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Biomedical subjects

W K Hong

Publications and source records attributed to W K Hong.

At least 199 records · Page 11Linked to original sources
PubMed1996

Genetic instability and the development of recurrence of primary tumor and second primary tumor during head and neck tumorigenesis.

To determine whether the degree of genetic instability is associated with the development of recurrence of primary tumor (RPT) and second primary tumor (SPT), we examined 46 cases of head and neck squamous cell carcinomas (HNSCC) by nonisotopic in situ hybridization using chromosome specific DNA probes for chromosome 9 and 17. Forty-six cases were classified into three groups; group I, 15 cases without developing RPT and SPT; group II, 21 cases with RPT, and group III, 10 cases with SPT. We demonstrated the statistical significant increment of genetic instability in terms of normalized chromosome index (NCI) and polysomy index (PI) of chromosome 9 and 17 from normal adjacent to malignant lesions (ANL), to hyperplasia (HYP), to dysplasia (DYP), to squamous cell carcinomas (SCC). Our results demonstrated the trend of increased chromosome indices as the tissue progressed from ANL to SCC in group II over group I. However, when we compared the genetic instability between group I and the specimens from the patients who developed RPT within 6 months (group III), we found the significant increment of PI of both chromosome 9 (0.84 +/- 0.54 vs 1.25 +/- 0.46, p = 0.10) and 17 (1.02 +/- 0.62 vs 1.89 +/- 0.87, p = 0.06) on ANL in the later group. Our results also demonstrated the higher trend of genetic instability on ANL in group III over group I as shown by the statistical significance of NCI of both chromosome 9 (0.98 +/- 0.12 vs 1.06 +/- 0.02, p = 0.05) and 17 (1.02 +/- 0.09 vs 1.10 +/- 0.05, p = 0.05). These results suggested that the degree of genetic instability might be used as a potential molecular marker for the risk assessment of early RPT and SPT development during head and neck tumorigenesis.

Adult↗
PubMed1996

Genetic instabilities of chromosome 9, 17 and accumulation of p53 overexpression during multistage tumorigesis in head and neck cancer.

Malignant transformation and tumor progression are currently thought to be the result of the accumulation of genetic alterations in critical genes, the proto-oncogenes and the tumor suppressor genes. Among the tumor suppressor genes, the p53 tumor suppressor gene mutations are the most prevalent. In order to determine genetic instability and p53 expression, we analyzed the genetic changes of chromosome 9 and 17 by non-isotopic in situ hybridization in formalin-fixed, paraffin embedded tissues and calculated for normalized chromosome index (NCI) and polysomy index (PI), and the expression of p53 by using immunohistochemistry (IHC). The means of chromosome 9 and 17 NCI were found to increase gradually as the tissues progressed from normal to squamous cell carcinoma; 1.02 and 1.03, respectively, in normal adjacent tissue (ANL), 1.19 and 1.20 in hyperplasia (HYP), 1.28 and 1.31 in mild dysplasia (MD), 1.38 and 1.43 in moderate dysplasia (ModD), 1.39 and 1.66 in severe dysplasia/carcinoma in situ (SD/CIS), and 1.65 and 1.83 in squamous cell carcinoma (SCC). Moreover, the PI 9 and 17 means also increased as the tissues passed from histologically normal epithelium to HYP to dysplasia (DYP) to cancer. In ANL, PI 9 and 17 means were 0.90 and 1.53 percent, compared to 3.78 and 3.38 percent in HYP, 3.73 and 5.12 percent in MD, 5.66 and 8.47 percent in ModD, 13.56 and 20.99 percent in SD/CIS, and 17.74 and 22.50 percent in SCC. Interestingly, p53 expression also increased continuously, not only in amount but also in the incidence of its expression, as the tissues progressed from normal to cancer, 2.29 percent in ANL, 4.65 percent in HYP, 9.09 per cent in MD, 9.58 per cent in ModD, 29 percent in SD/CIS, and 38.67 per cent in SCC in the amount; and 3 of 33 (9%) in ANL, 6 of 37 (16%) in HYP, 5 of 21 (24%) in MD, 3 of 12 (25%) in ModD, 8 of 18 (44%) in SD/CIS, and 24 of 49 (49%) in SCC in the incidence. Our studies demonstrated that genetic instability and p35 expression occurred very early from ANL to SCC and increased gradually through HYP, DYP, to SCC in head and neck cancer. The genetic instability and the loss of normal p53 function play the potential role in multistep tumorigenesis in head and neck cancer and might be the useful biomarkers in assessing the risk of tumor development.

