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C K Law

Publications and source records attributed to C K Law.

34 records · Page 2Linked to original sources
PubMed1998

Nasopharyngeal carcinoma---time lapse before diagnosis and treatment.

This is a descriptive study of 168 patients with nasopharyngeal carcinoma who were referred to public oncology departments for primary treatment between July and September 1996. The mean duration from the onset of the symptoms to histological diagnosis was 5.0 months; the duration ranged from 6.1 months (for patients presenting with nasal symptoms) to 1.8 months (for those with cranial nerve dysfunction). The mean period between the onset of symptoms and the seeking of medical advice was 2.9months. For 54% of the patients, there was a further delay of up to 2.4 months between the initial medical consultation and referral to the appropriate specialist. The majority (84%) of patients attended public institutions for histological confirmation. The mean total time taken from the onset of symptoms to the commencement of radiotherapy was 6.5 months (range, 1.3-74.0 months)---45% of the delay was attributed to the patient, 20% to initial consultations, 14% to diagnostic arrangement, and 21% to preparation for radiotherapy. Concerted efforts are needed to minimise further the time between the onset of symptoms and treatment. A substantial reduction in this delay can be achieved if both public and primary care doctors were made more aware of the significance of relevant symptoms.

Journal Article↗
PubMed1996

Staging of nasopharyngeal carcinoma: evaluation of N-staging by Ho and UICC/AJCC systems. Union Internationale Contre le Cancer. American Joint Committee for Cancer.

To evaluate the prognostic accuracy of N-staging by Ho's and the UICC/AJCC systems, 5020 patients with undifferentiated or poorly differentiated squamous cell carcinoma of the nasopharynx treated at the Queen Elizabeth Hospital, Hong Kong in the period 1976-1985 were analysed retrospectively. They were initially staged with Ho's system, but detailed records of nodal involvement allowed accurate retrospective restaging with the UICC/ AJCC (1988) system. Staging assessment depended almost entirely on physical examination; only 14% of patients had additional investigations with computed tomography. To evaluate the independent significance of different nodal parameters, T-stage adjusted analyses of the 4730 patients presenting without distant metastases were performed. Both N-staging systems showed a strongly significant overall correlation with distant failures and cancer-specific deaths. A significant trend was also shown for nodal failures in node-positive patients. Ho's system was superior in predicting distant failures, while the UICC/AJCC system was superior for nodal failures. However, even with due adjustment for level, the independent significance of nodal size, laterality and fixity could be demonstrated. After adjustment for UICC/AJCC N-stage, both level and fixity were also significant. Furthermore, when adjusted for all other meaningful parameters, there were no significant differences between ipsilateral and contralateral involvement, upper and mid-level extent, and nodal size < or = 3 cm or > 3- < or = 6 cm. N-staging can be further optimized by a newly proposed system incorporating fixity (movable versus fixed), level (upper-mid versus lower), size (greatest diameter < or = 6 cm versus > 6 cm), and laterality (unilateral versus bilateral) as staging criteria.

Adolescent↗
PubMed1996

N-staging of nasopharyngeal carcinoma: discrepancy between UICC/AJCC and Ho systems. Union Internationale Contre le Cancer. American Joint Committee for Cancer.

To enable clinicians to have a better understanding of the limitations of the UICC/AJCC and Ho N-staging systems for nasopharyngeal carcinoma, 4730 patients without distant metastases at diagnosis were retrospectively analysed. The two systems agreed in 54% (1867/3451) of node-positive patients, and their treatment results were taken as the reference for comparison. To identify the most appropriate N-stage for the discrepant groups, their outcomes were measured against the respective reference. All patients with single, ipsilateral and small nodes, irrespective of their relative position in the upper-mid neck should be classified as N1, while those with multiple, bilateral/contralateral or medium-sized node(s) are effectively N2, even if nodal involvement is confined to the upper neck. All patients with extension to the supraclavicular fossa (irrespective of size) and those with nodes larger than 6 cm at the greatest diameter (irrespective of level) should be classified and treated as N3, especially as, in this group, half of the patients died of distant metastases and trials of adjuvant systemic therapy have to be considered. Areas of inaccurate prognostication by the respective system should be noted to avoid misguiding treatment strategy. The present analyses support our previous suggestions that both the level of extent and the bulk of nodal deposits are important prognostic factors. While supraclavicular involvement is a significant demarcation, there is little justification for further division into upper and mid-levels. The merits of both systems should be duly recognized and combined for the further improvement of prognostic accuracy.

Adolescent↗
PubMed1995

Elimination of dose limiting toxicities of cisplatin, 5-fluorouracil, and leucovorin using a weekly 24-hour infusion schedule for the treatment of patients with nasopharyngeal carcinoma.

