Guanine nucleotide-binding protein 1 is one of the key molecules contributing to cancer cell radioresistance.

Standard fractionated radiotherapy for the treatment of cancer consists of daily irradiation of 2-Gy X-rays, 5 days a week for 5-8 weeks. To understand the characteristics of radioresistant cancer cells and to develop more effective radiotherapy, we established a series of novel, clinically relevant radioresistant (CRR) cells that continue to proliferate with 2-Gy X-ray exposure every 24 h for more than 30 days in vitro. We studied three human and one murine cell line, and their CRR derivatives.

Prevalence of level V metastasis in head and neck squamous cell carcinoma.

Conclusion: The results of this study accord with those of past reports about the prevalence of level V metastasis in head and neck squamous cell carcinoma (HNSCC) cases. Because of the low rate of level V metastasis, and from the viewpoint of standard postoperative radiotherapy, selective neck dissection without level V dissection may be possible in cases without clinical evidence of level V metastasis on both the ipsilateral and contralateral sides. In addition, degree of pathological differentiation and pN stage >N2b are suggested risk factors for level V metastasis.

The first report of bilateral retropharyngeal lymph node metastasis from papillary thyroid carcinoma and review of the literature.

The sites of lymph node metastasis of papillary thyroid carcinomas are typically the paratracheal and jugular lymph nodes. On the other hand, metastasis to the retropharyngeal or parapharyngeal nodes from papillary thyroid carcinomas is very rare. During the last two decades, limited to cases with a histologically definite diagnosis by surgery, only 39 cases have been reported.

Inverted papilloma of the middle ear: a case report and review of the literature.

Papilloma of the middle ear is extremely rare; to our knowledge there have been only 9 reports (13 cases) in the literature. Aggressive surgical excision is the only curative treatment and radiation therapy is necessary if there is evidence of focal squamous cell carcinoma. We describe a case of a 65-year-old male with inverted papilloma of the middle ear.

Hybrid carcinoma of the parotid gland: report of a case (epithelial-myoepithelial carcinoma and salivary duct carcinoma) and review of the literature.

Hybrid tumors of salivary glands are rare neoplasms. We describe a case of a 74-year-old male with a hybrid carcinoma composed of epithelial-myoepithelial and salivary duct carcinomas of the right parotid gland. The presence of two components was verified by differential immunohistochemical staining.

Chondrosarcoma of the nasal septum: A case report.

Chondrosarcoma make up only 10-20% of malignant primary bone tumors, with 5-10% located in the head and neck (Downey TJ, Clark SK, Moore DW. Chondrosarcoma of the nasal septum. Otolaryngol Head Neck Surg 2001;125:98-100), and nasal septal chondrosarcoma is extremely rare.

Meningioma of the paranasal sinus: a case report.

Extracranial meningioma of the paranasal sinus is a very rare condition of unclear etiology. Surgical excision is currently the only curative treatment but sometimes entails difficulties because of the complicated anatomic loci of the tumor. For the case reported here, we used a navigation system in endoscopic surgery for an extracranial meningioma of the paranasal sinus and were able to remove the tumor without complications by a transnasal approach alone.

Differences in the expression of genes between normal tissue and squamous cell carcinomas of head and neck using cancer-related gene cDNA microarray.

Conclusion: This study clearly showed the molecular characteristics of head and neck squamous cell carcinoma (HNSCC) on the basis of gene expression patterns.

Objective: cDNA microarray has recently been shown to have the ability to represent the expression patterns of large numbers of genes from a small amount of tissue, potentially enabling definition of groups of patients with similar biological behavior of cancer. Although gene expression profiling using this technique has proven helpful for predicting the prognosis in various cancers, little is known regarding HNSCC.

Identification of differentially expressed genes in salivary gland tumors with cDNA microarray.

Objective: The final goal of this study is to develop a pre-operative fine needle aspiration biopsy (FNA) diagnostic system based on gene expression profiles. As the first step to that end, the present study was performed to determine whether the cDNA microarray system is applicable for histological evaluation of parotid gland tumors.

Methods: We investigated molecular characteristics on the basis of gene expression patterns of the two most common types of salivary gland tumors (pleomorphic adenomas and Warthin tumors) and normal salivary gland tissues, using the cDNA microarray system.