Faculty Bibliography

BACKGROUND: Metastasis to the cervical (neck) lymph nodes is one of the most significant clinical factors responsible for death from oral squamous cell carcinoma (SCC). Therefore, the lymph nodes are frequently removed when the tumor is excised (neck dissection), even though the majority of patients will not benefit from the extra surgery. Two subtypes of oral SCC distinguished by the presence of tumor genomic aberrations +3q, -8p, +8q and/or +20 differ in risk for metastasis - high for the 3q8pq20 subtype, harboring one or more of the aberrations and low for the non-3q8pq20 subtype, lacking these alterations. A prior analysis of the literature suggested genes differentially methylated in the two subtypes. Therefore, the goal of this study was to further investigate the methylation status of candidate biomarkers of the non-3q8pq20 subtype, and evaluate their utility for identifying patients at low risk for metastasis. METHODS: Methylation status of genes in a cohort of 52 oral SCC patients with at least five year follow up was determined by pyrosequencing. Gene expression levels were determined by quantitative RT-PCR. Growth following re-expression of HOXA9 in cultured oral SCC cells was assessed by proliferation and colony formation assays. RESULTS: A pilot study evaluating methylation levels of HOXA9, MT1A and HOXA11 promoters in DNA from 12 tumors (six each of the 3q8pq20 and non-3q8pq20 subtypes) revealed that only HOXA9 was differentially methylated. Significant differences in methylation levels of HOXA9 were observed amongst the 52 oral SCCs with respect to genomic subtype and nodal status (p = 0.014, and p = 0.024, respectively, Wilcoxon rank sum test). High levels of HOXA9 methylation and low levels of expression in oral SCC cell lines were observed compared to HaCaT, a non-tumorigenic keratinocyte cell line. Re-expression of HOXA9 in the SCC4 oral cancer cell line resulted in diminished proliferation and colony formation. CONCLUSIONS: HOXA9 methylation is frequent in oral cancers and levels are higher in tumors with greater risk of metastasis. Expression of HOXA9 is low in cells with high levels of methylation and reduced expression appears to confer a growth advantage.

Diffuse intrinsic pontine glioma (DIPG) is a fatal brain cancer that arises in the brainstem of children, with no effective treatment and near 100% fatality. The failure of most therapies can be attributed to the delicate location of these tumors and to the selection of therapies on the basis of assumptions that DIPGs are molecularly similar to adult disease. Recent studies have unraveled the unique genetic makeup of this brain cancer, with nearly 80% found to harbor a p.Lys27Met histone H3.3 or p.Lys27Met histone H3.1 alteration. However, DIPGs are still thought of as one disease, with limited understanding of the genetic drivers of these tumors. To understand what drives DIPGs, we integrated whole-genome sequencing with methylation, expression and copy number profiling, discovering that DIPGs comprise three molecularly distinct subgroups (H3-K27M, silent and MYCN) and uncovering a new recurrent activating mutation affecting the activin receptor gene ACVR1 in 20% of DIPGs. Mutations in ACVR1 were constitutively activating, leading to SMAD phosphorylation and increased expression of the downstream activin signaling targets ID1 and ID2. Our results highlight distinct molecular subgroups and novel therapeutic targets for this incurable pediatric cancer.

OBJECTIVES/HYPOTHESIS: Recent data have suggested that in-office potassium titanyl phosphate (KTP) laser treatment for benign vocal fold lesions yields significant reduction in lesion size with favorable effects on both mucosal wave and glottic closure. However, these previous studies omitted voice-related outcomes. We sought to compliment these previous data with voice-related outcomes in a cohort of patients undergoing KTP ablation of vocal fold polyps. STUDY DESIGN: Retrospective outcomes study. METHODS: Voice Handicap Index (VHI)-10 and acoustic measures were reviewed for 31 consecutive patients with benign vocal fold polyps treated with in-office KTP laser surgery. All data were analyzed statistically via a mixed model fit to analyze the data from each of three clinical visits. RESULTS: Across all patients, the mean VHI-10 scores decreased at first follow-up from 19.7 to 9.7 (P < .0001). At subsequent follow-up visits, the VHI-10 scores remained stable (mean, 8.3). This shift in VHI scores was accompanied by favorable improvements in both noise-to-harmonic ratio and speaking fundamental frequency in both males and females. CONCLUSIONS: In-office KTP ablation of vocal fold polyps had a favorable effect on patient-reported handicap as determined by the VHI-10. This treatment also slightly altered physiologic measures of voice; however, these measures did not achieve statistical significance. LEVEL OF EVIDENCE: 4. Laryngoscope, 2013.

OBJECTIVES/HYPOTHESIS: Currently, no standard exists for reporting treatment results for the potassium titanyl phosphate (KTP) laser. The goal of this study was to establish a validated classification schema for reporting immediate tissue effects after laser treatment. STUDY DESIGN: Evaluation of KTP laser video sequences by academic laryngologists with use of the rating system. METHODS: A five-point classification system was developed; this included noncontact angiolysis, epithelial blanching, epithelial disruption, contact epithelial ablation, and contact epithelial ablation with tissue removal. Video recordings were made prospectively for each treatment effect. Ten treatment recordings, with two repeated recordings, were presented to seven academic laryngologists, who were asked to categorize each based on the given classification scheme. RESULTS: Overall accuracy for the combined reviewers in rating the treatments was 82%. Six of seven reviewers showed perfect intrarater reliability. Accuracy in rating clips did not correlate with the previous number of 532-nm KTP or 585-nm pulsed dye laser procedures performed but showed a trend toward correlating with total years in practice. This study reveals that standardized reporting of effects of the KTP laser is feasible. CONCLUSIONS: We believe that results of KTP treatment should be reported using a validated classification system of immediate laser effect, along with specific laser settings. This classification system allows for future systematic evaluation of long-term treatment results prospectively from single laser treatments.

OBJECTIVES/HYPOTHESIS/OBJECTIVE:Hypocalcemia is common in the initial period after total laryngectomy. The purpose of the present study was to study the incidence of and risk factors for postlaryngectomy hypocalcemia at our institution. STUDY DESIGN/METHODS:Retrospective review of 65 consecutive total laryngectomies. METHODS:Clinical data and calcium levels for the first postoperative week were collected. Biochemical hypocalcemia was defined as any corrected calcium level of < 2.0 mmol/l in the first postoperative week. Severe hypocalcemia was defined as a calcium of < 1.8 mmol/l, or symptoms of hypocalcemia. Risk factors for hypocalcemia were studied. RESULTS:Five cases were excluded due to concomitant abdominal surgery (3), preoperative hypocalcemia (1), and no postoperative calcium levels (1). A total of 43% of patients had postoperative biochemical hypocalcemia. On univariate analysis, bilateral neck dissection was significant for hypocalcemia (P = 0.02), with pT4 classification having borderline significance (P = 0.07). On multivariate analysis, bilateral neck dissection (P = 0.02) and salvage surgery were significant (P = 0.03), with pT4 stage again having borderline significance (P = 0.05). Extent of thyroidectomy, extent of pharyngectomy, and preoperative tracheostomy were not significant. Fifteen patients (25%) had severe hypocalcemia. There were no significant risk factors for severe hypocalcemia identified. CONCLUSIONS:Hypocalcemia is common after total laryngectomy, particularly in the postradiotherapy setting and in patients undergoing bilateral neck dissection. Preservation of one thyroid lobe does not appear to significantly reduce the risk.