Treatment
➤ Patients with metastatic triple negative breast cancer with expression
of programmed cell death ligand-1 (PD-L1-positive) and no existing
contraindications may be offered the addition of immune checkpoint
inhibitor to chemotherapy (atezolizumab plus nab-paclitaxel or
pembrolizumab plus chemotherapy) as first-line therapy. (Strong
recommendation; EB-B-M)
➤ Patients with metastatic triple negative breast cancer without
expression of programmed cell death ligand-1 (PD-L1-negative)
should be offered single agent chemotherapy rather than combination
chemotherapy as first-line treatment, although combination regimens
may be offered for symptomatic or immediately life-threatening
disease for which time may allow only one potential chance for
therapy. (Strong recommendation; EB-B-M)
Practical Information: Patients may be offered either platinum- or non-platinum-
based regimens based on individualized patient and provider assessment of
preferences, risks, and benefits.
➤ Patients with metastatic triple negative breast cancer who have
received at least two prior therapies for metastatic disease
should be offered treatment with sacituzumab govitecan. (Strong
recommendation; EB-B-H)
➤ Patients with metastatic triple negative breast cancer with germline
BRCA1 or 2 mutations who have previously been treated with
chemotherapy in the neoadjuvant, adjuvant, or metastatic disease
setting may be offered an oral PARP inhibitor (olaparib or talazoparib)
rather than chemotherapy. (Strong recommendation; EB-B-M)
Practical Information: Small single-arm studies show that oral PARP inhibitor
therapy demonstrates high response rates in metastatic breast cancer encoding DNA
repair defects, such as germline PALB2 mutation carriers and somatic BRCA
mutations. It should also be noted that the randomized PARP inhibitor trials made
no direct comparison with taxanes, anthracyclines, or platinums. Comparative
efficacy against these compounds is unknown.
