Physician treatment of metastatic triple-negative breast cancer in the immuno-oncology era: a discrete choice experiment.

Aim: Guidelines list atezolizumab with nab-paclitaxel (ANP) as the preferred first-line (1L) therapy for metastatic triple-negative breast cancer (mTNBC) with PD-L1 expression ≥1%, but which clinical attributes impact ANP prescribing? Materials & methods: Medical oncologists participated in a discrete choice experiment (DCE) with four hypothetical mTNBC clinical scenarios to assess influences of: PD-L1 expression, menopausal status, prior adjuvant therapy and bulky liver metastases. Results: A total of 47% chose ANP in 1L irrespective of menopausal status, prior adjuvant therapy or tumor bulk. PD-L1 expression was the only attribute with a significant impact on ANP preference, with 69% choosing ANP for those with ≥1% expression versus only 26% for those with <1% (p < 0.00001). Conclusion: ANP choice for 1L mTNBC deviated from guidelines.