Tissue-specific gene expression of head and neck squamous cell carcinoma in vivo by complementary DNA microarray analysis.

OBJECTIVES: To identify distinct gene expression profiles of human head and neck squamous cell carcinomas (HNSCCAs) using complementary DNA (cDNA) microarray analysis and to create a preliminary, comprehensive database of HNSCCA gene expression. PATIENTS AND METHODS: Nine patients with histologically confirmed HNSCCAs, staged according to the American Joint Committee on Cancer, were enrolled. The HNSCCA tumor tissue and normal mucosal tissue were harvested at the time of surgery. A cDNA library was constructed from the paired fresh-frozen human surgical specimens of HNSCCAs and nonmalignant epithelial tissues. Biotinylated RNA was transcribed from the cDNA library and hybridized to high-density microarrays containing approximately 12 000 human genes. Altered gene expression of HNSCCAs was identified by comparison to corresponding normal mucosal tissues after a bayesian statistical analysis of variance. Results were analyzed using the gene database of the National Institutes of Health. Hierarchical clustering of the genomic data sets was determined by similarity metrics based on Pearson correlation. RESULTS: Hierarchical clustering analysis revealed that the gene expression profiles obtained from the nonselected panel of 12 000 genes could distinguish the tumors from nonmalignant tissues. Gene expression changes were reproducibly observed in 227 genes representing previously identified chemokines, tumor suppressors, differentiation markers, matrix molecules, membrane receptors, and transcription factors that correlated with neoplasia, including 46 previously uncharacterized genes. Moreover, significant expression of the collagen type XI alpha1 gene and a novel gene was reproducibly observed in all 9 tumors, whereas these genes were virtually undetectable in their corresponding, adjacent nonmalignant tissues. CONCLUSIONS: Complementary DNA microarray analysis of human HNSCCAs has produced a preliminary, comprehensive database of tumor-specific gene expression profiles and provided important insights into modeling gene expression changes implicated in carcinogenesis. A large-scale analysis of gene expression carries the future potential of identifying sensitive molecular markers for early tumor detection, prognosis, and novel targets for interceptive therapeutics.

A precision method for contouring bioresorbable implants in craniomaxillofacial surgery.

Bioresorbable implants (meshs and plates) are increasingly used in reconstructive craniofacial and skull base surgery. Usually these implants must be contoured to fit the complex craniofacial anatomy ex vivo; occasionally final contouring is performed in vivo and must be done without damaging surrounding structures (e.g., dura, brain). We report a precision method for in vivo contouring of bioresorbable implants using the Shaw hemostatic thermal scalpel.

Sentinel node biopsy in lieu of neck dissection for staging oral cancer.

IMPORTANCE: Neck dissection is the standard staging procedure to ascertain the pathologic status of cervical lymph nodes in patients with oral cavity squamous cell carcinoma (OSCC), but it results in multiple morbidities. OBJECTIVE: To examine outcomes of patients with OSCC who underwent sentinel node biopsy (SNB) as the sole neck staging procedure. DESIGN: Retrospective review of patients who underwent SNB during the period 2005 through 2011. SETTING: National Cancer Institute­designated comprehensive cancer center. PARTICIPANTS: Thirty-eight patients with clinically T1 or T2N0 OSCC. INTERVENTIONS: Preoperative lymphoscintigraphy with intraoperative gamma probe localization was used. Sentinel lymph nodes were serially sectioned, formalin fixed, and examined at 3 levels. All patients with positive SNB results underwent neck dissection, and the patients with negative SNB results were observed clinically. MAIN OUTCOMES AND MEASURES: Sensitivity and predictive value of SNB, recurrence rates, and disease-specific survival rates. RESULTS: There were 18 T1 and 20 T2 tumors. Five patients had positive SNB results, of whom 3 had additional positive nodes on subsequent neck dissection. Two of 33 patients with negative SNB results developed a regional recurrence. The sensitivity and negative predictive value for staging the neck with SNB alone were 71% (5 of 7) and 94% (31 of 33), respectively. Mean follow-up was 31 months. The mean disease-free survival duration for patients with positive and negative SNB results was 30 and 65 months, respectively (P = .08). The disease-specific survival rate for patients with positive and negative SNB results was 80% and 91%, respectively. There was no significant difference in disease-specific survival between patients with true-negative and false-negative SNB results (34 vs 44 months; P = .38). CONCLUSIONS AND RELEVANCE: The majority of patients with positive results on SNB had additional positive nodes on neck dissection. A low rate of isolated neck recurrence was found in patients with negative results on SNB. Individuals with negative results on SNB exhibited better overall and disease-specific survival than those with positive results.

