Ngan-Ming Tsang

Nasal NK/T Cell Lymphoma in Taiwan: A Clinicopathologic Study of 22 Cases, with Analysis of Histologic Subtypes, Epstein-Barr Virus LMP-1 Gene Association, and Treatment Modalities

Nasal NK/T cell lymphoma is a distinctive type of extranodal lymphoma with an unique immunophenotype and a strong association with Epstein-Barr virus (EBV). It is one of the common extranodal lymphomas in Taiwan. We studied 22 cases of nasal NK/T cell lymphoma to characterize their clinicopathologic features and to explore the possible differences between histologic subtypes and their clinical behavior as well as the prevalence of 30-base pair (bp) deleted latent membrane protein-1 (LMP-1) gene of the EBV. They consisted of 5 cases of small cell type (SC), 6 cases of medium-sized cell type (MC), 6 cases of large cell type (LC), and 5 cases of pleomorphic cell type (PC). Twelve patients were men and 10 were women (1.2 to 1), and their ages ranged from 34 to 75 years with a median age of 55.5 years. The median ages of the LC type and PC type were older than the other 2 types. No other clinical features differed significantly among the 4 subtypes. Nasal obstruction was the most common initial presenting symptom. All but 1 case had stage IE disease at the time of diagnosis. Five cases developed extranasal involvement and skin was the most common site. No bone marrow involvement was detected. The majority of patients received local radiotherapy and chemotherapy. Local irradiation was more effective than chemotherapy alone. We achieved an overall survival of 63.6% at 5 years as estimated by the Kaplan-Meier analysis, which was better than other series. All cases displayed an immunophenotypic profile of CD3ε+, CD20-, CD56+, and TIA-1+ except that 1 case was CD3ε-. Fourteen of 22 cases (64%) expressed LMP-1. Nine cases of various cell types (41%) were also CD30+. Among the 4 histologic subtypes, the SC type differed from the other types by the absence of angiodestruction and necrosis, although angioinvasive growth was seen in 2 of them. Pseudoepitheliomatous hyperplasia was seen in only 3 cases of the SC type, and all 5 cases of the SC type were CD30-. No statistical difference in survival was found among the 4 histologic subtypes or between CD30+ and CD30-cases. All 22 cases were positive for EBV by polymerase chain reaction and Epstein-Barr virus early RNA (EBER) in-situ hybridization. A high prevalence rate of 86% (19/22) of the 30-base pair (bp) deleted LMP-1 gene was found, but 81.5% (22/27) of the EBV-positive control reactive lymphoid tissues also had the 30-bp deleted LMP-1 gene. Therefore, the high prevalence of the 30-bp deleted LMP-1 gene found in NK/T cell lymphoma could be due to the high prevalence of the deleted variant in this geographic region. However, it remains possible that the high prevalence of the deleted LMP-1 gene contributed to the increased incidence of EBV-associated nasal NK/T cell lymphoma in Taiwan.

Nasopharyngectomy for recurrent nasopharyngeal carcinoma: a review of 53 patients and prognostic factors

Conclusions. Salvage surgery is a justified treatment for primary recurrence of nasopharyngeal carcinoma (NPC). Skull base surgery can play a role in rescuing patients with more advanced local recurrence of NPC. Objectives. The purpose of this study was to report the local control and overall survival outcome of patients with (NPC) with local failure who received salvage nasopharyngectomy and to identify prognostic factors. Patients and methods. Fifty-three consecutive patients who had primary recurrence of NPC and underwent salvage surgery with curative intention from July 1993 to December 2006 were retrospectively reviewed. The follow-up time ranged from 5.1 to 142.2 months. The numbers of cases of recurrent NPC stage were as follows: stage I, 26; stage II, 9; stage III, 10 and stage IV, 8. Fifty patients had one course of radiation therapy while 3 had two courses of radiation therapy before the salvage surgery. For the nasopharyngectomy, 2 patients underwent endoscopic approach and 33 underwent facial translocation, while 18 had craniofacial resection. Postoperative adjuvant treatment included radiation therapy, 4 cases; radiosurgery, 8 cases; concurrent chemoradiation therapy, 7 cases; and chemotherapy, 2 cases. Results. The 5-year local control rates were T1, 58.3%; T2, 27.8%; T3, 53.3%; T4, 75.0%; and all stages, 53.6%. The 5-year overall survival rates were stage I, 64.8%; stage II, 38.1%; stage III, 25.9%; stage IV, 46.9%; and all stages, 48.7%. Multivariate analysis revealed that gender, margin status, adjuvant treatment type and parapharyngeal space involvement were significant impact factors of local control, whereas dura or brain involvement, local recurrence and adjuvant treatment type were significant impact factors of survival.