Carcinoma, Squamous Cell↗
PubMed1996

Increased epidermal growth factor receptor expression in metaplastic bronchial epithelium.

Epidermal growth factor receptor (EGFr) is expressed in human bronchial epithelial cells, and non-small cell lung cancers express increased EGFr. Squamous metaplasia of the bronchial epithelium occurs in chronic smokers and is considered an early premalignant change. In this study, EGFr expression was examined in biopsies of histologically normal and metaplastic bronchial tissues obtained from 69 smokers who were enrolled in a randomized placebo-controlled chemoprevention trial. This trial tested the effects of 6 months of treatment with 13-cis retinoic acid (13cRA) on bronchial metaplasia. EGFr expression was examined as a marker of bronchial metaplasia and response to 13cRA treatment. In bronchial biopsies obtained from patients in this study, EGFr expression was higher in metaplastic biopsies than in normal biopsies (P = 0.02). Smoking cessation during treatment correlated with reduced metaplasia (P < 0.001) and EGFr expression (P = 0.02), but multivariate analysis suggested that this effect of smoking cessation on EGFr expression was dependent upon reversal of bronchial metaplasia. 13cRA treatment did not alter EGFr expression (P = 0.23). Baseline EGFr expression levels in metaplastic biopsies did not predict metaplasia reversal. This study demonstrated that increased EGFr expression is a biomarker of bronchial metaplasia, but it did not support the hypothesis that EGFr is a biomarker of retinoid response in lung cancer chemoprevention trials.

Analysis of Variance↗
PubMed1996

Phase I trial of 9-cis retinoic acid in adults with solid tumors.

Retinoids have been shown to be potent inhibitors of epithelial carcinogenesis. Recent evidence has demonstrated that retinoid actions are mediated through nuclear receptors, which are proteins encoded by the retinoic acid receptor and retinoid X receptor gene families. These receptors are activated by binding to specific retinoids; of the known naturally occurring retinoids, 9-cis retinoic acid is unique in its ability to bind to both receptor families. Because of its unique receptor-binding characteristics, 9-cis retinoic acid may have biological activity not possible with other retinoids. For this reason, we conducted a Phase I trial of 9-cis retinoic acid in adult patients with solid tumors. Twenty-two patients were treated twice daily with p.o. 9-cis retinoic acid at doses ranging from 20 mg/m2/day to 150 mg/m2/day. The patients had non-small cell lung cancer (n = 8), breast cancer (n = 5), colorectal cancer (n = 3), head and neck cancer (n = 2), nonmelanoma skin cancer (n = 2), or ovarian cancer (n = 2). The dose-limiting (WHO grade III) toxic effects, which occurred at the 150-mg/m2/day dose level, were headaches and diarrhea. Less severe (grades I and II) toxic effects included cheilitis, dry skin, conjunctivitis, fatigue, hypertriglyceridemia, alkaline phosphatase elevation, myalgia/arthralgia, and hypercalcemia. Of the 15 patients evaluable for tumor response, no objective responses were observed. Pharmacokinetic analysis revealed a reduction in peak 9-cis retinoic acid plasma levels with chronic administration. Based on this study, the recommended Phase II dose of 9-cis retinoic acid in adult patients with solid tumors is 100 mg/m2/day administered in a divided dose twice daily.

Adult↗
PubMed1996

Differential induction of apoptosis by all-trans-retinoic acid and N-(4-hydroxyphenyl)retinamide in human head and neck squamous cell carcinoma cell lines.

