Umamaheswar Duvvuri

Frequent mutation of the PI3K pathway in head and neck cancer defines predictive biomarkers

Genomic findings underscore the heterogeneity of head and neck squamous cell carcinoma (HNSCC). Identification of mutations that predict therapeutic response would be a major advance. We determined the mutationally altered, targetable mitogenic pathways in a large HNSCC cohort. Analysis of whole-exome sequencing data from 151 tumors revealed the phosphoinositide 3-kinase (PI3K) pathway to be the most frequently mutated oncogenic pathway (30.5%). PI3K pathway-mutated HNSCC tumors harbored a significantly higher rate of mutations in known cancer genes. In a subset of human papillomavirus-positive tumors, PIK3CA or PIK3R1 was the only mutated cancer gene. Strikingly, all tumors with concurrent mutation of multiple PI3K pathway genes were advanced (stage IV), implicating concerted PI3K pathway aberrations in HNSCC progression. Patient-derived tumorgrafts with canonical and noncanonical PIK3CA mutations were sensitive to an mTOR/PI3K inhibitor (BEZ-235), in contrast to PIK3CA-wild-type tumorgrafts. These results suggest that PI3K pathway mutations may serve as predictive biomarkers for treatment selection.

Highly accurate diagnosis of cancer in thyroid nodules with follicular neoplasm/suspicious for a follicular neoplasm cytology by ThyroSeq v2 next-generation sequencing assay.

Fine‐needle aspiration (FNA) cytology is a common approach to evaluating thyroid nodules, although 20% to 30% of FNAs have indeterminate cytology, which hampers the appropriate management of these patients. Follicular (or oncocytic) neoplasm/suspicious for a follicular (or oncocytic) neoplasm (FN/SFN) is a common indeterminate diagnosis with a cancer risk of approximately 15% to 30%. In this study, the authors tested whether the most complete next‐generation sequencing (NGS) panel of genetic markers could significantly improve cancer diagnosis in these nodules.

TMEM16A, induces MAPK and contributes directly to tumorigenesis and cancer progression

Frequent gene amplification of the receptor-activated calcium-dependent chloride channel TMEM16A (TAOS2 or ANO1) has been reported in several malignancies. However, its involvement in human tumorigenesis has not been previously studied. Here, we show a functional role for TMEM16A in tumor growth. We found TMEM16A overexpression in 80% of head and neck squamous cell carcinoma (SCCHN), which correlated with decreased overall survival in patients with SCCHN. TMEM16A overexpression significantly promoted anchorage-independent growth in vitro, and loss of TMEM16A resulted in inhibition of tumor growth both in vitro and in vivo. Mechanistically, TMEM16A-induced cancer cell proliferation and tumor growth were accompanied by an increase in extracellular signal-regulated kinase (ERK)1/2 activation and cyclin D1 induction. Pharmacologic inhibition of MEK/ERK and genetic inactivation of ERK1/2 (using siRNA and dominant-negative constructs) abrogated the growth effect of TMEM16A, indicating a role for mitogen-activated protein kinase (MAPK) activation in TMEM16A-mediated proliferation. In addition, a developmental small-molecule inhibitor of TMEM16A, T16A-inh01 (A01), abrogated tumor cell proliferation in vitro. Together, our findings provide a mechanistic analysis of the tumorigenic properties of TMEM16A, which represents a potentially novel therapeutic target. The development of small-molecule inhibitors against TMEM16A may be clinically relevant for treatment of human cancers, including SCCHN.

Water magnetic relaxation dispersion in biological systems: The contribution of proton exchange and implications for the noninvasive detection of cartilage degradation

Magnetic relaxation has been used extensively to study and characterize biological tissues. In particular, spin-lattice relaxation in the rotating frame (T1ρ) of water in protein solutions has been demonstrated to be sensitive to macromolecular weight and composition. However, the nature of the contribution from low frequency processes to water relaxation remains unclear. We have examined this problem by studying the water T1ρ dispersion in peptide solutions (14N- and 15N-labeled), glycosaminoglycan solutions, and samples of bovine articular cartilage before and after proteoglycan degradation. We find in model systems and tissue that hydrogen exchange from NH and OH groups to water dominates the low frequency water T1ρ dispersion, in the context of the model used to interpret the relaxation data. Further, low frequency dispersion changes are correlated with loss of proteoglycan from the extra-cellular matrix of articular cartilage. This finding has significance for the noninvasive detection of matrix degradation.

