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Biomedical subjects

A P Yuen

Publications and source records attributed to A P Yuen.

At least 19 recordsLinked to original sources
PubMed2001

Prognostic significance of serum p53 protein and p53 antibody in patients with surgical treatment for head and neck squamous cell carcinoma.

OBJECTIVES: This study aims at investigating the prognostic values of serum p53 protein and anti-p53 antibody in patients undergoing surgical treatment for head and neck squamous cell carcinoma (HNSCC). METHODS: Serum p53 protein and anti-p53 antibody concentrations were determined by an enzyme-linked immunosorbent assay (ELISA) in 75 patients with HNSCC and 28 healthy controls. In 28 patients, formalin-fixed tumor tissues were also available for immunohistochemical staining by an anti-p53 DO7 monoclonal antibody. The results were correlated with the clinicopathologic parameters. RESULTS: The mean preoperative serum concentration of p53 protein in patients with HNSCC was significantly higher than healthy controls (59.45 pg/mL vs 16.4 pg/mL, p =.007). Preoperative serum p53 antibody was present in 23 (31%) patients and was present in one healthy control. Eighteen (62%) tumor tissues showed p53 overexpression by immunohistochemistry. The presence of serum anti-p53 antibody before operation was associated with a significantly higher incidence (65%) of nodal metastasis compared with 27% nodal metastasis in patients with absence of serum anti-p53 antibody (p =.002). CONCLUSION: Preoperative serum p53 antibody was a significant prognostic factor for nodal metastasis of HNSCC.

Adult↗
PubMed2001

A comparative study of the clinicopathological significance of E-cadherin and catenins (alpha, beta, gamma) expression in the surgical management of oral tongue carcinoma.

PURPOSE: E-cadherin and catenins are important epithelial adhesion molecules in normal epithelium. Loss of E-cadherin-catenin adhesion is an important step in the progression of many epithelial cancers. E-cadherin and catenins expression in carcinoma of the tongue were evaluated in relation to their clinicopathological features and prognostic values. METHOD: Immunohistochemical staining was carried out with E-cadherin and (alpha, beta, gamma)-catenin monoclonal antibodies for 85 surgical specimens of oral tongue carcinoma, nine matched metastatic lymph nodes, and seven locally recurrent tumours. RESULTS: There was under-expression in 85% of E-cadherin, 94% of alpha-catenin, 89% of beta-catenin, and 83% of gamma-catenin in the primary tumours. There was no correlation of E-cadherin/catenin expression with sex, age, cancer stage, and differentiation. Nodal metastasis was found in 68% of patients with weak expression of gamma-catenin compared with 9% with strong expression in primary tumours (chi-square, P = 0.02). E-cadherin was a significant prognostic factor for survival and recurrence; patients with weak E-cadherin expression had 53% 5-year survival compared with 85% with strong expression (Wilcoxon, P = 0.0159). CONCLUSIONS: Both E-cadherin and catenins were highly under-expressed in oral tongue carcinoma, metastatic lymph node, and recurrent tumour. gamma-catenin had predictive value for nodal metastasis. E-cadherin was, however, a more important prognostic factor for recurrence and survival.

Adolescent↗
PubMed2001

The clinicopathological significance of bcl-2 expression in the surgical treatment of laryngeal carcinoma.

Bcl-2 expression was studied by immunohistochemistry on laryngectomy specimens from 176 patients. Of the 176 tumours, 11% had positive bcl-2 staining. Bcl-2 expression was significantly correlated with tumour grade: 5% of well-differentiated tumours, 12% of moderately-differentiated tumours and 23% of poorly-differentiated tumours had positive expression of bcl-2. Nodal metastases were also found to be significantly related to bcl-2 expression: 36% of nodal metastases for negative bcl-2 expression compared with 70% for positive expression. The risk of nodal metastases increased significantly with the presence of bcl-2 expression, moderate or poor differentiation and supraglottic involvement. The risk of nodal metastases increased significantly with the presence of increasing numbers of risk factors: 11% without risk factor, 21% with one risk factor, 49% with two risk factors and 77% with three risk factors. Bcl-2 expression in laryngeal carcinoma is significantly correlated with tumour grade and nodal metastases. It has added prognostic value for nodal metastases together with tumour grade and site of tumour involvement.

Carcinoma, Squamous Cell↗
PubMed2001

Prospective randomized study of post-operative chemotherapy with levamisole and UFT for head and neck carcinoma.

