characterize real-world longitudinal chemotherapy treatment patterns and predictors of AEs in mTNBC. Methods: We assessed all pts with mTNBC aged 18-60 years starting first-line (1L) chemotherapy from 01/01/2011 to 12/31/2015 in the IMS LifeLink database, which does not report on investigational therapies. Longitudinal treatment patterns, treatment duration, and AEs were characterized by line-of-therapy (LOT). The primary and secondary endpoints were any AE and treatment duration. Multivariable logistic and Cox regression analyses were used to identify clinical risk factors for AEs and predictors of longer treatment duration, respectively. Results: 1,447 mTNBC pts receiving ≥1 LOT were identified (median [range] age, 51 [24-60] years), of which 54% received ≥2 and 8% ≥3 LOT. Combination therapy (combi-Tx) was used as 1L for 73%, second-line (2L) for 22%, and third-line (3L) for 32% of pts. The most common combi-Tx was cyclophosphamide/doxorubicin (1L: 40%; 2L: 5%), and carboplatin/gemcitabine in 3L (17%). The most common 1L and 2L monotherapies (mono-Tx) were taxanes (10% and 66%), and 3L capecitabine (13%). Median treatment duration for 1L to 3L was 56-58 days, and for combi- vs mono-Tx in 1L, 50 vs 71 days. The proportion of pts experiencing any AE was 34% during 1L, 38% during 2L, and 56% during 3L therapy. After adjusting for key confounders including Charlson comorbidity index, independent risk factors for AEs were later LOT, 3L vs 1L (OR = 3.20, 95%CI: 2.13-4.79), and younger age groups vs age 55-60 (OR = 1.94, 95%CI: 1.48-2.55). Additional analysis will assess independent predictors of treatment duration. Conclusions: This real-world study reveals considerable treatment heterogeneity and short treatment durations even with conventional combination chemotherapies. Among non-Medicare mTNBC pts, younger age is a risk factor for AEs possibly due to more aggressive therapies. More treatment options are needed for pts with mTNBC.