Retinoids have been shown to act as cytostatic agents against a variety of tumor cell types, including squamous carcinoma cells. Recently it was reported that certain retinoids can induce apoptosis as well. Because we are investigating the potential of retinoids in chemoprevention and therapy for head and neck premalignant and malignant lesions, we compared the effects of all-trans-retinoic acid (ATRA) and N-(4-hydroxyphenyl)retinamide (4HPR) on seven human head and neck squamous cell carcinoma cell lines (17A, 17B, 22A, 22B, 38, SqCC/Y1, and 1483). Six of the seven cell lines showed dramatic morphological changes after treatment with 10 micrometer 4HPR, whereas no such changes were induced by 10 micrometer ATRA. To determine whether these retinoids can induce apoptosis, we analyzed both detached and attached cells after 2, 5, and 7 days of treatment for evidence of DNA fragmentation by DNA electrophoresis on agarose gels. In five of the seven cell lines, a DNA ladder was observed after treatment with 10 micrometer 4HPR for 5 or 7 days, whereas treatment with ATRA resulted in a less pronounced effect. In 17B cells, a clear DNA ladder was observed as early as 2 days after treatment with 4HPR; however, neither ATRA nor 9-cis-retinoic acid was as effective. In addition, morphological changes associated with apoptotic cell death, such as chromatin condensation and nuclear segmentation, were observed by propidium iodide staining and by electron microscopic analysis after 4HPR treatment. These results demonstrate that 4HPR causes apoptosis in several head and neck squamous cell carcinoma cell lines and that it is more potent in this effect than ATRA.

Antineoplastic Agents↗
PubMed1995

Prospective study of combination chemotherapy with cyclophosphamide, doxorubicin, and cisplatin for unresectable or metastatic malignant pleural mesothelioma.

BACKGROUND: This study was designed to determine the efficacy and side effects of a combination of cyclophosphamide (C), doxorubicin (D), and cisplatin (P) in patients with inoperable, unresectable, or metastatic malignant pleural mesothelioma. METHODS: Twenty-three patients with unresectable or metastatic malignant pleural mesothelioma were entered onto the study. The median age was 62 years (range, 42-74 years); there were 20 males and 3 females; the median performance status was 1 (Zubrod's scale). The histologic types included epithelial (14 patients), sarcomatoid (4 patients), unclassified (4 patients), and mixed type (1 patient). Twenty patients were known to have been exposed to asbestos and 3 were not. All patients were treated with the following starting dose of chemotherapy: a cycle comprised of C, 500 mg/m2 intravenously, day 1; D, 50 mg/m2 intravenously, day 1; and P, 80 mg/m2 intravenously, day 1 every 3 weeks. The cisplatin dose was reduced to 50 mg/m2 for the subsequent courses. For the assessment of tumor response, all patients had computed tomography scans of the chest after each three cycles of chemotherapy. RESULTS: Overall, 7 of 23 patients (30%) had partial responses (durations of responses [weeks]: 158+, 91+, 70+, 41+, 40, 39, 25), three had minor responses, and 14 had stable or progressive disease. One partial responder later underwent surgical resection and no viable tumors cells were found in the pathologic specimen. All patients have stopped treatment, and eight are still alive. The most common side effect was granulocytopenia (grade 4, 52%; grade 3, 17%). Other hematologic side effects were modest. Nonhematologic side effects included mild to moderate nausea and vomiting, neutropenic fever (three patients), peripheral neuropathy (one patient), and congestive heart failure (one patient). The overall median duration of survival was 60 weeks. CONCLUSION: Combination chemotherapy with CDP was well tolerated and had significant activity against unresectable or metastatic malignant pleural mesothelioma. The median duration of responses was 60 weeks; however, the survival rate was far from satisfactory. Continued development of new approaches including the biologic understanding of tumor development and testing new agents is warranted.

Adult↗
PubMed1995

Anti-retinoic acid (RA) antibody binding to human premalignant oral lesions, which occurs less frequently than binding to normal tissue, increases after 13-cis-RA treatment in vivo and is related to RA receptor beta expression.

