Biomedical subjects

J F Foley

Publications and source records attributed to J F Foley.

At least 37 records · Page 2Linked to original sources

PubMed1993

A randomized phase II trial of amonafide or trimetrexate in patients with advanced non-small cell lung cancer. A trial of the North Central Cancer Treatment Group.

BACKGROUND: In an effort to identify new active chemotherapeutic agents against non-small cell lung cancer (NSCLC), the authors conducted a randomized Phase II trial to evaluate the efficacy of amonafide or trimetrexate in patients with Stage IV disease. METHODS: This was a multicenter Cooperative Oncology Group trial. All patients had advanced NSCLC and were previously untreated with chemotherapy. Patients were randomized to treatment after enrollment. Amonafide was administered as a 24-hour continuous infusion (1600 mg/m2) every 21 days. Trimetrexate (150 mg/m2) was administered intravenously over 30 minutes every 2 weeks. The primary endpoints of the study were clinical response and toxic effects. All patients were observed for survival. RESULTS: Thirty-five patients received amonafide and were assessable. There were no complete responses and two partial responses (6%). Thirty-seven patients were treated with trimetrexate. There were no complete responses and five (14%) partial responses. Myelosuppression was the primary toxic effect observed with amonafide treatment. Trimetrexate was associated infrequently with clinically significant side effects. CONCLUSIONS: Amonafide is inactive against NSCLC, and no additional studies with this agent are planned. Trimetrexate has some activity against NSCLC, but its role in the future therapy of this disease is questionable.

Adenine↗

PubMed1993

Comparison of pulmonary O6-methylguanine DNA adduct levels and Ki-ras activation in lung tumors from resistant and susceptible mouse strains.

The role of O6-methylguanine (O6MG) DNA adduct formation and persistence in the formation of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumors from resistant C57BL/6 and susceptible A/J mice was investigated. In addition, the frequencies of pulmonary tumor formation and Ki-ras activation were defined in C57BL/6 mice treated with NNK or vinyl carbamate (VC), and the role of the p53 gene in pulmonary carcinogenesis in these resistant mice was examined. One day after treatment with 100 mg/kg NNK, O6MG adduct concentrations were twofold to eightfold higher in Clara cells and type II cells than in small cells or whole lungs from both mouse strains. The concentrations of O6MG in isolated cells decreased at a similar rate in the two strains of mice. Lung tumors were detected by 27 mo of age in 18% of the C57BL/6 mice after a single 100 mg/kg dose of NNK and in 46% of these mice after a single 60 mg/kg dose of VC. In contrast, the tumor incidence in untreated C57BL/6 mice was 4%. Only one of 22 lung tumors from C57BL/6 mice treated with NNK contained an activated Ki-ras gene that was associated with an O6MG DNA adduct, whereas previous studies detected activated Ki-ras oncogenes in most of the NNK-induced lung tumors analyzed from susceptible A/J and resistant C3H mice. The small differences in formation and persistence of the O6MG adduct in whole lung or isolated lung cells from A/J and C57BL/6 strains do not account for the differences in either susceptibility for tumor formation or activation of the Ki-ras gene between these strains. In contrast to the low number of NNK-induced tumors with Ki-ras mutations in the resistant mice, 11 of 20 lung tumors from VC-treated mice contained activated Ki-ras genes. Neither p53 tumor suppressor gene mutations nor overexpression of the p53 protein were detected in spontaneous or chemically induced lung tumors in C57BL/6 mice. Thus, although Ki-ras activation was detected in some tumors, pathways independent of ras activation and p53 inactivation also appear to be involved in lung tumorigenesis in this resistant mouse strain.

Animals↗

PubMed1993

Ras proto-oncogene activation in liver and lung tumors from B6C3F1 mice exposed chronically to methylene chloride.

