Case-fatality study of workers and residents with radiographic asbestos disease in Libby, Montana

Background

Vermiculite ore from Libby, Montana contains on average 24% of a mixture of toxic and carcinogenic amphibole asbestiform fibers. These comprise primarily winchite (84%), with smaller quantities of richterite (11%) and tremolite (6%), which are together referred to as Libby amphibole (LA).

Methods

 A total of 1883 individuals who were occupationally and/or environmentally exposed to LA and were diagnosed with asbestos‐related pleuropulmonary disease (ARPPD) following participation in communitywide screening programs supported by the Agency for Toxic Substances and Disease Registry (ATSDR) and followed up at the Center for Asbestos Related Disease (CARD) between 2000 and 2010. There were 203 deaths of patients with sufficient records and radiographs. Best clinical and radiologic evidence was used to determine the cause of death, which was compared with death certificates.

Results

Asbestos‐related mortality was 55% (n = 112) in this series of 203 patients. Of the 203 deaths, 34 (17%) were from asbestos‐related malignancy, 75 (37%) were from parenchymal asbestosis, often with pleural fibrosis, and 3 (1.5%) were from respiratory failure secondary to pleural thickening.

Conclusions

Asbestos is the leading cause of mortality following both occupational and nonoccupational exposure to LA in those with asbestos‐related disease.

Lung cancer screening in patients with Libby amphibole disease: High yield despite predominantly environmental and household exposure

Background

Lung cancer screening with low‐dose computed tomography (CT) scanning (LDCT) is accepted as a screening tool, but its application to populations exposed to recognized occupational or environmental carcinogens is limited. We apply LDCT to a population with a predominantly nonoccupational exposure to a recognized human lung carcinogen, Libby amphibole asbestos (LA).

Methods

Patients in an asbestos disease clinic in Libby, Montana who were aged 50 to 84 years, greater than or equal to 20 pack‐year history of tobacco use (irrespective of quit date), and asbestos‐related pleuropulmonary disease on high‐resolution CT scan were offered free annual lung cancer screening over a 39‐month period.

Results

Of 2897 clinic patients, 1149 (39.7%) met eligibility criteria, and 567 (49%) were screened with 1014 low‐dose CT scans. Most screened patients had principally environmental (333 or 59%) or household exposure (145 or 25%) to LA. Seventeen primary lung cancers were identified, mostly in early stages: 10 at stage 1, two at stage 2, three at stages 3 to 4, and two at limited small‐cell cancers. The screening yield was 1.9 at baseline scan and 1.5% on the first annual scan.

Conclusions

Consistent with the guidelines of the National Comprehensive Cancer Network and American Association of Thoracic Surgery, LDCT for early lung cancer detection should be offered to people with significant exposure to occupational or environmental human lung carcinogens.

A Phase I Study of Light Dose for Photodynamic Therapy Using 2-[1-Hexyloxyethyl]-2 Devinyl Pyropheophorbide-a for the Treatment of Non-Small Cell Carcinoma In Situ or Non-Small Cell Microinvasive Bronchogenic Carcinoma: A Dose Ranging Study

INTRODUCTION

We report a phase I trial of photodynamic therapy (PDT) of carcinoma in situ (CIS) and microinvasive cancer (MIC) of the central airways with the photosensitizer (PS) 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a (HPPH). HPPH has the advantage of minimal general phototoxicity over the commonly used photosensitizer porfimer sodium (Photofrin; Pinnacle Biologics, Chicago, IL).

METHODS

The objectives of this study were (1) to determine the maximally tolerated light dose at a fixed photosensitizer dose and (2) to gain initial insight into the effectiveness of this treatment approach. Seventeen patients with 21 CIS/MIC lesions were treated with HPPH with light dose escalation starting from 75 J/cm2 and increasing to 85, 95,125, and 150 J/cm2 respectively. Follow-up bronchoscopy for response assessment was performed at 1 and 6 months, respectively.

RESULTS

The rate of pathological complete response (CR) was 82.4% (14 of 17 evaluable lesions; 14 patients) at 1 month and 72.7% (8/11 evaluable lesions; 8 patients) at 6 months. Only four patients developed mild skin erythema. One of the three patients in the 150 J/cm2 light dose group experienced a serious adverse event. This patient had respiratory distress caused by mucus plugging, which precipitated cardiac ischemia. Two additional patients treated subsequently at this light dose had no adverse events. The sixth patient in this dose group was not recruited and the study was terminated because of delays in HPPH supply. However, given the observed serious adverse event, it is recommended that the light dose does not exceed 125 J/cm2.

CONCLUSIONS

PDT with HPPH can be safely used for the treatment of CIS/MIC of the airways, with potential effectiveness comparable to that reported for porfimer sodium in earlier studies.

Vitamin D and Dental Caries in Children

The purpose of this study was to assess the relationship between vitamin D status and dental caries in Canadian school-aged children participating in the Canadian Health Measures Survey (CHMS). The CHMS was a national cross-sectional study involving physical assessments, laboratory analysis, and interviews. Analysis was restricted to data for 1,017 children 6 to 11 y of age. Outcome variables included the presence of caries and overall total caries score (dmft/DMFT index). Levels of 25-hydroxyvitamin D (25(OH)D) were measured from serum samples obtained from participants. Bivariate analysis, logistic regression for the presence of caries, and multiple linear regression for total caries scores were used. Significance was set at P ≤ 0.05. Overall, 56.4% of children experienced caries, and the mean dmft/DMFT score was 2.47 (95% CI 2.09 to 2.84). The unadjusted odds of children with 25(OH)D levels ≥75 nmol/L having experienced caries was 0.57 (95% CI 0.39 to 0.82), while the odds for caries at the ≥50 nmol/L level was 0.56 (95% CI 0.39 to 0.89). After controlling for other covariates, backward logistic regression revealed that the presence of caries was significantly associated with 25(OH) levels <75 nmol/L and <50 nmol/L, lower household education, not brushing twice daily, and yearly visits to the dentist. Similarly, multiple linear regression revealed that total dmft/DMFT caries scores were also associated with 25(OH)D concentrations <75 nmol/L, not brushing twice daily, lower household education, and yearly visits to the dentist. Data from a cross-sectional, nationally representative sample of Canadian children suggest that there is an association between caries and lower serum vitamin D. Improving children’s vitamin D status may be an additional preventive consideration to lower the risk for caries.