Nuclear retinoic acid receptor beta (RAR-beta) expression decreases in human premalignant oral lesions (POLs). RAR-beta suppression could result from a decrease in the cellular level of retinoids because RAR-beta gene transcription is enhanced by retinoids. To explore this hypothesis, we compared the binding of a monoclonal antibody (mAb) against all-transretinoic acid (RA; anti-RA mAbs) to normal oral tissue and POLs. All 7 normal specimens stained positive with the antibody compared to only 20 of 43 POLs; similarly, 7 of 7 normal specimens contained RAR-beta mRNA compared to only 14 of 43 POLs. Twenty-four specimens were available before and after a 3-month treatment with 13-cis-RA in vivo. Anti-RA mAb binding to these specimens increased from 10 of 24 before to 22 of 24 after treatment, and the expression of RAR-beta mRNA increased from 7 of 24 before to 21 of 24 after treatment, respectively. There was a strong agreement between the binding of anti-RA mAbs and the expression of RAR-beta. Thus, we propose that the binding of anti-RA mAbs reflects the level of retinoids in the tissues and that this level is related strongly to RAR-beta expression.

Antibodies, Monoclonal↗
PubMed1995

Retinoid refractoriness occurs during lung carcinogenesis despite functional retinoid receptors.

Retinoids have demonstrated activity in the prevention of second primary tumors in patients with non-small cell lung cancer (NSCLC). They also contribute to the normal growth and differentiation of human bronchial epithelial (HBE) cells. Because retinoids mediate their actions through retinoid nuclear receptors (RARs and RXRs), aberrant signaling through retinoid receptors could contribute to lung carcinogenesis. Using a lung carcinogenesis model consisting of normal, premalignant, and malignant HBE cells, we examined all-trans retinoic acid (t-RA)-induced changes in cellular growth. These studies revealed that t-RA treatment inhibited the growth of normal HBE cells, but premalignant and malignant HBE cells were relatively resistant to t-RA. Coincident with the development of retinoid refractoriness, basal expression of the retinoic acid nuclear receptor beta (RAR-beta) increased. Analysis of receptor function by gel shift and transient transfection assays of normal, premalignant, and malignant HBE cells demonstrated that receptor-DNA binding and transcriptional activation properties were intact in the t-RA-refractory malignant HBE cells. To compare these findings to NSCLCs in patients, we investigated retinoid receptor expression in NSCLC biopsies. A subset of the tumors expressed RAR-beta, reflecting the RAR-beta expression observed in the malignant HBE cells in culture. These findings demonstrate that retinoid receptor function was intact in the t-RA-refractory malignant HBE cell line, suggesting that the defect in retinoid signaling in this lung carcinogenesis model is not intrinsic to the retinoid receptors.

Animals↗
PubMed1995

Chemoprevention trials and surrogate end point biomarkers in the cervix.

Cervical cancer is the second most common malignancy in women worldwide and remains a significant health problem for women, especially minority and underserved women. Despite an understanding of the epidemiologic risks, the screening Papanicolaou smear, and morbid and costly treatment, overall survival remains 40%. New strategies, based on the clinical and molecular aspects of cervical carcinogenesis, are desperately needed. Chemoprevention refers to the use of chemical agents to prevent or delay the development of cancer in healthy populations. Chemoprevention studies have several unique features that distinguish them from classic chemotherapeutic trials; these features touch on several disciplines and weave knowledge of the biology of carcinogenesis into the trial design. In the design of chemoprevention trials, four factors are important: high risk cohorts must be identified; suitable medications must be selected; study designs should include Phases I, II, and III; and studies should include the use of surrogate end point biomarkers. Surrogate end point biomarkers are sought because the cancer develops over a long period of time, and studies of chemopreventives would require a huge number of subjects followed for many years. Surrogate end point biomarkers serve as alternative end points for examination of the efficacy of chemopreventives in tissue. High risk cohorts include women with cervical intraepithelial neoplasia (CIN) or squamous intraepithelial lesions (SIL). Nutritional studies have helped define micronutrients of interest (folate, carotenoids, vitamin C, vitamin E). Other medications of interest include retinoids (4-hydroxyphenylretinamide [4-HPR], retinyl acetate gel, topical all-trans-retinoic acid), polyamine synthesis inhibitors (alpha-difluoromethylornithine [DFMO]), and nonsteroidal anti-inflammatory drugs (ibuprofen). Phase I chemoprevention studies of the cervix have tested retinyl acetate gel and all-trans-retinoic acid. Phase II trials of all-trans-retinoic acid, beta-carotene, and folic acid have been and are being carried out, whereas Phase III trials of all-trans-retinoic acid have been completed and have shown significant regression of CIN 2 but not CIN 3. Phase I studies of DFMO and Phase II studies of DFMO and 4-HPR are underway. Surrogate end point biomarkers under study include (1) quantitative cytology and histopathology; (2) human papillomavirus type testing; (3) biologic measures of proliferation, regulation, differentiation, and genomic instability; and 4) fluorescence spectroscopic emission. Clinical trials with biologic end points will contribute to our understanding of the neoplastic process and hence aid us in developing new preventive and therapeutic strategies.

