Discrepancy in the assessment of tumor response in patients with pancreatic cancer: WHO versus RECIST criteria.

PURPOSE: The Response Evaluation Criteria in Solid Tumors (RECIST) have largely replaced the World Health Organization (WHO) criteria as a preferred method for assessing tumor response in clinical trials. We hypothesized that due to frequent asymmetric growth pattern, as well as somewhat diffuse margins of pancreatic cancer, the use of WHO vs. RECIST criteria may result in significantly different tumor response assessments. The purpose of this retrospective study was to compare the WHO (bidimensional) to RECIST (unidimensional) in assessing treatment response in pancreatic cancer patients enrolled in clinical trials. MATERIALS AND METHODS: We have evaluated the contrast- enhanced computed tomography (CT) images from 12 pancreatic cancer patients with measurable disease enrolled in two phase I/II clinical trials at the Arizona Cancer Center, between July 2000 and July 2003. The tumor measurements were re-calculated by RECIST and WHO criteria and were compared. RESULTS: In 3 out of the 12 patients (25%) there was discordant response categorization when WHO criteria were used instead of RECIST. Clinical presentations in all 3 patients were more consistent with WHO categorization. CONCLUSION: Our retrospective data analysis suggests that use of different tumor response criteria (RECIST vs. WHO) may result in different assessments of treatment efficacy in patients with pancreatic cancer on clinical trials. This finding warrants further confirmation in a larger prospectively designed trial.

Interaction of lactoferrin, monocytes, and T lymphocyte subsets in the regulation of steady-state granulopoiesis in vitro.

Colony-stimulating activities (CSA) are potent granulopoietic stimulators in vitro. Using clonogenic assay techniques, we analyzed the degree to which mononuclear phagocytes and T lymphocytes cooperate in the positive (production/release of CSA) and feedback (inhibition of CSA production/release) regulation of granulopoiesis. We measured the effect of lactoferrin (a putative feedback regulator of CSA production) on CSA provision in three separate assay systems wherein granulocyte colony growth of marrow cells from 22 normal volunteers was stimulated by (a) endogenous CSA-producing cells in the marrow cells suspension, (b) autologous peripheral blood leukocytes in feeder layers, and (c) medium conditioned by peripheral blood leukocytes. The CSA-producing cell populations in each assay were varied by using cell separation techniques and exposure of isolated T lymphocytes to methylprednisolone or to monoclonal antibodies to surface antigens and complement. We noted that net CSA production increased more than twofold when a small number of unstimulated T lymphocytes were added to monocyte cultures. Lactoferrin's inhibitory effect was also T lymphocyte dependent. The T lymphocytes that interact with monocytes and lactoferrin to inhibit CSA production are similar to those that augment CSA production because their activities are neither genetically restricted not glucocorticoid sensitive, and both populations express HLA-DR (Ia-like) and T3 antigens but not T4 or T8 antigens. These findings are consistent with results of our studies on the mechanism of lactoferrin's inhibitory effect with indicate that mononuclear phagocytes produce both CSA and soluble factors that stimulate T lymphocytes to produce CSA, and that lactoferrin does not suppress monocyte CSA production, but does completely suppress production or release by monocytes of those factors that stimulate T lymphocytes to produce CSA. We conclude that mononuclear phagocytes and a subset of T lymphocytes exhibit important complex interactions in the regulation of granulopoiesis.

ATP assay: ability to distinguish cytostatic from cytocidal anticancer drug effects.

A bioluminescence assay for ATP was adapted to human cancer cell lines and used to study the effect of anticancer drugs on malignant cell growth by following serial ATP measurements. Eleven drugs were tested against a colon cancer cell line (WiDR). Excellent correlation was observed between simultaneously performed soft-agar colony-forming assays and the ATP assay. In addition, cytostatic (growth inhibitory) drug effects could be distinguished from cytocidal (lethal) effects by using the ATP assay. Cytocidal drugs resulted in a reduction of ATP level below baseline levels, whereas cytostatic drugs merely yielded a reduction in the rate of increase in ATP level, i.e., slower growth. Such characterizations are not possible in colony-forming assays. Changes in ATP were correlated with the number of viable cells present. Drug concentration and duration of exposure both were important. Some drugs became cytocidal only when exposures longer than the customary 1 hour were used. The ATP assay has excellent potential as a simple, inexpensive, and rapid technique for new drug screening in cell lines, with classification of drug effects as cytostatic or cytocidal.