BACKGROUND: Cisplatin, 5-flourouracil (5-FU), and leucovorin (PFL) chemotherapy has been reported to be effective in the treatment of cancers but severe mucositis or neutropenia are dose limiting toxicities. This Phase II study evaluated the anticancer effect and the toxicities of a new weekly 24-hour infusional PFL chemotherapy in patients with nasopharyngeal carcinoma (NPC). METHODS: Forty-two patients with stage IV NPC were studied. Cisplatin 25 mg/m2/d, 5-FU 2200 mg/m2/d, and leucovorin 120 mg/m2/d were adminstered weekly by 24-hour intravenous continuous infusion in an outpatient setting. Clinical response and toxicity were evaluated weekly. RESULTS: The complete response rate (CR) was 30% and the partial response (PR) rate 60% in the localized previously untreated group. The CR rate was 22.7% and PR rate 45.5% in local recurrent/metastatic group. The overall response rate was 79%. Eighty-one percent of patients who had no previous chemotherapy and 67% of patients who had previous chemotherapy responded to weekly PFL. There were no dose limiting toxicities. No patient had grade 3 or 4 mucositis or neutropenia. Thirty-two patients (76%) had no oral mucositis. Seven patients (17%) had grade 1 mucositis and 3 patients (7%) had grade 2 mucositis. CONCLUSIONS: Elimination of dose limiting toxicities is possible using a weekly 24-hour infusion schedule of PFL chemotherapy while retaining significant anticancer activity as demonstrated in these patients with advanced NPC. To discover whether this schedule is superior to cisplatin and 5-FU or other PFL chemotherapy regimens requires further investigation.

Adult↗
PubMed1995

Primary lymphoepithelioma-like carcinoma of the lung. A clinicopathologic study of 11 cases.

BACKGROUND: Lymphoepithelioma-like carcinoma (LELC), best known to occur in the nasopharynx, can arise in a variety of sites, such as the salivary gland, thymus, lung, stomach, and skin. Primary LELC of the lung is very rare, with only limited information in the literature. METHODS: The clinicopathologic features of 11 patients with pulmonary LELC collected from two regional hospitals in Hong Kong are described. RESULTS: The patients, all Chinese, were aged 38 to 73 years (median, 54 years), with equal sex incidence. Two of the 8 patients were smokers. Four presented with coin lesions incidentally discovered on chest X-ray, five with cough and blood-stained sputum, and two with pleural effusion. The tumor formed a discrete (9 patients) or an ill-defined (1 patient) nodule in the lung, or, rarely, showed extensive bilateral pulmonary involvement (1 patient). The major bronchi were not involved except in 1 patient. Three patients had lymph node metastasis at presentation; two of them had bone metastasis, one at presentation and one after 9 months. The tumors had pushing margins, and grew in the form of anastomosing islands and sheets, comprising syncytial-appearing large cells with vesicular nuclei and prominent nucleoli. They were infiltrated by an appreciable number of small lymphocytes and plasma cells. Intratumoral amyloid globules were found in one tumor. In five patients, the tumor showed intraepithelial growth within the small bronchi; this could represent either the in-situ phase of the tumor or pagetoid spread into the bronchial epithelium. The neoplastic cells of all patients harbored Epstein-Barr virus (EBV) as demonstrated by in situ hybridization for EBV-encoded small nuclear RNAs. All eight Asian patients with pulmonary LELC previously reported in the literature similarly have been EBV-positive, whereas the four reported Caucasian patients all have been EBV-negative. CONCLUSION: Lymphoepithelioma-like carcinoma of lung occurring in Asians is an EBV-associated neoplasm; it also appears to occur at a higher frequency in Asians than Caucasians. It usually presents as a solitary subpleural nodule, and there is no strong association with cigarette smoking. Most patients have early stage disease at presentation. From the limited available data, the behavior of LELC of lung is highly variable, ranging from apparent curability by excision (particularly for localized disease) to highly aggressive, extensive disease at presentation.

Adult↗
PubMed1992

Pharmacokinetic and pharmacodynamic studies with mitoxantrone in the treatment of patients with nasopharyngeal carcinoma.

