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Biomedical subjects

S S Leong

Publications and source records attributed to S S Leong.

At least 19 recordsLinked to original sources
PubMed2006

Phase II trial of gemcitabine and cisplatin sequentially administered in Asian patients with unresectable or metastatic non-small cell lung cancer.

INTRODUCTION: The aim of this study was to assess toxicity and response in the sequential administration of gemcitabine followed by cisplatin in unresectable or metastatic non-small cell lung cancer. MATERIALS AND METHODS: Twenty-three patients were enrolled in this study. Gemcitabine was given at 1,250 mg/m2 on days 1 and 8, for four 21-day cycles. RESULTS: There were 4 patients with partial responses. 5 patients with stable disease and 10 patients with progressive disease, giving a response rate of 21%. The median time to disease progression was 3.3 months. The median overall survival was 14.6 months. Toxicities graded 3 or 4 included anaemia (13.0%), neutropaenia (13.0%), supraventricular tachycardia (4.3%), and nausea and vomiting (4.3%). CONCLUSION: Although these results show similar efficacy to single-agent treatment regimens, the low toxicity profile and promising survival outcome with this regimen are important points for consideration.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2005

Concurrent chemoradiotherapy followed by surgery in locally advanced squamous cell carcinoma of the oesophagus: a single centre experience.

INTRODUCTION: Data on combined modality treatment for locally advanced squamous cell carcinoma of the oesophagus involving Asian patients are limited. MATERIALS AND METHODS: A retrospective study of 56 consecutive patients with this condition treated with concurrent chemoradiotherapy followed by surgery in a single tertiary institution in Singapore was performed. RESULTS: The median overall survival of the entire cohort was 14.1 months [95% confidence interval (CI); range, 8.6 to 19.6 months]. In patients who underwent successful oesophagectomy after chemoradiotherapy (n = 17), the median survival was 27.8 months compared to 9.8 months for those who did not have surgery (n = 39) (P = 0.046, log-rank test). The median time to first relapse for the entire cohort was 16.1 months (95% CI, 7.7 to 24.5 months). The time to first relapse was 23.9 months in the subgroup of patients with successful surgery and 12.1 months in the group which did not (P = 0.147, log-rank test). The high proportion of patients who were medically unfit for surgery or declined surgery may have conferred a selection bias. CONCLUSION: Concurrent chemoradiotherapy followed by surgery is feasible in selected patients. The benefit of adding of surgery to chemoradiotherapy is still controversial and we await the results of randomised controlled trials comparing chemoradiotherapy with surgery versus chemoradiotherapy alone.

Carcinoma, Squamous Cell↗
PubMed2004

A case of metastatic squamous cell carcinoma of the hypopharynx manifesting as acute abdomen.

INTRODUCTION: Squamous cell head and neck cancers are usually confined to local and regional sites but occasionally, patients may present with rare manifestations of distant metastases. CLINICAL PICTURE: A 23-year-old female was treated with concurrent chemo-radiotherapy for stage IVA post-cricoid squamous cell carcinoma. A month later, she presented with acute abdomen and was found to have extensive peritoneal nodules at laparotomy. Intestinal obstruction soon followed. TREATMENT: She was managed conservatively for the intestinal obstruction and given weekly paclitaxel. OUTCOME: She continued to deteriorate and succumbed shortly after the diagnosis of carcinomatosis peritoneii. CONCLUSION: This rare and aggressive presentation reminds us to be cognizant of relapsed head and neck cancers manifesting atypically, and the need for more aggressive search of distant disease in at least some subgroups of head and neck cancer.

Abdomen, Acute↗
PubMed2003

A multicenter phase II study of the efficacy and safety of docetaxel plus cisplatin in Asian chemonaïve patients with metastatic or locally advanced non-small cell lung cancer.