Functions of lncRNA HOTAIR in lung cancer

Long non-coding RNAs (lncRNAs) govern fundamental biochemical and cellular processes. lncRNA HOX transcript antisense RNA (HOTAIR) represses gene expression through recruitment of chromatin modifiers. The expression of HOTAIR is elevated in lung cancer and correlates with metastasis and poor prognosis. Moreover, HOTAIR promotes proliferation, survival, invasion, metastasis, and drug resistance in lung cancer cells. Here we review the molecular mechanisms underlying HOTAIR-mediated aggressive phenotypes of lung cancer. We also discuss HOTAIR’s potential in diagnosis and treatment of lung cancer, as well as the challenges of exploiting HOTAIR for intervention of lung cancer.

Comparison of performance status with peak oxygen consumption in operable patients with non-small-cell lung cancer

BACKGROUND AND OBJECTIVE

In this era of increasing options for treatment of 'surgical' lung cancer patients, preoperative physiologic assessment of accurate patient selection is becoming more important. The variability in an objective measure of cardiorespiratory fitness (peak oxygen consumption (VO2peak )) across performance in operable non-small-cell lung cancer (NSCLC) patients enrolled in the Cancer and Leukemia Group B trial was compared.

METHODS

Using a cross-sectional design, 392 NSCLC patients underwent an incremental cardiopulmonary cycling exercise test to symptom limitation with expired gas analysis to determine VO2peak . Performance status (PS) was assessed using the Eastern Cooperative Oncology Group (ECOG) tool.

RESULTS

There was a significant decrease in VO2peak across increasing ECOG categories (P < 0.0001). However, there was a large range in VO2peak for any given ECOG category with overlap between categories (ECOG 0: 5.0-31.5 mL/kg/min; ECOG 1: 4.3-24.8 mL/kg/min; ECOG 2: 8.9-21.9 mL/kg/min; ECOG 3; 3.3-11.7 mL/kg/min).

CONCLUSIONS

PS scoring systems do not provide a sensitive measure of functional status. Objective measures such as VO2peak may be a useful in the clinical management of oncology patients.

lincRNA HOTAIR as a novel promoter of cancer progression

Large intergenic non-coding RNAs (lincRNA) regulate development and disease via interactions with their protein partners. Expression of the lincRNA HOX transcript antisense RNA (HOTAIR) is elevated in a variety of malignancies and linked to metastasis and poor prognosis. HOTAIR promotes proliferation, invasion, and metastasis in the preclinical studies of cancer through modulation of chromatin modifying complexes. In the current review we discuss the molecular mechanisms of HOTAIR-mediated aggressive phenotypes of cancer, HOTAIR's potential in cancer intervention, and challenges in exploration of HOTAIR in cancer biology.

Lung cancer screening update

Lung cancer is the leading cause of cancer-related mortality globally and the American cancer society estimates approximately 226,160 new cases and 160,340 deaths from lung cancer in the USA in the year 2012. The majority of lung cancers are diagnosed in the later stages which impacts the overall survival. The 5-year survival rate for pathological st age IA lung cancer is 73% but drops to only 13% for stage IV. Thus, early detection through screening and prevention are the keys to reduce the global burden of lung cancer. This article discusses the current state of lung cancer screening, including the results of the National Lung Cancer Screening Trial, the consideration of implementing computed tomography screening, and a brief overview of the role of bronchoscopy in early detection and potential biomarkers that may aid in the early diagnosis of lung cancer.

Peak oxygen consumption and long-term all-cause mortality in nonsmall cell lung cancer

BACKGROUND

Identifying strong markers of prognosis is critical to optimize treatment and survival outcomes in patients with nonsmall cell lung cancer (NSCLC). The authors investigated the prognostic significance of preoperative cardiorespiratory fitness (peak oxygen consumption [VO(2peak)]) among operable candidates with NSCLC.

METHODS

By using a prospective design, 398 patients with potentially resectable NSCLC enrolled in Cancer and Leukemia Group B 9238 were recruited between 1993 and 1998. Participants performed a cardiopulmonary exercise test to assess VO(2peak) and were observed until death or June 2008. Cox proportional models were used to estimate the risk of all-cause mortality according to cardiorespiratory fitness category defined by VO(2peak) tertiles (<0.96 of 0.96-1.29/>1.29 L/min⁻¹) with adjustment for age, sex, and performance status.

RESULTS

Median follow-up was 30.8 months; 294 deaths were reported during this period. Compared with patients achieving a VO(2peak) <0.96 L/min⁻¹, the adjusted hazard ratio (HR) for all-cause mortality was 0.64 (95% confidence interval [CI], 0.46-0.88) for a VO(2peak) of 0.96 to 1.29 L/min⁻¹, and 0.56 (95% CI, 0.39-0.80) for a VO(2peak) of >1.29 L/min⁻¹) (P(trend) = .0037). The corresponding HRs for resected patients were 0.66 (95% CI, 0.46-0.95) and 0.59 (95% CI, 0.40-0.89) relative to the lowest VO(2peak) category (P(trend) = .0247), respectively. For nonresected patients, the HRs were 0.78 (95% CI, 0.34-1.79) and 0.39 (95% CI, 0.16-0.94) relative to the lowest category (P(trend) = .0278).

CONCLUSIONS

VO(2peak) is a strong independent predictor of survival in NSCLC that may complement traditional markers of prognosis to improve risk stratification and prognostication.

Abstract A22: Spirometric surveillance for premalignant and malignant bronchial lesions

Background: Chronic obstructive pulmonary disease (COPD) and lung cancer (LC) are diseases that share common risk factors. It has been reported that more than half of the patients diagnosed with LC also suffer from COPD. Although COPD is a well known risk factor for LC, the relationship between impaired lung function (LF) and the incidence and progression of pre-malignant lesions (PMLs) in the central airways is still unclear.

Methods: The study included 217 high-risk patients from a hospital-based lung cancer surveillance cohort who underwent bronchoscopy with endobronchial biopsy of suspicious lesions, at the Roswell Park Cancer Institute, Buffalo, New York. All patients had lung function measurement within 6 months preceding their baseline biopsy. Baseline histopathology diagnoses included 91squamous metaplasia (SM), 25 squamous dysplasia (SD), 1 in-situ carcinoma and 5 invasive bronchial carcinoma. Follow-up bronchoscopy and biopsy were performed on 69 patients. Sixteen patients had a progression of the baseline lesion to a higher grade. The relationship between the baseline LF measures and the incidence and progression of PMLs were examined using regression models.

