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Biomedical subjects

W K Hong

Publications and source records attributed to W K Hong.

At least 325 records · Page 18Linked to original sources
PubMed1991

Resectability of small-cell lung cancer following induction chemotherapy in patients with limited disease (stage II-IIIb).

A prospective study of multimodality therapy was conducted incorporating adjuvant resection in patients who presented with limited small-cell lung cancer (SCLC). This preliminary report addresses the resectability rate after induction chemotherapy. Twenty-five patients (1 with Stage II, 12 with Stage IIIa, and 12 with Stage IIIb disease) completed the induction regimen of 3 cycles of intravenous cyclophosphamide 750 mg/m2 on day 1, vincristine 2 mg on day 3, cisplatin 20 mg/m2 on days 1-3, and etoposide 100 mg/m2 on days 1-3, (every 3-4 weeks). Patients with complete response or partial response, 10 (40%) and 14 (56%) patients, respectively, were considered for surgical resection. Six were ineligible for surgery because of medical or surgical contraindications, and four refused surgery. Of the 14 patients taken to surgery, 10 had resectable disease (40% of the original group of 25). Three pneumonectomies, two bi-lobectomies, two lobectomies, and two wedge resections were performed. In the remaining patient multiple biopsies revealed no residual disease and resection was not performed. Surgery-related complications included one death, one bronchopleural fistula, and one episode of pneumonia. Induction chemotherapy was generally well tolerated. These preliminary data demonstrate that a significant percentage of patients with SCLC, Stages II-IIIb, can feasibly be resected after response to brief induction chemotherapy.

Adult↗
PubMed1991

Phase II trial of carboplatin plus cisplatin in recurrent and advanced squamous cell carcinoma of the head and neck.

Cisplatin is one of the most active chemotherapeutic agents for the treatment of squamous carcinoma of the head and neck; however, neurotoxicity and nephrotoxicity are dose-limiting. The analog, carboplatin, is a promising new agent with similar activity but a different spectrum of toxicity. To evaluate if a therapeutic advantage could be achieved with acceptable toxicity, a combination of carboplatin 350 mg/m2 and cisplatin 50 mg/m2 were administered every 28 days to patients with recurrent or metastatic disease who had received no prior chemotherapy. Of 24 patients enrolled in this study, 21 were assessable for response and toxicity. Five partial responses were observed (24%; 95% confidence interval [Cl], 4.9% to 38.6%). No complete response occurred. Two of these patients received definitive radiotherapy and achieved complete responses. The median survival of all patients was 24 weeks. Hematologic toxicity was dose-limiting necessitating a decrease in the starting dose of carboplatin to 300 mg/m2. Nonhematologic toxicity was infrequent and mild. Significant renal impairment occurred in only two patients. Although treatment with the combination of carboplatin and cisplatin is feasible, we found no therapeutic advantage in terms of an increased response or survival.

Adult↗
PubMed1991

Recent advances in cancer chemoprevention.

The CCPC 90 conference and workshop included presentations by basic scientists describing the key in vitro and in vivo model systems used to study epithelial carcinogenesis and its associated biochemical and molecular alterations. A major conference theme was the identification of markers identifying specific carcinogenic stages. Current work focuses on defining the biology of preneoplasia, the critical specific molecular events in multistep carcinogenesis, and the dynamic interplay between viral, behavioral, dietary, and genetic factors in human carcinogenesis. Studies of molecular epidemiology and genetic susceptibility are identifying new risk groups and contributing to preventive strategies. Another major theme of the conference was the concept of field carcinogenesis and the study of carcinogen-exposed tissue "at risk" for the development of cancer. A specific example discussed by several investigators was the issue of SPT development in head and neck and lung cancers. Novel studies of biologic markers for use in early detection and as intermediate end points were described. The latter application, if validated in human trials, may allow short-term screening of chemopreventive agents and determinations of optimal doses/schedules for phase III chemoprevention trials. These biomarker trials may serve as a bridge between preclinical work and full-scale randomized trials. The status of the major phase III clinical trials was presented. Major problems in chemoprevention trials include (1) selection of agents, doses, and schedules, (2) lack of pharmacologic and pharma quality control, (5) adherence (drop-out and drop-in), and (6) trial-specific feasibility/recruitment, issues.

Animals↗
PubMed1991

Chemoprevention in head and neck cancer.