Ornithine decarboxylase and polyamine levels in columnar upper gastrointestinal mucosae in patients with Barrett's esophagus.

Ornithine decarboxylase (ODC) activity was elevated in the premalignant metaplastic columnar epithelium (mean activity, 0.13 unit/mg protein, N = 18 individual samples from 18 patients), compared to either adjacent gastric (mean activity, 0.02 unit/mg protein, N = 9) or small intestinal (mean activity, 0.02 unit/mg protein, N = 9) epithelium in patients with Barrett's esophagus. Enzyme activity ranged from 0 (less than detectable) to more than 0.5 unit/mg protein in the metaplastic tissue. However, neither putrescine, spermidine, spermine (as individual parameters), nor total polyamine contents were related to ODC activity in the individual patient biopsies. Spermidine/spermine ratios ranged from 0.38 to 2.18 and were also not related to enzyme activity in any apparent manner. Nevertheless, cell strains derived from the metaplastic tissue were growth inhibited by alpha-difluoromethylornithine, an enzyme-activated, suicide inhibitor of ODC. In two different cell strains derived from Barrett's epithelium, growth was affected with drug concentrations as low as 0.05 mM. While the mechanism responsible for the elevation in enzyme activity is unknown, the regulation of polyamine metabolism appears to be altered in this premalignant tissue. The growth inhibition of Barrett's epithelium-derived cell lines by ODC inhibitors suggests a potential role for these compounds in the treatment of this disease.

Treatment of advanced breast cancer with mitomycin C combined with vinblastine or vindesine.

Mitomycin C together with either vindesine or vinblastine was given to 48 patients with previously treated advanced breast cancer. Thirteen (35%) of the 37 evaluable patients had a complete (one patient) or partial (12 patients) response. Overall median duration of response was 189 days (range, 90-700 days). Fifteen patients received mitomycin C and vindesine with six responses (40%) and a median response duration of 247 days (range, 162-700 days). Twenty-two patients received mitomycin C and vinblastine with seven responses (32%) and median response duration of 164 days (range, 90-330 days). Response duration for patients treated with mitomycin C plus vindesine was longer than that associated with mitomycin C plus vinblastine (p = 0.09). Significant toxicity included myelosuppression and neurologic symptoms, but was uncommon (less than 10% of patients). Therefore, the combination of mitomycin C and a vinca alkaloid appears to be useful in far-advanced refractory breast cancer.

The myelodysplastic syndromes: biology and implications for management.

Since the initial efforts to characterize the myelodysplastic syndromes in 1976, an extensive body of information has accumulated defining biologic features and the relation to clinical aspects of disease. While the pathogenesis of these disorders remains incompletely understood, laboratory investigations indicate that they are clonal disorders affecting hematopoietic stem cells characterized by a progressive imbalance between self-renewal and differentiation. Despite karyotypic resemblance to acute myeloid leukemia, fundamental biologic differences may underly the disappointing results achieved to date with intensive chemotherapy. The recent availability of recombinant hematopoietic growth factors for use in clinical trials has shown that the maturation defect in many instances can be overcome with administration of lineage-restricted recombinant hematopoietins. Routine use of these promising agents must await results of randomized clinical trials to determine the impact of prolonged treatment on leukemic evolution and disease-related morbidity.

Phase I trial of esorubicin (4'deoxydoxorubicin).

A phase I study of 4'deoxydoxorubicin (esorubicin) was performed on an every-21-day bolus intravenous (IV) schedule in 36 patients with advanced cancer. Thirty-four patients were evaluable for toxicity analysis. Toxicity included mild nausea, occasional local skin reactions, and mild to moderate alopecia. Myelo-suppression was dose limiting. Clinically evident congestive heart failure was not observed. However, two patients developed premature ventricular contractions. Overall, esorubicin was better tolerated than doxorubicin at equally potent doses. Although response analysis was not the primary objective of this phase I study, minor responses were observed in melanoma, breast cancer, lymphoma, and gastric cancer. On the basis of this study, a starting dose of 30 mg/m2 IV every 21 days is recommended for good-risk patients with escalation to 32.5 mg/m2 depending on bone marrow tolerance. For patients with poor bone marrow reserve, a starting dose of 25 mg/m2 every 21 days is recommended. Phase II trials with esorubicin in this dosage schedule are clearly warranted in a wide variety of metastatic neoplasms including a substantial population of patients who have not received prior chemotherapy.