AIMS: To evaluate the efficacy and safety of docetaxel-cisplatin in patients with metastatic or locally advanced non-small cell lung cancer (NSCLC). METHODS: Chemotherapy-naïve patients with histologically confirmed TNM stage III or IV NSCLC were recruited from 12 Asian trial centers. Patients received docetaxel (75 mg/m2) and cisplatin (75 mg/m2) every 3 weeks for 6 cycles. RESULTS: 130 of 146 patients were evaluable for efficacy (60% stage IV). Three complete and 58 partial responses were observed (overall response rate: 46.9%; 95% CI: 38.3-55.5%). Median time to progression was 6.9 months and median survival was 14.0 months; 1-year survival was 59.5%. Grade 3/4 neutropenia, thrombocytopenia and anemia occurred in 69.2%, 6.2% and 18.5% of patients, respectively. Grade 3/4 vomiting was observed in 13.7% and grade 3/4 neurosensory effects were observed in 2.7% of patients. There was one case of treatment-related death due to sepsis. CONCLUSION: Docetaxel-cisplatin is an effective and well-tolerated treatment in Asian patients with NSCLC.

Adult↗
PubMed2003

Design of a prognostic index score for metastatic nasopharyngeal carcinoma.

The survival outcome of patients with systemic cancer differs significantly between individuals even within the same tumour type. We set out to illustrate this by analysing the factors determining survival in patients with metastatic disease from nasopharyngeal carcinoma (NPC) and to design a scoring system based on these prognostic factors. Patients referred between January 1994 and December 1999 were retrospectively analysed. Factors analysed included patient (age group, gender, performance status (BS) at diagnosis of metastases), disease (number of metastatic sites, specific metastatic sites, disease-free interval (DFI), metastases at presentation, presence of locoregional recurrence), and laboratory factors (leucocyte count, haemoglobin level, albumin level). Univariate and multivariable analyses were performed using the Cox proportion hazards model. A numerical score was derived from the regression coefficients of each independent prognostic variable. The prognostic index score (PIS) of each patient was calculated by totalling up the scores of each independent variable. Independently significant, negative prognostic factors were liver metastasis, lung metastasis, anaemia, poor PS, distant metastasis at initial diagnosis, and a DFI of <6 months. Three prognostic groups based on the PIS were obtained: (i) good risk (PIS=0-6); (ii) intermediate risk (7-10); (iii) poor risk (>or=11). The median survivals for these groups were 19.5, 10, and 5.8, months, respectively, (log rank test: P<0.0001). The variable prognosis of patients with disseminated NPC can be assessed by using easily available clinical information (patient, disease and laboratory factors). The PIS system will need to be validated on prospectively collected data of another cohort of patients.

Adult↗
PubMed2002

Gemcitabine in metastatic nasopharyngeal carcinoma of the undifferentiated type.

BACKGROUND: We conducted two parallel phase II trials in chemonaïve and previously treated patients with metastatic nasopharyngeal carcinoma (NPC) to evaluate the tumour response, progression-free and overall survival, and toxicity of gemcitabine. PATIENTS AND METHODS: Gemcitabine 1250 mg/m2 was given on days 1 and 8 of a 21-day cycle. Patients with an Eastern Cooperative Oncology Group performance status <2, adequate renal, hepatic and bone marrow function, and radiologically measurable NPC were eligible. RESULTS: Twenty-five chemonaïve and 27 previously treated patients were enrolled. The overall response rate was 28% [95% confidence interval (CI) 14% to 48%] for the chemonaïve and 48% (95% CI 31% to 66%) for previously treated patients. Toxicities greater than or equal to grade 3 occurred in 15 (60%) chemonaïve and 13 (48%) previously treated patients. Neutropenia was uncommon in chemonaïve patients, but occurred in 37% of previously treated patients. The median time to progression was 3.6 months (range 0.9-7.9) for chemonaïve and 5.1 months (0.9-13.1) for previously treated patients. Median overall survival time was 7.2 months (1.4-15.6) and 10.5 months (2.4-15.0) for chemonaïve and previously treated patients, respectively. CONCLUSIONS: Gemcitabine has moderate activity in NPC with minimal toxicity, and is also an effective salvage agent for patients who have failed or progressed after treatment with other agents.

Adult↗
PubMed2001

Recurrent nasopharyngeal carcinoma presenting as diffuse dermal lymphatic infiltration in the neck: three case reports.