AIMS: A prospective randomized study was conducted to evaluate the benefit of adjuvant levamisole/UFT (futraful and uracil) chemotherapy in head and neck squamous cell carcinoma. METHODS: Sixty-five patients with stage III and IV squamous cell carcinomas of oral cavity, oropharynx, hypopharynx and larynx with no distant metastasis were randomized for the chemotherapy study. Thirty-one patients were randomized for chemotherapy and two of them were subsequently excluded. In this study, a total of 29 patients on levamisole/UFT therapy and 34 patients on the control group were analysed. The main outcome was measured by the 5-year disease-free actuarial survival rate. RESULTS: The rates of distant metastasis were 10% for chemotherapy group and 32% for control group (P=0.06). The 5-year disease-free actuarial survival rates for patients with and without adjuvant chemotherapy were 57% and 39% respectively (P=0.207). CONCLUSIONS: A trend of better distant control in head and neck cancer patients with post-operative adjuvant oral chemotherapy was observed. The side effects were minimal. However, there was no statistically significant improvement in the overall long-term survival. It may be of value to conduct a large-scale multi-centre prospective randomized study to verify the efficacy of levamisole and UFT as post-operative adjuvant chemotherapy for the control of distant metastasis in high-risk population.

Adjuvants, Immunologic↗
PubMed2000

A comparison of the prognostic significance of tumor diameter, length, width, thickness, area, volume, and clinicopathological features of oral tongue carcinoma.

BACKGROUND: The present study aims at evaluation of the prognostic value of tumor size including diameter, length, thickness, width, area, and volume in the prediction of nodal metastasis, local recurrence, and survival of oral tongue carcinoma. The results will have important implications for the management of patients. METHODS: Eighty-five glossectomy specimens of oral tongue carcinoma were serially sectioned in 3 mm thickness for the tumor size evaluation with computer image analyzer. RESULTS: Among all the tumor size parameters being evaluated, tumor thickness was the only significant factor for the prediction of local recurrence, nodal metastasis, and survival. With the use of 3 mm and 9 mm division, tumor of up to 3 mm thickness has 10% nodal metastasis, 0% local recurrence, and 100% 5-year actuarial disease-free survival; tumor thickness of more than 3 mm and up to 9 mm has 50% nodal metastasis, 11% local recurrence, and 77% 5-year actuarial disease free survival; tumor of more than 9 mm has 65% nodal metastasis, 26% local recurrence, and 60% 5-year actuarial disease-free survival. CONCLUSIONS: Tumor thickness should be considered in the management of patients with oral tongue carcinoma.

Adolescent↗
PubMed2000

Cyclin D1 expression in oral squamous cell carcinomas: clinicopathological relevance and correlation with p53 expression.

The aim of the present study is to study the relationship between cyclin D1 and the clinicopathological features of oral squamous cell carcinomas. The cyclin D1 and p53 expression in oral squamous cell carcinomas from 56 patients (45 men, 11 women) was studied by immunohistochemistry using monoclonal antibodies. The correlation between cyclin D1 and the clinicopathological features of the oral cancers was evaluated. Cyclin D1 expression was found in 63% of oral squamous cell carcinomas; it was often weak but was more frequently positive in high-grade lesions (P=0.019). The expression was positively correlated with p53 expression (P= 0.06). Radiation therapy did not alter the expression of either cyclin D1 or p53 proteins. Expression of these proteins was not related to the age, gender or survival of the patients, or to stages of the tumors. The cyclin D1 expression was more frequently seen in patients with squamous cell carcinomas of oropharynx, palate, floor of mouth and gingiva. To conclude, cyclin D1 was frequently expressed in oral squamous cell carcinomas. This expression was related to the grade of the tumors and was not similar in various regions in the oral cavity, which may indicate the different tumor biology of cancers from these regions.

Adult↗
PubMed2000

Correlation of pure tone audiogram results and hearing benefit of tympanoplasty for chronic suppurative otitis media.

The aim of this study was to evaluate the correlation between pure tone audiogram results and the subjective sensation of hearing benefit of patients who had tympanoplasty for chronic suppurative otitis media. This is a prospective study of 115 patients who had tympanoplasty between 1992 and 1994. The outcome, including a pure tone audiogram and the subjective sensation of hearing benefit, was evaluated at 1 year after operation. There were 63 (55%) patients with subjective hearing benefit after the tympanoplasty. The subjective sensation of hearing benefit correlated with the magnitude of the air conduction (AC) threshold reduction, and increased from 39% for an AC reduction of less than or equal to 10 dB to 100% for an AC reduction of more than 30 dB. The effect of the interaural AC threshold difference on the subjective sensation of hearing was not significant; improvement was felt by 92% of patients when the operated ear became the better hearing ear, and by 73% of patients when the operated ear remained the worse hearing ear. There was considerable discrepancy between the subjective hearing benefit and the pure tone audiogram results. A combination of parameters, including the air-bone gap, the AC threshold, and the subjective hearing change, is recommended in reporting the results of tympanoplasty.

