Physician treatment preferences for metastatic triple negative breast cancer (mTNBC) in an era of immunotherapy.

Abstract

e13095 Background: TNBC accounts for 10-20% of all breast cancer and has poor prognosis. Guidelines now list atezolizumab with nab-paclitaxel (ANP) as preferred for mTNBC w/ PD-L1 expression > 1%. We sought to assess current mTNBC prescribing and sequencing preferences for first-line (1L), second-line (2L), and third-line (3L) therapy among U.S. community oncologists (c-oncs). Methods: C-oncs were presented 4 hypothetical mTNBC clinical scenarios (CS 1-4) via web-based survey. CS differed by PD-L1 expression, menopausal status, prior adjuvant therapy and nature of metastases (bulky liver, lung, bone) but were otherwise uniform in terms of being asymptomatic, BRCA negative, with identical response extent and duration of each line of therapy. Respondents selected their preferred treatment for 1L, 2L, and 3L in each CS in the following categories: single agent (SA) chemotherapy, combination chemotherapy (CC), or ANP. The proportion of c-oncs selecting each treatment approach per CS for each line of therapy was calculated. We describe these preference patterns and how these may deviate from current guidelines. Results: 47 c-oncs participated from across the U.S. (northeast = 23%, midwest = 28%, south = 32%, west = 17%): mean years in practice was 22.7 and mean number of mTNBC patients under treatment was 18.8. The proportion of c-oncs preferring SA, CC or ANP per CS per line of therapy is listed in the table. Deviations from guidelines include preferences for: 1L ANP despite PD-L1 < 1% (26% in CS 1 and 4); 1L CC (45%) in asymptomatic bone only disease (CS1); 2L CC (19-34%) in asymptomatic visceral metastases (CS 2, 3 and 4). The SA 2L (74%)/3L (90%) preferences: capecitabine (36% 2L; 18% 3L) and eribulin (24% 2L; 35% 3L). Gemcitabine + carboplatin was the preferred CC regimen in 2L (50%) and 3L (28%). Conclusions: There is deviation from current guidelines in the treatment preferences for mTNBC patients among c-oncs, specifically the preference for ANP in PD-L1 negative patients and CC in 2L and 3L for asymptomatic patients. [Table: see text]