Results: Patients with forced expiratory volume in 1 second percent predicted (FEV1%) of &lt;50% had 4.5 times greater risk of being diagnosed with PML/cancer, when compared to patients with FEV1% ≥80. Increased risk was noted for all grades of PMLs and cancers, with the risk being almost 8 times for squamous dysplasia [Odds ratio = 7.95; 95%confidence interval (CI) =1.77–35.6]. Similarly, FEV-1/FVC ratio of &lt;50% was associated with 3 times greater risk of detecting a PML/cancer. When COPD was classified based on GOLD criteria, the patients with severe COPD had 2.7 times and 4.8 times greater risk of being detected with SM and SD, respectively. The risk persisted for SD even when an age standardized classification was used to define COPD. COPD patients also had a non-statistically significant 2.5 times greater risk of their baseline lesion progressing to a higher grade [Hazard Ratio 2.48 (95% CI 0.65 – 9.41), p-value - 0.18)]. The mean time to progression from a lower grade lesion to a higher grade was 27 months for patients with COPD and 50 months for patients without COPD.

Conclusion: Impaired LF can be a good predictor of occurrence and progression of PMLs in central airways of high risk patients. Spirometric measurement of lung function can be used as an additional tool for identifying target populations in need of more aggressive LC surveillance.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):A22.

Abstract A21: Lung cancer surveillance with CT scan and autofluorescence bronchoscopy

Background: More than 75% of lung cancer patients are diagnosed at an advanced stage, when the survival rate is less than 15%. Sputum cytology, x-ray and CT scan have been evaluated as screening tools for early lung cancers, without much success. Auto-fluorescence bronchoscopy (AFB) has been recently shown to be effective in diagnosing central bronchial cancers. Combined surveillance with both spiral CT scan and AFB might help to increase the detection rate of the both central and peripheral lung cancers.

Methods: The study included 205 patients who were enrolled in the High Risk Lung Cancer Surveillance Cohort at Roswell Park Cancer Institute (RPCI) with at least 2 of the following risk factors: (1) radiographically documented pulmonary asbestosis or; (2) a history of previously treated aero-digestive cancer or; (3) &gt; 20 pack years smoking history or; (4) COPD with an FEV1 &lt; 70% of predicted. Patients underwent spirometry testing, chest X-ray, sputum cytology, non-enhanced low dose spiral CT scan of the chest, and conventional white light/AF bronchoscopy with biopsy.

Results: A total of 20 invasive cancers/CIS were diagnosed in the 205 patients. Seven were diagnosed at baseline, 4 within 1 year of enrollment and 9 on follow up of more than 1 year. Between them, AFB and CT scan diagnosed all baseline cancers. Only 3/7 cancers were detected on x-ray screening and only 1/7 patients demonstrated atypia on sputum cytology. Overall, 17 invasive cancers and 3 CIS were diagnosed during the surveillance study. All the 3 CIS were identified only on AFB. Of the 17 invasive cancers, CT scan detected 15 cancers (88%) and AFB detected 5 of these cancers (30%). CT scan showed a 67% relative increase in sensitivity for detecting prevalent cancers and 3 times greater sensitivity for incident and prevalent cancers compared to x-ray screening. CT scan and AFB detected 19 of the 20 CIS/cancers (95%), whereas x-ray and sputum cytology together detected only 5/20 CIS/cancers (25%). The sensitivity of CT scan and AFB in diagnosing pre-malignant lesions and cancers improved by almost two and half times relative to x-ray and sputum.

Conclusion: The addition of AFB exam to yearly spiral CT scan of the chest could be a more efficient surveillance tool to identify early stage lung cancers, both in the central and peripheral lung. A greater efficiency and cost effectiveness can be achieved by limiting the use of the combination of AFB and CT scan in very high risk patients, selected based on their exposures and risk factors.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):A21.

CALGB 140803—Association between cardiorespiratory fitness and overall survival in operable lung cancer patients: Ancillary analysis of protocol 9238

7518

Background: Cardiorespiratory fitness is a well-established independent predictor of all-cause mortality in a broad range of adult populations. The association between cardiorespiratory fitness and mortality has not been investigated among individuals diagnosed with cancer. We examined the association between cardiorespiratory fitness and all-cause mortality in 398 patients with non-small cell lung cancer (NSCLC). Methods: Using a prospective, observational design, patients with known or suspected NSCLC enrolled in CALGB 9238 were studied. Prior to pulmonary resection, all participants performed an incremental exercise test with expired gas analysis to assess cardiorespiratory fitness (i.e., peak oxygen consumption; VO2peak) and were observed for death or until June 2008. Cox proportional hazards models were used to estimate the risk of all-cause mortality according to cardiorespiratory fitness category defined by VO2peak (<0.96 / 0.96–1.29 / >1.29 L.min-1) with adjustment for age, gender, and performance status. Results: Of the 398 patients, 335 underwent surgical resection and 63 were deemed not eligible for resection. Median follow-up was 30.8 months, 294 deaths were reported during this period. For the entire sample, mortality rates declined across increasing VO2peak categories (adjusted Ptrend= 0.012). Compared with patients achieving a VO2peak <0.96 L.min-1, the adjusted hazard ratio (HR) for all-cause mortality was 0.64 (95% CI, 0.46 to 0.88) for a VO2peak of 0.96–1.29 L.min-1, and 0.56 (95% CI, 0.39 to 0.80) for a VO2peak of >1.29 L.min-1. The corresponding HRs for surgical patients were 0.65 (95% CI, 0.44 to 0.96) and 0.62 (95% CI, 0.42 to 0.90) relative to the lowest VO2peak category (ptrend=0.03), respectively. For non-surgical patients, the HRs were 0.74 (95% CI, 0.32 to 1.75) and 0.43 (95% CI, 0.18 to 1.00) relative to the lowest category (ptrend<0.04). Conclusions: Low VO2peak is associated with poorer survival among surgical candidates with NSCLC. Further work is required to investigate the prognostic value of objective measures of functional capacity in NSCLC and other cancer populations.

No significant financial relationships to disclose.

Abstract B55: Factors predicting the progression of premalignant bronchial lesions

B55

Background

Lung cancer (LC) is the most common cause of cancer death in the world. Metaplasia, dysplasia and carcinoma in situ (CIS) have been identified as precursors to squamous cell carcinoma (SCC) of lung. However, the natural history of these lesions and the risk factors related to their progression has not yet been clearly described.

Methods

The cohort included 412 high risk patients who underwent screening autofluorescence bronchoscopy (AFB) at the Lung Cancer Screening Clinic at the Roswell Park Cancer Institute, Buffalo, New York. Follow up AFB procedures were performed on 124 patients (average 2.6 AFB/ patient), and 335 baseline lesions (134 benign, 144 metaplasia and 57 dysplasia) were followed up for an average of 16 months after their first AFB. Development of a CIS/SCC was considered to be an endpoint; otherwise patients were followed till March, 2008.