It is not a coincidence that the aerodigestive tract has proven such a fertile ground for the evaluation of chemoprevention. The incidence of second primaries and the concept of field cancerization made the need for prevention acute and showed the limitations of even the most curative of treatments. New and presumably less toxic agents are being evaluated; chemoprevention is being applied to asymptomatic populations at higher risk for lung, colon, breast, and other neoplasias. Biomarkers may be instrumental in rapid development of these new clinical applications, but much is still to be done. Yet unanswered is whether suppression of premalignant lesions will ultimately decrease cancer incidence. Survival in the second primary prevention trial has not thus far shown a significant improvement and toxicities were significant. Many questions remain in the study of chemoprevention; head and neck cancer provides a conducive model in which these answers might be found.

Biomarkers, Tumor↗
PubMed1990

Prevention of second primary tumors with isotretinoin in squamous-cell carcinoma of the head and neck.

BACKGROUND: Patients with head-and-neck cancers who are free of disease after local therapy remain at high risk for both recurrent and second primary tumors. Retinoids have proved efficacious in the treatment of premalignant oral lesions and are promising agents for the prevention of epithelial carcinogenesis. METHODS: We prospectively studied 103 patients who were disease-free after primary treatment for squamous-cell cancers of the larynx, pharynx, or oral cavity. After completion of surgery or radiotherapy (or both), these patients were randomly assigned to receive either isotretinoin (13-cis-retinoic acid) (50 to 100 mg per square meter of body-surface area per day) or placebo, to be taken daily for 12 months. RESULTS: There were no significant differences between the two groups in the number of local, regional, or distant recurrences of the primary cancers. However, the isotretinoin group had significantly fewer second primary tumors. After a median follow-up of 32 months, only 2 patients (4 percent) in the isotretinoin group had second primary tumors, as compared with 12 (24 percent) in the placebo group (P = 0.005). Multiple second primary tumors occurred in four patients, all of whom were in the placebo group. Of the 14 second cancers, 13 (93 percent) occurred in the head and neck, esophagus, or lung. CONCLUSIONS: Daily treatment with high doses of isotretinoin is effective in preventing second primary tumors in patients who have been treated for squamous-cell carcinoma of the head and neck, although it does not prevent recurrences of the original tumor.

Adult↗
PubMed1990

Changes in keratin expression during 7,12-dimethylbenz[a]anthracene-induced hamster cheek pouch carcinogenesis.

This study was undertaken to explore the expression of keratins in the hamster cheek pouch carcinogenesis model, using monospecific keratin antibodies and a technique that allows immunoblotting analysis of tissues embedded in paraffin. Changes in keratin expression were correlated with histopathological changes and with the expression of the enzyme gamma-glutamyl transpeptidase. The right cheek pouch of 20 male golden Syrian hamsters was treated with 0.5% 7,12-dimethylbenz[a]anthracene for 16 weeks. As previously described by other laboratories, this treatment resulted in hyperplastic and dysplastic lesions and benign and malignant tumors. The keratins assayed in this study were K14 (Mr 55,000), K1 (Mr 67,000), and K13 (Mr 47,000). The normal hamster cheek pouch epithelium expressed K14 in the basal layer and K13 in the suprabasal and differentiated layers, whereas K1 was not detected by either immunohistochemistry or immunoblotting. Concomitant with 7,12-dimethylbenz[a]anthracene-induced hyperplasia, there were some topographical alterations in the distribution of K14. In this case, K14 was no longer restricted to the basal layer but was also expressed in differentiated cells. The same pattern was also observed in dysplastic lesions and in squamous cell carcinoma. Furthermore, expression of the K13 differentiation-associated keratin was preserved in this hyperplastic epithelium during all the stages of carcinogenesis, including either anaplastic or differentiated areas. In contrast, after 2 weeks of 7,12-dimethylbenz[a]anthracene treatment, K1 expression started as a weak and patchy pattern in suprabasal cells, becoming stronger and more homogeneous at 8 and 16 weeks of treatment. However, K1 was almost absent in squamous cell carcinoma, where only small very well differentiated areas were stained. We also observed gamma-glutamyl transpeptidase-positive foci in earlier stages of carcinogenesis, concomitant with the expression of the K1 keratin. However, it was not possible to find a perfect topographical correspondence between the two events. Alterations in the pattern of keratin expression appear to be a common feature during the development of squamous cell carcinoma in different systems and could be an excellent tool to study carcinogenesis and chemoprevention.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1990

Bronchial micronuclei as a marker of an early stage of carcinogenesis in the human tracheobronchial epithelium.

