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Dental Articulators↗
Biomedical subjects
S F Leung
Publications and source records attributed to S F Leung.
Prognostic factors in nasopharyngeal carcinoma investigated by computer tomography--an analysis of 659 patients.
A total of 659 freshly diagnosed nasopharyngeal carcinoma (NPC) (1984-1987), were investigated by computed tomography (CT), treated with locoregional radiotherapy to radical dose, and given neoadjuvant chemotherapy (CHEMO) with 2-3 courses of cisplatinum and 5-fluorouracil for bulky (greater than or equal to 4 cm) cervical nodal metastasis and booster radiotherapy (PPB) for parapharyngeal disease. All except 15 patients were fully evaluable with complete data entry till death or to the last follow-up (minimum 2 years). The data have been analysed extensively to identify variables of potential prognostic significance. The assessed factors include patients' sex and age, nasal involvement (NAS), oropharyngeal involvement (ORO), parapharyngeal involvement (PAR), muscle involvement (MU), skull base involvement (BS), cranial nerves (II-VIII) palsy (CN1), cranial nerves (IX-XII) palsy (CN2), intracranial extension (IC), laryngopharyngeal extension (HYP), confinement to nasopharynx (NP), Ho's N-stage (Nho), maximal nodal size (Nmax), nodal mobility (Nf- fixed, Npf- doubt in mobility, Nm- mobile), nodal laterality (unilateral, contralateral, bilateral), nodal multiplicity (single, multiple), and presentation with distant metastasis (M1). These factors have been assessed as to their interdependence and correlation with the clinical course (study endpoints) using both monovariate analyses and Cox's Regression model. Significant association among Ho's T2 and T3 features was identified. Advanced Ho's N-stage correlated significantly with bulky nodes, multiple nodes, fixed nodes, and, contralateral and bilateral nodes. Poor prognostic factors found to be significant by both monovariate analyses and Cox's Regression model included the M1, Nho (advanced), CN1, BS, and CN2 for the actuarial survival (ASR) for all patients (659), the Nho (advanced), CN1, CN2, and BS for the ASR for the non-metastatic patients (628), the absence of NP and the male sex for the local failure rate (628), the Nho (advanced), CN2, and BS for the distant metastasis rate (628), and the Nho (advanced), CN1, and BS for the disease-free survival (DFS) (628). In addition, old age, male sex, and the presence of parapharyngeal disease were probably significant in predicting poor survival (ASR); CN1 was probably significant in predicting more local failures, and, the parapharyngeal disease and the intracranial extension for more distant metastases. The Ho's N-staging is superior to the other N-stage classifications, because once the Ho's N-stage has been determined, other nodal characteristics including nodal size, multiplicity, laterality, and fixity, are prognostically insignificant.
Age Factors↗
Soft tissue sarcoma: the experience of a regional hospital in Hong Kong.
The clinical features and treatment results of 66 soft tissue sarcomas (STS) were reported from a regional hospital in Hong Kong. The nature of the locoregional treatment and the grade were the chief prognostic factors governing survival and local control. Radical surgery (amputation/radical local resection) was determined by the site, the extent of the STS and potential functional loss. Complete resection with a variable margin followed by post-operative radiotherapy (60-70 Gy) produced survival and local tumour control similar to that of radical surgery. Incomplete surgery (partial excision/biopsy only) was associated with significantly poorer, survival and local tumour control, despite the administration of radiotherapy. Palliative chemotherapy for metastatic or recurrent STS has been disappointing, with low tumour response rates, while first line and adjuvant chemotherapy was difficult to assess for its efficacy in the present study. The overall survival of non-metastatic STS was comparable to that reported from developed countries. Suggestions are made to improve treatment results of STS in Hong Kong.
Actuarial Analysis↗
High-dose-rate remote afterloading irradiation of carcinoma of the cervix in Hong Kong: unexpectedly high complication rate.