Results

Fourty one percent (55/134) of benign lesions progressed to higher grade lesions (46 to metaplasia and 9 to dysplasia). Among metaplasia, 46% regressed, while 38% persisted, 14.6% (21/144) progressed to dysplasia and 1.4% (2/144) progressed to CIS/SCC. Among dysplasia, 31% regressed to benign, 37% regressed to metaplasia, 30% (17/57) persisted and 1.8% (1/57) progressed to CIS/SCC. Adjusted logistic regression was used to examine the risk factors for progression of lesions. Baseline benign lesions in males had more than 3 times greater chance of progressing compared to females [Adjusted odds ratio (AOR): 3.21, 95% confidence interval (CI):1.25-8.25, p value: 0.02]; after adjusting for age, pack years of smoking and COPD history. Benign lesions identified on former smokers had almost 3 times the risk of progressing (AOR: 2.97, 95%CI: 0.26-34.2) and benign lesions on current smokers had more than 8 times the risk of progressing (AOR: 8.22, 95%CI: 0.70-96.0), compared to never smokers (p trend: 0.008). Heavier smokers were at a greater risk of their lesions progressing. In patients with &gt;50 pack years of smoking, benign lesions had 7 times greater risk (AOR: 7.70, 95%CI: 0.57-99.8), and metaplastic lesions had 3 times greater risk of progressing (AOR: 3.50, 95%CI: 1.40-8.76), compared to never smokers. However, similar increased risk estimates were not noted for dysplasias in patients with &gt;50 pack year of smoking (AOR: 0.82, 95%CI: 0.09-7.14). All the smoking risk estimates were adjusted for age, gender and COPD history. COPD was associated with 4 times the risk of benign lesions progressing (AOR: 4.42, 95%CI: 1.33-14.7). COPD was associated with 80% and 23% non statistically significant increase in risk of progression for metaplasia and dysplasia, respectively. Asbestos exposure was associated with more than twice the risk of metaplastic lesions progressing. Central bronchial lesions had a non statistically significant 59% greater chance of progression, compared to peripheral bronchial lesions (AOR: 1.59, 95%CI: 0.82-3.07). Left bronchial lesions had a non statistically significant 73% greater chance of progression, compared to right bronchial lesions (AOR: 1.73, 95%CI: 0.80-3.76).

Conclusion

Our results show that metaplastic lesions might also progress to an invasive SCC. Male gender, current smoking, heavier smoking and COPD might be associated with progression of low grade lesions to higher grade. Central and left bronchial lesions might have a slightly greater risk of progression of premalignant lesions.

Citation Information: Cancer Prev Res 2008;1(7 Suppl):B55.

Vitamin D receptor expression in normal, premalignant, and malignant human lung tissue

BACKGROUND

There is a strong interest in identifying chemopreventive agents that might help decrease the burden of lung cancer. The active metabolite of vitamin D, 1,25-dihydroxycholecalciferol (calcitriol), has been shown to have antiproliferative effects in several tumor types, mediated by the vitamin D receptor (VDR). This is the first comprehensive survey of VDR expression in a series of human lung tissues, including normal and premalignant central airway biopsies and lung tumors.

METHODS

Immunohistochemical expression of nuclear and cytoplasmic VDR was examined in 180 premalignant or malignant bronchial biopsies from bronchoscopy of 78 high-risk individuals at the Roswell Park Cancer Institute and also in 63 tumor samples from 35 lung cancer patients from the University of Chicago Hospitals. Associations between clinicopathologic data and VDR expression were examined.

RESULTS

VDR expression was present in many samples. In biopsies, VDR was commonly detected throughout the full epithelial layer. Most histologically normal (60%, 53 of 88) and metaplastic (61%, 39 of 64) samples had moderate to high nuclear intensity; dysplastic samples mostly had low nuclear intensity (10 of 18, 55%). In tumor samples, 62% (38 of 61) were lacking cytoplasmic VDR, with nuclear expression present in 79%(49 of 62). Analysis of all samples revealed a positive linear trend between proportion of samples with greater nuclear than cytoplasmic intensity and increasing histologic grade (P < 0.01).

CONCLUSIONS

VDR expression spanned the lung carcinogenesis spectrum. Nuclear expression was similar across various histologies, whereas cytoplasmic expression decreased with increasing histologic grade. These results indicate that there is potential for the use of calcitriol as a chemopreventive agent against the development of lung cancer.

Hormone replacement therapy as a risk factor for non-small cell lung cancer: results of a case-control study

PURPOSE

It was the aim of this study to assess the risk of lung cancer in postmenopausal women who received hormone replacement therapy (HRT).

EXPERIMENTAL DESIGN

This case-control study involves women who received medical services at Roswell Park Cancer Institute (RPCI) in Buffalo, New York, between 1982 and 1998, and who agreed to complete an epidemiological questionnaire. Participants with missing smoking data were excluded. The case group consisted of 595 women with primary lung cancer. Controls included 1,195 women, randomly selected from a pool of 5,845 eligible individuals, who received medical services at RPCI for non-neoplastic conditions; they had come to RPCI with a suspicion of neoplastic disease, but were diagnosed with neither benign nor malignant conditions. Controls were frequency matched 2:1 to cases on 5-year age intervals and exposure to smoking (ever/never). Cases and controls were comparable for age (means 61.3 and 61.0 years) and ever smoking (90%).

RESULTS

There were more former smokers among the cases (67 vs. 59% in controls); cases were less likely to be high school educated, were thinner, and were less likely to report HRT use compared with controls. Overall, hormone use was associated with a significant reduction in risk of lung cancer (adjusted odds ratio = 0.67; 95% confidence interval 0.53-0.85). Stratified analyses showed significant reductions in lung cancer risk in former smokers and women with normal to low body mass index.

CONCLUSION

This study supports the hypotheses that there is a protective effect of HRT use on lung cancer risk in women.

Autofluorescence bronchoscopy for lung cancer surveillance based on risk assessment

BACKGROUND

This is a preliminary report of an ongoing prospective bimodality lung cancer surveillance trial for high-risk patients. Bimodality surveillance incorporates autofluorescence bronchoscopy (AFB) and spiral CT (SCT) scanning in high-risk patients as a primary lung cancer surveillance strategy, based entirely on risk factors. AFB was used for surveillance and findings were compared with conventional sputum cytology for the detection of malignancy and pre-malignant central airway lesions.