In the bronchial epithelium, smoking initiates a multistep process that first appears histologically as premalignant squamous metaplasia/dysplasia, a biological predecessor of squamous-cell lung cancer. Reflecting chromosomal damage from a carcinogenic insult, micronuclei may reveal earlier events in the carcinogenic sequence. We prospectively evaluated and correlated micronucleus count, histology (index of metaplasia) and smoking exposure in 35 consecutive subjects (9 active smokers, 10 previous smokers and 16 never-smokers) undergoing diagnostic bronchoscopy. Samples for micronuclei and histological evaluation were taken from the main carinal mucosa in each subject for site-specific comparisons. The median and mean micronucleus counts per 1,000 cells were significantly higher in active smokers than in non-smokers (subjects who had never smoked and previous smokers): median counts were 3.7 vs. 1.4, p = 0.03; mean counts were 4.7 vs. 1.9, p = 0.01. There was no significant difference, however, in micronucleus counts between subjects who had never smoked and previous smokers. Bronchial metaplasia and smoking history were not associated. Our findings suggest that micronuclei are a readily quantitated, early intermediate-endpoint marker for detecting tobacco-initiated tracheobronchial carcinogenesis.

Adult↗
PubMed1990

Expression of epidermal growth factor receptor, polyamine levels, ornithine decarboxylase activity, micronuclei, and transglutaminase I in a 7,12-dimethylbenz(a)anthracene-induced hamster buccal pouch carcinogenesis model.

The expression of epidermal growth factor receptor and transglutaminase type I, polyamine (putrescine, spermidine, and spermine) levels, ornithine decarboxylase activity, and micronuclei occurrence were assessed in the 7,12-dimethylbenz(a)anthracene (DMBA)-induced hamster buccal pouch model to elucidate the role and timing of changes in different growth and differentiation markers during carcinogenesis. DMBA (0.5%) in heavy mineral oil was applied to the right buccal pouch 3 times per wk for up to 16 wk; controls received heavy mineral oil alone. Hamsters were killed after 0, 4, 8, and 16 wk. Frozen tissue was chemically analyzed for polyamine levels and ornithine decarboxylase activity and was also used for immunohistochemical analysis of transglutaminase I. Paraffin-embedded sections were used for epidermal growth factor receptor immunohistochemical determinations and for micronucleated cell assays. Hyperplasia was detected by histological analysis at 4 wk, dysplasia with or without papillomatous changes at 8 wk, and squamous cell carcinoma at 16 wk. Epidermal growth factor receptor was not expressed in the normal buccal epithelial layer, at a moderate level in both the superficial keratin and basal cell layers in hyperplastic epithelium, and at very high levels in both dysplasia and squamous cell carcinoma. Transglutaminase I was expressed at a limited level in normal buccal mucosa, was expressed at a low level in the basal layer of hyperplastic lesions, was somewhat elevated in dysplasia, and was markedly enhanced in squamous cell carcinoma. Putrescine and spermidine levels and ornithine decarboxylase activity increased dramatically after 8 and 16 wk of DMBA. Micronucleated cells increased after 4 wk of DMBA treatment, that high level sustained during all stages of carcinogenesis. We suggest that these biological markers could be excellent intermediate end points in assessing the effects of various chemopreventive agents to be tested in the hamster buccal pouch model and in human clinical trials.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1990

Flow cytometric analysis of the DNA content of non-small cell lung cancer. Ploidy as a significant prognostic indicator in squamous cell carcinoma of the lung.

To assess the prognostic value of DNA ploidy in non-small cell lung cancer (NSCLC), we performed a flow cytometric study using paraffin-embedded archival material from 158 patients who underwent surgical resection between 1980 and 1982. Single-variable histograms were examined and the results of these histograms were correlated with clinicopathologic characteristics and outcome. Histograms that could be analyzed were obtained in 146 cases, of which 85 (58%) were aneuploid and 61 (42%) were diploid. Survival analysis showed that patients with diploid squamous cell carcinomas (SCC) survived significantly longer than those with aneuploid SCC (a 5-year survival rate of 70% as compared with 26% [P = 0.002], respectively), and the results were independent of stage. However, DNA ploidy was not a significant prognostic factor in non-SCC (P = 0.337). Ploidy did not correlate with other clinicopathologic variables such as stage, nodal status, degree of differentiation, nuclear grade, and mitotic rate. These results suggest that DNA ploidy, as determined by flow cytometric analysis, provides an independent prognostic variable for patients with SCC and that it should be considered in treatment planning. However, non-SCC of lung may have different biologic variables, and their prognostic variables should be evaluated separately.

