Mesenchymal Stem/Stromal Cell Therapy for Radiation-Induced Xerostomia in Previous Head and Neck Cancer Patients: A Phase II Randomized, Placebo-Controlled Trial.

PURPOSE: No effective treatment exists for radiation-induced xerostomia. The objective of this study was to compare the effect of adipose-derived mesenchymal stem/stromal cell (ASC) injection, relative to placebo, on salivary gland function in patients with radiation-induced xerostomia. PATIENT AND METHODS: In this single-centre, double-blind, placebo-controlled trial, patients with hyposalivation were randomised to receive ultrasound-guided injections of allogeneic ASCs or placebo into the submandibular glands. Patients were followed for 4 months. We evaluated unstimulated whole salivary flow rate (UWS), stimulated salivary flow rate, and patient-reported outcomes. Adverse events were recorded and immune response determined in blood samples. RESULTS: We enrolled 120 patients. ASC treatment resulted in a statistically significant UWS increase of 0.04 [95% confidence interval (CI), 0.02-0.06] mL/min (38%) compared with pretreatment baseline whereas placebo treatment did not cause a significant increase [0.01 (95% CI, -0.01 to 0.04) mL/min (21%)]. Both the ASC and placebo treatment yielded notable symptom reductions, with dry mouth decreasing by 13.6 and 7.7 units, sticky saliva decreased by 14.8 and 9.3 units, swallowing difficulties decreased by 7.9 and 8.0 units, and the summary score of the Xerostomia Questionnaire decreased 5.9 and 5.1 units for the ASC and placebo arms, respectively. We found no statistically significant group difference between the ASC and placebo arms for any of the outcomes. CONCLUSIONS: We could not confirm superiority of the ASC relative to placebo. ASC therapy significantly improved UWS in previous patients with head and neck cancer, whereas placebo resulted in an insignificant increase.

A Contemporary Systematic Review on Repartition of HPV-Positivity in Oropharyngeal Cancer Worldwide.

Significant variation in human papillomavirus (HPV) prevalence in oropharyngeal squamous cell carcinoma (OPSCC) across countries ranging from 11% in Brazil to 74% in New Zealand has been reported earlier. The aim of this study was to systematically review the most recently published studies on the occurrence of HPV in OPSCC globally. PubMed and Embase were systematically searched for articles assessing the occurrence of HPV+ OPSCC published between January 2016 and May 2021. Studies with a study period including 2015 and the following years were included. Both HPV DNA and/or p16 were accepted as indicators of HPV+ OPSCC. 31 studies were enrolled comprising 49,564 patients with OPSCC (range 12-42,024 patients per study) from 26 different countries covering all continents. The lowest occurrences of HPV+ OPSCC were observed in India (0%) and Spain (10%) and the highest occurrences were observed in Lebanon (85%) and Sweden (70%). We observed great variation in HPV prevalence in OPSCC worldwide varying from 0% to 85%. The highest occurrences of HPV+ OPSCC were found in general in Northern European countries, USA, Lebanon, China, and South Korea. We observed a trend of increase in HPV-positivity, indicating a mounting burden of HPV+ OPSCC.