Audiometry, Pure-Tone↗
PubMed2000

Effect of the external nasal dilator on nasal minimal cross-sectional area in orientals as assessed by acoustic rhinometry.

OBJECTIVE: This study aimed to evaluate the effect of the external nasal dilator on the dimension of the nasal valve in Orientals. DESIGN: A cohort study of normal subjects. SETTING: Academic institution. METHODS: The nasal fossae of normal subjects were assessed by acoustic rhinometry before and after application of the external nasal dilator. MAIN OUTCOME MEASURES: The minimal cross-sectional area of the nasal fossae and the total cross-sectional area of the nose. RESULTS: Nasal fossae of 25 normal subjects were evaluated. There was a significant increase of 0.10 cm2 (SD = 0.16) or a 17% increase in the minimal cross-sectional area of the 50 nasal cavities after application of the external nasal dilator (Wilcoxon's matched-pairs signed rank test, p = .0001). A significant increase in the total minimal cross-sectional area for the whole nose after application was also present (0.19 cm2, SD = .27, or 16%; Wilcoxon's matched-pairs signed rank test, p = .0032). CONCLUSIONS: The external nasal dilator results in an increase in the minimal cross-sectional area of the nasal airway in Orientals.

Cohort Studies↗
PubMed1999

Long-term sensorineural hearing deficit following radiotherapy in patients suffering from nasopharyngeal carcinoma: A prospective study.

BACKGROUND: This was a prospective study to evaluate the effect of radical external irradiation on inner ear function after treatment of nasopharyngeal carcinoma. METHODS: Pure tone audiograms were performed at regular intervals before, after, and up to 4.5 years following completion of radiotherapy. RESULTS: Two hundred ninety-four patients (526 ears) were included. Within 3 months after radiotherapy, deterioration of bone conduction threshold at 4 kHz and pure tone average (average of 0.5 kHz, 1 kHz, and 2 kHz) were noted in 164 ears (31%) and 75 ears (14%), respectively. Patients older than 50 years and ears with threshold below 60 dB at 4 kHz before radiotherapy were significant factors (p < 0.01 and p < 0. 001) associated with a 4 kHz loss. In 40% of these ears, recovery was evident at 2 years. With follow-up for 4.5 years, the probability of significant threshold deterioration increased with time. CONCLUSION: Sensorineural hearing loss started soon after radiotherapy. Early changes could be reversible while the probability of persistent hearing loss continued to increase.

Adolescent↗
PubMed1999

Clinicopathological analysis of elective neck dissection for N0 neck of early oral tongue carcinoma.

BACKGROUND: The study aims at evaluation of the efficacy of elective neck dissection as a staging and therapeutic procedure for N0 neck of early carcinoma of the oral tongue by whole organ serial sectioning. METHODS: There were 50 stage I and II patients. The neck dissection specimens were whole organ sectioned in 3-mm intervals for the evaluation of nodal metastasis. RESULTS: There were 18 (36%) patients with subclinical nodal metastasis. The total number of metastatic nodes were 31 (1%) among all 2,826 nodes being examined. The metastatic foci had a median size of 3 mm and occupied a median of 6% of the cross sectional area of the involved nodes. The ipsilateral level II nodes were the commonest (26%) site of metastasis. Metastatic nodes were present in 34% patients who had negative preoperative radiological assessment and in 20% patients who had negative intraoperative frozen section sampling of neck nodes. Patients with subclinical nodal metastasis had a high incidence of regional recurrence (62%) and low survival (27%) when postoperative radiotherapy was not given after elective neck dissection. CONCLUSIONS: Ipsilateral level I,II,III neck dissection is an adequate diagnostic procedure for staging of the N0 neck of early oral tongue carcinoma. Its diagnostic role cannot be replaced by the available pre-operative radiological screening and intra-operative frozen section sampling. However, elective selective neck dissection is an effective but not adequate therapeutic procedure, and post-operative adjuvant radiotherapy and chemotherapy have to be considered for all pathologically positive necks.

Adolescent↗
PubMed1999

Measurement of nasal geometry by acoustic rhinometry in normal-breathing Asian children.