Response of oral leukoplakia to beta-carotene.

Leukoplakia is associated with increased risk of oral cancer and is considered a premalignant lesion. Retinoids, particularly 13-cis retinoic acid, can frequently reverse leukoplakia. However, these drugs have considerable toxicity and are not suitable for large-scale use in the prevention of oral cancer. Beta-carotene is a naturally occurring, nontoxic carotenoid with biologic properties that suggest that it might be efficacious against oral leukoplakia. In 1986, we began a randomized study of 13-cis retinoic acid (1 mg/kg/d) versus beta-carotene (30 mg/d) in leukoplakia. However, owing to the marked differences in toxicity between the two compounds outlined in the consent form, 11 of the initial 16 eligible patients refused to participate unless they were "guaranteed" beta-carotene. Therefore, the study design was changed to a phase II trial of beta-carotene in which the compound was given daily for 3 months. Responding patients were continued for another 3 months of treatment. All lesions were examined histologically at entry. Responses were monitored by bidimensional measurements and photography done at entry, then monthly while on treatment and at study completion. Twenty-four evaluable patients were treated, and 17 had major responses (two complete, 15 partial), a response rate of 71% (95% confidence limits, 53% to 89%). There was no significant toxicity requiring drug discontinuation or dose reduction. These results indicate that beta-carotene has substantial activity in oral premalignancy. Because of its lack of toxicity, it is an excellent candidate for a preventive agent for oral cancer.

Antioxidants and the prevention of coronary heart disease.

Oxygen-free radical reactions have been implicated in many chronic disease processes, including atherosclerotic cardiovascular disease. Recent studies of lipid metabolism have suggested that oxidative modification of low-density lipoprotein accelerates atherogenesis. Micronutrient antioxidants, including alpha-tocopherol and beta-carotene, however, can neutralize oxygen-free radicals and inhibit low-density lipoprotein oxidation. This review examines (1) the role of oxidized low-density lipoprotein in atherogenesis, (2) the association between nutritional antioxidant intake and atherosclerosis, and (3) observational and clinical trial data on the effect of antioxidants in reducing the risk of coronary heart disease. While evidence suggests that antioxidant supplements protect against coronary heart disease, definitive recommendations await results from ongoing randomized trials of primary and secondary prevention.

Chemopreventive studies in Barrett's esophagus: a model premalignant lesion for esophageal adenocarcinoma.

Barrett's esophagus is a premalignant lesion in which the lower esophagus is lined with metaplastic columnar epithelium rather than the normal stratified squamous epithelium. It is a precursor lesion for adenocarcinoma of the esophagus. We are studying Barrett's esophagus as a model premalignant lesion for adenocarcinoma from the standpoint of identifying biologic markers of increased cancer risk as well as therapeutic strategies for eradicating the lesion. Ornithine decarboxylase (ODC) activity in Barrett's mucosa was significantly higher than in normal adjacent mucosa from the same patient. However, polyamine content was not significantly altered, suggesting dysregulation of the polyamine pathway. Flow cytometry is being used to assess the presence of aneuploidy and its significance in a premalignant lesion. Initial results have demonstrated that aneuploidy and dysplasia can be discordant. Cytogenetic analysis using short-term epithelial cultures established from endoscopic biopsies of the lesion has demonstrated the presence of clonal karyotypic abnormalities. The clinical significance of aneuploidy and abnormal karyotype, however, remains to be proved. Chemopreventive intervention trials have included use of 13-cis-retinoic acid. Considerable toxicity was encountered, and the lesion showed no change in extent in 11 evaluable patients. A subsequent clinical trial with a biologic endpoint used alpha-difluoromethylornithine (DFMO), an irreversible inhibitor of ODC, to test whether a low dose could produce changes in polyamine content in gastrointestinal mucosa.(ABSTRACT TRUNCATED AT 250 WORDS)

Potential role of beta-carotene in prevention of oral cancer.