DOG1: a novel marker of salivary acinar and intercalated duct differentiation

Anoctamin-1 (ANO1) (DOG1, TMEM16a) is a calcium-activated chloride channel initially described in gastrointestinal stromal tumors, but now known to be expressed in a variety of normal and tumor tissues including salivary tissue in murine models. We herein perform a comprehensive survey of DOG1 expression in 156 cases containing non-neoplastic human salivary tissues and tumors. ANO1 mRNA levels were significantly higher (8-fold increase, P<0.0001) in normal parotid tissue (n=6) as compared with squamous mucosa (n=15). By immunohistochemistry, DOG1 showed a diffuse moderate (2+) apical membranous staining pattern in normal serous acini, 1+ apical membranous pattern in mucous acini, and variable 1–2+ apical staining of distal intercalated ducts. Myoepithelial cells, striated and excretory ducts were invariably negative. All acinic cell carcinomas (n=28) were DOG1 positive demonstrating a complex mixture of intense (3+) apical membranous, cytoplasmic and complete membranous staining. Most ductal tumor types were negative or only showed a subset of positive cases. Within the biphasic tumor category, adenoid cystic carcinomas (18/24 cases) and epithelial–myoepithelial carcinomas (8/15 cases) were frequently positive, often showing a distinctive combined apical ductal and membranous/cytoplasmic myoepithelial staining profile. Thus, DOG1 staining is a marker of salivary acinar and to a lesser extent intercalated duct differentiation. Strong staining can be used to support the diagnosis of acinic cell carcinoma. DOG1 may also be a marker of a ‘transformed’ myoepithelial phenotype in a subset of biphasic salivary gland malignancies.

Endoscopic endonasal resection of esthesioneuroblastoma : A multicenter study

Background This study reports the combined experience of the University of Miami and University of Pittsburgh with endoscopic endonasal resection of esthesioneuroblastoma (ENB). A retrospective case series review was performed in a tertiary care university hospital. Methods Twenty-three patients, 16 men and 7 women, were reviewed. Mean age was 56.6 years (15-79 years). Nineteen patients received primary endoscopic endonasal anterior skull base resection. Of these, the modified Kadish stage at presentation was A in 2 patients, B in 11 patients, C in 5 patients, and D in 1 patient. Three patients had revision surgeries for recurrent tumors. The main outcome measures were complete resection and margin assessment, short-term and long-term complications, and recurrence rate. Results Complete resection and negative intraoperative resection margins were achieved endoscopically in 17 of the primarily treated cases. The two other cases had one patient that required an additional craniotomy approach to complete the resection of a positive lateral dual margin, another patient had positive margins at the orbital apex. All patients tolerated the endoscopic procedure very well with no meningitis. There were four cerebral spinal fluid leaks. Mean follow-up period for the primarily treated cases was 45.2 months (11-152 months), all were disease free at the most recent available follow-up. Conclusion In experienced hands and carefully selected patients, endoscopic resection of ENB respects the principles of oncologic surgery, providing an adequate exposure for margin assessment as well as reliable reconstruction of the anterior skull defect with a relatively low morbidity.

A new paradigm for the diagnosis and management of unknown primary tumors of the head and neck: A role for transoral robotic surgery

In 2% to 3% of patients with cancer metastatic to cervical lymph nodes, a primary tumor will not be found despite exhaustive diagnostic efforts. The treatment for these patients includes cervical lymphadenectomy followed by radiation to areas with increased risk of harboring a mucosal primary. Wide‐field radiation therapy increases the incidence of xerostomia and dysphagia. Localizing a primary tumor has thus both therapeutic and quality‐of‐life implications, allowing possible complete surgical excision, concentrated radiation therapy, and potential deintensification of adjuvant therapy. With improved visualization and freedom of motion, transoral robotic surgery (TORS) is an innovative surgical modality that allows resection of oropharyngeal subsites with minimal morbidity.