BACKGROUND: Any malignancy has the propensity to metastasize to skin. The frequency of skin metastases vary in different tumors and occur in about 0.7% to 10% of all patients diagnosed with cancer. It is rare in nasopharyngeal carcinoma. METHOD: Three cases of relapsed nasopharyngeal carcinoma with diffuse dermal involvement were described. Their clinical presentation, results of investigations, and response to treatment were reviewed. Literature review of similar forms of presentation was done by means of a MEDLINE search. RESULTS: At the time of dermal relapse, all three patients had a uniform clinical picture of facial, periorbital, and lip swelling associated with stridor and dysphagia. Histologic findings showed dermal infiltrates of malignant cells, and CT scan showed diffuse infiltration of the subcutaneous tissue. Despite chemotherapy, the clinical course was relentless. CONCLUSION: This report describes a presentation of disease that is underdiagnosed and heightens awareness of oncologists to this form of recurrence in nasopharyngeal carcinoma.

Adult↗
PubMed2001

Primary intrathoracic malignant effusion: a descriptive study.

BACKGROUND: Patients who present with malignant pleural/malignant effusion without a definite primary site are not well described in the medical literature. In the course of our clinical practice, we have observed certain traits that are peculiar to patients with such a presentation. We have applied the term primary intrathoracic malignant effusion (PIME) to describe this condition. STUDY OBJECTIVES: Patients must fulfill the following criteria before a diagnosis of PIME can be made: clinical presentation dominated by pleural/pericardial effusion; histologic proof of malignancy obtained from the pleura and/or pericardium; no definite primary site in the lungs or elsewhere from CT scan of the chest, chest radiograph, or physical and endoscopic examination; no history of malignancy; and no history of asbestos exposure. Exposure to environmental tobacco smoke (ETS) among the nonsmokers was examined in a case-control setting. METHODS: We conducted a retrospective search of our database of patients who were referred to the Department of Medical Oncology with a diagnosis of pleural/pericardial effusion from January 1993 to January 2000. RESULTS: Seventy-one of 200 patients from our database met the criteria. A significant majority of the patients were women (65%) and nonsmokers (72%). All patients had adenocarcinoma shown on biopsy. The majority of patients (63%) had disease localized to the intrathoracic serosal surfaces; the rest had distant metastases involving the lung (50%), bone (27%), liver (19%), brain (8%), and skin (4%). Six patients had two or more sites of distant metastases. There was a significant association with ETS exposure when compared to a control group comprised of patients with colonic cancer, matched for sex and age. The median survival was 10 months for patients with disease localized to the pleura/pericardium and 7 months for those with distant metastases. Thirty-eight patients (54%) received chemotherapy. All had platinum-based chemotherapy, except for three patients. The median survival for patients treated or not treated with chemotherapy was 12 months and 5 months, respectively. This difference in survival was statistically significant (p = 0.003). CONCLUSIONS: PIME should be viewed as a distinct entity. Its etiology remains largely unknown, although exposure to environmental tobacco smoke may play a part. Platinum-based chemotherapy may have a positive biological effect on this disease. More studies are required to elucidate the epidemiology, possible etiologic factors, and treatment options for this group of patients.

Adult↗
PubMed1999

Concurrent chemoradiotherapy followed by adjuvant chemotherapy in Asian patients with nasopharyngeal carcinoma: toxicities and preliminary results.

PURPOSE: Nasopharyngeal carcinoma (NPC) is endemic in Singapore. Nearly 60% of the patients diagnosed with NPC will present with locally advanced disease. The North American Intergroup study 0099 reported improved survival outcome in patients with locally advanced NPC who received combined chemoradiotherapy when compared to radiotherapy alone. Hence we explored the feasibility and efficacy of a similar protocol in our patients. METHODS AND MATERIALS: Between June 1996 and December 1997, 57 patients were treated with the following schedule as described. Radical radiotherapy (RT) of 66-70 Gy to the primary and neck with cisplatin (CDDP) 25 mg/m2 on days 1-4 given by infusion over 6-8 hours daily on weeks 1, 4, and 7 of the RT. This is followed by a further 3 cycles of adjuvant chemotherapy starting from week 11 from the first dose of radiation (CDDP 20 mg/m2/d and 5-fluorouracil [5-FU] 1 gm/m2/d on days 1-4 every 28 days). RESULTS: The majority of patients (68%) had Stage IV disease. About 54% of patients received all the intended treatment; 75% received all 3 cycles of CDDP during the RT phase and 63% received all three cycles of adjuvant chemotherapy. The received dose intensity of CDDP and 5-FU of greater than 0.8 was achieved in 58% and 60% of the patients respectively. Two treatment-related deaths due to reactivation of hepatitis B and neutropenic sepsis respectively, were encountered. At median follow-up of 16 months, 14 patients had relapsed, 12 systemically and 2 loco-regionally. CONCLUSION: Due to the acceptable tolerability of such a protocol in our cohort of patients, we have embarked on a Phase III study to confirm the results of the 0099 Intergroup study in the Asian context.

