Grade selection.

Immune checkpoint inhibition has demonstrated clinical advantages in a minority of patients with head and neck cancers. Wouldn’t it be great to reserve this treatment for those most likely to benefit? This retrospective study doesn’t evaluate some new-fangled (read: expensive) genomic test, but rather a tried and true pathologic feature we all know and love: histologic grade. Among 60 patients receiving ICI for recurrent or metastatic head and neck squamous cell carcinoma, a clinical response was achieved in 1235 (34%) with high-grade (i.e. poorly-differentiated) tumors versus only 2/25 (8%) with low-grade (well- to moderately-differentiated) tumors. On multivariate analysis, high-grade tumors had 5x the odds of clinical benefit with ICI. Delving further, this could be due to the observation that, among the small number of available genomic profiles, high-grade tumors (n=8) had a higher mean mutational burden (8.6 mut/Mb) than low-grade tumors (n=4, 3.6 mut/Mb). | Alkhatib, JAMA Otolaryngol Head Neck Surg 2022