Aneuploidy↗
PubMed1995

Structure and function of the HOX A1 human homeobox gene cDNA.

Homeobox genes code for transcription factors and are arranged in clusters, named A, B, C and D, found on four separate chromosomes in vertebrates. They contain a homeobox DNA sequence which codes for the homeodomain, a region of amino acids responsible for the DNA binding exhibited by these proteins. During embryonic development, the homeobox genes are both spatially and temporally regulated. In teratocarcinoma cell cultures, homeobox genes are regulated by retinoic acid (RA). The cDNAs from the first gene in the human HOX A cluster, HOX A1 (1.6), were cloned and the nucleotide sequence of a full-length cDNA was determined. It is highly homologous to its murine counterpart. Another HOX A1 cDNA was cloned, corresponding to an alternatively spliced form. In vitro translation of the full-length cDNA clone gave rise to a protein of 36 kDa. In PA-1 human teratocarcinoma cells HOX A1 is the earliest HOX A gene to be expressed after treatment with RA. To test whether HOX A1 could function as a early regulator of other HOX A cluster genes, we cotransfected into PA-1 human teratocarcinoma cells sense and antisense HOX A1 cDNAs expressed from an SV40 promoter with a 5.4-kb RA-sensitive HOX A4 (1.4) promoter-cat reporter. We found no effect of HOX A1 on the HOX A4 promoter. However, cotransfection of HOX A5 (1.3) was able to inhibit the HOX A4 promoter activity.

Alternative Splicing↗
PubMed1995

Suppression of retinoic acid receptor-beta in premalignant oral lesions and its up-regulation by isotretinoin.

BACKGROUND: Retinoids are effective in the treatment and prevention of certain human cancers. Most of their actions are thought to result from changes in gene expression mediated by nuclear retinoic acid receptors and retinoid X receptors. We conducted a study to determine whether the expression of these receptors was altered in premalignant oral lesions and, if so, whether their expression could be restored by treatment with isotretinoin. METHODS: We performed in situ hybridization of retinoic acid receptors and retinoid X receptors using antisense riboprobes in specimens of oral mucosa from 7 normal subjects and specimens of premalignant oral lesions from 52 patients before treatment with isotretinoin and from 39 of the 52 patients after three months of treatment. RESULTS: All the normal specimens expressed retinoic acid receptor-beta messenger RNA (mRNA). In contrast, retinoic acid receptor-beta mRNA was detected in only 21 of the 52 premalignant oral lesions (P = 0.003). Thirty-five of the 39 specimens available for evaluation after treatment expressed retinoic acid receptor-beta mRNA (P < 0.001). All normal and premalignant specimens expressed similar levels of mRNA for retinoic acid receptor-alpha and retinoic acid receptor-gamma and the three types of retinoic X receptors, alpha, beta, and gamma. The levels of retinoic acid receptor-beta mRNA increased in the specimens from 18 of the 22 patients who had responses to isotretinoin and in 8 of the 17 specimens from the patients without responses (P = 0.04). CONCLUSIONS: The expression of retinoic acid receptor-beta mRNA is selectively lost in premalignant oral lesions and can be restored by treatment with isotretinoin. Restoration of the expression of retinoic acid receptor-beta mRNA is associated with a clinical response. Retinoic acid receptor-beta may have a role in mediating the response to retinoids and may be a useful intermediate biologic marker in trials of these agents for the prevention of oral carcinogenesis.

Adult↗
PubMed1995

Interdigitating versus concurrent chemotherapy and radiotherapy for limited small cell lung cancer.