One hundred and thirty-six patients with biopsy-proven carcinoma of cervix were treated with external beam irradiation to the whole pelvis (46 Gy in 23 fractions) and three weekly applications of high-dose-rate (HDR) intracavitary brachytherapy of 7 or 8 Gy per fraction to point A (2 cm above and 2 cm lateral to the cervical os). The actuarial 5-year survival rate was 72% (Stage IB 85%; IIA 64%; IIB 70%; IIIA 25%; IIIB 53%). Patient age above 61 years and Stage III disease were adverse determinants for survival as shown by multivariate analysis. Late complications developed in 47% (65/137) of patients. Grade 3 or above complications occurred in the bladder, small bowel and sigmoid colon/rectum in 5%, 3% and 7% of patients, respectively. The most significant determinant of severe rectal complications was the addition of a lower vaginal tandem (P less than 0.01); the other determinants of rectal complications included a uterine length greater than 5 cm, a total biologically effective dose to the rectum of more than 120 Gy3 and Stage III disease.
Adult↗
Expression of beta-2-microglobulin by nasopharyngeal carcinoma.
Serum beta-2-microglobulin (beta 2M) levels of 274 Chinese patients with different stages of nasopharyngeal carcinoma at presentation and that of 35 patients who developed distant metastases post-treatment were assayed. beta 2M level was found to increase with advancing stage of disease, with statistically significant differences among early-stage, advanced-stage, and metastatic disease. Elevated pre-treatment beta 2M levels were expressed more frequently by tumours with lower degree of histological differentiation. The sensitivity of serum beta 2M for diagnosis of nasopharyngeal carcinoma, however, is low.
Female↗
Combined chemotherapy and radiotherapy versus best supportive care in the treatment of inoperable non-small-cell lung cancer.
Between October 1984 and July 1988, 119 patients with limited-stage inoperable non-small-cell lung cancer (NSCLC) were randomized to receive either active treatment (arm 1) or best supportive treatment (arm 2). Arm 1 patients received 3 courses of chemotherapy with cisplatin (100 mg/m2, day 1) and etoposide (125 mg/m2 i.v., day 1; 250 mg/m2 p.o., day 2-3), followed by radiotherapy (4,000 cGy/20 fractions/4 weeks). Arm 2 patients only received best supportive care. Fifty-three and 66 patients were randomized to arms 1 and 2, respectively. Thirty-eight patients in arm 1 and 57 in arm 2 were evaluable for survival. Median survivals of arms 1 and 2 were 12.4 and 8.7 months, respectively (p = 0.047). In the multivariate analysis, only age and histology were independent prognostic variables in predicting survival. The overall response rate after chemotherapy was 20.6% (complete remission 5.9%, partial remission 14.7%). Toxicities were mainly anemia, leukopenia, vomiting and alopecia. This study suggests that active treatment has marginal survival benefit in NSCLC though with considerable toxicities.
Actuarial Analysis↗
Asymptomatic temporal lobe injury after radiotherapy for nasopharyngeal carcinoma: incidence and determinants.
Computed tomography (CT) scans were performed on a cohort of 60 patients for detection of temporal lobe injury (TLI) at 1-3.5 years after radiation therapy for nasopharyngeal carcinoma. Nine cases of TLI were identified, five of which were asymptomatic. The earliest case of asymptomatic TLI was found at 2.2 years after radiation therapy and the earliest symptomatic case at 2.3 years. A significantly higher incidence of TLI was found in patients with decreased temporal lobe shielding consequent to omitted eyeshield to the anterior photon beam and in patients treated with a hyperfractionation schedule giving 67.2 Gy in 42 fractions in 6 weeks. The incidence in these subgroups at 2-3.5 years after radiation therapy was 56% (5/9 patients) and 35% (8/23 patients), respectively. No patient in this study had TLI in the absence of these two factors. The implications of the results are discussed.
Dose-Response Relationship, Radiation↗
Efficacy of low-dose iodine-131 ablation of post-operative thyroid remnants: a study of 69 cases.
Low-dose iodine-131 of mean activity 1117 MBq was used to ablate post-operative thyroid remnants in 69 patients with differentiated thyroid cancer. Successful ablation was defined as uptake of less than 1% at 48 h and absence of visible image on the post-ablation scan. Ablation by one dose was successful in 95% of patients after total or subtotal thyroidectomy, and 56% of patients after partial or hemithyroidectomy. All patients with uptake of 10% or less on the pre-ablation scan had successful ablation. The results are compared with other reports using low-dose radioiodine ablation and the significance of the findings discussed.