METHODS

402 patients registering at Roswell Park Cancer Institute were evaluated with spirometric testing, chest radiography, history and physical examination, of which 207 were deemed eligible for the study. For eligibility, patients were required to have at least two of the following risk factors: (1) > or =20 pack year history of tobacco use, (2) asbestos-related lung disease on the chest radiograph, (3) chronic obstructive pulmonary disease with a forced expiratory volume in 1 s (FEV(1)) <70% of predicted, and (4) prior aerodigestive cancer treated with curative intent, with no evidence of disease for >2 years. All eligible patients underwent AFB, a low-dose SCT scan of the chest without contrast, and a sputum sample was collected for cytological examination. Bronchoscopic biopsy findings were correlated with sputum cytology results, SCT-detected pulmonary nodules and surveillance-detected cancers. To date, 186 have been enrolled with 169 completing the surveillance procedures.

RESULTS

Thirteen lung cancers (7%) were detected in the 169 subjects who have completed all three surveillance studies to date. Pre-malignant changes were common and 66% of patients had squamous metaplasia or worse. Conventional sputum cytology missed 100% of the dysplasias and 68% of the metaplasias detected by AFB, and failed to detect any cases of carcinoma or carcinoma-in-situ in this patient cohort. Sputum cytology exhibited 33% sensitivity and 64% specificity for the presence of metaplasia. Seven of 13 lung cancers (58%) were stage Ia or less, including three patients with squamous cell carcinoma. Patients with peripheral pulmonary nodules identified by SCT scanning of the chest were 3.16 times more likely to exhibit pre-malignant changes on AFB (p<0.001).

CONCLUSION

Bimodality surveillance will detect central lung cancer and pre-malignancy in patients with multiple lung cancer risk factors, even when conventional sputum cytology is negative. AFB should be considered in high-risk patients, regardless of sputum cytology findings.

HER-2/neu protein expression and gene alteration in stage I-IIIA non-small-cell lung cancer: a study of 140 cases using a combination of high throughput tissue microarray, immunohistochemistry, and fluorescent in situ hybridization

Regarding HER-2/neu expression (gene or protein level) in lung cancer, several studies with inconsistent results have been recently reported, partially due to variable techniques used and/or heterogeneous populations examined. The objective of this study was to examine HER-2/neu expression in a well-defined cohort of non-small-cell lung cancers (NSCLC) and in nonneoplastic lung tissue utilizing a combination of high-density tissue microarray, immunohistochemistry (IHC), and fluorescent in situ hybridization (FISH) under uniform test conditions. One hundred forty stage I-IIIA primary NSCLCs and 38 non-neoplastic lung samples were examined. IHC, using an FDA-approved Hercept monoclonal antibody kit, was performed and HER-2/neu gene alteration was assessed by FISH. The association of expression of HER-2/neu with clinicopathologic parameters was analyzed. Ninety-four percent of tumor samples (131/140) were fully interpretable after tissue processing. Twenty-five of them (19%) overexpressed (2+, 3+) HER-2/neu, while 106 (81%) had no or weak expression. All thirty-four interpretable non-neoplastic lung samples were negative for HER-2/neu alteration at protein and gene level. HER-2/neu protein overexpression correlated well with HER-2/neu gene amplification (r =.83, P < 0.001). HER-2/neu overexpression was significantly associated with histologic subtype: 19 adenocarcinomas (19/82, 23%) versus 4 squamous cell carcinomas (4/44, 9%) overexpressed Her-2/neu (P = 0.04). Statistical significance was observed between HER-2/neu expression and tumor differentiation, with strong positive (3+) expression observed more frequently in poorly differentiated tumors (P = 0.01). Patients with HER-2/neu abnormalities, particularly HER-2/neu gene amplification, exhibited a shorter survival (P = 0.043). The statistically significant difference (P < 0.005) between HER-2/neu alteration in tumor samples(25/131, 19%) and in the nonneoplastic tissue (0/34, 0%) implies that HER-2/neu may have a role in the carcinogenesis of NSCLC. The findings provide evidence supporting the hypothesis that the HER-2/neu receptor may represent a useful molecular target in the treatment of NSCLC. The significant association of HER-2/neu expression and gene amplification with poorly differentiated carcinoma compared with well differentiated carcinoma suggests that HER-2/neu may be involved in NSCLC tumor evolution. Patients with HER-2/neu gene amplification and strong positive expression of HER-2/neu protein showed a strong tendency toward shorter survival.

Upregulation of the tissue inhibitor of metalloproteinase-1 protein is associated with progression of human non-small-cell lung cancer

PURPOSE

Tissue inhibitors of metalloproteinases (TIMPs) are naturally occurring inhibitors of matrix metalloproteinases (MMPs). It has been shown that TIMP-1 may be a multifunctional protein. Little is known about the role of TIMP-1 in progression and metastasis of human lung cancer (tumor inhibiting or tumor promoting), although studies using a variety of techniques have analyzed the expression of TIMP-1 mRNA and/or protein in human cancers.

PATIENTS AND METHODS

We examined the expression of TIMP-1 protein by immunohistochemistry in patients (n = 160) with primary respectable (stage I to IIIA) non-small-cell lung cancer (NSCLC).

RESULTS

Twenty-seven percent of the tumors (43 of 160) demonstrated elevated expression of this protein. We demonstrate that overexpression of TIMP-1 protein is associated with an adverse outcome. In addition, disease stage, patient's age, and performance status were all significantly related to survival. In multivariate analyses, patients with high TIMP-1 expression had a 90% increased risk of death when compared with those with low expression (relative risk, 1.92; 95% CI, 1.19 to 3.09; P =.008). TIMP-1 expression did not correlate with expression of MMP-2 and MMP-9.

CONCLUSION

These results suggest that TIMP-1, independent of its inhibiting activity of MMPs, may have other function(s) critical for NSCLCs. The significance of our results is two-fold. The adverse outcome in patients with overexpression of TIMP-1 indicates its potential prognostic value in NSCLC. Thus, TIMP-1 overexpression may serve to help identify patients with particularly aggressive disease for adjuvant treatments. In addition, the TIMP-1 molecule may represent a novel therapeutic target for treatment of some NSCLCs.