Adult↗
PubMed1999

Vinorelbine, ifosfamide and cisplatin in advanced non-small cell lung cancer.

Between September 1994 and July 1997, 78 patients with advanced/metastatic, non-small cell lung cancer (NSCLC) were selected for the NIP (vinorelbine, ifosfamide, and cisplatin) protocol. The study group included 43 males; age range 34-74 years; median age 56 years; median follow-up for all patients was 14 months and for surviving patients, 30 months. Histological distribution included 55 adenocarcinomas (70.5%), 8 squamous cell carcinomas, and 9 large cell carcinomas. Stage distribution was 14 stage IIIB (malignant effusions) and 64 stage IV or recurrent metastatic; sites of metastasis were lungs, -26; liver-19; bones-27; brain-7; adrenals-3; distant nodes-2; skin-2. The NIP regimen was well tolerated by most of the patients but nausea/vomiting was noted in 55% of the cycles administered, most of them of grade 1-2 severity. Fifteen neutropenic episodes (5%) were encountered. Response to NIP was: 44 partial responses (56%); 1 complete response (1%); overall response, 58%. For stage IIIB, overall response was 36%, while for stage IV/metastatic, overall response was 63%. The median time to progression was 7 months for stage IIIB and 8 months for stage IV/metastatic disease and the overall median survival achieved was 14 months, with 60% of patients alive after one year. No significant difference in survival outcome was noted between patients with metastatic disease and those with stage IIIB (malignant effusion) disease. The NIP regimen has produced encouraging results in advanced NSCLC, as well as a favourable toxicity profile. The efficacy of NIP as a palliative tool should be assessed. A randomized trial to compare NIP with a two-drug combination of vinorelbine and cisplatin has been initiated.

Adult↗
PubMed1999

Induction chemotherapy followed by concurrent chemoradiotherapy in stage III unresectable non-small cell lung cancer.

The favourable experience with the combination regimen of vinorelbine, ifosfamide and cisplatin (NIP) in patients with metastatic non-small cell lung cancer (NSCLC) has led to a protocol assessing this regimen as an induction treatment in patients with stage III unresectable NSCLC, followed by thoracic radiotherapy with concurrent daily cisplatin as a radiosensitizer. Two cycles of NIP were administered 21 days apart; each cycle comprised i.v. vinorelbine 25 mg/m2 on days 1 and 8, i.v. ifosfamide 3 g/m2 on day 1 with MESNA as uroprotection, and i.v. cisplatin 50 mg/m2 on day 1. Radical thoracic radiotherapy commenced on day 43 to a total dose of 64 Gy and i.v. cisplatin 6 mg/m2 was given concurrently prior to each fraction of radiation as a sensitiser. Two more cycles of NIP were given to patients who responded favourably to the induction treatment about 2 weeks after completion of radiation. Between July 1995 and July 1997, 44 patients were treated with this protocol. This treatment schedule was generally well tolerated. Grade 3-4 neutropenia occurred in 50% of the patients and neutropenic sepsis was seen in 8. Grade 3-4 oesophagitis was uncommon. Most of the patients were able to complete the induction and concurrent chemoradiotherapy phase. Major response occurred in 75% of the patients with 2 (4.5%) complete responses (CR). A total of 6 patients achieved CR after chemoradiotherapy. At a median follow-up of 35 months, the median overall survival for all patients was 15 months with a 3-year survival rate of 24%. The median overall survival for stage IIIA patients was 19 months with a 3-year survival rate of 39% in contrast to 13 months' median overall survival and only 15% 3-year survival rate for stage IIIB. The NIP regimen results in a high response rate in NSCLC and this treatment programme seems to benefit selected patients with stage III disease.