Screening nasopharyngeal carcinoma by detection of the latent membrane protein 1 (LMP-1) gene with nasopharyngeal swabs

Nasopharyngeal carcinoma (NPC) is a common head and neck cancer in Taiwan. The goals of the current study were to investigate whether a nasopharyngeal swab technique could provide enough DNA for polymerase chain reaction (PCR) analysis of the Epstein–Barr virus (EBV)–derived latent membrane protein 1 (LMP‐1) gene and to determine the feasibility and reliability of diagnosing NPC by detection of LMP‐1 in the nasopharynx.

Treatment of Squamous Cell Carcinoma of the Retromolar Trigone

Objectives: Retromolar trigone (RMT) squamous cell carcinoma is uncommon but notorious for poor prognosis. We reviewed our experience in the management of RMT cancer to determine survival rates and to identify prognostic factors.

Linear accelerator-based radiosurgery in the management of skull base meningiomas.

From May 1994 to December 1999, 43 patients with meningiomas in the base of the skull underwent linear accelerator (LINAC)-based stereotactic radiosurgery (SRS) at Chung Gung Memorial Hospital. SRS was performed as a primary treatment in 14 patients, and after resection in 29 patients. The mean tumor volume was 5.68u2009cc, and the mean target surface dose was 16u2009Gy, delivered with an average of three isocenters. The median follow-up was 74.5 months. The 7-year local control rate and 7-year overall survival rate were 89.7% and 80.2%, respectively. The 7-year local control was 100% and 84.4% in SRS alone group and surgical excision with SRS group (p = 0.21), respectively. A stationary tumor following SRS was seen in 23 (53.5%) patients, partial shrinkage was seen in 16 (37.2%) patients, and complete disappearance in one patient was seen (2.3%). Furthermore, disease progression was noted in three (7%) patients, one of whom died of disease. The median time to tumor response was 15.4 months (range 5.8–52.8 months). Cases remained stable or had improved neurological statuses without any deterioration in 37.9% and 78.7% of the groups treated with surgery and SRS and SRS alone, retrospectively. In summary, LINAC-based SRS is an effective and safe modality of treating unresectable or partially resected meningiomas in the base of the skull. For tumors with diameters of 3u2009cm or less, particularly in patients without or with minimal clinical neurological symptom, SRS alone can provide a good local control without causing cranial neuropathy.

Plasma epstein‐barr virus DNA concentration and clearance rate as novel prognostic factors for metastatic nasopharyngeal carcinoma

To investigate the pretreatment copy number and the clearance rate of plasma Epstein‐Barr virus (EBV) DNA as novel prognostic outcome markers for metastatic nasopharyngeal carcinoma (NPC).