Recent data suggests that retinoids and carotenoids may be effective in reversing a putative "field cancerization" defect in the epithelium at risk for oral cancer. Animal experiments have shown that these compounds can inhibit cancer formation. Several clinical trials have demonstrated the ability of retinoids to reverse oral leukoplakia. However, toxicities associated with retinoids at the doses used in these studies limits their potential for chemoprevention. Because of its lack of toxicity, beta-carotene is a very attractive agent for chemoprevention. It suppresses micronuclei in exfoliated oral mucosal cells from subjects at risk for oral cancer and recently has been shown to be active in reversing leukoplakia. Another area under investigation is the possibility of preventing second primary tumors in patients cured of their initial cancer who have an increased risk of developing new cancers of the upper acrodigestive tract.

Demonstration of a field defect in gastric intestinal metaplasia by biological marker analysis.

Gastric intestinal metaplasia (GIM) is a precursor lesion for gastric cancer. It most frequently involves the antrum and the angularis. At endoscopy, it is not possible to visually distinguish GIM from normal stomach. Furthermore, GIM frequently has a patchy distribution with areas of metaplasia coexisting with adjacent areas of other histologies, including normal stomach. In this study we sought to determine whether a "field defect" could be demonstrated in subjects with GIM, involving the entire region of the stomach. The biologic markers tested were ornithine decarboxylase (ODC) activity and bromodeoxyuridine labeling index (LI). Antral biopsies were obtained from 13 subjects with known GIM and 9 controls (no GIM based on multiple biopsies and absence of methylene blue staining). Three adjacent biopsies were obtained for ODC, LI, and histology. Group I consisted of a set of 3 biopsies from the 9 controls. In the 13 subjects with GIM, 2 sets of 3 biopsies were taken with methylene blue guidance in an attempt to obtain both GIM-free (group II) and GIM-containing (group III) tissue. ODC activities were markedly and statistically significantly (P = 0.0001) elevated in groups II and III versus group I; the mean +/- SDs were 0.075 +/- 0.117 for group I, 1.20 +/- 0.83 for group II, and 1.14 +/- 0.76 for group III. Group II versus Group III values were not different (P = 0.979). LI was less discriminatory with more overlap between the groups. The highest LI was in group II, which was significantly different from group I (P = 0.014) and group III (P = 0.006).(ABSTRACT TRUNCATED AT 250 WORDS)

Gastrointestinal tissue polyamine contents of patients with Barrett's esophagus treated with alpha-difluoromethylornithine.

alpha-Difluoromethylornithine (DFMO), an investigational chemopreventive agent, suppresses polyamine contents and decreases epithelial carcinogenesis in experimental models. The ability of this drug to decrease polyamine contents in human esophageal tissues has not yet been determined. Eight patients with Barrett's esophagus were treated with DFMO at a dose of 1.5 g/m2/day for 12 weeks. Four sites (Barrett's lesion, adjacent normal squamous esophagus, gastric tissue, and small bowel) were biopsied in each patient before, during, and after DFMO treatment in order to assess the effects of this drug on tissue polyamine levels. Ornithine decarboxylase activities and polyamine contents varied in each site analyzed. The rank orders were Barrett's > small bowel congruent to normal esophagus > gastric tissue for ODC activities, and small bowel > or = Barrett's congruent to normal esophagus > gastric tissue for putrescine contents. Spermidine, but not spermine, contents in the Barrett's lesions and normal squamous esophageal tissue were suppressed by systemic DFMO treatment and recovered to untreated control values when DFMO therapy was discontinued. Systemic DFMO treatment did not affect the levels of either of these two amines in gastric tissue and small bowel. Since DFMO can suppress polyamine contents in several gastrointestinal tissues, including Barrett's mucosa, we conclude that it is an effective agent with which to test the hypothesis that depletion of spermidine contents may prevent the development of adenocarcinoma of the esophagus in this specific patient group.

Polyamine contents in rectal and buccal mucosae in humans treated with oral difluoromethylornithine.

