Yong-Kie Wong

Outcomes of oral squamous cell carcinoma in Taiwan after surgical therapy: factors affecting survival.

PURPOSE The study goal was to determine which clinical features correlated with 5-year survival in patients surgically treated for oral squamous cell carcinoma (OSCC) in Taiwan. PATIENTS AND METHODS The records of 378 OSCC patients surgically treated with or without chemotherapy and radiotherapy were reviewed retrospectively. Their 5-year survival in relation to age, gender, tumor site, lymph node involvement, presence of distant metastasis, staging, differentiation, and risk factors, including betel quid (BQ) chewing, cigarette smoking, and alcohol consumption, was analyzed. RESULTS The majority of the patients were men (male-to-female ratio, 5.87:1) with the mean age of 57.1 +/-11.7 years. Tumors occurred mainly at the buccal mucosa (BM) (100 of 378, 26.5%), gingiva (105 of 378, 27.8%), and tongue (103 of 378, 27.2%). Neck nodal metastasis occurred frequently at the floor of the mouth (in >60% of cases), followed by the gingiva (45.7%), buccal mucosa (34%), and tongue (20.4%), whereas early distant metastasis was rare (5.3%). There were 104 (27.5%) stage 1, 96 (25.4%) stage 2, 98 (25.9%) stage 3, and 80 (21.2%) stage 4 patients. OSCC at the BM and gingiva was most (and at the tongue least) associated with risk factors of BQ use and smoking. The 5-year survival was 75%, 65.6%, 49%, and 30% for patients with stage I, II, III, and IV, respectively. The size, nodal involvement, distant metastasis, staging, differentiation, and BQ use significantly affected the survival (P <.05, Kaplan-Meier analysis). BQ use also correlated most significantly with the younger age of occurrence of OSCC patients. CONCLUSIONS Our data suggest that early treatment is the key to increasing the survival of OSCC patients. Periodic screening of high-risk populations for OSCC represents an urgent need in Taiwan.

Nutritional factors and survival of patients with oral cancer.

Our objective was to determine the survival rate of patients with oral cancer who were treated at a medical center in central Taiwan. Furthermore, we attempted to investigate whether nutritional factors influence the survival.

Risk factors for wound infection after surgery in primary oral cavity cancer patients.

Objectives: Few studies have discussed the predictive factors of surgical wound infection (WI) in primary oral cavity cancer patients. Therefore, we aimed to determine the relevant factors associated with postoperative WI in a large group of patients with oral cavity cancers.

Increased expression of amyloid precursor protein in oral squamous cell carcinoma

In our previous study, we identified amyloid precursor protein (APP) in an oral squamous cell carcinoma (OSCC)‐enriching subtractive hybridization library. Our present study attempts to define the significance of APP expression in the genesis of OSCC. RT‐PCR analysis showed increase in APP mRNA expression for more than 2‐fold in 76% of OSCC (n = 55) relative to corresponding non‐cancerous matched tissues (NCMT). The majority of esophageal SCCs also had increase in APP mRNA expression. OSCC patients exhibiting increase in APP mRNA expression had significantly lower survival rate compared to patients exhibiting the opposite status. Western blotting analysis identified APP751 and APP770 as the major APP isoforms in oral keratinocytes. A high correlation between mRNA and protein expressions of APP was noted in OSCC/NCMT pairs. Immunohistochemistry further showed a remarkable increase of APP in OSCC tissue relative to NCMT. Treatment with an antisense oligonucleotide against APP reduced cellular and secreted APP as well as growth in an OSCC cell line. Our study provides novel clues that APP expression is involved in the proliferation and carcinogenesis of OSCC. Correlated with such pathogenesis was the survival of its victims. The degree of APP expression could serve as an invaluable marker for oral carcinogenesis.

Impact of recurrence interval on survival of oral cavity squamous cell carcinoma patients after local relapse

OBJECTIVE: The aim of this study was to investigate whether the recurrence interval influenced the survival of oral cavity squamous cell carcinoma patients after relapse. STUDY DESIGN AND SETTING: Retrospective charts were reviewed at a medical center. METHODS: We retrospectively reviewed 1687 chart records of oral cancer patients. Statistical methods included descriptive statistics, bivariate analyses, Kaplan-Meier survival analyses, and Cox proportional hazard models for investigating the relationship between the recurrence interval and survival of oral cancer patients after relapse. RESULTS: Local recurrence rate was 31.3 percent. Kaplan-Meier survival analyses showed the 5-year overall survival after recurrence was 31.56 percent. Cox proportional hazard model revealed that those with recurrence interval less than 18 months tended to have a higher probability of death than those with recurrence interval greater than or equal to 18 months (relative risk, 1.743; 95% confidence interval, 1.298–2.358). CONCLUSION: The interval from initial treatment to recurrence is an independent prognostic factor for oral squamous cell carcinoma patients. Those with a shorter disease-free interval tend to have a less favorable outcome.

