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W H Kwan

Publications and source records attributed to W H Kwan.

32 records · Page 2Linked to original sources
PubMed1996

In vitro uptake of bromodeoxyuridine by human nasopharyngeal carcinoma (NPC) and its relation to clinical findings.

A cell kinetic study of 27 newly diagnosed patients with nasopharyngeal carcinoma (NPC) using the in vitro bromodeoxyuridine (BrdU) technique was performed. The results were reproducible as demonstrated by three independent sections performed on each patient. No correlation between BrdU labelling index (LI) and Ho's clinical staging was found. A higher LI was associated with the development of distant metastases (P = 0.057). Statistically significant correlation was found between low LI and longer duration required to achieve complete remission in the primary site of disease (P = 0.026). This study suggests a potential role for in vitro BrdU labelling index as a prognosticator for NPC prior to treatment.

Adult↗
PubMed1996

Strong association between hyperferritinaemia and metastatic disease in nasopharyngeal carcinoma.

We have investigated the role of serum ferritin, in relation to disease stages, in patients with nasopharyngeal carcinoma. Patients with localised disease (Ho's stage I-IV) had levels which were not significantly different from age, sex matched normal subjects and there was no relationship between mean serum ferritin levels and stage. However, in patients with metastatic disease levels were grossly elevated with mean levels increased more than 6-fold compared to normal subjects and patients with localised disease. Furthermore, among the small group of patients with localised disease but hyperferritinaemia, the subsequent development of metastatic disease within 1 year was significantly much higher (32.4%) than in those with levels falling within the reference range (10.3%). Hyperferritinaemia is strongly associated with, and may predict, metastatic disease in patients with nasopharyngeal carcinoma.

Adult↗
PubMed1996

Nasopharyngeal carcinoma with metastatic disease to mediastinal and hilar lymph nodes: an indication for more aggressive treatment.

Nasopharyngeal carcinoma (NPC) is a highly chemo- and radiosensitive tumour, distinctive from other head and neck squamous cell carcinomas. Distant metastatic rates correlate directly with T and N stages. The prognosis of metastatic NPC is grave and long term survivors are anecdotal. We encountered an 18-year-old man with locoregionally advanced NPC, who was initially treated with neoadjuvant chemotherapy and radiotherapy, but subsequently relapsed 6 months later in the superior mediastinal and right hilar nodal regions. Further chemotherapy and consolidation radiotherapy resulted in complete remission. He is currently alive and free of disease 5 years and 6 months after the completion of salvage treatment. We recommend aggressive treatment of NPC with isolated intrathoracic nodal relapse and imaging of the mediastinum for non-metastatic Ho's Stage N3 NPC patients.

Adolescent↗
PubMed1996

A retrospective study of the role of intracavitary brachytherapy and prognostic factors determining local tumour control after primary radical radiotherapy in 903 non-disseminated nasopharyngeal carcinoma patients.

The aims of this retrospective study were to determine the role of intracavitary brachytherapy given shortly after external beam radiotherapy in the primary radical treatment of non-metastatic nasopharyngeal (NPC) cancer patients, and the prognostic factors governing local tumour control. From 1984 to 1989, 903 patients with non-disseminated NPC who had had no previous treatment were managed at the Prince of Wales Hospital, where investigation and treatment methods had been standardized according to a departmental protocol. The external radiotherapy dose of 60.0-62.5 Gy in 6 weeks was given to all patients. Parapharyngeal booster radiotherapy with a single photon beam to 20 Gy in 2 weeks was given to those with parapharyngeal tumour extension. Computed tomography of the nasopharynx and skull base, and pretreatment nasopharyngoscopy and biopsy were performed in all patients. Nasopharyngoscopy was repeated at 4 weeks after the last day of external irradiation. Local persistence in 99 patients was treated additionally by intracavitary brachytherapy to 24 Gy in three fractions over 15 days. Fifty-one patients with early stage primary disease (Ho Stage T1 and T2n (nasal)) who responded completely to external radiotherapy were given adjuvant intracavitary brachytherapy to 18 Gy in three fractions over 15 days. Intracavitary therapy was an inadequate salvage treatment for the locally persisting T3, T20 (oropharyngeal) and T2p (parapharyngeal) disease, but there was a trend towards improved local control after intracavitary brachytherapy for the locally persisting T1 tumours. Adjuvant brachytherapy did not enhance local tumour control for the early T-stage tumours that completely responded to external radiotherapy. Both forms of intracavitary brachytherapy were safe with few and acceptable complications. In the 903 non-disseminated NPCs, the patient's age and tumour involvement of the skull base and cranial nerves were significant independent prognostic factors governing local tumour control. In the 358 patients with Ho T3 disease, tumour involvement of the orbits and the laryngopharynx significantly worsened local tumour control. The presence of local persistence at 4 weeks after external radiotherapy, for which therapeutic brachytherapy was given, was marginally significant as a prognostic factor in addition to the presence of cranial nerve palsy.