PURPOSE: Sequencing and timing of chemotherapy and radiotherapy for limited small-cell lung cancer (LSCLC) was studied in two consecutive trials. METHODS AND MATERIALS: In the interdigitating (IDG) trial, three cycles of COPE (cyclophosphamide 750 mg/M2 i.v. Day 1, vincristine 2 mg i.v. Day 8, cisplatin [DDP] 20 mg/M2 Days 1-3, etoposide 100 mg/M2 i.v. Days 1-3), were followed by thoracic radiation therapy (1.5 Gy bid 5-6 h apart, repeated twice at 3-week intervals) to give 45 Gy in 9 weeks; COPE was given during the intervals and for two more cycles. Operable patients had thoracotomy followed by IDG. Prophylactic cranial irradiation (PCI), 2.0 Gy x 15 fractions with a total dose of 30 Gy in 3 weeks, was given to the complete responders (CR) after completion of chemotherapy. In the concurrent (CON) trial, patients received DDP 60 mg/M2 i.v. Day 1, and etoposide 120 mg/M2 i.v. Days 1-3 for four cycles, every 3 weeks, and concurrent thoracic radiation therapy to 45 Gy with either 1.8 Gy daily, for 5 weeks or 1.5 Gy bid for 3 weeks. Prophylactic cranial irradiation (PCI) was given to the complete responders, 2.5 Gy daily for 2 weeks (25 Gy) (approximately 3 months after the initiation of treatment). RESULTS: The IDG group had 28 evaluable patients with median follow-up of 17.5 months. The CON group had 33 evaluable patients with median follow-up of 21 months. Overall survival rates for IDG patients were 79% at 1 year, 39% at 2 years, 30% at 3 years, and 27% at 4 years compared to 93%, 70%, 51%, and 46%, respectively, for the patients treated with CON (p = 0.01). Loco-regional recurrence (44%) and distant metastasis (48%) was more frequent as the first site of failure in the IDG group compared to the CON group (30% and 30%, respectively). Brain metastases constituted 30% of first metastases with IDG compared to none with CON. Esophagitis was significantly greater with CON. Hematologic and pulmonary toxicity were similar with IDG and CON. One death due to infection was seen in each treatment group. CONCLUSION: Concurrent chemoradiotherapy appears to be more effective than IDG. Earlier administration of PCI with concurrent chemotherapy and thoracic irradiation may reduce the risk of brain metastasis.

Adult↗
PubMed1995

p53 and retinoid chemoprevention of oral carcinogenesis.

We studied p53 protein's pattern of expression, association with retinoid response or resistance, and modulation by retinoid intervention in oral premalignancy. These p53 analyses were included in a prospective trial of the retinoid isotretinoin (1.5 mg/kg/day for 3 months) in 40 patients (45 oral premalignant lesions). Seven nonsmoking subjects (eight oral biopsies) were included as a control. Protein levels of p53 were determined separately for the whole epithelium and the basal, parabasal, and superficial layers. A wide range of accumulated p53 protein levels occurred in 40 (89%) of 45 lesions in basal and parabasal but not superficial layers. No p53 protein was detected in any normal controls. Accumulation of p53 increased in direct association with histological grade (P = 0.0004). An inverse relationship occurred between the levels of accumulated p53 protein and response to isotretinoin (P = 0.006). High-dose isotretinoin did not modulate accumulated p53 protein expression.

Adult↗
PubMed1995

Laryngeal preservation for advanced laryngeal and hypopharyngeal cancers.