Methylene chloride has been the subject of recent toxicological and carcinogenesis studies because of significant human exposure and widespread use in industrial processing, food preparation and agriculture. In this study, liver and lung tumors, induced in female B6C3F1 mice by inhalation of 2000 p.p.m. methylene chloride (6 h/day, 5 days/week continuous exposure), were examined for the presence of activated ras proto-oncogenes. DNA was isolated from 49 spontaneous and 50 methylene chloride-induced liver tumors and screened by oligonucleotide hybridization of PCR amplified H-ras gene fragments for codon 61 mutations. In the chemically induced tumors, 38 mutations were detected, 16 C to A transversions in base 1, 16 A to G transitions in base 2 and 6 A to T transversions in base 2. This mutation profile was similar to that identified for the H-ras gene in the spontaneous liver tumors and suggests that methylene chloride acts in liver by promoting cells with spontaneous lesions. Tumors in which H-ras codon 61 mutations were not detected were examined for the presence of transforming genes by the nude mouse tumorigenicity assay. Except for activated K-ras genes detected in DNA from two methylene chloride induced tumors and one spontaneous tumor, no other transforming genes were identified. DNA from 54 lung tumors was screened by direct sequencing of PCR amplified DNA fragments of the K-ras gene for first and second exon mutations, and 12 mutations were identified, 5 in exon one and 7 in exon 2. The low number of spontaneous tumors available in this study limits the interpretation of the data, and thus the frequency and spectrum of K-ras activation in the methylene chloride induced tumors was not significantly different from that in the seven spontaneous tumors analyzed. Since K-ras activation was not detected in 80% of the tumors, the nude mouse tumorigenicity assay was used to examine the lung tumors for the presence of other transforming genes. At present no transforming genes other than ras genes were identified in either liver or lung tumors.

3T3 Cells↗

PubMed1993

Characterization of p53 mutations in methylene chloride-induced lung tumors from B6C3F1 mice.

Mutations of the p53 tumor suppressor gene are the most common defined genetic alterations seen in a wide variety of human cancers. In contrast, little is known about the importance of the p53 gene in chemically induced tumors of rodents, which are widely used as models for the evaluation of human health risks. In this study we examined 54 methylene chloride-induced and seven spontaneously arising lung tumors from female B6C3F1 mice for losses of heterozygosity (LOH) at markers near the p53 gene on chromosome 11. LOH was detected in seven methylene chloride-induced lung carcinomas by Southern analysis of a restriction fragment length polymorphism and PCR analysis of five simple sequence length polymorphisms. In each case allele loss was observed at all six markers; thus, these chromosomal alterations were likely to have resulted from mitotic nondisjunction. In contrast, LOH was not detected in 20 liver tumors from methylene chloride-treated mice at the Acrb locus, which is tightly linked to the p53 gene on chromosome 11. In addition single strand conformation polymorphism analysis was performed to screen for mutations in the most conserved regions of the p53 gene (exons 5 to 8). Consequently, potential mutations identified by direct sequencing, were only detected in four of the seven tumor samples with LOH, but not in any of the remaining lung tumors. Overexpression of the p53 protein by immunohistochemical staining was detected only in the four tumors that contained p53 point mutations and in a focal area of another tumor. Finally, using a simple sequence length polymorphism within the retinoblastoma tumor suppressor gene, LOH on mouse chromosome 14 was also detected in three lung carcinomas and one liver tumor. Inactivation of p53 and possibly the retinoblastoma tumor suppressor gene appear to be infrequent events in lung and liver tumors from methylene chloride treated mice.

Animals↗

PubMed1993

Inhalation exposure to a hepatocarcinogenic concentration of methylene chloride does not induce sustained replicative DNA synthesis in hepatocytes of female B6C3F1 mice.