Difluoromethylornithine (DFMO) is an investigational chemopreventive agent that inhibits ornithine decarboxylase (ODC) activity, lowers cellular polyamine concentrations, and decreases cell proliferation in vivo and in vitro. In five subjects we have compared the polyamine concentrations in rectal mucosal biopsies and in exfoliated buccal mucosal cells (EBM) before and after DFMO treatment to assess the suitability of EBM as an easily accessible marker tissue for DFMO suppression of polyamine synthesis in the rectal mucosa. One month of 3 g/m2/day of DFMO treatment caused a statistically significant decrease in putrescine and spermidine concentrations in rectal mucosa biopsy specimens but not in EBM samples. ODC activity in EBM was high (approximately 1 mumol/min/mg protein), resistant to DFMO inhibition (Ki = 4200 microM), dependent on GTP concentration (maximal at 0.1 mM), and was reduced concomitantly with bacterial concentration by antiseptic mouthwashing. Bacteria adherent to EBM were visible by electron microscopy. Forty bacterial colonies/ng protein were culturable from washed EBM samples. Oral bacteria preclude the use of EBM samples as a marker tissue of DFMO effect in the rectal mucosa, but oral DFMO therapy is effective in depleting polyamines in rectal mucosa.

Gastric intestinal metaplasia in ethnic groups in the southwestern United States.

The incidence of gastric cancer has declined dramatically in the United States during this century. However, the incidence of gastric cancer among Hispanics, Blacks, and Native Americans remains 2-3-fold higher than among Whites in this country. Populations with an increased risk of gastric cancer have predominantly the "intestinal" type of gastric cancer, and intestinal metaplasia is regarded as a histological precursor lesion of this type of gastric cancer. We sought to establish the prevalence of intestinal metaplasia, identify associated epidemiological factors, and improve detection of this lesion in a patient population undergoing clinically indicated endoscopy in the Southwestern United States. Among the 440 patients studied, we observed an overall crude prevalence of intestinal metaplasia of 19%. However, the crude prevalence among Hispanics and Blacks was found to be markedly higher than among non-Hispanic Whites (50% versus 13%). Two biopsy protocols (two biopsies versus four biopsies) were used during this study, with a significantly higher rate of intestinal metaplasia detection under the four-biopsy protocol. Adjusting for protocol, we found that age and ethnicity were significantly and independently associated with the prevalence of intestinal metaplasia. The odds of intestinal metaplasia diagnosis was significantly higher in Hispanics compared to non-Hispanic Whites (P < 0.001), and the prevalence of intestinal metaplasia increased with advancing age (P = 0.01). The presence of Helicobacter pylori was also significantly associated with the presence of intestinal metaplasia (P = 0.02), although the direction of the association differed between Hispanics and non-Hispanic Whites.

Ornithine decarboxylase and polyamines in colorectal neoplasia and mucosa.

Ornithine decarboxylase (ODC) and polyamines are intimately involved in normal cellular proliferation and are likely to play a role in carcinogenesis. ODC activity and polyamine content were measured in tissue samples obtained during colonoscopy from 48 benign neoplastic polyps (20 tubular adenomas; 28 villous adenomas), 18 cancers (including 5 malignant polyps), and adjacent mucosa. ODC activity in polyp and cancer tissue specimens was higher than in adjacent mucosa in 75 and 83% of pairs, respectively. Similarly, putrescine, spermidine, and spermine contents were higher in the majority of polyps and cancers compared to adjacent mucosa. ODC activity and polyamine content in colonic mucosa from 10 patients without a history of colorectal neoplasia were not different from adjacent mucosal values in the patients with neoplasia. In conclusion, ODC and polyamines are elevated in the majority of colorectal neoplasms, but amounts in normal mucosa do not differentiate between patients with cancer, benign neoplastic polyps, and normal subjects.

Reproducibility of the measurement of colonic proliferation using bromodeoxyuridine across laboratories.

