Raymond K. Tsang

Array-based comparative genomic hybridization analysis identified cyclin D1 as a target oncogene at 11q13.3 in nasopharyngeal carcinoma

Nasopharyngeal carcinoma is highly prevalent in Southern China and Southeast Asia. To unveil the molecular basis of this endemic disease, high-resolution comparative genomic hybridization arrays were used for systematic investigation of genomic abnormalities in 26 nasopharyngeal carcinoma samples. A comprehensive picture of genetic lesions associated with tumorigenesis of nasopharyngeal carcinoma was generated. Consistent chromosomal gains were frequently found on 1q, 3q, 8q, 11q, 12p, and 12q. High incidences of nonrandom losses were identified on chromosomes 3p, 9p, 11q, 14q, and 16q. In addition to previously characterized regions, we have identified several novel minimal regions of gains, including 3q27.3-28, 8q21-24, 11q13.1-13.3, and 12q13, which may harbor candidate nasopharyngeal carcinoma-associated oncogenes. In this study, gain of 11q13.1-13.3 was the most frequently detected chromosomal aberration and a 5.3-Mb amplicon was delineated at this region. Within this 11q13 amplicon, concordant amplification and overexpression of cyclin D1 (CCND1) oncogene was found in nasopharyngeal carcinoma cell lines, xenografts, and primary tumors. Knockdown of cyclin D1 by small interfering RNA in nasopharyngeal carcinoma cell lines led to significant decrease of cell proliferation. The findings suggest that cyclin D1 is a target oncogene at 11q13 in nasopharyngeal carcinoma and its activation plays a significant role in nasopharyngeal carcinoma tumorigenesis.

Strong Immunohistochemical Expression of Vascular Endothelial Growth Factor Predicts Overall Survival in Head and Neck Squamous Cell Carcinoma

BackgroundHead and neck squamous cell carcinoma (HNSCC) has high morbidity and mortality, and its relationship with tumor angiogenesis as measured by mircovessel density (MVD) or vascular endothelial growth factor (VEGF) expression has shown mixed results, with some, but not others, reporting correlation with outcome.MethodsA retrospective study of 186 patients with HNSCC was performed. Patients were evaluated for MVD and VEGF and to correlate the levels with clinical parameters, including age at diagnosis, sex, site of tumor, stage, survival (disease free and overall), pathological tumor grade, and the presence of lymph node metastases.ResultsThe 186 cancers included the following sites: oral tongue (n = 69), palate (n = 9), maxillary sinus (n = 8), floor of mouth (n = 13), oropharynx (n = 27), hypopharynx (n = 26) and larynx (n = 34). Over three-quarters of patients had advanced tumor (stage III/IV) and 58.6% had lymph node metastases. MVD and VEGF were assessed in 166 and 164 cases, respectively, but these were not correlated with site and grade. The 3-year overall and disease-free survival rates were 55.4% and 53.2%, respectively. Both univariate and multivariate survival analysis showed that advanced T stage, nodal metastasis, and strong VEGF intensity were independent adverse predictors for overall and disease-free survival. In stage IV disease, strong VEGF immunoreactivity was found to be the single adverse factor affecting the overall survival and a contributory factor for disease-free survival.ConclusionsVEGF immunoreactivity is a strong predictor of adverse outcome, particularly in locoregionally advanced disease.

Combined transnasal endoscopic and transoral robotic resection of recurrent nasopharyngeal carcinoma

We report a case of resecting a recurrent nasopharyngeal carcinoma using a combined technique of transoral robotic surgery and transnasal endoscopic surgery.

Sensitivity and specificity of Epstein-Barr virus IgA titer in the diagnosis of nasopharyngeal carcinoma: A three-year institutional review

IgA antibody titers to the Epstein‐Barr virus (EBV) viral capsid antigen (EBV IgA‐VCA) and to the EBV early antigen (EBV IgA‐EA) are used to screen for nasopharyngeal carcinoma (NPC). This study evaluates the sensitivity and specificity of EBV IgA‐VCA and EBV IgA‐EA titers in screening patients for NPC and in those diagnosed with NPC at our institution.

Transoral robotic surgery of the parapharyngeal space: a case series and systematic review.