We have used methylene chloride as a model to study cellular and molecular processes responsible for liver tumor induction by chlorinated hydrocarbons. Because of current interest in the role of enhanced cell proliferation in tumor induction, measurement of S-phase hepatocytes was incorporated into recently conducted toxicity and carcinogenicity studies. In prechronic studies, female B6C3F1 mice were exposed to 0, 1000, 2000 or 8000 p.p.m. methylene chloride by inhalation, 5 days per week, for up to 4 weeks followed by a 1 and 2 week recovery period. Mice exposed to concentrations of 2000, 4000 or 8000 p.p.m. methylene chloride had sustained increased liver weight commencing after 1 week of exposure and returning to normal after the 1 or 2 week recovery period. The increased liver weight was attributed to hepatocellular hypertrophy secondary to intracellular glycogen accumulation. Tritiated thymidine was administered by osmotic minipumps to label S-phase hepatocytes over a 6 day period. At most intervals examined there was decreased hepatocyte labeling in mice exposed to methylene chloride. However, there was a transitory increased number of S-phase hepatocytes observed at the 2 week interval in the 1000, 4000 and 8000 p.p.m. methylene chloride groups. In a chronic study, female mice were exposed to 2000 p.p.m. methylene chloride for up to two years. Following labeling with BRDU using 6 day minipumps, a statistically significant decrease in S-phase hepatocytes was observed after 13 weeks of methylene chloride exposure. A minor increased labeling index (LI) observed at 52 weeks was not considered to be a methylene chloride treatment-related effect. Retrospective immunohistochemical staining for proliferating cell nuclear antigen (PCNA) in liver sections containing foci of cellular alteration allowed demonstration of S-phase hepatocytes in these clonally expanded preneoplastic lesions. While foci frequently had higher LI's than surrounding normal hepatocytes, there was no difference in the mean LI of foci from methylene chloride-treated mice versus foci occurring spontaneously in control mice. The absence of a sustained increase in S-phase hepatocytes in female B6C3F1 mice suggests that enhanced cell proliferation is not a major mechanistic factor associated with the observed hepatocarcinogenicity of methylene chloride.

Administration, Inhalation↗

PubMed1993

Effect of varying exposure regimens on methylene chloride-induced lung and liver tumors in female B6C3F1 mice.

Methylene chloride is a high production chemical used in a variety of applications resulting in estimated occupational and consumer exposures of at least one million people per day. Results of previously reported chronic evaluations of inhaled methylene chloride indicated that it caused mammary tumors in Fischer 344 rats and neoplasia in the lungs and liver of B6C3F1 mice. Mechanism(s) for methylene chloride-induced carcinogenesis have not been adequately elucidated. In this paper we describe the histologic evaluation of animals at a number of intermittent times for the purposes of assessing the progressive development of liver and lung neoplasia. Additionally, a series of stop-exposure treatments was conducted to evaluate the role of different methylene chloride exposure durations on the induction of hepatic and pulmonary neoplasia in female mice. Inhalation exposure to 2000 p.p.m. methylene chloride for 6 h per day, 5 days per week, for 104 weeks resulted in an 8-fold increase in the incidence of exposed animals having a lung adenoma or carcinoma (63 versus 7.5%; P < 0.01) and a 13-fold increase in the total number of pulmonary adenomas and carcinomas per animal at risk (0.97 versus 0.075; P < 0.01). This exposure also caused a 2.5-fold increase in the incidence of mice having liver tumors (69 versus 27%; P < 0.01) and a 3-fold increase in the total number of hepatic adenomas and carcinomas per animal at risk (1.34 versus 0.46; P < 0.01). Methylene chloride exposure hastened the first appearance of lung tumors (by 1 year) compared to that observed in control animals; chemical-induced and spontaneous liver tumors first occurred simultaneously. A shorter exposure duration was sufficient to attain maximal numbers of lung tumors than that needed for a maximal liver tumor burden. Lung tumor multiplicity was substantially increased by having additional time after cessation of the chemical treatment. This contrasts with the findings in liver, where additional post-exposure latency time did not effect tumor multiplicity compared to that of mice evaluated immediately after cessation of exposure. The incidence of lung alveolar hyperplasia in methylene chloride exposed animals was very low, even in tumor-bearing animals and the hyperplasias were not seen until at least 13 weeks after appearance of adenomas and carcinomas. Thus, the genesis of methylene chloride induced lung tumors in B6C3F1 mice is not preceded by overt cytotoxicity, enhanced cell proliferation nor observed hyperplasia.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenoma↗

PubMed1993

Dose response for TCDD promotion of hepatocarcinogenesis in rats initiated with DEN: histologic, biochemical, and cell proliferation endpoints.

