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A Rogatko

Publications and source records attributed to A Rogatko.

At least 19 recordsLinked to original sources
PubMed2004

Measurable immune dysfunction and telomere attrition in long-term allogeneic transplant recipients.

This study was conducted to determine if the accelerated telomere attrition that occurs as a consequence of allogeneic stem cell transplantation leads to measurable functional defects. Telomere lengths in mononuclear leukocytes obtained from 15 long-term allogeneic stem cell transplant recipients and their respective donors were determined by Southern hybridization and densitometric analysis. Functional assays evaluated the ability of these cells to proliferate in response to a mitogenic stimulus and to differentiate under appropriate cytokine stimulation. Lymphocyte proliferation in response to phytohemagglutinin was determined by measurement of (3)[H]thymidine uptake. The ability of circulating myeloid cells to differentiate was determined after incubation of peripheral blood mononuclear cells with IL-3 and GM-CSF. A total of 13 patients demonstrated telomeric loss, ranging from 0.1 to 3.7 kbp. Strikingly, lymphocytes from 14 of the 15 patients demonstrated a significant decrease in proliferation when compared to their respective donors (68%+/-22, P=0.001). All patients demonstrated at least a 50% decrease in the number of myeloid colony-forming units when compared to their respective donors (P<0.0001). A decreased ability of hematopoietic cells to proliferate and differentiate is phenotypically consistent with an aged immune system. This may correlate with diminished clinically relevant immune responses to infection or vaccination, as seen in the elderly.

Adult↗
PubMed2001

Patient specific dosing in a cancer phase I clinical trial.

Recent improvements in our understanding of drug metabolism have led to the development of anticancer therapies that accommodate patient differences in drug tolerance. Such methods adjust the dose level according to measurable patient characteristics in order to obtain a target drug exposure. This paper describes the utilization of a patient specific dosing scheme in the statistical design of a phase I clinical trial involving patients with advanced adenocarcinomas of gastrointestinal origin. During the trial, dose levels were adjusted according to each patient's pretreatment concentration of an antibody that was shown in preclinical testing to moderate the effect of the agent under investigation. The design of the trial permitted a continual adjustment of the model used to tailor the dose to each patient's individual needs.

Adenocarcinoma↗
PubMed2001

Phase I trial of multiple cycles of high-dose carboplatin, paclitaxel, and topotecan with peripheral-blood stem-cell support as front-line therapy.

PURPOSE: To determine the safety and feasibility of delivering multiple cycles of front-line high-dose carboplatin, paclitaxel, and topotecan with peripheral-blood stem-cell (PBSC) support. PATIENTS AND METHODS: Patients were required to have a malignant solid tumor for which they had received no prior chemotherapy. Mobilization of PBSC was achieved with either filgrastim alone or in combination with cyclophosphamide and paclitaxel. Patients then received three or four cycles of high-dose carboplatin (area under the concentration-time curve [AUC] 16), paclitaxel (250 mg/m(2)), and topotecan (10-15 mg/m(2)), with the latter two agents administered as 24-hour infusions and supported with PBSC and filgrastim. Cycles were repeated every 28 days. RESULTS: Twenty patients were enrolled onto the trial and were assessable for toxicity and clinical outcome. Dose-limiting toxicities were stomatitis and prolonged hematopoietic recovery. The maximum-tolerated dose of topotecan was 12.5 mg/m(2) when given with high-dose carboplatin and paclitaxel for three cycles. Four cycles were able to be given with a dose of topotecan of 10 mg/m(2). The pharmacokinetics of each compound were not affected by the other agents. Eleven (85%) of 13 patients with assessable disease responded. CONCLUSION: Multiple cycles of high-dose carboplatin, paclitaxel, and topotecan can be safely administered with filgrastim and PBSC support. The recommended doses for phase II study are carboplatin AUC 16, paclitaxel 250 mg/m(2), and topotecan 10 mg/m(2). Trials are currently being conducted with this regimen as front-line treatment in patients with advanced ovarian cancer and extensive small-cell carcinoma. This approach remains experimental and should be used only in the context of a clinical trial.

Adult↗
PubMed2001

Vascular endothelial growth factor and soft tissue sarcomas: tumor expression correlates with grade.