Adenocarcinoma↗
PubMed1990

Inhibition of growth and squamous-cell differentiation markers in cultured human head and neck squamous carcinoma cells by beta-all-trans retinoic acid.

Vitamin A and some of its metabolites such as beta-all-trans retinoic acid (RA) have been implicated in the regulation of differentiation of normal and malignant epithelial cells in vivo and in vitro. In the present study the effects of RA on the growth and differentiation of 7 cell lines derived from human head and neck squamous-cell carcinomas (HNSCCs) were examined. RA (greater than 0.01 microM) inhibited the proliferation in monolayer culture of 6 of 7 HNSCC cell lines. One cell line (UMSCC-35) was very sensitive, 5 (UMSCC-10A, -19, -30, -22B and HNSCC 1483) were moderately sensitive, and 1 (HNSCC 183) was insensitive. Three of the cell lines (UMSCC-22B, -30, and HNSCC 1483) were capable of forming colonies in semisolid medium--a capability that was suppressed by RA. The HNSCC cell lines expressed various levels of the squamous-cell differentiation markers type I (particulate, epidermal) transglutaminase (TGase) and cholesterol sulfate (CS). RA treatment (I microM, 6 days) decreased TGase activity by more than 50% in 3 (UMSCC-10A, -22B and 1483) of the 7 cell lines, and the effect on UMSCC-22B was dose-dependent. Type II TGase (soluble, tissue type) activity was detected in 3 cell lines, and after RA treatment its activity increased in HNSCC 1483 and 183 cells and decreased in UMSCC-19. Following RA treatment, CS levels decreased by 20, 25, 70, 76, 89 and 91% in cell lines UMSCC-30, -10A, 183, UMSCC-35, -22B, and HNSCC 1483, respectively. The suppression by RA of CS accumulation in the 1483 cells was dose-dependent. Cholesterol sulfotransferase activity, which is responsible for CS synthesis, was suppressed by 40-97% after RA treatment of UMSCC-19, -22B, and HNSCC 1483. Our results demonstrate that RA inhibits the growth and decreases the level of 2 squamous differentiation markers in HNSCC cells.

Carcinoma, Squamous Cell↗
PubMed1990

Phase II study of 10-ethyl-10-deaza-aminopterin (10-EdAM; CGP 30 694) for stage IIIB or IV non-small cell lung cancer.

Thirty-one patients with stage IIIB or IV non-small cell lung cancer (NSCLC) were treated with intravenous 10-EdAM on a weekly basis. The starting dose was 80 mg/m2, with subsequent doses adjusted depending on evidence of toxicity. There were 20 men and 11 women with a median age of 58 years (range, 33-75). Response was evaluated in 30 patients, 5 with evaluable but not measurable tumors and 25 with measurable indicator lesions. There were no complete remissions; 3 patients achieved partial remission. Nine patients had a minor response, 6 showed no change, and 12 had progressive disease. Median survival for all 31 patients was 43 weeks (range, 12-65+). During the first 3-week period, the 10-EdAM dose was reduced or withheld in 19 patients (because of stomatitis in 12, SGPT elevation in 3, skin rash in 2, and granulocytopenia in 2), escalated in 11 patients, and unchanged in 1 patient. A mean of 34-88 mg/m2 of 10-EdAM (median, 50) was given per week during the first 5-week period. Myelotoxicity was infrequent and there was no significant nephrotoxicity. Considering the modest side effects of this treatment and the conservative dose-modification schedule which mandated substantial dose reductions, we conclude that 10-EdAM is a promising antitumor agent for NSCLC.

Adult↗
PubMed1990

Phase II study of tallysomycin S10b in patients with advanced head and neck cancer.