The present study examines the dose-response relationship for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) promotion of histologic and biochemical parameters by using a two-stage model for hepatocarcinogenesis in female Sprague-Dawley rats initiated with a single intraperitoneal dose of 175 mg of diethylnitrosamine (DEN)/kg body weight at 70 days of age. Starting 2 weeks after initiation, treatment groups of 8-10 rats were given TCDD by gavage in corn oil once every 2 weeks for 30 weeks. Doses were 3.5, 10.7, 35.7, and 125 ng TCDD/kg body weight/day. A significant body weight reduction was present in the noninitiated group that received 125 ng TCDD. Relative liver weight was statistically increased in initiated rats treated with > or = 10.7 ng TCDD and in noninitiated rats treated with > or = 35.7 ng TCDD. Histopathologic evidence of cytotoxicity was dose-related in all TCDD-treated groups. There was a statistically significant dose response in the bromodeoxyuridine (BrdU) S-phase labeling index (LI) in the DEN-initiated rats (p < 0.01) and a marginally significant trend in the saline-treated rats (p = 0.10), but proliferating cell nuclear antigen S-phase LI and growth fraction within altered hepatic foci showed no increase. Among the DEN-initiated groups there was a significant increase in glutathione S-transferase altered hepatic foci stereological parameters in the 125 ng TCDD group. This study demonstrates that dose-response relationships for TCDD's effects on cell proliferation growth of altered hepatic foci are different from previously reported effects on P450 gene expression, indicating that different biological or biochemical responses may exhibit different dose-response relationships.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Detecting proliferating cell nuclear antigen in archival rodent tissues.

The detection of proliferating cell nuclear antigen (PCNA), an endogenous cell replication marker, has lacked sensitivity in paraffin-embedded archival tissues fixed in formalin. An enhanced immunohistochemical procedure to detect PCNA has been successfully applied to rat and mouse tissues. Tissue sections are heated in a microwave oven in the presence of an antigen-retrieval solution of heavy-metal salts. Positive immunostaining of S-phase cells, an indication of DNA replicative activity, has been consistently obtained in tissues fixed for more than 24 months in formalin and in paraffin blocks stored for up to 19 months. Use of this technique will allow retrospective staining of rodent tissues from previously conducted toxicity and carcinogenicity studies.

Animals↗

PubMed1993

Effect of methylene chloride inhalation on replicative DNA synthesis in the lungs of female B6C3F1 mice.

In the National Toxicology Program 2-year inhalation study of dichloromethane (DCM), there was a significant increase in pulmonary neoplasms in female B6C3F1 mice exposed to 2000 ppm (overall rates of 30/48 versus 5/50 in control). Replicative DNA synthesis was examined to evaluate the potential role of treatment-induced lung cell proliferation on pulmonary carcinogenicity. Tritiated thymidine incorporation was assessed in methacrylate plastic sections after 1, 2, 3, or 4 weeks of inhalation exposure to 2000 ppm or 8000 ppm DCM. Similar measurements of labeling indexes were made after 13 and 26 weeks of exposure to 2000 ppm DCM using bromodeoxyuridine as the labeling agent. In all cases the labeling agent was delivered over a 6-day period using osmotic minipumps. The labeling index (LI) of bronchiolar epithelium (two branches proximal to the terminal bronchiole) of mice exposed to 2000 ppm DCM for 2-26 weeks decreased to 40-60% of the control. Terminal bronchioles showed a similar decrease in LI. Mice exposed to 8000 ppm DCM had a less dramatic decrease in LI. No pathological change was found in the exposed lungs. It is concluded that inhalation exposure to DCM for up to 26 weeks reduces cell turnover of bronchiolar cells in female B6C3F1 mice.

Administration, Inhalation↗

PubMed1992

A phase III trial of mitomycin C alone versus mitomycin C, vinblastine, and cisplatin for metastatic squamous cell lung carcinoma.