Oncologic Outcomes After Transoral Robotic Surgery : A Multi-institutional Study

IMPORTANCE Large patient cohorts are necessary to validate the efficacy of transoral robotic surgery (TORS) in the management of head and neck cancer. OBJECTIVES To review oncologic outcomes of TORS from a large multi-institutional collaboration and to identify predictors of disease recurrence and disease-specific mortality. DESIGN, SETTING, AND PARTICIPANTS A retrospective review of records from 410 patients undergoing TORS for laryngeal and pharyngeal cancers from January 1, 2007, through December 31, 2012, was performed. Pertinent data were obtained from 11 participating medical institutions. INTERVENTIONS Select patients received radiation therapy and/or chemotherapy before or after TORS. MAIN OUTCOMES AND MEASURES Locoregional control, disease-specific survival, and overall survival were calculated. We used Kaplan-Meier survival analysis with log-rank testing to evaluate individual variable association with these outcomes, followed by multivariate analysis with Cox proportional hazards regression modeling to identify independent predictors. RESULTS Of the 410 patients treated with TORS in this study, 364 (88.8%) had oropharyngeal cancer. Of these 364 patients, information about post-operative adjuvant therapy was known about 338: 106 (31.3) received radiation therapy alone, and 72 (21.3%) received radiation therapy with concurrent chemotherapy. Neck dissection was performed in 323 patients (78.8%). Mean follow-up time was 20 months. Local, regional, and distant recurrence occurred in 18 (4.4%), 15 (3.7%), and 10 (2.4%) of 410 patients, respectively. Seventeen (4.1%) died of disease, and 13 (3.2%) died of other causes. The 2-year locoregional control rate was 91.8% (95% CI, 87.6%-94.7%), disease-specific survival 94.5% (95% CI, 90.6%-96.8%), and overall survival 91% (95% CI, 86.5%-94.0%). Multivariate analysis identified improved survival among women (P = .05) and for patients with tumors arising in tonsil (P = .01). Smoking was associated with worse overall all-cause mortality (P = .01). Although advanced age and tobacco use were associated with locoregional recurrence and disease-specific survival, they, as well as tumor stage and other adverse histopathologic features, did not remain significant on multivariate analysis. CONCLUSIONS AND RELEVANCE This large, multi-institutional study supports the role of TORS within the multidisciplinary treatment paradigm for the treatment of head and neck cancer, especially for patients with oropharyngeal cancer. Favorable oncologic outcomes have been found across institutions. Ongoing comparative clinical trials funded by the National Cancer Institute will further evaluate the role of robotic surgery for patients with head and neck cancers.

A Prospective Phase 2 Trial of Reirradiation With Stereotactic Body Radiation Therapy Plus Cetuximab in Patients With Previously Irradiated Recurrent Squamous Cell Carcinoma of the Head and Neck

PURPOSE Salvage options for unresectable locally recurrent, previously irradiated squamous cell carcinoma of the head and neck (rSCCHN) are limited. Although the addition of reirradiation may improve outcomes compared to chemotherapy alone, significant toxicities limit salvage reirradiation strategies, leading to suboptimal outcomes. We therefore designed a phase 2 protocol to evaluate the efficacy of stereotactic body radiation therapy (SBRT) plus cetuximab for rSCCHN. METHODS AND MATERIALS From July 2007 to March 2013, 50 patients >18 years of age with inoperable locoregionally confined rSCCHN within a previously irradiated field receiving ≥60 Gy, with a Zubrod performance status of 0 to 2, and normal hepatic and renal function were enrolled. Patients received concurrent cetuximab (400 mg/m(2) on day -7 and then 250 mg/m(2) on days 0 and +8) plus SBRT (40-44 Gy in 5 fractions on alternating days over 1-2 weeks). Primary endpoints were 1-year locoregional progression-free survival and National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0 graded toxicity. RESULTS Median follow-up for surviving patients was 18 months (range: 10-70). The 1-year local PFS rate was 60% (95% confidence interval [CI]: 44%-75%), locoregional PFS was 37% (95% CI: 23%-53%), distant PFS was 71% (95% CI: 54%-85%), and PFS was 33% (95% CI: 20%-49%). The median overall survival was 10 months (95% CI: 7-16), with a 1-year overall survival of 40% (95% CI: 26%-54%). At last follow-up, 69% died of disease, 4% died with disease, 15% died without progression, 10% were alive without progression, and 2% were alive with progression. Acute and late grade 3 toxicity was observed in 6% of patients respectively. CONCLUSIONS SBRT with concurrent cetuximab appears to be a safe salvage treatment for rSCCHN of short overall treatment time.

A transoral highly flexible robot: Novel technology and application.

Organ preservation surgery is a major focus in head and neck oncology. Current approaches are aimed toward improving quality of life and decreasing treatment‐related morbidity. Transoral robotic surgery was developed to overcome the limitations of traditional surgical approaches. The most widely used robotic system is the da Vinci Surgical System. Although the da Vinci offers clear surgical advantages over traditional approaches, its rigid operative arms prevent complex maneuverability in three‐dimensional space. The ideal surgical robot would configure to the anatomy of the patient and maneuver in narrow spaces. We present the first cadaveric trials of the use of a highly flexible robot able to traverse the nonlinear upper aerodigestive tract and gain physical and visual access to important anatomical landmarks without laryngeal suspension.