Andrew J. Rosko

How does diabetes accelerate Alzheimer disease pathology

Diabetes and Alzheimer disease (AD)—two age-related diseases—are both increasing in prevalence, and numerous studies have demonstrated that patients with diabetes have an increased risk of developing AD compared with healthy individuals. The underlying biological mechanisms that link the development of diabetes with AD are not fully understood. Abnormal protein processing, abnormalities in insulin signaling, dysregulated glucose metabolism, oxidative stress, the formation of advanced glycation end products, and the activation of inflammatory pathways are features common to both diseases. Hypercholesterolemia is another factor that has received attention, owing to its potential association with diabetes and AD. This Review summarizes the mechanistic pathways that might link diabetes and AD. An understanding of this complex interaction is necessary for the development of novel drug therapies and lifestyle guidelines aimed at the treatment and/or prevention of these diseases.

Diagnostic modalities for distant metastasis in head and neck squamous cell carcinoma: are we changing life expectancy?

To determine if the various imaging modalities for distant metastasis (DM) diagnosis alters life expectancy in head and neck squamous cell carcinoma (HNSCC).

The Role of Oxidized Cholesterol in Diabetes-Induced Lysosomal Dysfunction in the Brain

Abnormalities in lysosomal function have been reported in diabetes, aging, and age-related degenerative diseases. These lysosomal abnormalities are an early manifestation of neurodegenerative diseases and often precede the onset of clinical symptoms such as learning and memory deficits; however, the mechanism underlying lysosomal dysfunction is not known. In the current study, we investigated the mechanism underlying lysosomal dysfunction in the cortex and hippocampi, key structures involved in learning and memory, of a type 2 diabetes (T2D) mouse model, the leptin receptor deficient db/db mouse. We demonstrate for the first time that diabetes leads to destabilization of lysosomes as well as alterations in the protein expression, activity, and/or trafficking of two lysosomal enzymes, hexosaminidase A and cathepsin D, in the hippocampus of db/db mice. Pioglitazone, a thiazolidinedione (TZD) commonly used in the treatment of diabetes due to its ability to improve insulin sensitivity and reverse hyperglycemia, was ineffective in reversing the diabetes-induced changes on lysosomal enzymes. Our previous work revealed that pioglitazone does not reverse hypercholesterolemia; thus, we investigated whether cholesterol plays a role in diabetes-induced lysosomal changes. In vitro, cholesterol promoted the destabilization of lysosomes, suggesting that lysosomal-related changes associated with diabetes are due to elevated levels of cholesterol. Since lysosome dysfunction precedes neurodegeneration, cognitive deficits, and Alzheimer’s disease neuropathology, our results may provide a potential mechanism that links diabetes with complications of the central nervous system.

Correlation of Crtc1/3-Maml2 fusion status, grade and survival in mucoepidermoid carcinoma

OBJECTIVE Mucoepidermoid carcinoma (MEC) is the most common malignant tumor of the salivary glands. Tumor stage and grade have historically been important predictors of survival. An oncogenic CRTC1- or CRTC3-MAML2 gene fusion has been identified in a number of MECs. Historically, these gene fusions have been associated with lower grade tumors and better survival. However, reported gene fusion rates and prognosis varies widely across studies, and have not controlled for tumor grade. We sought to identify gene fusion rates and outcomes in our cohort of MEC patients. MATERIALS AND METHODS An IRB-approved retrospective cohort of patients with MEC was identified at the University of Michigan. Clinical, histologic, and outcome data was collected from medical records. RNA was isolated from formalin fixed paraffin-embedded tumor sections, and qRT-PCR was performed to identify CRTC1/3-MAML2 gene fusions. Sanger sequencing of qRT-PCR products was used to confirm gene fusions. RESULTS Overall, 90 patient MEC tumors were collected (58 low-grade, 25 intermediate-grade, and 7 high-grade). Gene fusions were identified in 59% (53/90) of tumors. On univariate and bivariate analysis, fusion status did not significantly associate with grade or survival. CONCLUSION We have identified a high rate of CRTC1/3-MAML2 gene fusions in a large cohort of MEC. We do not identify any correlation between fusion status with tumor grade or survival. These findings suggest further characterization of MECs is needed before considering the CRTC1/3-MAML2 gene fusion as a prognostic biomarker. Additional genetic drivers may account for survival and grade in MECs.

