Background/Aims: Hyaluronic acid (HA) regulates cell adhesion, migration and proliferation in various cancers. The clinical implications of HA in resected head and neck squamous cell carcinoma have not been elucidated. We investigated the clinical significance and prognostic value of the expression of tumoral and stromal HA and its related proteins in oropharyngeal and oral cavity cancer. Methods: Resected tissues from oropharyngeal or oral cavity cancer patients undergoing surgery were analysed in tissue microarrays divided into stroma and cancer panels. The expression levels of HA, HA synthases and hyaluronidases were also assessed by immunohistochemistry. Results: A total of 160 resected oropharyngeal or oral cavity cancer tissues were analysed. Stromal HA expression was observed more frequently in human papilloma virus (HPV)-negative tumors, but other clinicopathological characteristics did not differ. In patients with HPV-negative oral cavity cancers, high stromal HA expression was associated with significantly shorter recurrence-free survival and overall survival compared with low stromal HA expression. The expression of HA in both tumors and stroma was significantly correlated with poorer outcomes than other combinations in patients with HPV-negative oral cavity cancers. However, these prognostic roles of HA were not observed in patients with HPV-negative oropharyngeal cancers. In the HPV-stratified multivariate analysis, high stromal HA expression remained an independent indicator of poor prognosis in terms of recurrence-free survival. Conclusions High stromal HA and expression of HA in both tumors and stroma were correlated with poor prognosis in HPV-negative oral cavity cancer, but not in HPV-negative oropharyngeal cancers.

Background: Concerns about the rise in antimicrobial resistance have led to renewed interest in phage therapy worldwide, but perceptions among relevant medical professionals in Korea remain largely unknown. Materials and Methods: We conducted a semi-quantitative online survey to evaluate the Korean infectious disease specialists' perception of phage therapy. Results: We sent out the link to the questionnaire to 380 subjects and received 91 replies, with 90/91 respondents identifying as Korean infectious diseases specialists or trainees. Ten out of 91 (11.0%) respondents scored themselves as well-informed about phage therapy. The majority (93.4%) of respondents would consider using phage therapy if the safety of the phage formulation is guaranteed, and 80% of respondents would consider participating in clinical trials with phage therapy given adequate support. The biggest concern was uncertainty about safety (73.6%) and efficacy (65.9%). Acinetobacter baumannii was ranked as a high priority for phage therapy research, as were bone and joint infections. Conclusion Korean infectious diseases specialists are receptive to phage therapy, but a better understanding of safety, efficacy and clinical trials are warranted to progress phage therapy within the Korean healthcare system.