Histological differentiation of primary oral squamous cell carcinomas in an area of betel quid chewing prevalence

OBJECTIVES: This study evaluated associations between the histological differentiation of oral squamous cell carcinoma and additional clinicopathological manifestations, adverse events after treatment, and the outcomes of patients in a region prevalent for betel quid chewing. STUDY DESIGN: Case series with chart review. SETTING: Tertiary referral center. SUBJECTS AND METHODS: A total of 150 patients with primary oral squamous cell carcinomas who underwent surgery with or without adjuvant therapy were enrolled. RESULTS: Well, moderate, and poorly differentiated oral squamous cell carcinomas were reported in 54 (36%), 84 (56%), and 12 (8%) patients, respectively. There were no significant differences among different histological differentiations in age, sex, tumor, node, metastasis stage, bone invasion, depth of invasion, and history of carcinogen exposure. However, we found significant associations between tumor histological differentiation and nodal metastasis (P < 0.0001), extracapsular spread (P = 0.002), and perineural invasion (P < 0.0001). In the analysis of adverse events for survival during patient follow-up, oral squamous cell carcinomas with poor differentiation had a higher probability of developing neck recurrence (P = 0.001) and distant metastasis (P = 0.019), but not local recurrence or a second primary cancer. For survival analysis, univariate analysis showed that patient age, tumor stage, extracapsular spread, presence of perineural invasion, and tumor differentiation were significant factors. Multivariate analysis further demonstrated that poor differentiation (P = 0.007) was still a statistically significant factor. CONCLUSION: The current study demonstrates that poorer tumor histological classifications of oral squamous cell carcinoma are significantly associated with positive nodal status, extracapsular spread, perineural invasion of primary tumors, and the probability of developing neck recurrence and distant metastasis after treatment.

The role of supraomohyoid neck dissection in patients of oral cavity carcinoma

The aim of this study was to evaluate the role of supraomohyoid neck dissection (SOHND) in oral carcinoma patients with clinically negative neck nodes. From July 1993 to June 1998, 140 patients with oral carcinomas and clinically negative lymph nodes in the neck underwent elective SOHND in Chang Gung Memorial Hospital, Taiwan. Thirty-seven patients had postoperative radiotherapy.Thirty-four (24.3%) patients had occult cervical metastases. The overall regional control rates were 93.4% vs. 85.3% for pathologically negative vs positive nodes, respectively, with or without adjuvant radiotherapy. Adjuvant radiotherapy significantly improved ipsilateral regional control (P=0.012) in patients with occult cervical metastases but not in patients with negative neck disease. (P=1.0) SOHND is both a diagnostic and therapeutic procedure in patients with negative neck disease. Its therapeutic role in patients with positive neck disease remains controversial. Postoperative radiotherapy significantly improve ipsilateral neck control in patients with occult cervical metastasis.

Endoscopic management of skull base osteoradionecrosis.

Objective Osteoradionecrosis is one of the most serious complications in radiotherapy of nasopharyngeal carcinoma. We describe a new endoscopic approach to resolve resultant skull base osteoradionecrosis. The objective of this study is to evaluate the efficacy of endoscopic management of skull base osteoradionecrosis.

Molecular Diagnosis of Nasopharyngeal Carcinoma: Detecting LMP-1 and EBNA by Nasopharyngeal Swab

OBJECTIVES: The aim of this study was to investigate the feasibility of molecular diagnosis of nasopharyngeal carcinoma (NPC) by combining nasopharyngeal swab and polymerase chain reaction (PCR) to detect Epstein-Barr virus (EBV) derived latent membrane protein-1 gene (LMP-1) and Epstein-Barr nuclear antigen gene (EBNA). METHODS: 437 adults underwent nasopharyngoscopy, possible biopsy, and nasopharyngeal swab to obtain nasopharyngeal cells for the detection of LMP-1 and EBNA by PCR. RESULTS: By detecting LMP-1 and EBNA in the nasopharyngeal swabs, NPC could be diagnosed with a false-positive rate of 1.7% (6/354), a false-negative rate of 8.6% (6/70), a sensitivity of 91.4% (64/70), a specificity of 98.3% (348/354), positive predictive value of 91.4% (64/70), and negative predictive value of 98.3% (348/354). CONCLUSION: Detecting EBV genomic LMP-1 and EBNA by nasopharyngeal swab verifies NPC with a sensitivity of 91.4% and specificity of 98.3%. The nasopharyngeal swab coupled with PCR based EBV LMP-1 and EBNA detection could serve as a good supplement to pathological diagnosis of NPC.