Thyroid transcription factor-1 expression prevalence and its clinical implications in non-small cell lung cancer: a high-throughput tissue microarray and immunohistochemistry study

Thyroid transcription factor 1 (TTF-1), a homeodomain-containing transcription factor, plays a pivotal role in lung development, cell growth, and differentiation processes. The current literature reports considerable variation in frequency of TTF-1 protein expression in human non-small cell lung cancer (NSCLC). TTF-1 expression has not been extensively investigated as a prognostic marker in NSCLC. To assess the prevalence of TTF-1 expression, and to evaluate its potential role in disease prognosis, 140 stage I-IIIA NSCLCs with long-term follow-up were studied under uniform conditions using high-density tissue microarray (TMA) combined with immunohistochemistry. Patient survival and association of TTF-1 expression with clinicopathologic parameters were analyzed. One hundred twenty-six tumor samples were fully assessable after tissue processing. Sixty-four samples (50.8%) expressed TTF-1 and 62 (49.2%) displayed no expression. TTF-1 expression was significantly (P < 0.001) correlated with histological subtype: 51 adenocarcinomas (AdCs) (51 of 75; 68%) versus 9 squamous cell carcinomas (SCCs) (9 of 43; 21%) were TTF-1 positive. TTF-1 expression, performance status, nodal status, and tumor stage were significantly related to patient survival. In multivariate analysis, positive TTF-1 expression tended to favor a better patient outcome (P = 0.05). Overall, NSCLC patients with positive TTF-1 expression had a median survival of greater than 57.3 months, whereas those with negative expression had a median survival of 39.4 +/- 5.2 months (log-rank test, P = 0.0067). In this study we found that TTF-1 is predominately expressed in adenocarcinoma. The loss of TTF-1 expression was associated with aggressive behavior of NSCLCs. The results from this study strongly indicate that further investigation is warranted to better define the role of TTF-1 as a prognostic factor in this malignancy.

Validated liquid chromatographic method for the determination of bexarotene in human plasma

A new liquid chromatographic method is described for the determination of the anti-tumour agent bexarotene in human plasma over the range 0.500-1500 ng/ml, using 1 ml of sample. Sample preparation consists of liberating the analyte from plasma lipids by adding acetonitrile, followed by acidification of the plasma and liquid extraction using a mixture of isoamyl alcohol and pentane or hexane. Separation and quantitation are performed by reversed-phase column liquid chromatography with fluorescence detection. Parameters affecting the performance of these steps are discussed. Validation results on linearity, selectivity, accuracy, precision, recovery and stability are shown, as well as the application of the method to samples from clinical trials.

Topical treatment of cutaneous lesions of acquired immunodeficiency syndrome-related Kaposi sarcoma using alitretinoin gel: results of phase 1 and 2 trials

OBJECTIVE

To evaluate the efficacy and safety of topical alitretinoin gel (9-cis-retinoic acid [LGD1057], Panretin gel; Ligand Pharmaceuticals, Inc, San Diego, Calif) in cutaneous Kaposi sarcoma (KS).

DESIGN

Open-label, within-patient, controlled, dose-escalating phase 1 and 2 clinical trials. In all patients, 1 or more cutaneous KS lesions were treated with alitretinoin gel, and at least 2 other lesions served as untreated controls for up to 16 weeks. Alitretinoin (0.05% or 0.1% gel) was applied twice daily for the first 2 weeks and up to 4 times daily thereafter, if tolerated.

SETTING

Nine academic clinical centers.

PATIENTS

One hundred fifteen patients with biopsy-proven acquired immunodeficiency syndrome (AIDS)-related KS.

MAIN OUTCOME MEASURES

AIDS Clinical Trials Group response criteria.

RESULTS

Statistically significant clinical responses were observed in 31 (27%) of 115 patients for the group of treated index lesions compared with 13 (11%) for the group of untreated control lesions (P<.001). Responses occurred with low CD4(+) lymphocyte counts (<200 cells/microL) and in some patients with refractory response to previous systemic anti-KS therapy. The incidence of disease progression was significantly lower for treated index lesions compared with untreated control lesions (39/115 [34%] vs 53/115 [46%]; P =.02). Alitretinoin gel generally was well tolerated, with 90% of treatment-related adverse events confined to the application site and only mild or moderate in severity.

CONCLUSIONS

Alitretinoin gel has significant antitumor activity as a topical treatment for AIDS-related KS lesions, substantially reduces the incidence of disease progression in treated lesions, and is generally well tolerated.

A Phase I study of LGD1069 in adults with advanced cancer

LGD1069 [Targretin; 4-[1-(5,6,7,8-tetrahydro-3,5,5,8,8-pentamethyl-2-naphtalenyl) propenyl] benzoic acid] is a novel synthetic retinoid X receptor-selective retinoid that has been recently identified. The goals of this study were to determine the safety, toxicity, pharmacokinetics (PKs), and metabolic profile of LGD1069 in advanced cancer patients. Sixty patients received oral LGD1069 at doses ranging from 5-1000 mg/m2/day with PK sampling performed on days 1 and 15. No dose-limiting toxicities (DLTs) were observed up to the 500 mg/m2/day dose level. DLT observed at and above 650 mg/m2/day included skin desquamation, hyperbilirubinemia, transaminase elevation, leukopenia, and diarrhea. Asymptomatic, dose-related alterations in lipid and thyroid metabolism were also observed. DLTs frequently observed with retinoic acid receptor-selective retinoids and pan agonists, including headache, mucocutaneous toxicity, and hypercalcemia, were not dose-limiting with LGD1069. Day 1 LGD1069 Cmax and area under the curve values increased dose-proportionately up to 800 mg/m2/day. Repeat-dose (day 15) area under the curve values varied between 25 and 105% of day 1 values. Although no objective tumor responses were observed, tumor progression may have been substantially arrested or delayed in non-small cell lung cancer (5 of 16) and in head and neck cancer (1 of 5), as well as other tumor types. At the higher dose levels, the molar concentration of LGD1069 was up to 10-fold higher than observed with other retinoids, yet toxicity was minimal. LGD1069 is an retinoid X receptor-selective retinoid agonist with a more favorable PK and toxicity profile than previously studied retinoids and merits further investigation as a chemopreventive and anticancer agent. On the basis of this Phase I trial, the recommended Phase II dose is 500 mg/m2/day.

Preliminary phase II clinical and pharmacokinetic study of 9-cis retinoic acid in advanced cervical cancer. New York Gynecologic Oncology Group

PURPOSE

9-cis retinoic acid (ALRT 1057; 9cRA) is a promising new retinoid that binds to all known retinoic acid receptors (RAR and RXR), potentially providing it with a broader spectrum of biologic activity than either 13-cis retinoic acid or all-trans retinoic acid. It has been shown to be at least as active as all-trans retinoic acid as a differentiation-inducing and antiproliferative agent in both in vivo and in vitro tumor model systems.