OBJECTIVE: The purpose of this study was to obtain normal values of nasal geometry in Asian children with no nasal problems using the acoustic rhinometry method. METHOD: Acoustic rhinometric measurement of the nasal fossae was performed in pediatric patients coming for general surgical operations with no nasal problem. RESULTS: A cohort study of 183 children in an acute care hospital with full elective and emergency surgical services was undertaken. The mean minimal cross-sectional area (MCA), which was functionally important for nasal breathing, was found to be 0.32 cm2 (SD = 0.13) and situated at 1.40 cm (SD = 0.26) from the anterior nare. Normal values for area, length, and volume of the nose in these children as a group and at different ages from 1 to 11 years old were obtained. CONCLUSIONS: Acoustic rhinometry was found to be well tolerated by the children. The MCA was confirmed to be situated at the anterior part of the nose and had a positive correlation with an increase in age.

Acoustics↗
PubMed1998

Local recurrence of carcinoma of the tongue after glossectomy: patient prognosis.

We conducted a retrospective review of the prognosis for patients with local recurrence after surgical treatment of carcinoma of the tongue. Glossectomy for squamous cell carcinoma of the tongue was performed in 167 patients. Local recurrence developed in 32 patients including 21 with local recurrence alone, 10 with locoregional recurrence and one with locodistant recurrence. The incidence of local recurrence increased with tumor stage (from 16% of T1 tumors to 46% of T4 carcinomas). Eleven (34%) patients underwent surgical salvage for local recurrence, with only one (9%) patient surviving free of carcinoma at 43 months post-surgical salvage. All of the remaining 21 patients with local recurrence were treated palliatively and all died within one year. Patients who underwent surgical salvage had significantly higher survival rates compared to those treated palliatively. Close follow-up after glossectomy is important for early detection of local recurrence amenable to surgical salvage. However, the overall prognosis for patients with local recurrence was poor, with a three-year actuarial survival rate of only 3%. Therefore, prevention of local recurrence with adequate initial surgical treatment is essential.

Adult↗
PubMed1997

Assessment of tracheoesophageal speech in a tonal language. A prospective study.

BACKGROUND: Tracheoesophageal puncture followed by insertion of a voice prosthesis is an increasingly popular method for voice rehabilitation after total laryngectomy. OBJECTIVE: To perform a functional assessment of voice produced by means of the Blom-Singer valve in a tonal language (Cantonese). DESIGN: Prospective study. SETTING: Hospital referral center. MAIN OUTCOME MEASURE: A 5-point scoring scale was adopted for 15 test items of speech assessment grouped into 4 categories: phonatory skills, articulation, additional factors, and general judgment. The sum of the scores for the 15 items was the final speech score. The final speech score was rated as poor, satisfactory, or excellent if it was in the range of less than 30, 31 to 45, or 46 to 75, respectively. RESULTS: Forty-four users of the Blom-Singer valve who had undergone total laryngectomy and primary tracheoesophageal puncture were available for functional assessment. The final speech score was poor in 2 patients (5%), satisfactory in 4 (9%), and excellent in 38 (86%). CONCLUSION: Chinese patients can speak satisfactory tonal language with the Blom-Singer voice prosthesis.

Adult↗
PubMed1997

Submucosal tumor extension in hypopharyngeal cancer.

OBJECTIVES: To study the incidence and extent of submucosal tumor extension in hypopharyngeal cancer and to evaluate the impact on the tumor recurrence and overall survival rates. METHODS: Fifty-seven resected specimens of hypopharyngeal cancer were studied in detail from January 1986 to December 1989 by use of the whole-organ, step-serial sectioning technique. RESULTS: Three types of submucosal tumor extension could be identified. Type I extension was characterized by a tumor with a smooth round contour that extended submucosally. The mucosa was thereby elevated and was detectable on gross inspection at operation. In type II extension, tongues and islands of tumor infiltrated within the submucosa, and these were not noticeable on gross examination. Skip metastasis in the submucosa where the submucosal tumor was completely separated from the main tumor bulk was classified as type III extension. Thirty-three patients (58%) had submucosal tumor extension. The frequencies (and extents of submucosal tumor extension) in the superior, medial, lateral, and inferior directions were 16% (3-10 mm), 37% (2-37 mm), 26% (2-37 mm), and 28% (3-35 mm), respectively. Two thirds of the submucosal extension was type I (22 of 33), and only 1 patient had a true skip lesion submucosally (type III extension). Type II submucosal extension was found in one third of the patients (11 of 33). This occurred significantly more often in the patients who had received radiotherapy before surgery (82% [9/11]; P < .001; 95% confidence interval, 1.28-4.44). The presence of submucosal tumor extension had no effect on the tumor recurrence and overall survival rates. CONCLUSIONS: The incidence of submucosal tumor extensions in hypopharyngeal cancer is high (58%), but most (67%) of them can be detected grossly at operation. The presence of submucosal tumor extension does not adversely affect the survival and tumor recurrence rates.