Prognostic Factors in Patients With Buccal Squamous Cell Carcinoma: 10-Year Experience

PURPOSE Squamous cell carcinoma (SCC) of the buccal mucosa accounts for 23% to 37% of all intraoral cancer cases in Taiwan. Because of the high recurrence rate and invasive tumor behavior, the prognosis is generally poor. The aim of this study was to evaluate the prognostic significance of clinicopathologic factors on survival rates for patients with buccal SCC in a medical center in central Taiwan. MATERIALS AND METHODS Between March 1995 and December 2002, patients admitted to hospital and diagnosed as having buccal SCC were enrolled in the study. There were 415 patients (406 men and 9 women) 25 to 84 years old (mean age, 51.1 ± 11.4 years). The chart records were retrospectively reviewed. Relevant clinical features in each patient, such as primary tumor size, tumor stage, initial treatment modalities, surgical margin status, cervical nodal metastasis status, and histopathologic grade, were compared for survival analysis. RESULTS Three hundred ninety-four patients received surgical intervention. Univariate analysis of relevant prognostic factors showed that positive surgical margin, positive cervical nodal metastasis, positive extracapsular spread, larger tumor, and advanced tumor stage were associated with poor prognosis. Multivariate analysis identified the factors that independently influenced the survival rate as advanced stage disease (stage III: relative risk [RR], 3.09; P = .006; stage IV: RR, 4.64; P < .001), positive surgical margin (RR, 2.02; P = .001), and extracapsular spread of cervical lymph node metastasis (RR, 6.89; P < .001). CONCLUSIONS This study represents the largest series in the literature and highlights the importance of tumor stage, surgical margin status, and extracapsular spread of cervical nodal metastasis as the most important prognostic factors in patients with buccal SCC.

Multiple molecular alterations of FHIT in betel-associated oral carcinoma

To determine the alterations of the FHIT (fragile histidine triad) gene in oral squamous cell carcinoma (OSCC), this study examined mutation, promoter methylation, mRNA transcription, and protein expression of FHIT in OSCC associated mostly with the use of betel and/or tobacco. Analyses of the coding exons (exons 5–9) identified a deletion of one base in intron 4 in one tumour and a deletion of exon 7 in two tumours. Using bisulphite genomic sequencing, 28% of theinformative subjects exhibited promoter methylation. An aberrant FHIT transcript spanning from exon 3 to exon 10, which was verified by RT‐PCR analysis, was identified in 36% of the OSCC subjects, 50% of the oral pre‐invasive lesions, and 5% of the non‐cancerous match tissue.An abnormal immunohistochemical level of Fhit was detected in 41% of OSCC subjects. Astatistically significant association was found between aberrant transcription of the FHIT geneand an abnormal level of Fhit immunoreactivity. The results indicated that alteration ofFHIT is a frequent occurrence in OSCC and thus suggests that the aberrance in FHIT transcription could be an early event of oral carcinogenesis. Copyright

Effects of KRAS mutation and polymorphism on the risk and prognosis of oral squamous cell carcinoma.

Mutations or single nucleotide polymorphism (SNP) of relevant genes may affect the risk and prognosis of malignancies. The purpose of this study was to analyze whether the KRAS polymorphisms and mutations can be useful prognostic or risk markers in oral squamous cell carcinoma (OSCC).

Comparison of the Effectiveness of Autologous Fibrin Glue and Macroporous Biphasic Calcium Phosphate as Carriers in the Osteogenesis Process With or Without Mesenchymal Stem Cells

Background: Facial bone reconstruction has been a challenge for oral and maxillofacial surgeons for a long time. Recently, some studies have reported the use of stem cells in facial reconstruction to achieve osteogenesis. However, to ensure that stem cells remain in the recipient site, a biocompatible carrier is needed to transfer the stem cells. Fibrin glue has been shown to promote hemostasis in wound management and accelerate soft tissue healing, but the role of fibrin glue in bone regeneration remains debatable. The purpose of this study was to compare the effectiveness of autologous fibrin glue and macroporous biphasic calcium phosphate (MBCP) as carriers in the osteogenesis process with/without mesenchymal stem cells. Methods: Fifteen New Zealand white rabbits were used in this study. Mesenchymal stem cells were harvested from the iliac bone, and autologous fibrin glue was made from peripheral blood. Three cranial defects with a diameter of 6 mm were created over the cranial bone in each rabbit. The 15 animals were separated into 2 groups. The first group contained 12 rabbits. The grafted substances placed over the regions of defect were: (1) stem cells plus autologous fibrin glue; (2) stem cells plus MBCP; (3) defect alone as control. In the second group of 3 rabbits, the cranial defects were grafted with: (1) autologous fibrin glue alone; (2) MBCP alone; (3) defect alone as control. Rabbits were sacrificed at 1, 2 and 3 months post operation. Radiography and histology were used to detect bone formation. Results: Stem cells plus autologous fibrin glue induced more bone formation 2 months post operation and more mature bone was found 3 months post operation compared with the other groups. MBCP with or without stem cells showed moderate tissue reaction, including giant cell, histiocyte and eosinophil cell accumulation. Conclusion: Using stem cells plus autologous fibrin glue as the carrier may accelerate new bone regeneration.

Osteoradionecrosis of mandible bone in patients with oral cancer—associated factors and treatment outcomes

The purpose of this study was to investigate factors associated with osteoradionecrosis (ORN) of the mandible bone in a large cohort of patients with oral cancer.