Impact of Histologic Risk Factors on Recurrence Rates for Oral Cavity Squamous Cell Carcinoma

OBJECTIVES

This study assesses the impact of adverse histologic risk factors including worst pattern of invasion (WPOI), predominant pattern of invasion (PPOI), tumor budding, and tumor infiltrating lymphocytes (TILS), on risk of recurrence in patients with early-stage Oral Cavity Squamous Cell Carcinoma (OCSCC).

METHODS

Retrospective chart review was performed at a single institution to identify patients with OCSCC who underwent surgical excision. Inclusion criteria included T1-T2 stage disease based on AJCC seventh edition guidelines, no cervical lymph node involvement, no perineural invasion (PNI), no lymphovascular invasion (LVI), no post-operative adjuvant radiation therapy, and cancer involving only the oral tongue or floor of mouth. Patients were excluded if they had positive final margins. A subset of 35 patients were selected for additional histologic review to determine WPOI, PPOI, TB, and TILS. Bivariable and multivariable cox analysis were performed to determine variables associated with recurrence.

RESULTS

One hundred and sixty-one patients met criteria and were included in the analysis. Variables that were significantly associated with recurrence on bivariable analysis included tumors with high risk PPOI (groups 4 and 5; P = .021), TB with 10 or more buds (P = .021), T-stage (P = .001), neck dissection (P = .03), and depth of invasion (DOI) >4 mm (P = .044). Multivariable cox proportional hazards found T-stage (HR: 6.40; 95% CI 1.67, 24.50; P = .007), neck dissection (HR: 0.23; 95% CI 0.07, 0.82; P = .023), and TBs (HR: 1.17; 95% CI 1.05, 1.30; P = .006) to be most predictive of recurrence.

CONCLUSIONS

TB is a strong predictor of recurrence. WPOI, PPOI, and TILS were not statistically significant risk factors for recurrence.

The Long "Race" to Diversity in Otolaryngology

The number of health disparities disproportionately affecting minority communities continue to rise. Thus, it is imperative to assess whether equity within medical school enrollment and along the academic pipeline has mirrored this growth, especially among elite surgical specialties such as otolaryngology. Census and educational data from 2010 and 2018 were used to assess the current otolaryngology, surgery, and internal medicine physician and faculty workforce diversity across each stage of the academic medicine trajectory by race and ethnicity. We found that disparities exist in medical school enrollment for minority students such that Hispanic/Latinx representation was only 30% and Black representation only 50% of their respective proportions in the US population in 2018. Disparities in achieving full professorship were also observed across all 3 specialties but most prominently in otolaryngology, with 1% Black representation among otolaryngology professors in 2018. A collective strategy toward diversifying the otolaryngology workforce should be explored.

Significance of Nodal Metastasis in Parotid Gland Acinar Cell Carcinoma

OBJECTIVES

To evaluate the rate of lymph node metastasis in parotid gland acinar cell carcinoma, to identified factors associated with increased risk of metastasis, and to evaluate the effect of nodal metastasis on survival.

METHODS

This is a retrospective cohort study utilizing data from a large population-based cancer database. Data were extracted from the Surveillance, Epidemiology, and End Results (SEER) 18 database. The study cohort included patients with parotid gland acinar cell carcinoma diagnosed between 2000 and 2015.

RESULTS

The overall rate of lymph node metastasis was 6.8%. T3/T4 (OR 6.17, 95% CI, 3.03 to 13.16) disease along with High Grade (OR 15.95) disease were associated with increased risk of nodal metastasis. Non-white, non-Black race was associated with decreased risk. Age and sex were not associated with nodal metastasis. Nodal metastasis was associated with worse OS (HR 6.27, 95% CI, 3.85 to 10.20) and DSS (HR 6.96, 95% CI, 3.81 to 12.73) after adjusting for covariates.

CONCLUSION

Parotid gland acinar cell carcinoma carries a low risk of nodal metastasis. Both advanced T stage and high grade are associated with increased risk of nodal metastasis. Nodal metastasis is associated with decreased overall survival.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:E1125-E1129, 2021.

Identification of early inflammatory changes in the tympanic membrane with Raman spectroscopy

The tympanic membrane (TM) is a dynamic structure that separates the middle ear from the external auditory canal. It is also integral for the transmission of sound waves. In this study, we demonstrate the feasibility of using Raman spectroscopy to identify early chemical changes resulting from inflammation in the TM that can serve as an indicator of acute otitis media. Bacterial lipopolysaccharide (LPS) was injected trans-tympanicaly in a murine model. Presence of inflammatory response was assessed with binocular microscopy, confirmed with histopathology and immunofluorescence staining. Successful discrimination suggesting spectral differences among the control and LPS treated groups was achieved using principal component analysis. Raman imaging revealed major differences in collagen distribution and nucleic acid content. Image segmentation analysis on the trichrome stained tissue sections was performed to corroborate the Raman spectra. The spectral co-localization study suggests changes in the expression of collagen IV specific signals in LPS treated samples. The overall findings of the study support prospective application of RS in the diagnosis and therapeutic monitoring of otitis media.

P/Q Type Calcium Channel Cav2.1 Defines a Unique Subset of Glomeruli in the Mouse Olfactory Bulb

Voltage-gated calcium (Cav) channels are a prerequisite for signal transmission at the first olfactory sensory neuron (OSN) synapse within the glomeruli of the main olfactory bulb (MOB). We showed previously that the N-type Cav channel subunit Cav2.2 is present in the vast majority of glomeruli and plays a central role in presynaptic transmitter release. Here, we identify a distinct subset of glomeruli in the MOB of adult mice that is characterized by expression of the P/Q-type channel subunit Cav2.1. Immunolocalization shows that Cav2.1+ glomeruli reside predominantly in the medial and dorsal MOB, and in the vicinity of the necklace glomerular region close to the accessory olfactory bulb. Few glomeruli are detected on the ventral and lateral MOB. Cav2.1 labeling in glomeruli colocalizes with the presynaptic marker vGlut2 in the axon terminals of OSNs. Electron microscopy shows that Cav2.1+ presynaptic boutons establish characteristic asymmetrical synapses with the dendrites of second-order neurons in the glomerular neuropil. Cav2.1+ glomeruli receive axonal input from OSNs that express molecules of canonical OSNs: olfactory marker protein, the ion channel Cnga2, and the phosphodiesterase Pde4a. In the main olfactory epithelium, Cav2.1 labels a distinct subpopulation of OSNs whose distribution mirrors the topography of the MOB glomeruli, that shows the same molecular signature, and is already present at birth. Together, these experiments identify a unique Cav2.1+ multiglomerular domain in the MOB that may form a previously unrecognized olfactory subsystem distinct from other groups of necklace glomeruli that rely on cGMP signaling mechanisms.