Adenocarcinoma↗
A comparison of Ho's, International Union Against Cancer, and American Joint Committee stage classifications for nasopharyngeal carcinoma.
Five hundred sixty-four nasopharyngeal carcinomas (NPC), mostly of undifferentiated histologic type, were studied for survival, distant metastasis, and local recurrence. All had computerized tomography of the nasopharynx and skull base (CT-NP) and fiberoptic nasopharyngoscopy for evaluation of the primary tumor. Regional disease was assessed by palpation. A computer data base was formed on presentation, containing all information required for staging according to Ho's, the International Union Against Cancer (UICC), and the American Joint Committee (AJC) classifications. The three were compared for their efficacy in predicting prognosis. Ho's classification was superior to the other two because its overall stages differed from one another more significantly in the actuarial survival (ASR), disease-free survival (DFS), and freedom from distant metastasis (FDM) rates, and its N staging was more accurate in predicting FDM. Stages T1 and T2 of UICC/AJC were similar in the freedom from local recurrence rate (FLR) and should be grouped together, equivalent to Ho's T1. A more even patients number distribution among the stages also favored the use of Ho's classification.
Carcinoma↗
Staging bone scintigraphy in nasopharyngeal carcinoma.
Bone scintigraphy was performed on 163 new cases of nasopharyngeal carcinoma without clinical evidence of distant metastases. Among the 10 abnormal bone scans one patient had radiographic skeletal metastases corresponding to the areas of increased tracer uptake. Two patients with abnormal bone scans subsequently developed radiographic metastases at the site of abnormal tracer uptake. The detection rate of asymptomatic skeletal metastases on presentation was thus 1.8% (3/163), and the predictive value of an abnormal scan for metastases 30% (3/10). Bone scintigraphy is not justified as a routine staging investigation for nasopharyngeal carcinoma, although it can be considered for a subset of patients considered at high risk of distant metastases.
Bone Neoplasms↗
Staging abdominal ultrasonography in nasopharyngeal carcinoma.
Abdominal ultrasonograms were performed on 81 unselected patients with newly-diagnosed nasopharyngeal carcinoma without clinical evidence of distant metastases. Two patients had ultrasonographic features suspicious of, but not diagnostic of, hepatic metastases. One of these two patients developed hepatic metastases six months after the examination while the other was free of metastases at follow-up 33 months afterwards. Of the 79 patients without evidence of metastases on ultrasonogram, two developed hepatic metastases after 22 and 32 months. Based on these results, we do not recommend abdominal ultrasonography as a routine staging investigation for nasopharyngeal carcinoma.
Carcinoma↗
Epstein-Barr virus in oropharyngeal and nasopharyngeal secretions of patients with nasopharyngeal carcinoma and control subjects.
The frequency of oropharyngeal excreters of the Epstein-Barr virus among patients with nasopharyngeal carcinoma in Hong Kong was compared with those of healthy adults in Hong Kong and California. 6 (3%) of 177 patients, 11 (12%) of 92 Hong Kong residents, and 20 (15%) of 132 Californians were excreters. The virus was detected in the nasopharyngeal secretion of only 1 of 67 patients and in 2 of 73 healthy adults. No convincing evidence for neutralizing antibody in the throat wash and nasopharyngeal secretions of the patients could be obtained. Epstein-Barr viral gene sequencing could not be detected in the throat washes from 27 patients with nasopharyngeal carcinoma, 8 patients with infectious mononucleosis, and 15 healthy adults and in the nasopharyngeal secretions of 35 patients and 17 controls. We conclude that patients with nasopharyngeal carcinoma are no more likely to be oropharyngeal or nasopharyngeal excreters of the Epstein-Barr virus than healthy adults. One possible explanation for this unexpected finding is that the virus infections in nasopharyngeal carcinoma cells are predominantly nonproductive.
Adolescent↗
Ovarian ablation failures by radiation: a comparison of two dose schedules.