BACKGROUND: In an effort to confirm the efficacy of mitomycin C against metastatic squamous cell lung carcinoma and to compare the efficacy of single-agent therapy with a combination containing cisplatin, the authors conducted a randomized Phase III trial of mitomycin C alone versus mitomycin C, vinblastine, and cisplatin (MVP). METHODS: All patients had advanced squamous cell lung carcinoma, and survival was the primary end point. There were 133 eligible patients who received either mitomycin C alone (n = 64) or MVP (n = 69). The two groups were similar with respect to performance score, disease status, age, sex, and stage. RESULTS: The major objective response rates were 30% (95% confidence interval [CI], 18-41%) and 43% (95% CI, 32-55%) for mitomycin C alone and MVP, respectively (P = 0.1). The median time to progression was 83 days for mitomycin C alone, compared with 119 days for MVP (P = 0.026). The median survival time was 114 days for mitomycin C and 163 days for MVP (P = 0.09). The 1-year survival rates were equivalent. Myelosuppression was the major toxicity, and there were significantly greater leukocyte nadirs with MVP therapy (P < 0.001). CONCLUSION: Mitomycin C has antitumor activity against squamous cell lung carcinoma when used alone or in combination with MVP. The regimen containing cisplatin had marginally increased activity that did not translate into a clinically significant survival advantage.

Adult↗

PubMed1992

Role of the alveolar type II cell in the development and progression of pulmonary tumors induced by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone in the A/J mouse.

The role of the type II cell in the development of pulmonary tumors induced in the adult A/J mouse (6 weeks of age) by treatment with a single dose (100 mg/kg, i.p.) of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) was investigated. Twenty-four h following treatment with NNK, the concentration of O6-methylguanine was similar in Clara and type II cells. However, hyperplasias were detected only along the alveolar septa in lungs 14 weeks after carcinogen treatment. Examination of the ultrastructure of several hyperplasias revealed that the proliferating cells resembled type II pneumocytes. The proliferating cells were cuboidal in shape, with centrally localized ovoid nuclei characterized by minor indentations. Lamellar bodies, one of the major hallmarks of the type II cell, were present in the cytoplasm. The progression of pulmonary lesions was followed by sacrificing mice at 4-week intervals from 14 to 54 weeks after treatment with NNK. From 34 to 42 weeks after treatment, progression to neoplasia was demonstrated by a decline in the frequency of hyperplasias and an increase in the frequency of adenomas. Approximately 50% of the adenomas were observed arising within hyperplasias. Carcinomas appeared to increase in frequency 34 weeks after carcinogen treatment and comprised greater than 50% of the pulmonary lesions by 54 weeks. Approximately 30% of the carcinomas were observed arising within adenomas. The growth pattern of carcinomas began to change from solid to mixed (solid and papillary) 42 weeks after NNK. Moreover, electron micrographic analysis demonstrated that, within a hyperplasia, proliferating type II cells could change from cuboidal to columnar in shape and could also exhibit nuclear indentations, both characteristics displayed by the Clara cell. Thus, this divergence of the type II cell from its well characterized morphological features indicates that the selective growth advantage which these initiated cells possess can result in changes to the normal ultrastructure of this cell as it progresses toward malignancy. DNA was isolated from 20 hyperplasias and screened for the presence of an activated K-ras gene. This gene was activated in 17 of 20 lesions, with 85% of the mutations involving a GC to AT transition within codon 12 (GGT to GAT), a mutation consistent with base mispairing produced by the formation of the O6-methylguanine adduct. This specificity for activation of the K-ras gene was identical to that observed previously in adenocarcinomas induced by NNK.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenoma↗

PubMed1991

A prospective, randomized evaluation of intensive-course 5-fluorouracil plus doxorubicin as surgical adjuvant chemotherapy for resected gastric cancer.

This study evaluated combined 5-fluorouracil (5FU) and doxorubicin as postoperative adjuvant chemotherapy for patients who had undergone potentially curative resection of a primary gastric adenocarcinoma. One hundred twenty-five eligible and evaluable patients were stratified according to extent of surgical resection, location of the primary tumor within the stomach, and lymph node status. They were then randomized to either receive three cycles of chemotherapy or be observed. The median time from patient entry was 7 years. Results showed no significant difference in time to recurrence. The 5-year survival rate was 33% for the observation arm and 32% for the adjuvant therapy arm. The data excluded a 16% improvement in the 5-year survival rate for patients receiving chemotherapy with a P value less than 0.05. There were two drug-related fatalities due to sepsis. These results demonstrate no substantive benefit for this chemotherapy regimen as postoperative adjuvant treatment of resected gastric cancer.