The pharmacokinetics and pharmacodynamics of mitoxantrone were studied in 15 patients with advanced nasopharyngeal carcinoma (NPC) after single intravenous rapid infusion (12 to 14 mg/m2). Mitoxantrone plasma concentrations and urinary excretion were measured specifically with the use of a high-performance liquid chromatographic method with ultraviolet detection at 242 and 658 nm. The pharmacokinetic parameters are described adequately by a three-compartment model with a terminal half-life of 71.5 +/- 40.1 hours and a volume of distribution of 5037 +/- 2377 l. The total plasma clearance was 743 +/- 462 ml/minute, and the renal clearance was 18.8 +/- 8.49 ml/minute. Within 72 hours, 1.8 +/- 0.6% of the administration dose was excreted in urine as mitoxantrone parent compound. From the urinary excretion rate data, glomerular filtration and possible tubular reabsorption were the mechanisms involved in the urinary excretion of mitoxantrone. The values for unbound fraction (%) in plasma at time 0 and 5 minutes were 2.88 +/- 0.91% and 3.25 +/- 1.19%, with an average of 3.04 +/- 1.01%. The degree of protein binding of mitoxantrone was not affected by concentration (P greater than 0.05) in Chinese patients with NPC. The response rate for mitoxantrone was poor in this study. Clinical studies have demonstrated that mitoxantrone was generally well tolerated. Only very low incidences of nausea, vomiting, and alopecia were observed. The mild and rapidly reversible dose-limiting hematologic toxic effects have proven leukopenia. Although the toxicities reported here were tolerated for most patients, other combination regimens including mitoxantrone or other administration routes may be considered and need to be evaluated carefully.

Adult↗
PubMed1992

Norms and alcohol consumption: Japanese in Japan, Hawaii and California.

The study compared age/sex norms and alcohol consumption of a sample of Japanese from Japan and Japanese Americans in Hawaii and California. Age norms included acceptable drinking levels for the following age groups: 16, 21, 40 and 60, both male and female. There were significant differences in norms across the sites with the Japanese in Japan holding the most tolerant views of heavier drinking for men, followed by California and Hawaii. The Japanese-American samples were more tolerant of female drinking than were the Japanese. There was a high degree of similarity between Hawaii and California, whereas Japanese respondents in Japan differed in their responses. A correlation between drinking and norms by site indicated a high degree of congruence between drinking and more tolerant norms for drinking in all of the samples: Those who drank the most also had the most permissive norms toward drinking. The differences in norms between Japanese in Japan and Japanese Americans were explained in terms of enculturation and acculturation.

Acculturation↗
PubMed1991

Nasopharyngeal carcinoma with bone marrow metastasis.

Five of 23 patients with recurrent nasopharyngeal carcinoma (NPC) were diagnosed to have bone marrow metastasis. They all had advanced local-regional disease, and were treated with neoadjuvant chemotherapy and definitive radiotherapy after the initial diagnosis. Bone marrow metastasis developed 4-24 months later. The clinical features were anemia (5 of 5), leukopenia (3 of 5), thrombocytopenia (4 of 5), sepsis (3 of 5), tenderness of the sternum (3 of 5), and fever (4 of 5). Patients frequently had elevation of serum lactic dehydrogenase (LDH), alkaline phosphatase (ALK-P), and IgG and IgA antibody titers to Epstein-Barr viral capsid antigen when bone marrow involvement was diagnosed. However, clinical manifestations and laboratory tests were not specific. It is important that three patients had normal bone scans. All five patients had a rapid downhill course; four patients died within 23 days, and the fifth 3 months after the diagnosis of bone marrow metastasis. We concluded that bone marrow was a common metastatic site in NPC patients. Bone marrow metastasis adversely affected patients' survival and required a high index of suspicion for diagnosis. We suggested that bone marrow biopsy should be considered as a routine staging procedure in NPC patients and indicated especially when patients presented with abnormal blood counts, sepsis, bone pain, or tenderness of the sternum. It may be positive in the face of a normal bone scan.

Adult↗
PubMed1990

Novel assay method for mitoxantrone in plasma, and its application in cancer patients.

Mitoxantrone is an anthracene derivative that acts as a cytostatic in a variety of cancers. A quantitative analytical method has been established for the determination of mitoxantrone in plasma. The method employed C18 reversed-phase ion-pair chromatography with an isocratic mobile phase of 50.0% methanol in 10 mM phosphate buffer (pH 3.0) plus 0.09% 1-pentanesulphonic acid and ultraviolet detection. Sample preparation consisted of two extraction steps using same organic solvent system at different pH to remove plasma impurities efficiently. Potential adsorption of mitoxantrone onto glassware was considered. Silanization of all glassware with 5% dichlorodimethylsilane in chloroform increased the extraction recovery in plasma from 50 to 85% with high reproducibility. Mitoxantrone was unstable in human plasma. To maintain plasma sample integrity, each millilitre of sample should be fortified with 0.1 ml of 5% vitamin C (in citrate buffer) and kept frozen until analysis. Using this new method, the calibration curve of mitoxantrone in plasma in the range of interest (1-500 ng/ml) showed good linearity (r = 0.996) and precision (both between-day and within-day coefficients of variation less than 10%). The lower detection limit of this assay method was 1 ng. The application of this method allowed us to study the stability of mitoxantrone in plasma, and the pharmacokinetics of mitoxantrone in nasopharyngeal carcinoma patients receiving 12 mg/m2. The study revealed a prolonged terminal phase half-life for mitoxantrone.