Reconstruction of segmental mandibular defects by distraction osteogenesis for mandibular reconstruction.

BACKGROUND: Distraction osteogenesis is an established technique for the lengthening of long bones and correction of selected craniofacial deformities. Regenerate osteoid bone matrix formed during the distraction phase is malleable and can recreate the three-dimensional form of native bones. Animal experiments and early clinical experience have confirmed that distraction osteogenesis can be used for the reconstruction of segmental bony defects. Herein we discuss the principles of distraction osteogenesis in reference to reconstruction of segmental bony defects and report its clinical application of the mandible continuity defects. PATIENTS AND METHODS: Four patients (age, 7-83 years) with critical segmental mandibular defects (range, 3.5 cm-6.5 cm), resulting from ablative oncologic head and neck surgery underwent primary mandibular reconstruction by transport distraction osteogenesis. Two defects were at the angle and body region, one at the body, and the other at the parasymphysis and body region. Synthes Titanium Multi-vector and Leibinger Multi-guide distractors in bifocal (n = 2) and trifocal (n = 2) architecture were used after the stabilization of the segmental continuity defect using a defect-bridging mandibular reconstruction plate. Osteodistraction was carried out at a rate of 1 mm per day, with once or twice a day rhythm, after a 1-week latency period. The consolidation period was equal to the period of distraction. RESULTS: All patients tolerated the distraction procedure. Satisfactory bone formation was observed in two patients, and partial bone formation was seen in one patient. Treatment failure was encountered in one patient who had a second oral cavity primary tumor observed during the consolidation period, requiring interruption of the treatment sequence. CONCLUSIONS: Mandibular reconstruction with distraction osteogenesis is a potentially useful technique in selected patients with segmental mandibular continuity defects after ablative head and neck cancer surgery.

Biodegradable polymer-mediated intratumoral delivery of cisplatin for treatment of human head and neck squamous cell carcinoma in a chimeric mouse model.

BACKGROUND: The effectiveness of chemotherapeutic agents is proportional to the dose of the agents at their targets; however, the dose is limited by systemic toxicity. Attempts have been made to improve therapeutic effectiveness by increasing maximum tolerated dose (MTD) of chemotherapeutic agents using various local and regional drug delivery systems. Herein we report the use of an injectable biodegradable polymer to deliver cisplatin for intratumoral treatment of human head and neck squamous cell carcinoma (HNSCC) in a chimeric mouse model. The objectives of this research project were (1) to determine the release kinetics of cisplatin from the polymer delivery system, (2) to identify the MTD of polymer-delivered cisplatin, and (3) to evaluate its therapeutic efficacy. METHODS: To determine the in vivo release kinetics, cisplatin-loaded polymer was injected subcutaneously into rats. Implants were removed and analyzed for remaining cisplatin by a high-performance liquid chromatography technique. Sera from these rats were assayed for platinum by atomic absorption spectrophotometry. For MTD determination, SCID mice were engrafted subcutaneously with fresh biopsy specimens of HNSCC. Various doses of free or polymer-loaded cisplatin were injected intratumorally. MTD was estimated based on the threshold at which all mice survived. The antitumor efficacy of free and polymer-loaded cisplatin at their respective MTD was assayed on the same chimeric mouse model. RESULTS: The polymer delivery system released 80% of the loaded cisplatin in vivo over a 7-day period. The polymer-delivered cisplatin exhibited higher MTD (36 mg/kg) than free cisplatin (18 mg/kg) and had a statistically significant tumor suppression effect compared with free cisplatin when used at their respective MTD. CONCLUSIONS: The polymer delivery system can sustain cisplatin release for a period of 7 days. It can increase MTD and potentially enhance the antitumor efficacy of cisplatin against human head and neck cancers.

Ameloblastic carcinoma: report of an aggressive case with multiple bony metastases.

Ameloblastic carcinoma is a rare primary tumor of the maxillofacial skeleton with a distinct predilection for the mandible. These lesions may initially show histologic features of ameloblastoma that dedifferentiate over time. Other ameloblastic carcinomas initially present with morphologic features suggestive of ameloblastoma with areas of epithelial dedifferentiation. We herein report a rare case of aggressive ameloblastic carcinoma in a 22-year-old white man who developed widespread bony metastases and expired 4 years after initial diagnosis.