Actuarial Analysis↗
PubMed1996

Early tumour response and treatment toxicity after hyperfractionated radiotherapy in nasopharyngeal carcinoma.

The aim of the present study was to undertake a planned interim analysis of a prospective randomized trial comparing the tumour response and the acute and subacute complications of hyperfractionated radiotherapy and conventional radiotherapy in non-metastatic nasopharyngeal carcinoma (NPC). 100 patients with newly diagnosed non-metastatic NPC were randomized to receive either conventional radiotherapy (Arm I) or hyperfractionated radiotherapy (Arm II). Stratification was done according to the T-Stage (modified Ho's T-Stage classification). The biological effective dose (10 Gy) to the primary and the upper cervical lymphatics were 75.0 and 73.1 for Arm I and 84.4 and 77.2 for Arm II, respectively. Hyperfractionated radiotherapy was associated with significant mucositis which is of higher grade than conventional radiotherapy (p = 0.0001), but the duration of mucositis was similar between the two Arms and all study patients completed radiotherapy on schedule without interruption of radiotherapy. Early survival and tumour recurrence rates were comparable between the Arms. The preliminary results indicate that the hyperfractionated radiotherapy has excellent patient compliance in Chinese patients, with acceptable acute and subacute toxicities and the local and regional complete tumour response rates being comparable with conventional radiotherapy. The significance of the time required after start of radiotherapy to achieve a complete tumour response is discussed.

Carcinoma↗
PubMed1995

A retrospective study of the use of cisplatinum-5-fluorouracil neoadjuvant chemotherapy in cervical-node-positive nasopharyngeal carcinoma (NPC).

A retrospective study on 422 nasopharyngeal carcinoma (NPC) patients with cervical nodal metastases treated between 1984 and 1987 was performed. 169 received neoadjuvant chemotherapy (CHEMO) with cisplatinum and 5-fluorouracil for two or three courses prior to definitive radiotherapy and 253 were treated by radical radiotherapy alone (NCHEMO). While the primary tumour (T-stage) prognosticators had been comparable between the two groups, CHEMO had significantly more advanced cervical nodal metastases with bulkier nodes and more low-cervical and supraclavicular nodes (P < 0.05) which could account for its overall worse survival, poorer regional tumour control and a trend towards worse systemic tumour control. The worse regional control in CHEMO for Ho's N1 could be the result of more bulky nodes and more tumours infiltrating the skull base and/or causing cranial nerve(s) palsy. There was no statistical or apparent difference between CHEMO and NCHEMO for the same Ho's overall stages of NPC with comparable nodal and primary tumour characteristics for the clinical endpoints of actuarial survival rate (ASR), disease-free survival rate (DFS), free of local failure survival rate (FLF), and free from distant metastases survival rate (FDM), despite the presence of significantly more fixed nodes and bulky nodes. This suggests a possible beneficial effect of the neoadjuvant chemotherapy. However, multivariate analysis has not shown the administration of the neoadjuvant chemotherapy to be of prognostic significance. Even though the chemotherapy was well tolerated with little toxicity, we recommend against the routine use of neoadjuvant chemotherapy in cervical-node-positive NPC outside the context of a prospective randomised clinical trial.

Adolescent↗
PubMed1990

Nasopharyngeal carcinoma. Pattern of tumor regression after radiotherapy.