OBJECTIVE: To compare a single institutional experience with combination chemotherapy and radiation for laryngeal preservation with historical age-, sex-, stage-, and site-matched controls who underwent laryngectomy for cancer of the larynx or hypopharynx. DESIGN: Fifty-five patients with stage III or IV laryngeal and hypopharyngeal squamous carcinoma were prospectively entered into a protocol to receive three cycles of cisplatin (+/- bleomycin sulfate) and fluorouracil and radiation therapy from 1986 to 1991 (group 1). Following two cycles of chemotherapy, the clinical tumor response was assessed and responders received a third cycle of chemotherapy followed by definitive radiation therapy. Nonresponders underwent surgical salvage. Two patients in the surgical control group were matched to each protocol patient (n = 110, group 2) regarding site, stage, sex, and age (+/- 7 years) without knowledge of patient outcome. SETTING: A tertiary cancer referral center, The University of Texas M. D. Anderson Cancer Center, Houston. RESULTS: Following chemotherapy, the tumor response rate for group 1 was complete in 38% and partial in 31%. With a median follow-up of 24 months (group 1) and 37 months (group 2), the Kaplan-Meier 2-year disease-specific survival for group 1 and 2 was 63% and 74%, respectively (P = .251). Among group 1 patients, 67% retained their larynges. Local recurrences were more frequent among the laryngeal preservation group (P = .001), whereas distant metastasis was more frequent among controls (P = .35). Thirty-three percent (18/55) of group 1 patients required total laryngectomy. Examining these subsets of patients showed that of the 67% (n = 37) of patients who retained their larynges, their 2-year survival was 56%, not significantly different from their respective controls (n = 74), 71%. Additionally, 2-year survival among the 18 group 1 patients who required salvage laryngectomy was 75% as compared with 80% for their matched controls (n = 36). CONCLUSIONS: These results document the results of chemotherapy and radiation therapy in the treatment of patients with advanced laryngeal and hypopharyngeal cancers in preserving the larynx. Although local control is significantly compromised among these patients, there is no compromise in overall survival when combined with prompt surgical salvage.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Retinoids and chemoprevention: clinical and basic studies.

Retinoids, which include natural vitamin A (retinol) and its esters and synthetic analogues, are the best-studied class of agents in chemoprevention. There are more than 4,000 different retinoids which have a wide spectrum of preclinical activities, structures, pharmacological profiles, tissue distributions, receptor specificities, and toxicities. A number of retinoids have significant activity in many in vivo experimental systems including skin, bladder, lung, breast and oral carcinogenesis. In clinical trials, several retinoids have achieved significant activity in the reversal of head and neck, skin, and cervical premalignancy, and in the prevention of second primary tumors associated with head and neck, skin, and non-small cell lung cancer. Since 1984, our group has conducted a series of clinical trials to explore the chemopreventive potential of 13-cis-retinoic acid (13cRA) in the aerodigestive tract. We have conducted two consecutive randomized studies in subjects with premalignant lesions of the oral cavity. These studies showed that high-dose 13cRA alone can achieve significant short-term reversal of oral premalignancy, and that high-dose followed by low-dose 13cRA can maintain suppression of oral carcinogenesis. Three other randomized trials have confirmed significant retinoid activity in this human carcinogenic system. We also developed a randomized, placebo-controlled trial of adjuvant high-dose 13cRA in patients with head and neck cancer. Second primary tumor development was significantly decreased in the 13cRA group, but 13cRA had no impact on primary disease recurrence or survival. This presentation will update the current status of clinical trials and correlative laboratory studies of potential intermediate endpoint biomarkers in retinoid chemoprevention of aerodigestive tract carcinogenesis.

Anticarcinogenic Agents↗
PubMed1995

Inhibition of proliferation and induction of apoptosis in cervical carcinoma cells by retinoids: implications for chemoprevention.

The effects of retinoids including all-trans-retinoic acid (ATRA), 13-CIS-RETINOIC ACID (13CRA), and N-(4-hydroxyphenyl)retinamide (4-HPR) on several cervical carcinoma cell lines in culture were investigated as a prelude to investigating the mechanisms underlying the chemopreventive potential of retinoids in cervical cancer. We found that when used at a concentration of 1 microM, 13CRA and ATRA inhibited the proliferation of three cell lines (ME-180 [HPV 68], SiHa [HPV 18], and HT-3 [HPV-]) by about 80% after a seven-day treatment. Three other cell lines (MS-751 [HPV 18], HeLa [HPV 18], C-33A [HPV-]) were moderately inhibited (30-48%), and two (C-4 II [HPV 18], CaSki [HPV 16]) responded poorly (< 25% inhibition). 4-HPR failed to inhibit the growth of any of these cell lines when used at 1 microM; however, when used at 5 or 10 microM, it induced apoptosis as evidenced by DNA fragmentation in several of the cell lines and was more potent in this effect than 10 microM ATRA. Retinoids that induce apoptosis in malignant cells may be able to exert similar effects on premalignant cells. Such retinoids would be expected to exhibit greater potency as chemopreventive agents than retinoids that exert only cytostatic effects.

Anticarcinogenic Agents↗