Adenocarcinoma↗

PubMed1991

Phase II evaluation of menogaril in patients with advanced cervical carcinoma. A collaborative trial of the North Central Cancer Treatment Group and Mayo Clinic.

Fourteen patients with advanced/recurrent squamous cell carcinoma of the uterine cervix received menogaril, 200 mg/m2 by one hour intravenous infusion at four-week intervals. No objective regressions were observed. Median time to progression was less than two months and median survival was seven months. All patients experienced neutropenia. Platelet toxicity was negligible. Venous irritation and phlebitis occurred at the infusion site in 43% of patients. Menogaril as administered in this protocol is ineffective in treating previously irradiated advanced/recurrent squamous cell carcinoma of the uterine cervix and warrants no further investigation in this disease at the dosage and administration schedule used in this protocol.

Adult↗

PubMed1991

An enhancement method for immunohistochemical staining of proliferating cell nuclear antigen in archival rodent tissues.

An enhanced immunohistochemical procedure to detect proliferating cell nuclear antigen (PCNA), an endogenous cell replication marker, has been successfully applied to formalin-fixed, paraffin-embedded archival rat and mouse tissues. The procedure involves microwave oven heating of tissue sections in a commercially available antigen retrieval solution of heavy metal salts. Successful immunohistochemical staining of PCNA can be consistently obtained in tissues fixed for over 24 months in formalin and in sections made from paraffin blocks stored in our tissue archives for up to 19 months. Use of this technique will allow retrospective staining of rodent tissues for identification of S phase cells as an indication of DNA replicative activity in previously conducted toxicity and carcinogenicity studies.

Animals↗

PubMed1991

Improving accrual into cancer clinical trials.

It is thought by some that there are inadequate patient entries on high priority national cancer treatment protocols, resulting in intolerable delays in addressing crucial research issues. The North Central Cancer Treatment Group in Rochester, Minnesota generated a questionnaire with possible impediments to patient treatment entry as well as suggested measures for approving accrual. Of 334 questionnaires, 63% were completed and returned by medical oncologists, radiation therapists, surgeons and nurse/data managers. The most frequently listed impediments included patients' advanced age or fragility, inadequate health insurance, and excess travel distance. Protocol concerns included too many tests that were too complex and too costly. Practice concerns included physicians too busy and inadequate help. Suggestions toward improving patient accrual included subsidizing drugs, subsidizing nonessential tests for patient care, and increasing funding for support personnel. Popular suggestions for education efforts included teaching the importance of clinical trials, emphasizing personal benefit to the patient and recognition of physicians and institutions participating. It was felt that protocols should be simplified, be more consistent with practice, and be more flexible. These considerations are relevant not only in the interests of more effective clinical research but also in the interests of appropriate education of residents and oncology fellows involved in clinical trials.

Clinical Protocols↗

PubMed1990

Dose-response relationship between O6-methylguanine formation in Clara cells and induction of pulmonary neoplasia in the rat by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone.

The relationship between the formation of O6-methylguanine (O6MG) and the induction of lung, liver, and nasal tumors in the Fisher 344 rat by the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) was examined in a dose-response study. Animals were treated for 20 wk (3 times/wk) with concentrations of NNK ranging from 0.03 to 50 mg/kg to induce tumors. Steady-state concentrations of O6MG were quantitated, and cytotoxicity was assessed in target cells and tissues after 4 wk of treatment with NNK. No cytotoxicity was detected in the lung during treatment with NNK. The formation of O6MG was greatest in Clara cells compared with macrophages, type II cells, small cells, and whole lung at all doses examined. The difference in adduct concentration between the Clara cell and other pulmonary cell types was most pronounced with low doses of carcinogen. The O6MG:dose ratio, an index of alkylation efficiency, increased 29-fold as the dose of NNK was decreased from 50 to 1 mg/kg of carcinogen. In contrast, only a small increase in alkylation efficiency was observed in type II cells and whole lung. A significant number of tumors were induced in the lung at doses of 0.1 to 50 mg/kg with incidences ranging from 10% at the lowest dose up to 87% in the group of animals which received 50 mg/kg of NNK. A linear relationship was observed when the concentration of O6MG in Clara cells as a function of dose was plotted against the corresponding tumor incidence. This relationship was not observed using DNA adduct concentrations in type II cells or whole lung. The development of pulmonary tumors appeared to involve the formation of alveolar hyperplasias which progressed to adenomas and finally to carcinomas. The majority of adenomas were solid, whereas carcinomas were mainly papillary. Examination of the ultrastructure of the hyperplasias, adenomas, and carcinomas revealed morphological structures (e.g., lamellar bodies, tubular myelin) which are associated with type II cells. Thus, these data suggest that the majority of neoplasms in the lung begin as type II cell proliferations with progression to adenomas and carcinomas within the areas of hyperplasia. The lack of agreement between biochemical and morphological findings makes it difficult to hypothesize a cell of origin for the pulmonary neoplasms. In contrast to the lung, tumors were induced in the liver and nasal passages only after exposure to high doses of NNK. Moreover, both the formation of DNA adducts and cytotoxicity appear obligatory for the generation of tumors in these tissues.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1990