Adult↗
PubMed1999

The 1997 International Staging System for non-small cell lung cancer: have all the issues been addressed?

The International Staging System for Lung Cancer has been revised recently. Important changes have been made to allow better correlation of prognoses and direction of management. The classification of synchronous pulmonary nodules in the same lobe as the primary tumor as T4 stage IIIB may imply a poorer outcome than is warranted, while the designation of a similar stage for malignant pleural effusion may not be reflective of the very poor prognosis associated with this extent of disease.

Carcinoma, Non-Small-Cell Lung↗
PubMed1999

Single-agent gemcitabine and gemcitabine/irinotecan combination (irimogem) in non-small cell lung cancer.

Gemcitabine is a fluoridated pyrimidine related to cytosine arabinoside that has significant activity in solid tumor models. Irinotecan is a camptothecin analog with an active metabolite, SN-38, which inhibits topoisomerase I activity by stabilizing the topoisomerase I-DNA cleavable complex. Gemcitabine studies in non-small cell lung cancer conducted in the United States, as well as an international collaboration and clinical trials from Europe and Japan, found overall response rates of 20% to 26%, a median duration of response between 5 to 9 months, and a median duration of survival ranging from 7 to 12.3 months. Gemcitabine also has been shown to be more effective than best supportive care in non-small cell lung cancer. In a phase I trial of irinotecan (50, 75, 100, and 115 mg/m2) in combination with 1,000 mg/m2 gemcitabine, three patients had documented partial responses: one with pancreas cancer at irinotecan 100 mg/m2, one with pancreas cancer, and one with metastatic carcinoma of unknown primary at irinotecan 115 mg/m2. Three of five non-small cell lung cancer patients had stable disease for four or more cycles at irinotecan doses of 50, 75, and 100 mg/m2; no non-small cell lung cancer patients were treated at irinotecan 115 mg/m2. We recommend that a combination of gemcitabine 1,000 mg/m2 and irinotecan 100 mg/m2 given on days 1 and 8 every 3 weeks be used as the starting dose in future phase II studies. Furthermore, based on the absence of severe nonhematologic toxicity or grade IV hematologic toxicity in the majority of patients treated at the highest dose, escalation of irinotecan to 115 mg/m2 may be considered for subsequent cycles in patients who do not experience > or =grade I hematologic or non-hematologic toxicity during the first cycle of gemcitabine/irinotecan combination chemotherapy.

Antimetabolites, Antineoplastic↗
PubMed1998

Use of ondansetron in the control of emesis in autologous peripheral blood stem cell transplant (APBSCT) for solid tumours.

AIM: The use of autologous peripheral blood stem cell transplant (APBSCT) for solid tumours have increased exponentially in the last 5 years. While the use of 5-hydroxytryptamine 3 (5HT3) receptor antagonists has been shown to improve control of emesis in patients receiving conventional dose chemotherapy, similar literature in APBSCT is more limited. We report our experience in the use of ondansetron in APBSCT. METHOD: Twenty-three patients with solid tumours receiving high-dose chemotherapy with APBSCT were studied. All were started on intravenous ondansetron at 24 mg/day before commencement of the conditioning regimen and continued till vomiting had ceased for 24 hours. The conditioning regimen used was dependent on the tumour type and the duration ranged from 4 to 6 days. Control of emesis was assessed by the number of vomiting episodes in each 24-hour period, monitored throughout conditioning till discharge from hospital. RESULTS: Complete or major protection from vomiting was achieved in 83% of patients on day 1. During the entire conditioning period, 52% of patients achieved complete or major response to ondansetron. After the conditioning period (delayed emesis), 44% of patients achieved complete or major response. CONCLUSIONS: The control of emesis for patients undergoing high-dose chemotherapy with APBSCT is fair with ondansetron. Research on more effective combinations to further improve emetic control in this selected group of patients is needed.

Adolescent↗
PubMed1997

Splenic abscesses from 1987 to 1995.