Twenty patients with advanced head and neck tumors were entered in a phase II trial of tallysomycin S10b given intravenously at weekly doses of 2.5 mg/m2. All patients had received prior chemotherapy +/- radiotherapy. Sixteen patients were evaluable for response. Two had stable disease for 15 and 22 weeks respectively. None exhibited tumor shrinkage. Non-hematologic toxicities primarily consisted of gastrointestinal intolerance. Mild fever was noted in about half of the patients and increase in serum creatinine was observed in four. Other side effects consisted of decrease in pulmonary diffusion capacity and skin changes. In conclusion, tallysomycin S10b has no activity in previously treated head and neck cancer patients and has a toxicity spectrum similar to that of bleomycin.

Aged↗
PubMed1990

Ifosfamide with mesna uroprotection in the management of lung cancer.

Fourteen patients with extensive disease small cell bronchogenic carcinoma (SCBC) received ifosfamide at 2,000 mg/m2/day for 5 consecutive days with simultaneous mesna and vincristine while 26 patients with extensive disease non-small-cell bronchogenic carcinoma (N-SCBC) received the same regimen without vincristine. Eight partial responses (57%) were observed with a 40-week median survival in the case of SCBC and four partial remissions (15%) with a 31-week median survival in N-SCBC. Granulocytopenia was the dose-limiting toxicity, whereas urotoxicity was well controlled with mesna. Neuropsychiatric toxicity consisted of anxiety, agitation, confusion, and hallucination. Neurobehavioral testing detected worsened performance during ifosfamide treatment. Ifosfamide is one of the few active agents in N-SCBC.

Aged↗
PubMed1990

Fluorouracil, doxorubicin, cyclophosphamide, and cisplatin combination chemotherapy in advanced or recurrent salivary gland carcinoma.

Seventeen patients with recurrent or unresectable salivary gland carcinomas were treated with combination fluorouracil (5-FU), doxorubicin, cyclophosphamide, and cisplatin (FACP). Sixteen patients were assessable for response and toxicity. A total of 111 courses of chemotherapy were given, yielding one complete and seven partial responses, for an objective response rate of 50%. Two other patients had stable disease and two had a minor response. The median duration of objective response was 32 weeks (range, 4 to 72); median survival for the 16 patients was 72 weeks. Hematologic toxicity was significant, with 88% developing a nadir granulocyte count of less than 1,000 cells per microliter (median, 300 cells per microliter), and 53% a nadir platelet count of less than 100,000 cells per microliter (median, 68,000 cells per microliter). Seven patients (44%) developed neutropenic fever, and three (18%) developed an increase in serum creatinine greater than 1.5 mg/dL during the course of treatment. This combination of chemotherapy was active; however, an increased response rate was not observed above that reported for other combinations. Response duration, or overall patient survival, on this intensive regimen was similar as compared with other published therapeutic trials of this disease entity.

Adolescent↗
PubMed1990

Combination immunotherapy for non-small cell lung cancer. Results with interleukin-2 and tumor necrosis factor-alpha.

Sixteen patients with advanced non-small cell lung cancer were treated with a combination of low-dose interleukin-2 and tumor necrosis factor-alpha. Patients received a continuous 24-hour intravenous infusion of interleukin-2 at 1 X 10(6) Cetus U/m2 and a simultaneous daily intramuscular dose of tumor necrosis factor-alpha (25 to 100 micrograms/m2) for 5 consecutive days. These doses did not have antitumor activity when administered alone in previous trials. Treatment was given at 3-week intervals. Common side effects included fever, local skin reaction at the injection site of tumor necrosis factor-alpha, pancytopenia, and general malaise, all of which were reversible within 48 hours of cessation of therapy. The maximum tolerated doses with this combination were 1 X 10(6) U/m2/day of interleukin-2 and 50 micrograms/m2/day of tumor necrosis factor-alpha, with thrombocytopenia (less than 50K) being the dose-limiting toxicity. Twelve patients received two cycles or more and were evaluable for response. Measurable tumor regression occurred in four patients. An additional seven patients had radiographic stabilization of disease (median = 12 weeks) before progression. All patients had augmented lymphokine-activated killer and natural killer activity during therapy. Enhanced lysis of autologous tumor in vitro was demonstrated in four of four patients during therapy. We conclude that combination immunotherapy with low-dose interleukin-2 and tumor necrosis factor-alpha can mediate tumor regression and can be given with acceptable toxicity.

Adult↗