F18-FDG PET/CT imaging early predicts pathologic complete response to induction chemoimmunotherapy of locally advanced head and neck cancer: preliminary single-center analysis of the checkrad-cd8 trial.

AIM: In the CheckRad-CD8 trial patients with locally advanced head and neck squamous cell cancer are treated with a single cycle of induction chemo-immunotherapy (ICIT). Patients with pathological complete response (pCR) in the re-biopsy enter radioimmunotherapy. Our goal was to study the value of F-18-FDG PET/CT in the prediction of pCR after induction therapy. METHODS: Patients treated within the CheckRad-CD8 trial that additionally received FDG- PET/CT imaging at the following two time points were included: 3-14 days before (pre-ICIT) and 21-28 days after (post-ICIT) receiving ICIT. Tracer uptake in primary tumors (PT) and suspicious cervical lymph nodes (LN +) was measured using different quantitative parameters on EANM Research Ltd (EARL) accredited PET reconstructions. In addition, mean FDG uptake levels in lymphatic and hematopoietic organs were examined. Percent decrease (Δ) in FDG uptake was calculated for all parameters. Biopsy of the PT post-ICIT acquired after FDG-PET/CT served as reference. The cohort was divided in patients with pCR and residual tumor (ReTu). RESULTS: Thirty-one patients were included. In ROC analysis, ΔSUVmax PT performed best (AUC = 0.89) in predicting pCR (n = 17), with a decline of at least 60% (sensitivity, 0.77; specificity, 0.93). Residual SUVmax PT post-ICIT performed best in predicting ReTu (n = 14), at a cutpoint of 6.0 (AUC = 0.91; sensitivity, 0.86; specificity, 0.88). Combining two quantitative parameters (ΔSUVmax ≥ 50% and SUVmax PT post-ICIT ≤ 6.0) conferred a sensitivity of 0.81 and a specificity of 0.93 for determining pCR. Background activity in lymphatic organs or uptake in suspected cervical lymph node metastases lacked significant predictive value. CONCLUSION: FDG-PET/CT can identify patients with pCR after ICIT via residual FDG uptake levels in primary tumors and the related changes compared to baseline. FDG-uptake in LN + had no predictive value. TRIAL REGISTRY: ClinicalTrials.gov identifier: NCT03426657.

[Immunotherapy for HNSCC : Quo vadis?]. / Immuntherapie des HNSCC : Quo vadis?

BACKGROUND: Immunotherapy remains a hot topic with an endless stream of new upcoming clinical trials. The results of studies to date are promising for second-line palliative treatment of head and neck squamous cell carcinoma (HNSCC). The next step is testing these strategies in randomized trials for first-line and curative treatment in an adjuvant, neoadjuvant, and primarily nonsurgical setting. So far, established biomarkers have not proven reliable enough to predict response rates precisely. OBJECTIVES: On occasion of the annual meeting of the American Society of Clinical Oncology (ASCO), we aimed to invesitage the future of immunotherapies. METHODS: We collected the most promising upcoming studies alongside current research in the field of biomarkers with a  view to interesting new immunotherapeutic strategies. RESULTS: The search for appropriate biomarkers in particular seems to be a central research objective in the short term. There is a broad range of new agents that will be tested in clinical trials as well as the combination of immunotherapy with chemo- and chemoradiotherapy or other immune-modulating drugs. CONCLUSION: The real challenge will be to find the most fitting therapy for each patient out of a large panel of available regimens. Therefore, it is most important to find a set of reliable biomarkers that together could predict treatment response.

[Mucosal Melanoma of the Head and Neck]. / Schleimhautmelanome des Kopf-Hals-Bereichs.

Primary mucosal malignant melanoma of the head and neck is a rare tumor entity with poor clinical outcome. Its growth pattern is characterized by an infiltrative and local destructive behavior. So far no risk factors could be identified. There are practically no early symptoms of the disease, as intermitting nose bleeding or nasal obstruction typically occur in advanced stage. The standard of care remains radical tumor resection with adjuvant radiation in cases of close margin resection. Other therapeutic options like the use of interferon, antibodies or conventional chemotherapeutics have not demonstrated significant clinical benefit so far. Current efforts to investigate the biological and genomic characteristics of these tumors have been constrained by its low incidence. In order to better characterize this rare tumor entity and to establish effective novel targeted therapies it will be necessary to establish an interdisciplinary and multicentric task force.