METHODS

The New York Gynecologic Oncology Group undertook a prospective, multi-institutional phase II clinical and pharmacokinetic trial of 9cRA in patients with advanced or recurrent squamous cell or adenosquamous cell carcinoma of the uterine cervix. Patients received daily oral doses of 140 mg/m2 of 9cRA. 9cRA and its metabolites were determined by reversed-phase HPLC in plasma samples drawn at 0.5 to 8 hours.

RESULTS

Sixteen patients with advanced or recurrent carcinoma of the cervix were enrolled. Therapy was well tolerated with no unexpected toxicities. There were no complete or partial responses observed, indicating that a response rate of 20% or greater to this agent could be ruled out with 95% confidence. Pharmacokinetic parameters for 9cRA on day 1 were in agreement with previous studies. The area under the plasma versus time curves for 9cRA declined by 69% between days 1 and 8 with daily 9cRA dosing and remained at this low level in those patients evaluated on day 28. 4-oxo-9-cis retinoic acid (4-oxo-9cRA) was identified as a major plasma metabolite of 9cRA. Plasma levels of 4-oxo-9-cRA were initially 71% of those of 9cRA, but in contrast to 9cRA, there was no decline in plasma levels on days 8 and 28. The ratio of the area under the curve for the 4-oxo metabolite relative to that of the parent compound increased from less than 1 on day 1 to approximately 2.4 on days 8 and 28. Thus, despite early induction of its own metabolism, levels of total retinoid metabolites persisted at pharmacologic levels at day 28.

CONCLUSIONS

9cRA with this dose and schedule was inactive in women with advanced carcinoma of the cervix. Despite a decline in plasma levels of 9cRA over time, levels of the 4-oxo metabolite tended to persist. While the 4-oxo metabolite is less potent than the parent compound, these data nevertheless suggest that the lack of clinical activity in this patient population may not be attributable exclusively to suboptimal pharmacokinetic parameters.

Gloeolactone, a New Epoxy Lactone from a Blue-Green Alga

A novel lactone, gloeolactone (1), has been isolated from the blue-green alga, Gloeotrichia sp. The structure of this compound has been elucidated from a detailed analysis of the NMR spectra. This compound was shown to be toxic to brine shrimp.

Unusual central nervous system toxicity in a phase I study of N1N11 diethylnorspermine in patients with advanced malignancy

The objectives of this study were to determine the dose limiting toxicity (DLT) and other major toxicities, the maximum tolerated dose (MTD) and the human pharmacokinetics of N1N11 diethylnorspermine (DENSPM), a new polyamine analog which in experimental systems inhibits the biosynthesis of intracellular polyamines and promotes their degradation by inducing the enzyme spermine/spermidine N-acetyl transferase. These objectives were incompletely achieved because of the occurrence of an unusual syndrome of acute central nervous system toxicity which forms the basis of the present report. Fifteen patients with advanced solid tumors were entered into a phase I study of DENSPM given by a 1 h i.v. infusion every 12 h for 5 days (10 doses). The starting dose was 25 mg/m2/day (12.5 mg/m2/dose) with escalation by a modified Fibonacci search. Doses of 25 and 50 mg/m2/day were tolerated with only minor side effects of facial flushing, nausea, headache and dizziness (all grade I). At doses of 83 and 125 mg/m2/day, a symptom complex of headache, nausea and vomiting, unilateral weakness, dysphagia, dysarthria, numbness, paresthesias, and ataxia, was seen in 3 patients, one after 2 courses of 83 and 2 after 1 course of 125 mg/m2/day. This syndrome occurred after drug administration was complete and the patients had returned home. Lesser CNS toxicity was seen in 2 other patients at lower daily doses. Preliminary pharmacokinetics of DESPM measured in plasma by HPLC in 8 patients showed linearity with dose and a rapid plasma decay with a t1/2 of 0.12 h. We conclude that great caution is warranted in administering DENSPM on this schedule at doses of > or = 83 mg/m2/day.

Paclitaxel and carboplatin in early phase studies: Roswell Park Cancer Institute experience in the subset of patients with lung cancer

The combination of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) given by 3-hour infusion followed by carboplatin infused over 30 minutes has been evaluated in a series of phase I studies and is currently being explored in a phase II study in patients with limited- and extensive-stage small cell lung cancer. Pharmacokinetic measurements were performed at all dose levels in the phase I studies, in which the use of granulocyte colony-stimulating factor in previously treated patients enabled more than twice the dose of paclitaxel to be given with low to moderate doses of carboplatin (dosed to a target area under the concentration-time curve of 4.0 mg x min x mL[-1]). Treatment-naive patients tolerated high paclitaxel doses (270 mg/m2) with carboplatin (dosed to a target area under the curve of 4.5 mg x min x mL[-1]) without granulocyte colony-stimulating factor support. Twenty-three patients (including previously treated and untreated) with non-small cell lung cancer were entered at a variety of paclitaxel doses in the phase I studies. At 100 to 205 mg/m2 paclitaxel, none of nine treated patients responded; at 230 to 290 mg/m2, four (29%) of 14 responded. In the phase II study of paclitaxel 250 mg/m2 in previously untreated patients with small cell lung cancer, two of five evaluable patients with extensive-stage disease have shown a partial response. In a preliminary analysis of the pharmacodynamics of paclitaxel in relation to neurotoxicity (dose limiting in two of three phase I studies), neurotoxicity correlated with the total dose of paclitaxel, the area under the curve, and the peak paclitaxel concentration, but not with the length of time plasma paclitaxel levels remained above 0.05 micromol/L. These correlations were not strong, however, and analysis of these data is ongoing.

Early phase studies with paclitaxel/low-dose carboplatin in patients with solid tumors

In preparation for the design of phase II studies in lung cancer, low-dose carboplatin, fixed at a target area under the concentration-time curve (AUC) of 4.0 or 4.5 mg x min/mL, has been combined with escalating doses of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) in a series of studies to establish the maximum tolerated dose of the combination. In patients who had received prior chemotherapy, the maximum tolerated paclitaxel dose was 135 mg/m2 (carboplatin target AUC 4.0); the dose-limiting toxicity was febrile neutropenia. Without granulocyte colony-stimulating factor support in chemotherapy-naive patients (carboplatin target AUC 4.5), and with granulocyte colony-stimulating factor in chemotherapy-pretreated patients, the current paclitaxel dose is 290 mg/m2. The maximum tolerated dose has not been defined. In a study in which paclitaxel was given by 1-hour infusion with carboplatin (target AUC 4.5), a 205 mg/m2 dose was poorly tolerated. No evidence of pharmacokinetic interactions between paclitaxel and carboplatin was found. Twenty-one evaluable patients with lung cancer have been treated to date. There have been two partial responses, one minor response, and 10 patients with stable disease at paclitaxel doses of 100 to 270 mg/m2.

