Victor Shing Howe To

MicroRNA let-7 suppresses nasopharyngeal carcinoma cells proliferation through downregulating c-Myc expression

AimsThis study aimed at evaluating the potential anti-proliferative effects of the microRNA let-7 family in nasopharyngeal carcinoma (NPC) cells. In addition, the association between let-7 suppression and DNA hypermethylation is examined.Materials and methodsLevels of mature let-7 family members (-a, -b, -d, -e, -g, and -i) in normal nasopharyngeal cells (NP69 and NP460) and nasopharyngeal carcinoma cells (HK1 and HONE1) were measured by real-time quantitative PCR. Cell-proliferation assay and c-Myc immunohistochemical staining were performed on NPC cells transfected with let-7 precursor molecules. In addition, expression changes in let-7 family members in response to demethylating agents (5-azacytidine and zebularine) were also examined.ResultsIn comparison with the normal nasopharyngeal cells, let-7 (-a, -b, -d, -e, -g, and -i) levels were reduced in nasopharyngeal carcinoma cells. Ectopic expression of the let-7 family in nasopharyngeal carcinoma cells resulted in inhibition of cell proliferation through downregulation of c-Myc expression. Demethylation treatment of nasopharyngeal carcinoma cells caused activation of let-7 expression in poorly differentiated nasopharyngeal carcinoma cells only.ConclusionOur results suggested that miRNA let-7 might play a role in the proliferation of NPC. DNA methylation is a potential regulatory pathway, which is affected when let-7 is suppressed in NPC cells. However, the extent of DNA hypermethylation/hypomethylation in regulating let-7 expression requires further elucidation.

Multivariate analysis of prognostic factors for salvage nasopharyngectomy via the maxillary swing approach

The purpose of this study was to investigate the prognostic factors for salvage nasopharyngectomy.

Early results of robotic assisted nasopharyngectomy for recurrent nasopharyngeal carcinoma.

Minimally invasive nasopharyngectomy with the da Vinci surgical robot has been shown to be a feasible operation for salvage of recurrent nasopharyngeal carcinoma. The current case series presents the early results of robotic nasopharyngectomy.

EFFICACY OF SALVAGE NECK DISSECTION FOR ISOLATED NODAL RECURRENCES IN EARLY CARCINOMA OF ORAL TONGUE WITH WATCHFUL WAITING MANAGEMENT OF INITIAL N0 NECK

Recent studies have shown that salvage treatment may be effective for early tongue carcinoma with nodal failures after watchful waiting policy. We wanted to assess the efficacy of salvage neck dissection.

Review of Salivary Gland Neoplasms

Salivary gland tumours most often present as painless enlarging masses. Most are located in the parotid glands and most are benign. The principal hurdle in their management lies in the difficulty in distinguishing benign from malignant tumours. Investigations such as fine needle aspiration cytology and MRI scans provide some useful information, but most cases will require surgical excision as a means of coming to a definitive diagnosis. Benign tumours and early low-grade malignancies can be adequately treated with surgery alone, while more advanced and high-grade tumours with regional lymph node metastasis will require postoperative radiotherapy. The role of chemotherapy remains largely palliative. This paper highlights some of the more important aspects in the management of salivary gland tumours.

Efficacy of fine‐needle aspiration in diagnosing cervical nodal metastasis from nasopharyngeal carcinoma after radiotherapy

Our purpose was to study the effect of previous radiotherapy (RT) on the efficacy of fine‐needle aspiration (FNA) in diagnosing cervical nodal metastasis in nasopharyngeal carcinoma (NPC).

Long-term hearing results and otological complications of nasopharyngeal carcinoma patients: comparison between treatment with conventional two-dimensional radiotherapy and intensity-modulated radiotherapy.

Objective: To assess the long-term audiological outcome and otological complications of nasopharyngeal carcinoma patients who have received intensity-modulated radiotherapy (IMRT) versus conventional two-dimensional radiotherapy (2 DRT). Study Design: Prospective study on the audiological outcome and otological complications 5–9 years after radiotherapy. Methodology: Patients had pure-tone audiogram before radiotherapy and 5 years after radiotherapy. Otological examination was performed 5–9 years after radiotherapy by an otolaryngologist. Results: There is a significant deterioration of the hearing threshold 5 years after radiotherapy but there is no statistically significant difference in the deterioration of hearing between IMRT and 2 DRT. Six patients in the 2 DRT group and 1 patient in the IMRT group had osteoradionecrosis of the external auditory canal (p = 0.042). Conclusion: There are fewer incidences of osteoradionecrosis of the external auditory canal in patients treated with IMRT. There is no difference in bone conduction threshold in patients treated with IMRT or 2 DRT.

Extracapsular lymph node spread in recurrent nasopharyngeal carcinoma

To study the efficacy of combined neck dissection and brachytherapy for nodal metastasis with extracapsular spread (ECS) in recurrent nasopharyngeal carcinoma (NPC).

Radiation-induced squamous cell carcinoma of the nasopharynx after radiotherapy for nasopharyngeal carcinoma.

The purpose of this study was to investigate the treatment outcome of radiation‐induced squamous cell carcinoma (SCC) of the nasopharynx after radiotherapy (RT) for nasopharyngeal carcinoma (NPC).

Secondary head and neck cancer in patients with history of hematological malignancy

Head and neck cancer is a common second cancer in patients with a history of hematological malignancies. The purpose of this study was present the clinical characteristics and treatment outcomes of this group of patients.