Imaging may help predict efficacy of immune checkpoint inhibitors in head and neck cancer

Tumour burden, as assessed by imaging techniques, appears to substantially influence outcomes in patients with recurrent or metastatic head and neck cancer (RM-HNC) treated with immune checkpoint inhibitors (ICI), a recent study has found.

“We recommend to perform imaging examinations, including computed tomography, magnetic resonance imaging, and positron emission tomography (PET), before administration of ICIs to assess tumour spread and predict efficacy of ICIs,” the researchers said.

The researchers conducted a retrospective analysis of 94 patients on ICI monotherapy. Tumour burden was measured using PET and was expressed as the baseline number of metastatic lesions (BNML), the baseline sum of the longest diameters of the target lesions (BSLD), and the maximum standardized uptake value.

Primary clinical outcomes of interest were progression-free survival (PFS) and overall survival (OS).

Patients reached a median PFS of 7.1 months when BNML was categorized as low according to a cutoff value of 1; in the high-BNML group (BNML ≥2), median PFS was significantly shorter at 3.1 months. A similar trend was found for OS (31.5 vs 10.7 months; p=0.002).

At a threshold BSLD value of 28 mm, median PFS for the low- and high-BSLD subgroups was 9.1 and 3.5 months, respectively (p=0.003), while corresponding median OS values were 31.5 and 11.8 months (p<0.001).

Multivariate Cox proportional hazards model showed that high BNML (hazard ratio [HR], 1.98, 95 percent confidence interval [CI], 1.19–3.29; p=0.008) and high BSLD (HR, 2.57, 95 percent CI, 1.44–4.58; p=0.001) were significantly associated with poor PFS. The same was true for worse OS (high BNML: HR, 2.30, 95 percent CI, 1.21–4.36; p=0.011; high BSLD: HR, 4.26, 95 percent CI, 1.99–10.71; p<0.001).