Phase I study of paclitaxel and carboplatin: implications for trials in head and neck cancer

An ongoing phase I and pharmacokinetic trial of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) in combination with carboplatin is evaluating the maximum tolerated dose (MTD) of a 3-hour paclitaxel infusion combined with fixed doses of carboplatin in previously treated and untreated patients with a variety of advanced cancers. A patient's previous treatment status determines the fixed carboplatin dose: target area under the concentration-time curves of 4.0 and 4.5 mg.min/mL in previously treated and untreated patients, respectively. Studies 1 and 2 entered previously treated patients to establish the paclitaxel MTD without and with cytokine support: study 1 established 135 mg/m2 paclitaxel as the MTD without such support. In study 2, granulocyte colony-stimulating factor is administered, and the MTD has not yet been reached with paclitaxel doses of 135 mg/m2 to 230 mg/m2 assessed thus far and 250 mg/m2 now being evaluated. Objective responses have been seen in three of five patients with squamous cell carcinoma of the head and neck and in patients with non-small cell lung cancer and metastatic cancer of unknown primary site as well. Myelosuppression has been the dose-limiting toxicity, although significant nausea and vomiting and myalgia have been documented occasionally. Paclitaxel apparently has nonlinear pharmacokinetics with a beta half-life of 6.7 hours (SD +/- 1.3 hours). Future trials of paclitaxel/carboplatin will address the management of squamous cell carcinoma of the head and neck and non-small cell carcinoma of the lung.

Cardiac hypertrophy in rats after intravenous administration of CI-959, a novel antiinflammatory compound: morphologic features and pharmacokinetic and pharmacodynamic mechanisms

CI-959 is an antiallergic/antiinflammatory agent currently in development. In rats, daily bolus intravenous administration of CI-959 at doses > or = 10 mg/kg was associated with development of cardiac hypertrophy. There was no morphologic or biochemical evidence of myocyte injury, and cardiac hypertrophy rapidly reversed after treatment was discontinued. Cardiac hypertrophy was not evident when CI-959 was given orally or by continuous intravenous infusion with ALZA osmotic pumps. Maximum plasma drug concentrations (Cmax) were significantly higher when CI-959 was given by bolus intravenous injection, suggesting that cardiac effects were dependent on high Cmax concentrations. When neonatal rat cardiomyocytes were exposed to CI-959 in vitro, there was no evidence of myocyte enlargement or increased protein content. Cardiac hypertrophy was prevented by pretreatment with nonselective beta- and beta 1-selective adrenoceptor blockers as well as with central sympatholytics. beta 2- and alpha-adrenoceptor blockers were ineffective in preventing cardiac hypertrophy. Bolus intravenous CI-959 administration resulted in prolonged hypotension and associated increase in plasma catecholamine levels, with apparent inhibition of reflex tachycardia. We conclude that CI-959-associated cardiac hypertrophy in rats was not a direct drug effect but instead was probably mediated by endogenous catecholaminergic stimulation of cardiac beta 1-adrenoceptors.

Carboplatin for small cell lung cancer: progress toward greater efficacy and reduced toxicity

Small cell lung cancer, an aggressive malignancy characterized by early dissemination, is highly responsive to radiotherapy and cytotoxic chemotherapy. Since the introduction of combined-modality regimens that incorporate both radiotherapy and chemotherapy, the median survival time for patients with localized disease has increased to 12 to 15 months, but median length of survival of patients with extensive disease has remained at a plateau of only 6 to 8 months. New cytotoxic agents, such as ifosfamide, etoposide, and carboplatin, have contributed to a reduced toxicity profile and an increase in complete response rates to combination regimens of 40% to 50%, but they have not contributed to any major increase in long-term survival. Potential strategies for improving efficacy and reducing toxicity of the chemotherapy of small cell lung cancer are reviewed.

Subacute and subchronic toxicology studies of CI-986, a novel anti-inflammatory compound

CI-986 (5-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1,3,4-thiadiazole-2(3H)- thione-2-hydroxy-N,N,N-trimethylethanaminium salt) is a novel anti-inflammatory compound classified as a dual inhibitor of cyclooxygenase and 5-lipoxygenase. Studies were undertaken to characterize the preclinical toxicology of the compound. CI-986 was administered to rats for 2 weeks (0, 50, 250, 750, and 1500 mg/kg) or 13 weeks (0, 20, 250, 500, and 1000 mg/kg), dogs for 2 weeks (0, 50, 150, and 500 mg/kg) or 13 weeks (0, 20, 100, and 200 mg/kg), and to monkeys for 2 weeks (0, 50, 250, and 1000 mg/kg). No drug-related deaths resulted. Mild clinical signs of toxicity were noted in rats given doses of 250 mg/kg and above. Drug-related emesis and diarrhea were absent at the low dose in the dog and monkey but increased in incidence and severity at higher doses. Severe clinical signs in monkeys (emesis and diarrhea) necessitated the lowering of the top dose to 500 mg/kg/day (administered b.i.d.) during the second week of the monkey study. Slight decreases (< 23%) in serum protein and/or albumin were noted in all studies at the higher doses. A dose-related increase in alkaline phosphatase was noted in both dog studies, with no other drug-related effect on clinical pathology parameters. A gastric ulcer occurred in one rat administered 500 mg/kg CI-986 for 13 weeks. Gastrointestinal ulcers were not noted at any other dose in rats or at any dose in dogs or monkeys. A dose-related eosinophilia of glandular stomach submucosa was noted in rats after 2 and 13 weeks of drug administration but not in dogs or monkeys. In the 2-week rat study, mean combined sex plasma drug concentrations monitored 2 hr after dose on Day 14 were 0.59, 1.10, 2.64, and 3.43 micrograms/ml for the 50, 250, 750, and 1,500 mg/kg dose groups, respectively. In the 2-week dog studies, maximum plasma drug concentrations on Day 10 or Day 11 were achieved within 2 hr of dose with mean combined sex Cmax values of 0.73, 2.05, and 2.62 micrograms/ml for the 50, 250, and 750 mg/kg groups, respectively. Hepatic microsomal induction characterized by increased microsomal protein, increased microsomal cytochrome P450 content, and increased p-nitroanisole O-demethylation activity was noted in dogs and monkeys but not rats. CI-986 was well tolerated in rats and dogs at the doses employed and in monkeys at doses up to 500 mg/kg (b.i.d.).(ABSTRACT TRUNCATED AT 250 WORDS)