Occult Nodal Disease Prevalence and Distribution in Recurrent Laryngeal Cancer Requiring Salvage Laryngectomy

Objectives The indications for neck dissection concurrent with salvage laryngectomy in the clinically N0 setting remain unclear. Our goals were to determine the prevalence of occult nodal disease, analyze nodal disease distribution patterns, and identify predictors of occult nodal disease in a salvage laryngectomy cohort. Study Design Case series with planned data collection. Setting Tertiary academic center. Subjects Patients with persistent or recurrent laryngeal squamous cell carcinoma (LSCC) after radiation/chemoradiation failure undergoing salvage laryngectomy with neck dissection. Methods We analyzed a single-institution retrospective case series of patients between 1997 and 2014 and identified those who had clinically N0 (cN0) necks (n = 203). Clinical and pathologic data, including nodal prevalence and distribution, were collected and statistical analyses performed. Results Overall, cN0 necks had histologically positive occult nodes in 17% (n = 35) of cases. Univariate predictors of occult nodal positivity included recurrent T4 stage (34% T4 vs 12% non-T4; P = .0003) and supraglottic subsite (28% supraglottic vs 10% nonsupraglottic; P = .0006). Histologically positive nodes associated with supraglottic primaries were most frequently positive in ipsilateral levels II and III (17% and 16%). Positive nodes for glottic LSCC were most frequently positive in the ipsilateral and contralateral paratracheal nodes (11% and 9%). Conclusion Histologically positive occult nodes are identified in 17% of cN0 patients undergoing salvage laryngectomy with neck dissection. Occult nodal disease varies in frequency and distribution based on tumor subsite. Predictors of high (>20%) occult nodal positivity include T4 tumors and supraglottic subsite. In glottic LSCC, the most frequent sites of occult nodal disease are the paratracheal nodal basins.

Contemporary Management of Early-Stage Melanoma: A Systematic Review

Importance The incidence of melanoma is increasing, with 76 380 new cases of invasive melanoma and 68 480 new cases of melanoma in situ expected in 2016. Objective To review the contemporary management of early-stage melanoma. Evidence Review We searched PubMed, MEDLINE, and the Cochrane Database of Systematic Reviews databases from January 1, 2011, to May 1, 2016, yielding 966 articles. We focused our search on early-stage (melanoma in situ, stage I, and stage II) cutaneous melanoma. After excluding articles, 41 articles were manually reviewed. A review of the bibliographies of selected articles generated additional references. Findings While the majority of recent advances have been in the treatment of advanced melanoma, surgical excision with margins based on the presence and depth of invasion continues to be the cornerstone of management. Sentinel lymph node biopsy plays a central role in the staging and treatment of melanoma. Conclusions and Relevance Accurate diagnosis and adequate surgical excision are critical in reducing local recurrences and improving outcomes. Sentinel lymph node biopsy is useful in staging the regional nodal basin and guiding treatment in appropriately selected patients.

