Is PD-L1 Expression Predictive of Survival in Advanced Head/Neck Squamous Cell Cancer?
Posted: Monday, February 3, 2020
PD-L1 expression does not appear to be a prognostic indicator of survival in patients with recurrent or metastatic squamous cell carcinoma of the head and neck who are treated with standard-of-care chemotherapy, according to the retrospective SUPREME-HN study, published in the Journal of Translational Medicine. However, the researchers did find that PD-L1 expression varied substantially based on the primary tumor location. “PD-L1 expression may be positively or negatively prognostic when anatomic subsites within the head and neck are considered,” stated Sara I. Pai, MD, PhD, of Massachusetts General Hospital Cancer Center and Harvard Medical School, Boston, and colleagues.
In this international, noninterventional cohort study, archival tumor samples from 412 patients were analyzed using the VENTANA PD-L1 (SP263) assay. Patients were separated into cohorts based on tumor cell PD-L1 expression: ≥ 25% expression, 132 patients (32.0%); ≥ 10% expression, 199 patients (48.3%); and ≥ 50% expression, 85 patients (20.6%). Overall survival did not significantly differ across PD-L1 expression levels. Patients with PD-L1 expression ≥ 25% or < 25% of tumor cells had a median survival of 8.2 versus 10.1 months, and these findings were similar for patients with ≥ 10% and ≥ 50% PD-L1 expression.
The PD-L1 prevalence at tumor cells ≥ 25% was consistent across biopsy locations: primary tumors, recurrent sites, and metastatic sites. However, the prevalence varied substantially depending on the location of the primary tumor—from 43.5% with oral cavity tumors to 9.5% with hypopharyngeal tumors. For patients with tumors originating in the oral cavity and oropharynx, PD-L1 expression was linked to shorter survival, whereas higher PD-L1 expression was associated with longer survival in patients with hypopharyngeal primary tumors.
Based on the authors’ analysis of confounding factors in this patient population, “primary tumor location and demographic factors may be highly relevant to overall survival in patients with recurrent and/or metastatic squamous cell carcinoma of the head and neck,” they concluded.
Disclosure: The study authors’ disclosure information can be found at translational-medicine.biomedcentral.com.