INTRODUCTION: Vascular endothelial growth factor (VEGF), an endothelial-specific mitogen overexpressed in various epithelial malignancies is thought to be a potent regulator of angiogenesis. We hypothesized that some soft tissue sarcomas, due to their high propensity for hematogenous metastases (1) would overexpress VEGF, (2) that the degree of expression may represent a significant biologic predictor for disease-specific survival, and (3) that recurrent tumor would express as high or higher VEGF compared with the primary tumor. METHODS: Selected paraffin-embedded tissue of surgical specimens from 79 patients with soft tissue sarcomas, treated between 1989 and 1995 were stained with a rabbit polyclonal anti-VEGF antibody at a concentration of 2 microg/ml. Slides were assessed for VEGF expression as high or low by two investigators blinded to the clinicopathologic data. Twelve patients had VEGF expression of their primary tumors, and their recurrent tumors were compared. The Fishers' exact test assessed for differences in VEGF expression; survival analyses were performed according to the methods of Kaplan and Meier. RESULTS: Seventy-eight percent (29 of 37) of patients who died of disease had high VEGF expression. However, VEGF expression was not an independent predictor of either overall or disease-free survival. Tumor grade correlated with VEGF expression significantly. For the low-grade tumors, 7 of 13 expressed low VEGF, whereas for high-grade tumors, 53 of 66 expressed high VEGF (P = .016). Seven of the 12 paired tumor samples expressed identical VEGF immunostaining. CONCLUSIONS: The majority of high-grade soft tissue sarcomas in this study have high intensity VEGF expression. This finding may provide useful information on individual soft tissue sarcomas and offer the basis for therapeutic and biologic targeting in high-risk patients using anti-angiogenesis strategies. However, in our analysis, after accounting for tumor grade, VEGF does not seem to be an independent predictor of clinical outcome.

Adolescent↗
PubMed2001

Phase I trial of weekly paclitaxel plus oral estramustine phosphate in patients with hormone-refractory prostate cancer.

OBJECTIVES: To exploit the favorable dose intensity and safety profile of weekly paclitaxel, we conducted a Phase I trial of paclitaxel by 3-hour infusion in combination with estramustine phosphate (EM) in men with hormone-refractory prostate cancer (HRPC). The antimicrotubule drug combination of paclitaxel by 96-hour infusion plus EM is active in HRPC. METHODS: Twenty-four patients with metastatic HRPC and progressive tumor after antiandrogen withdrawal were enrolled in this study. Oral EM was taken at a dose of 600 mg/m(2) daily for the initial 21 patients and on a reduced schedule of 280 mg twice daily for the final 3 patients. Paclitaxel was escalated from 60 to 118 mg/m(2). RESULTS: The major toxicities were gastrointestinal and thromboembolic complications related to daily oral dosing of EM. Of the first 21 patients, one third (n = 7) discontinued therapy within 4 weeks because of protracted nausea and/or thrombotic complications. Dose-limiting toxicities at 118 mg/m(2) paclitaxel were fatigue and hepatotoxicity. Of 13 patients with measurable soft-tissue lesions, 6 had objective partial regressions, and 9 (37.5%) of 24 patients (95% confidence interval 19.1% to 59.1%) with elevated prostate-specific antigen levels had a 50% or greater decline of at least 4 weeks' duration. CONCLUSIONS: Weekly paclitaxel at doses of 60 to 107 mg/m(2) were feasible in combination with oral EM, but daily oral EM produced unacceptable toxicity. On the basis of these results, a Phase II trial of weekly paclitaxel with the reduced dose and schedule of EM was initiated by the Eastern Cooperative Oncology Group to assess further the benefits and risks of this treatment in men with metastatic HRPC.

Adenocarcinoma↗
PubMed2001

The influence of granulocyte macrophage colony-stimulating factor and prior chemotherapy on the immunological response to a vaccine (ALVAC-CEA B7.1) in patients with metastatic carcinoma.

Granulocyte macrophage colony-stimulating factor (GM-CSF) has been shown to be an effective vaccine adjuvant because it enhances antigen processing and presentation by dendritic cells. ALVAC-CEA B7.1 is a canarypox virus encoding the gene for the tumor-associated antigen carcinoembryonic antigen (CEA) and for a T-cell costimulatory molecule, B7.1. After an initial dose escalation phase, this study evaluated vaccination with 4.5 x 10(8) plaque-forming units ALVAC-CEA B7.1 alone (n = 30) or with GM-CSF (n = 30) in patients with advanced CEA-expressing tumors to determine whether the addition of the adjuvant GM-CSF enhances induction of CEA-specific T-cells. Patients were vaccinated with vaccine intradermally every other week for 8 weeks. GM-CSF was given s.c. for 5 days beginning 2 days before vaccination. Patients with stable or responding disease after four immunizations received monthly boost injections alone or with GM-CSF. Biopsies of vaccine sites were obtained 48 h after vaccination to evaluate leukocytic infiltration and CEA expression. Induction of peripheral blood CEA-specific T-cell precursors was assessed in HLA-A2 positive patients by an ELISPOT assay looking for the production of IFN-gamma. Therapy was well tolerated. All of the patients had evidence of leukocytic infiltration and CEA expression in vaccine biopsy sites. In the patients receiving GM-CSF, leukocytic infiltrates were greater in cell number but were less likely to have a predominant lymphocytic infiltrate compared with patients receiving vaccine in the absence of the cytokine adjuvant. After four vaccinations, CEA-specific T-cell precursors were statistically increased in HLA-A2 positive patients who received vaccine alone. However, the GM-CSF plus vaccine cohort of HLA-A2 positive did not demonstrate a statistically significant increase in their CEA-specific T-cell precursor frequencies compared with baseline results. The number of prior chemotherapy regimens was negatively correlated with the generation of a T-cell response, whereas there was a positive correlation between the number of months from the last chemotherapy regimen and the T-cell response. ALVAC-CEA B7.1 is safe in patients with advanced, recurrent adenocarcinomas that express CEA, is associated with the induction of a CEA-specific T-cell response in patients treated with vaccine alone but not with vaccine and GM-CSF, and can lead to disease stabilization for up to 13 months.