Adsorption↗
PubMed1987

Reactive hemophagocytic syndrome: a study of 7 fatal cases.

Reactive hemophagocytic syndrome is a clinico-pathologic entity characterized by systemic proliferation of non-neoplastic histiocytes showing phagocytosis of hemopoietic cells, resulting in blood cytopenia. It is best known to be associated with virus infection, but other associated diseases have also been implicated. The clinical and pathological findings of 7 fatal cases are described. The syndrome affected both sexes of a wide age range, and all patients had fever. Significant laboratory findings were blood cytopenia, abrupt drop in the blood cell counts, deranged liver function tests and abnormal coagulation profile. The associated diseases were diverse: two patients had bacterial infection; two had peripheral T-cell lymphoma; one had disseminated undifferentiated carcinoma of the ovary; one had both tuberculosis and disseminated nasopharyngeal carcinoma, and one had no obvious underlying disease. It is postulated that lymphokines secreted by lymphoid cells or tumor cells may be responsible for the systemic activation of histiocytes. The differential diagnosis from malignant histiocytosis is discussed.

Adolescent↗
PubMedDate not supplied

Assessment of the future resources and needs for hospitalization in Hong Kong SAR (Special Administrative District).

OBJECTIVES: To study the 'compression of morbidity' theory in the Hong Kong SAR by analysing the age and gender-specific hospitalization rates and the expected length of stay per patient for the period 1996-2000. 'Compression of morbidity' refers to the hypothesis that medical progress will reduce the duration of morbidity during life more significantly than increasing morbidity by extending life. DESIGN: This is a retrospective study based on hospital admissions data from the Hospital Authority of Hong Kong which covers 93% of the patient population. SETTING: Age and gender-specific hospitalization rates, expected length of stay and hospitalization needs for each specific age group in Hong Kong from 1996 to 2000, are estimated. MAIN RESULTS: There is no empirical support for compression theory; and there is no significant change in the hospital admission rates for the period 1996-2000. The total number of patient days is expected to increase by 80% because of the ageing effect alone. It is projected that the geriatric service will account for more than 60% of the hospital patient days utilization in 2029. The elderly dependency ratio will increase and the social burden for the next generation will be increased, as the working populations size continues to decrease due to low fertility in the Hong Kong SAR. CONCLUSION: The health care burden on the government is large and increasing. It is therefore essential to make plans to deal with the ageing population, which is predicted to be at its highest in 2020. The rising effect of public expectations on hospital services exerts further pressure on demand.

Adolescent↗
PubMedDate not supplied

A phase II study of carboplatin in nasopharyngeal carcinoma.

This is a phase II study to evaluate the efficacy and toxicity of short-course carboplatin in advanced-stage nasopharyngeal carcinoma (NPC). Thirty-three previously untreated stage III-IV NPC patients were studied. Carboplatin was given as a rapid intravenous injection every 3 weeks. The dose of carboplatin was calculated according to the individual patient's creatinine clearance and desired platelet nadir of 75,000/microliter according to the Egorin formula. Response and toxicity were evaluated. Thirty-two patients were evaluated for response. The median age was 54 years, range 30-70 years. Twenty-four patients had local regional disease and 8 patients had metastatic disease. The median dose of carboplatin given was 415 mg/m2 (range 91-791 mg/m2). Fourteen (44%) patients had a partial response with a 95% confidence interval of 26-62%. Fifteen (47%) patients had stable disease and 3 (9%) progressive disease. The overall median survival rate was not reached at 43 months. Overall toxicity was tolerable. Grade III-IV myelosuppression occurred in 4 (12%) patients. There were no other major toxicity- or treatment-related deaths. We conclude that carboplatin has a significant anticancer effect in advanced NPC. Thus carboplatin combination chemotherapy for the treatment of NPC is worthy of future clinical investigations.

Adult↗
PubMedDate not supplied

Weekly CAF chemotherapy for advanced breast cancer patients.

In a prospective phase II study, 102 women with advanced breast cancer were treated with low doses of cyclophosphamide, Adriamycin and 5-fluorouracil (CAF) at weekly intervals by intravenous injection. Seventy-five patients were evaluable for treatment response and the overall response rate was 52% (95% confidence interval, 41-63%). Of the evaluable patients, 15% had complete response and 37% had partial response. The median survival after therapy was 15.6 months, the median time to progression was 6.8 months and the median duration of response was 9.1 months. The main toxicities were mild vomiting and moderate myelosuppression. There was only 1 patient who experienced heart failure. Weekly CAF appears to have an efficacy with tolerable side effects comparable to standard CAF with an every-3-week schedule.

Adult↗