A phase III trial on the therapy of advanced pancreatic carcinoma. Evaluations of the Mallinson regimen and combined 5-fluorouracil, doxorubicin, and cisplatin.

One hundred eighty-seven patients with histologically proven advanced pancreatic adenocarcinoma were randomly assigned to therapy with 5-fluorouracil (5-FU) alone, to the Mallinson regimen (combined and sequential 5-FU, cyclophosphamide, methotrexate, vincristine, and mitomycin C), or to combined 5-FU, doxorubicin, and cisplatin (FAP). Patients with both measurable and nonmeasurable disease were included and the primary study end point was survival. Among 41 patients with measurable disease, objective response rates were 7% for 5-FU alone, 21% for the Mallinson regimen, and 15% for FAP. The median interval to progression for each of the three regimens was 2.5 months. Survival curves intertwined with the median survival times for 5-FU alone and the Mallinson regimen at 4.5 months and for FAP at 3.5 months. Compared with 5-FU alone, both the Mallinson regimen and FAP produced significantly more toxicity. Neither the Mallinson regimen nor FAP can be recommended as therapy for advanced pancreatic carcinoma. Any chemotherapy for this disease should remain an experimental endeavor.

Adenocarcinoma↗

PubMed1989

Randomized trial to evaluate the addition of tamoxifen to cyclophosphamide, 5-fluorouracil, prednisone adjuvant therapy in premenopausal women with node-positive breast cancer.

A randomized clinical trial was performed to determine if the addition of hormonal therapy with tamoxifen to a combination chemotherapy regimen was superior to the chemotherapy alone for adjuvant treatment of premenopausal women after mastectomy for node-positive breast cancer. The chemotherapy regimen utilized consisted of cyclophosphamide (C), 5-fluorouracil (F), and prednisone (P), and the doses employed were: C, 150 mg/m2 IV days 1 to 5; F, 300 mg/m2 IV days 1 to 5; and P, 10 mg orally three times daily on days 1 to 7. A total of ten courses of therapy, given every 6 weeks, was planned. Tamoxifen (T) was given at a dose of 10 mg twice daily and was stopped 6 weeks after the last course of CFP. Four hundred patients are fully eligible and evaluable. With a median observation time of 5.3 years, the proportion of recurrences on each arm were: CFP, 95 of 202 (47%); CFPT, 77 of 198 (39%). The relapse-free survival distribution for CFPT was superior to that for CFP, at a borderline level of significance (two-sided P = 0.06). When significant prognostic factors were considered in covariate analysis, CFPT was not significantly better than CFP (P = 0.43). This marked change in level was due to imbalance in several factors not considered in stratification. Currently, 31% of CFP and 25% of CFPT patients have died, and although there is a slight separation of the survival curves in favor of CFPT, the difference is not significant (P = 0.21). Analysis within receptor subsets also showed no significant advantage for the addition of tamoxifen. This study does not establish a significant advantage for the concurrent administration of tamoxifen with the CFP regimen. It does, however, clearly demonstrate the importance of examination of clinically important prognostic factors, even those not utilized in stratification, and consideration of these factors in covariate analysis if imbalances are present.

Adult↗