Prevalence and Outcomes of Head and Neck versus Non-Head and Neck Second Primary Malignancies in Head and Neck Squamous Cell Carcinoma: An Analysis of the Surveillance, Epidemiology, and End Results Database

Background/Aims: Patients with head and neck squamous cell carcinoma (HNSCC) are at risk for second primary malignancies (SPMs). The prevalence, distribution, and patient survival in head and neck versus non-head and neck SPMs are not fully elucidated. The objective of this study was to quantify the rate of SPMs in patients with HNSCC. Methods: This is a population-based cohort study using the Surveillance, Epidemiology, and End Results (SEER) database. Prevalence and location of SPMs, and survival data were analyzed. Results: There were 58,363 HNSCC patients, and the prevalence of HNSCC and non-HNSCC SPMs was 3.0% (1,746) and 8.8% (5,109), respectively. Overall survival (OS) was higher in patients with HNSCC SPMs compared to non-HNSCC SPMs (p < 0.001), with no difference in disease-specific survival. Patients with SPMs in the lung and esophagus had a worse OS (p < 0.001), and patients with SPMs in the prostate and breast had a better OS (p < 0.001). Conclusion: In HNSCC patients who develop SPMs, nearly 75% are non-HNSCC SPMs. Patients with non-HNSCC SPMs have a lower OS. Future clinical practice guidelines should take the risks and locations of SPM development into consideration for screening.

Preoperative Tracheostomy Is Associated with Poor Disease-Free Survival in Recurrent Laryngeal Cancer

Objectives It is unknown if preoperative tracheostomy for persistent/recurrent laryngeal squamous cell carcinoma (LSCC) plays a role in unrecognized local disease spread and disease recurrence after salvage laryngectomy. The goals of this study were to determine the effect of preoperative tracheostomy on disease-free survival (DFS) in patients with recurrent/persistent LSCC undergoing salvage laryngectomy. Study Design Retrospective case series derived from prospectively maintained database. Setting Tertiary care academic center. Subjects Patients with recurrent/persistent LSCC after radiation/chemoradiation (RT/CRT) who underwent salvage laryngectomy at the University of Michigan from 1997 to 2015. Methods Demographic, clinical, pathologic, and survival data were collected. Kaplan-Meier survival estimates were performed. Results DFS was worse for patients with tracheostomy prior to laryngectomy than patients without a tracheostomy (5 year: 39% vs 67%; P < .001). Patients with tracheostomy prior to RT/CRT compared to patients with tracheostomy after RT/CRT or patients without a tracheostomy had worse DFS (5-year: 25%, 49%, and 67%, respectively; P < .001). In bivariable analyses controlling for T classification, N classification, or overall stage, preoperative tracheostomy was associated with worse DFS. In multivariable analysis, presence of a preoperative tracheostomy had a worse DFS (hazard ratio, 1.63; 95% confidence interval, 1.00-2.67; P = .048). Conclusion Preoperative tracheostomy is associated with disease recurrence in patients with persistent/recurrent LSCC undergoing salvage laryngectomy, particularly in patients who had tracheostomy prior to completion of initial RT/CRT. Notably, preoperative tracheostomy as a causal factor vs marker for disease recurrence is difficult to ascertain. Nevertheless, clinicians should be aware of the increased risk of locoregional recurrence in patients with preoperative tracheostomy when counseling on surgical salvage and when considering the role of additional therapy.

Dorsal scapular artery as a recipient vessel in the vessel-depleted neck during free tissue transfer in head and neck reconstruction

The vessel‐depleted neck poses a unique challenge to the microvascular surgeon. Using 3D modeling and cadaveric dissection, we describe the approach and advantages of a known but less frequently used recipient vessel, the dorsal scapular artery, during free tissue transfer.

Genomic sequencing and precision medicine in head and neck cancers

Head and neck squamous cell carcinoma (HNSCC) remains a common and deadly disease. Historically, surgical and chemoradiation treatments have been met with modest success, and understanding of genetic drivers of HNSCC has been limited. With recent next generation sequencing studies focused on HNSCC, we are beginning to understand the genetic landscape of HNSCCs and are starting to identify and advance targeted options for patients. In this review, we describe current knowledge and recent advances in sequencing studies of HNSCC, discuss current limitations and future directions for further genomic analysis, and highlight the translational advances being undertaken to treat this important disease.