Adult↗
PubMed1997

Elective neck dissection versus observation in the treatment of early oral tongue carcinoma.

BACKGROUND: The aim of the present review is to evaluate the results of elective neck dissection and "watchful waiting" in the surgical treatment of stages I and II squamous cell carcinoma of oral tongue. METHODS: This is a retrospective study of patients with surgical treatment between January 1980 and December 1994. RESULTS: There were 63 patients including those with 34 T1 and 29 T2 carcinoma. The first sites of tumor recurrence were 5 (8%) local, 17 (27%) regional, 2 (3%) distant, 1 (2%) locoregional, and 1 (2%) both regional and distant. Of the 30 NO neck patients who had no elective neck dissection, the regional recurrence rate was 47%, and eventually 23% died of tumor related to regional recurrence. Elective neck dissection significantly reduced the regional recurrence rate to 9% and also significantly reduced the regional recurrence related mortality to 3%. Elective neck dissection also increased the 5-year disease-free actuarial survival rate to 86% compared with 55% for "watchful waiting." CONCLUSIONS: Regional recurrence was the most common cause of failure after surgical treatment of oral tongue carcinoma. Elective neck dissection significantly reduced mortality due to regional recurrence and also increased the overall survival. There was no significant difference between elective radical neck dissection and selective I, II, and III neck dissection in the improvement of treatment results. This retrospective study suggests that elective selective I, II, III neck dissection is a treatment strategy of choice for stages I and II carcinoma of the oral tongue. A prospective randomized study is worthwhile to further evaluate the benefit of elective neck dissection in the treatment of early carcinoma of the tongue.

Adult↗
PubMed1997

Prospective randomized study of thrice weekly six-month and nine-month chemotherapy for cervical tuberculous lymphadenopathy.

The aim of this study is to compare the efficacy of a thrice weekly 6-month regimen, 4S3H3R3Z3/2H3R3 (which consists of an initial 4 months of streptomycin (S), isoniazid (H), rifampicin (R), and pyrazinamide (Z) followed by 2 months of isoniazid and rifampicin), with a thrice weekly 9-month regimen, 4S3H3R3Z3/5H3R3 (which consists of an initial 4 months of streptomycin, isoniazid, rifampicin, and pyrazinamide followed by 5 months of isoniazid and rifampicin), in the treatment of cervical tuberculous lymphadenopathy. A total of 113 patients were recruited between August 1987 and December 1993. Twenty-two patients were excluded from the analysis because of defaulting treatment or modification of regimen. Ninety-one patients were included in the analysis. Forty-three patients were given the 6-month regimen, and 48 patients were given the 9-month regimen. Two (5%) patients of the 6-month regimen and one (2%) patient of the 9-month regimen had primary failure after completion of treatment (relative risk, 2.23; 95% confidence interval, 0.21 to 23.76). Of the 88 patients who had initial clinical remission after completion of treatment, the 5-year actuarial remission rates were 89% for the 6-month regimen and 90% for the 9-month regimen (Wilcoxon, p = 0.44). There were no significant differences of both primary failure rate and 5-year actuarial remission rate of the two regimens. The 6-month regimen is recommended as the initial treatment of tuberculous lymphadenopathy.

Administration, Oral↗
PubMed1997

Expression of p53 in recurrent nodal metastasis from nasopharyngeal carcinoma (NPC).

This study reports the incidence of p53 expression in 40 patients with recurrent nodal metastasis from nasopharyngeal carcinoma (NPC) and its prognostic value in this group of patients. Immunohistochemical staining using monoclonal antibody specific for human p53 protein was performed on the tumour-bearing nodes from 40 patients. The results were divided into four grades (I, negative; II, < 10% of cells positive; III, 10-50% of cells positive; and IV, > 50% of cells positive). The staining scores were correlated with histological tumour types, subsequent recurrence and survival. All patients had undergone neck irradiation. Lymph node specimens from six patients (15%) showed positive staining of nuclear p53 protein. The distribution among the different grades was: three (7.5%) for II, two (5%) for III and one (2.5%) for IV. Patients with p53-overexpressed tumours had a significantly higher number of tumour-bearing lymph nodes. There was no correlation of p53 expression with histological tumour types, second tumour recurrence and survival. Expression of p53 appears to be uncommon in patients with recurrent nodal metastases in NPC. It did not have prognostic value in this particular series of patients.

Adult↗