The purpose of this study was to evaluate the current use of transoral robotic surgery (TORS) in the treatment of parapharyngeal space (PPS) neoplasms through a case series and systematic analysis.

The Nuclear Localization of NFκB and p53 Is Positively Correlated with HPV16 E7 Level in Laryngeal Squamous Cell Carcinoma

The interaction between the HPV (human papilloma virus) 16 E7 and other cell growth factors, such as p53 and NFκB in laryngeal cancer is not clearly understood. The aim of this study was to examine the expression of these three proteins in tumor and non-tumor laryngeal tissues from patients with laryngeal squamous cell carcinoma. These three proteins were dominantly expressed in the nucleus and their levels were higher in the tumor tissue than in the non-tumor tissue, although the comparison between the tumor and non-tumor tissues of p53 staining did not reach significance. The intensity of the nuclear stain of E7 and p53 was stronger than that of p65, a subunit of NFκB. Correlation analysis revealed that there was a positive relationship between the level of HPV16 E7 and the expression of p65. The correlation between E7 and p53 was also significant, although to a lesser degree. The finding of nuclear localization of p65 suggests that NFκB is constantly activated in the laryngeal cancer cells, whereas the sequestration of p53 in the nucleus may represent a mutated form of p53, which is probably inactivated by HPV16 oncoproteins. In conclusion, this study suggests that the nuclear localization of NFκB and p53 may play a role in the development of human laryngeal squamous cell carcinoma infected with HPV16.

Nasopharyngectomy for locally advanced recurrent nasopharyngeal carcinoma: Exploring the limits

The purpose of this study was to present the outcome of nasopharyngectomy for locally advanced recurrent nasopharyngeal carcinoma (NPC).

Transoral robotic assisted nasopharyngectomy via a lateral palatal flap approach

INTRODUCTION Nasopharyngectomy has been established as a feasible curative treatment for salvaging recurrent nasopharyngeal carcinoma after radical radiotherapy. A large case series has also shown that the overall survival rate in nasopharyngectomy is comparable with reirradiation in small recurrent tumors. However, reirradiation has significant late complications from radiotherapy, and surgical salvage can avoid these complications. Open approach nasopharyngectomy usually requires osteotomies to the facial skeleton and a facial incision. To further decrease the morbidity of nasopharyngectomy, transnasal endoscopic approaches for resection of small recurrent tumors in the nasopharynx have been reported. Our unit has also reported our experience in nasopharyngectomy with a surgical robot. Nasopharyngeal carcinoma most commonly arises from the lateral aspect of the nasopharynx, in the fossa of Rosenmuller. The tumor frequently extends laterally into the parapharyngeal space. Endoscopic nasopharyngectomy with en bloc removal of the tumor in the parapharyngeal space is a challenging operation requiring a team skilled in the four-hands technique of endoscopic transnasal skull base surgery and removal of bones in the medial, posterior, and lateral wall of the maxillary antrum. Our previous description of robotic nasopharyngectomy employed a midline soft-palate split for exposure of the nasopharynx. Coupled with the versatile motion of the EndoWrist R instrument (Intuitive Surgical Inc., Sunnyvale, CA), this allowed en bloc resection of the lateral part of the nasopharynx. However, the lateral reach was still limited by the lateral soft palate. To refine the approach, we modified the approach to the nasopharynx with a lateral palatal flap approach instead of the midline soft-palate split. This lateral palatal flap approach has been devised in a cadaveric dissection. We have performed transoral robotic-assisted nasopharyngectomy of recurrent nasopharyngeal carcinoma via the lateral palate flap approach for a patient with recurrent nasopharyngeal carcinoma and now report our technique and result.

TREATMENT OF PROFUSE EPISTAXIS IN PATIENTS IRRADIATED FOR NASOPHARYNGEAL CARCINOMA

Background:  Profuse epistaxis in patients with nasopharyngeal carcinoma (NPC) previously treated with radiotherapy (RT) can be life threatening. Surgical means to prevent rebleeding may at times be difficult and unsuccessful. We aim to investigate the characteristics of this group of patients and our experience of endovascular embolization technique in the management of epistaxis in this group of patients.

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.