BACKGROUND: Isolated splenic abscesses is an uncommon clinical entity that is being increasingly recognized as a cause of intraabdominal sepsis in a wide variety of clinical situations, and involving a wide range of organisms. The increasing incidence of immunosuppressed states in this decade due to the use of chemotherapy for oncology, immunosuppression therapy for transplantation, and acquired immune deficiency syndrome, has changed the disease pattern of splenic abscesses. METHOD: Data from 287 cases reported in the English literature between 1987 and 1995 were collected, analyzed, and compared with two previous reviews of cases reported before 1987. RESULTS: Staphylococcus, Salmonella, and Escherichia coli are the most common organisms cultured. Immunosuppressed states were present in 33.5% of cases, with intravenous drug abuse and acquired immune deficiency syndrome accounting for half these cases. Computerized tomography and ultrasonography are diagnostic, with a sensitivity of 92.2% and 87.2%, respectively. Nonoperative management has a success rate of less than 65%, but salvage splenectomy does not increase mortality compared with splenectomy as initial therapy. CONCLUSIONS: Splenic abscesses are increasingly recognized with immunosuppressed states. Percutaneous radiologically guided drainage may be suitable in some cases, but splenectomy with appropriate antibiotics is the definitive treatment.

Abscess↗
PubMed1997

Usefulness of bacteriologic cultures in choice of antibiotics in patients with chemotherapy-induced neutropenic sepsis.

Neutropenic sepsis is a potential problem in cancer patients undergoing cytotoxic chemotherapy. Septic work-up including cultures from various sites is routinely done for these patients. To assess the usefulness of these cultures, a retrospective review of all patients admitted for neutropenic sepsis in the period from June 1994 to August 1995 was conducted. All patients included in the study had solid tumours which were being treated at our institution during the study period. All had fever and documented neutrophil count of < 1 x 10(9)/l on at least one occasion. There was a total of 41 patients with 52 episodes of neutropenic sepsis. Of the 52 episodes, there were positive cultures in 14 (27%) episodes, including 7 from blood, 2 from urine and 5 from skin. In the bacteriologic cultures, gram-negative bacteria were isolated in 11 episodes and gram-positive bacteria in 5 episodes (2 episodes had both gram-negative and gram-positive bacteria isolated, and 1 episode had two gram-negative bacteria). Majority of the patients (96%) were treated with a third generation cephalosporin with/without an aminoglycoside. This empirical treatment was effective with resolution of fever in 39 (75%). Thirteen (25%) had change of antibiotics because of deteriorating clinical state or drug resistance. Nine patients with unabated sepsis had bacteriological cultures which grew organisms resistant to the empirical antibiotics. Eight responded to the change of antibiotics. One patient with pseudomonas bacteraemia failed to respond to empirical treatment with ceftriaxone and died before antibiotics could be changed. Of the patients with positive cultures, the results of drug sensitivity made a difference to treatment. None of the patients with negative cultures died from sepsis. It appears that even though the rate of positive culture is low (27%), it is still useful as a guide when change of antibiotics is required.

Adolescent↗
PubMed1993

Ulcerative and plaque-like tracheobronchitis due to infection with Aspergillus in patients with AIDS.

Tracheobronchitis is an uncommon manifestation of infection due to Aspergillus species, occurring in < 7% of cases of pulmonary aspergillosis. At least 58 cases of invasive aspergillus tracheobronchitis have been described since 1962. We describe four patients with AIDS, all of whom were severely immunocompromised, who had ulcerative tracheobronchitis due to Aspergillus species demonstrated histologically. Three patients had received corticosteroids or were neutropenic at presentation. At bronchoscopy, three patients had some degree of diffuse tracheobronchitis, multiple ulcerative or "plaque-like" inflammatory lesions, and occasionally nodules involving the mainstem and segmental bronchi. The remaining patient had a single deep ulceration of the proximal trachea. Aspergillus was isolated from biopsy specimens from all four patients. There were varied degrees of invasion of the mucosa, submucosa, and cartilage on histological examination in three patients, one of whom had evidence of disseminated aspergillosis. Two patients subsequently developed pulmonary parenchymal disease due to Aspergillus. A review of aspergillus tracheobronchitis, including a discussion of airway disease in patients infected with human immunodeficiency virus, is presented.

AIDS-Related Opportunistic Infections↗