Sixty Chinese breast cancer patients underwent ovarian irradiation with one of two dose schedules: 12 Gy/4 fractions/4-6 days or 14 Gy/4 fractions/4-6 days. The ovarian ablation failure rates were 14% and 0% respectively in patients above 40 years of age. The overall ablation failure rate in younger patients was unacceptably high at 35%. The significance of the findings is discussed.
Adult↗
A retrospective comparison between different stage classifications for nasopharyngeal carcinoma.
From 1984 to 1987, 659 patients with untreated nasopharyngeal carcinoma (NPC) were investigated by computed tomography of the nasopharynx and skull base, and fibreoptic nasopharyngoscopy. Thirty-one patients presenting with distant metastasis were treated palliatively; 628 were treated with intent to cure. Prospective staging was performed for the Ho's classification but since all T- and N-stage data required for staging according to the Huang's, the Changsha and the UICC classifications were recorded and stored in a computer database, retrospective staging according to these classifications could be accurately performed. Ho's classification was concluded to be the best in view of highly significant differences between the overall stages in survival and between N-stages in distant metastasis. The number of prognostically distinct overall stages and N-stages was greatest for Ho's classification. Huang's T-stage classification was superior, however, because it emphasized the significant adverse effect on local tumour control of cranial nerve(s) palsy (Tn) and intracranial tumour extension (Tc). Changsha and UICC classifications were demonstrably less powerful in predicting NPC prognosis. Multiple sites of involvement within the nasopharynx by NPC had no adverse influence on local tumour control. The grouping together of both soft-tissue and skull-base lesions into Changsha's T3 has been shown to be unjustified because of significant differences in local failure.
Humans↗
Clinical features and management of distant metastases of nasopharyngeal carcinoma.
This is a retrospective study of 90 patients who developed distant metastases after radical radiotherapy for nasopharyngeal carcinoma. The skeleton was the commonest site of distant metastases. Clubbing, hypercalcemia and malignant fever occurred in about 10% of patients with pulmonary, skeletal and hepatic metastases respectively. An effective chemotherapeutic regimen for palliation of pulmonary and hepatic metastases was cisplatinum/carboplatin-5FU which gave a complete response rate of 29% and partial response rate of 21%. This was considered superior to some non-cisplatinum-containing regimens. One patient with hepatic metastases had good palliation by hepatic irradiation. The median survival of all patients with distant metastases was eight months. Five (6%) patients survived more than two years with one surviving free of disease at 31 months. Hepatic metastases and spinal cord compression were associated with short survivals.
Antineoplastic Combined Chemotherapy Protocols↗
Cranial nerve involvement by nasopharyngeal carcinoma: response to treatment and clinical significance.
The incidence of cranial nerve involvement in a group of 564 patients with nasopharyngeal carcinoma was 12%. Most of these patients had multiple cranial nerve involvement with the fifth and sixth nerves being most commonly affected. Different cranial nerves had different chances of recovery after radiotherapy. About half the patients with cranial nerve palsies had complete neurological recovery after radiotherapy. The cranial nerve response, however, was not a significant predictor of local tumour control.
Combined Modality Therapy↗
Treatment outcome of spinal cord compression by nasopharyngeal carcinoma.
Spinal cord compression occurred in 1.6% of a cohort of 626 patients with nasopharyngeal carcinoma during a median follow-up period of 22 months. The degree of motor deficit before treatment was the most important predictor of subsequent motor recovery. One patient had complete reversal of motor deficit and returned to an ambulatory state by chemotherapy alone. The development of spinal cord compression was associated with a short life expectancy in nasopharyngeal carcinoma.
Adult↗
Afterloading intracavitary radiation treatment of nasopharyngeal carcinoma. Description of a technique and preliminary treatment results.
A new technique for afterloading intracavitary treatment of nasopharyngeal carcinoma with iridium-192 sources is described, which allows good positioning and fixation of the sources. The method has been used both for treatment of tumour remnants or recurrences after previous external radiation treatment and for achieving a boost dose supplementary to external irradiation. The early results in 73 patients are described.
Brachytherapy↗