The primary tumor regression pattern of 50 patients with nasopharyngeal carcinoma was reported. The tumor regression was monitored either by indirect nasopharyngeal mirror examination and biopsy or fiberoptic endoscope and biopsy. Fiberoptic endoscope and biopsy was found to be more accurate in noting residual tumor. It is recommended that booster radiation dose to the residual primary tumors be withheld unless positive biopsy samples persist at 10 or more weeks after radiotherapy.

Biopsy↗
PubMed1989

Fiberoptic endoscopic examination and biopsy in determining the extent of nasopharyngeal carcinoma.

This is a prospective study on the use of flexible endoscope and multiple biopsies in the assessment of nasopharyngeal carcinoma in 72 patients. This study confirmed the presence of submucosal growth pattern in nasopharyngeal carcinoma in 72 patients. This study confirmed the presence of submucosal growth pattern in nasopharyngeal carcinoma and this occurred in 13.8% of patients. Occult microscopic extension of tumor not detectable by fiberoptic endoscopy occurred in another 51.4% of patients. It has also been shown that multiple biopsy is superior to clinical examination in evaluating the extent of disease in nasopharyngeal carcinoma. Multiple biopsies are suggested for the early detection of nasopharyngeal carcinoma in high-risk cases. Although the better-defined tumor extent do not currently influence the treatment policy of nasopharyngeal carcinoma, and it is too early to assess its prognostic significance, it betters our understanding of the behavior of this tumor. Future analysis in correlation with long-term follow-up data may help to improve the stage classification systems and treatment strategy.

Biopsy↗
PubMed1983

Nitrous oxide-induced myeloneuropathy.

A disabling peripheral myeloneuropathy developed in a health professional with a history of chronic exposure and abuse of nitrous oxide. The distinctive clinical symptoms were radicular sensory loss rather than purely distal, and a "reverse" Lhermitte's sign in the absence of signs of specific spinal cord involvement. The entity of nitrous oxide-induced myeloneuropathy is discussed with a review of the literature, as well as present information regarding the etiology, pathophysiology, symptoms, and treatment. In addition, a case report of nitrous oxide-induced myeloneuropathy is presented.

Adult↗
PubMedDate not supplied

Unusual case of leukoencephalopathy after bone marrow transplantation.

A girl with chronic myeloid leukemia received bone marrow transplantation with total body irradiation as part of a conditioning regimen. She developed leukoencephalopathy about 50 days after transplant. There was permanent neurologic impairment afterward. She had not received any cranial irradiation or intrathecal chemotherapy before transplant. She had received 10 months of interferon treatment before transplant, which might have played a part in the development of leukoencephalopathy.

Bone Marrow Transplantation↗
PubMedDate not supplied

Breast metastasis in adolescents with alveolar rhabdomyosarcoma of the extremities: report of two cases.

We describe two adolescent girls with alveolar rhabdomyosarcoma arising from extremities who developed bilateral breast metastasis in their clinical course. In both cases, there was widespread systemic disease at initial presentation. Although complete remission was achieved on the 25th week post-chemotherapy initiation, the first patient developed breast metastasis in addition to systemic recurrence on the 44th week and expired. For the second patient, breast metastasis was noted in addition to systemic disease at initial presentation. Aggressive chemotherapy with autologous transplant and radiotherapy were given in addition to bilateral subcutaneous total mastectomy. The patient remained in complete remission 3 months post-therapy. We postulate that adolescent females with alveolar rhabdomyosarcoma of the extremities have a high risk of developing breast metastasis in the pubertal period, and aggressive multidisciplinary treatment is indicated.

Adolescent↗
PubMedDate not supplied

Imaging of pediatric head and neck rhabdomyosarcomas with emphasis on magnetic resonance imaging and a review of the literature.

We present the magnetic resonance imaging (MRI), computed tomography (CT) and ultrasound appearances of three cases of pediatric head and neck rhabdomyosarcomas, involving the orbit, parameningeal region (nasopharynx and nasal sinus), and trapezius muscle anatomically. The histopathological subtypes included two embryonal and one alveolar. MRI is a superior imaging technique with its high contrast resolution of soft tissue tumors and multiplanar noninvasive capability. The literature on CT and MRI appearances of head and neck rhabdomyosarcomas is reviewed.

Adolescent↗