PD-L1 expression in recurrent head and neck squamous cell carcinoma.

PURPOSE: To evaluate the Programmed Cell Death Ligand (PD-L1) expression at diagnosis and relapse in patients with head and neck carcinoma (HNSCC) treated with radio(chemo)therapy. METHODS: PD-L1 immunohistochemistry was performed in tumor cells (TC) and immune cells (IC) in 44 patients and scored as 0 = 0%, 1 = < 5%, 2 = 6-49% or 3 = ≥ 50% cells. RESULTS: PD-L1 expression on TC before RT was scored as 0, 1, 2 and 3 in 28, 4, 8 and 4 patients, respectively. In 10 patients, IC did not show any PD-L1 expression; while in 8, 16, and 10 patients, PD-L1 expression was scored 1, 2 and 3, respectively. At relapse, 7/36 patients had a PD-L1 expression positivation in TC, while the opposite was observed in 6 patients. Overall, survival at 2 years was higher in patients with PD-L1 expression (90% versus 62.5%, p = 0.032). CONCLUSION: PD-L1 expression may vary throughout the course of the disease. A re-evaluation of PD-L1 expression on biopsies at the time of recurrence should be recommended.

Toxicity after volumetric modulated arc therapy for lung cancer: a monocentric retrospective study.

BACKGROUND: Intensity-modulated radiotherapy (RT) is now widely implemented and has replaced classical three-dimensional (3D)-RT in many tumor sites, as it allows a better target dose conformity and a better sparing of organs a risk (OAR), at the expense, however, of increasing the volume of low dose to normal tissues. Clinical data on toxicities using volumetric modulated arc therapy (VMAT) in lung cancer remain scarce. We aimed to report both acute (APT) and late (LPT) pulmonary and acute (AET) and late (LET) oesophageal toxicities in such setting. METHODS: All patients treated for a primary lung cancer with VMAT +/- chemotherapy (ChT) in our center from 2014 to 2018 were retrospectively included. Usual clinical, treatment and dosimetric features were collected. Univariate analysis was performed using the receiver operative characteristics approach while multivariate analysis (MVA) relied on logistic regression, calculated with Medcalc 14.8.1. RESULTS: In total, 167 patients were included, with a median age of 66 years (39-88 years). Median radiation dose was 66 Gy (30-66 Gy); 82% patients received concomitant (32.3%), induction (25.7%) or induction followed by concomitant ChT (24%). After a median follow-up of 14.0 months, the G ≥2 APT, AET, LPT and LET rates were 22.2%, 30.0%, 16.8% and 5.4%, respectively with low grade ≥3 toxicity rates (respectively, 3%, 6.6%, 3% and 0%). On MVA, APT was significantly associated with V30 to the homolateral lung, AET with age, LPT with MEVS while no feature remained significantly correlated with LET. CONCLUSIONS: Low rates of pulmonary and esophageal toxicity were observed in our cohort. Larger prospective studies are needed to confirm these results.