Positive Deep Initial Incision Margin Affects Outcomes in TORS for HPV+ Oropharynx Cancer.

OBJECTIVE: Evaluate the effect of initial incision margins (IIM) on clinical outcomes after transoral robotic surgery (TORS) for human papillomavirus positive (HPV+) squamous cell cancers of the oropharynx (OPSCC). METHODS: Retrospective chart review of patients undergoing TORS for HPV+ OPSCC from 2007 to 2015 was performed. Overall survival (OS), disease-specific survival (DSS), recurrence, and metastases were evaluated in the context of pathology, IIM, final margins, adjuvant therapy, and patient characteristics. RESULTS: Ninety-five patients with HPV+ OPSCC undergoing primary surgery were identified. 88% of these patients had no evidence of disease at the conclusion of the study (average follow-up 45 months). Twenty were identified that had true positive IIM and 16 had very close IIM, with the remainder demonstrating widely negative margins. Tumor very close to or involving the deep margin but not a mucosal margin was associated with a higher risk of recurrence. Perineural invasion and lymphovascular invasion were associated with positive IIM. Positive or very close IIM on the deep margin was found to impact DSS and recurrence. CONCLUSION: Obtaining negative IIM while performing TORS for HPV+ OPSCC is a modifiable factor that affects recurrence and DSS. Larger surgical margins should be considered in patients with perineural invasion or whose tumor abuts the initial deep margin. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:1132-1137, 2023.

Hepatitis virus capsid polymorph stability depends on encapsulated cargo size.

Protein cages providing a controlled environment to encapsulated cargo are a ubiquitous presence in any biological system. Well-known examples are capsids, the regular protein shells of viruses, which protect and deliver the viral genome. Since some virus capsids can be loaded with nongenomic cargoes, they are interesting for a variety of applications ranging from biomedical delivery to energy harvesting. A question of vital importance for such applications is how does capsid stability depend on the size of the cargo? A nanoparticle-templated assembly approach was employed here to determine how different polymorphs of the Hepatitis B virus icosahedral capsid respond to a gradual change in the encapsulated cargo size. It was found that assembly into complete virus-like particles occurs cooperatively around a variety of core diameters, albeit the degree of cooperativity varies. Among these virus-like particles, it was found that those of an outer diameter corresponding to an icosahedral array of 240 proteins (T = 4) are able to accommodate the widest range of cargo sizes.