Although measures of colonic cell proliferation are being used as potential intermediate markers in chemoprevention studies, measurement standardization is still ongoing. This study was designed to assess the reproducibility of the labeling index quantification, as measured by bromodeoxyuridine, across four laboratories experienced in its use. Each institution submitted 10 slides, with one circled area of each slide to be scored. Each site followed its standard procedures for scoring colonic crypts; no attempts to standardize these procedures were made. There was high concordance among the laboratories on whether scorable crypts were present on a particular slide, but only two pairs of laboratories demonstrated agreement statistically greater than that predicted by chance. The overall difference among the sites on the number of scorable crypts was marginally significant (P = 0.083), and there was a highly significant overall difference in the magnitude of the labeling index (P < 0.0001). Sites 1 and 2 tended to have similar results, as did sites 3 and 4, most likely due to common training. Even with these discrepancies, high correlation (r > 0.75) was observed among the reported labeling index values for each pair of laboratories. Without standardized training, these laboratories may differ in the crypts considered appropriate for counting and in whether cells are counted as labeled or unlabeled. These results suggest that standardized training in scoring across all sites performing labeling index determinations is required to assure reproducibility across sites or studies. These results may also help explain discrepancies in the average values of the labeling index reported in the literature.

Mitomycin C in the chemotherapy of advanced breast cancer.

Mitomycin C is a chemotherapeutic agent active against breast cancer. Because one of its potential toxicities is prolonged myelosuppression, it is not generally used in first-line chemotherapy regimens. However, several mitomycin C-containing combinations are effective in the salvage therapy of patients that have failed to respond to previous regimens. The choice of a salvage combination depends on the previous treatment received by an individual patient. Patients failing regimens based on CMF (cyclophosphamide, methotrexate, 5-fluorouracil [5-FU]) should be treated with combinations incorporating drugs not included in CMF. Active agents in this setting include mitomycin C, doxorubicin, and vinca alkaloids (usually vinblastine). Patients treated with combinations based on doxorubicin and cyclophosphamide (AC) are frequently administered a CMF-type regimen after a cumulative dose of doxorubicin has been reached. Therefore, they have often received doxorubicin, cyclophosphamide, methotrexate, and 5-FU. Salvage chemotherapy for failing patients in this setting is generally based on mitomycin C and/or vinblastine. Selection of a chemotherapeutic regimen for breast cancer must take into account the palliative nature of chemotherapy in this disease. Consequently, effective combinations that can be administered with minimal disruption of a patient's life-style are preferred.

Management of myelodysplastic syndromes.

The treatment of myelodysplastic syndromes is reviewed, with emphasis on recently published clinical trials. Pyridoxine is rarely effective, but a trial in patients with refractory anemia with ringed sideroblasts is justifiable. Corticosteroids do not appear indicated unless in vitro data suggest response. Androgens are generally not beneficial, although danazol merits further evaluation. Both 13-cis-retinoic acid and low-dose cytosine arabinoside have considerable toxicity and yield short-lived partial responses that may not have a significant impact on survival. Combination chemotherapy may be considered in selected patients with refractory anemia with excess of blasts, refractory anemia with excess of blasts in transformation, and chronic myelomonocytic leukemia; however, in general, its toxicity outweighs potential benefit. For unusual patients under 30 years old, bone marrow transplantation should be considered as first-line therapy. Until more effective and less toxic agents are available, supportive care may still be the most appropriate therapy for many of these generally elderly patients.

Effects of bone marrow fibroblastic cells and fibroblastic conditioned medium on HL-60 and KG-1.

The in-vitro effects of bone marrow fibroblastic cells (FC) and fibroblastic conditioned medium (FCM) on the proliferation and differentiation of two human leukemic cell lines, HL-60 and KG-1 were studied. When FC were seeded onto only one-half of the culture dish an increase in colony size of HL-60 and KG-1 was observed directly above the FC. FCM had a greater effect, resulting in approximately a four-fold increase in the size of HL-60 and KG-1 colonies. In regards to colony number, FCM from normals inhibited HL-60, but FCM from other sources had no effect. FCM from both normals and ANLL in CR inhibited KG-1 colony number in contrast to the lack of effect with FCM from ANLL at diagnosis and RAEB. Neither FC nor FCM had any effect on the differentiation of either cell line. Our results indicate that FC modulate the proliferation of both HL-60 and KG-1. Furthermore, in ANLL the effects of FC are dependent upon the stage of the disease.