Adult↗
PubMed2000

Phase II trial of induction high-dose chemotherapy followed by surgical resection and radiation therapy for patients with marginally resectable non-small cell carcinoma of the lung.

The combination of carboplatin and paclitaxel is an active regimen in non-small cell lung cancer (NSCLC). Historically, patients with stage III disease have manifested higher response rates than patients with metastatic disease, and patients achieving a pathologic complete response to induction chemoradiation therapy prior to surgery have shown better long-term outcome. Based upon our pilot data using high-dose carboplatin and paclitaxel, we designed a phase II trial in patients with marginally resectable stage IIIA NSCLC. Ten patients, with bulky nodal stage IIIA disease, initially received etoposide (2 g/m2) and granulocyte colony-stimulating factor (G-CSF) to mobilize peripheral blood stem cells (PBSC). Two cycles, 28 days apart, of carboplatin (AUC 12 in seven patients; AUC 16 in three patients) and paclitaxel (250 mg/m2) were administered with filgrastim (5 microg/kg) and PBSC support. After re-evaluation, patients underwent a thoracotomy followed by radiotherapy (44-60 Gy) if deemed resectable, or radiotherapy alone (60 Gy) if not resectable. The median age was 58.5 years (48-66) with a median ECOG performance status of 0 (0-1). Histology was adenocarcinoma in seven patients; the remainder had either squamous cell, large cell or bronchoalveolar carcinoma. Based on CT radiography, the overall response rate was 40%. Eight of ten patients underwent resection with four right pneumonectomies, three right upper lobectomies and one wedge resection of the right upper lobe. Six patients had a complete resection. Of eight patients resected, four were downstaged by induction therapy, three remained unchanged and one was found to have more extensive disease. The remaining two patients developed metastatic disease while receiving chemotherapy. The median dose of postoperative radiotherapy was 54 Gy (35-66 Gy). Actual median follow-up for all patients was 89 weeks (25 to 136+). The actuarial median overall survival was 124 weeks (25 to 136+) and time to progression was 57 weeks (17 to 136+). The median dose of carboplatin delivered expressed as mg/m2 was 779 (615-1540). Neutropenic fever occurred in two patients during the initial mobilization cycle only. The median number of units of RBC and/or platelets transfused was 0 (0-2 and 0-6, respectively). There were no significant non-hematologic toxicities. High-dose induction chemotherapy with stem cell rescue is feasible and safe with an acceptable response rate. Thoracotomy, including pneumonectomy and postoperative radiotherapy, were well tolerated by patients after undergoing high-dose induction chemotherapy with no apparent increase in peri-operative morbidity. The pathologic complete response rate was low--one out of ten patients. These results indicate that dose escalation of induction chemotherapy does not improve response rates even in this highly selected patient population. Accordingly, the complexity and potential toxicity of high-dose chemotherapy, as delivered in this trial as neoadjuvant treatment of non-small cell lung cancer, is not warranted.

Adenocarcinoma↗
PubMed2000

Pilot study of a dual gene recombinant avipox vaccine containing both carcinoembryonic antigen (CEA) and B7.1 transgenes in patients with recurrent CEA-expressing adenocarcinomas.

Coordinated presentation of antigen and costimulatory molecules has been shown to result in the induction of an antigen-specific T-cell response rather than the development of anergy. This study evaluated the vaccine ALVAC-CEA B7.1, a canary pox virus that has been engineered to encode the gene for the tumor-associated antigen carcinoembryonic antigen (CEA) and B7.1, a T-cell costimulatory molecule. Patients with CEA-expressing tumors were immunized with 2.5 x 10(7) (n = 3), 1.0 x 10(8) (n = 6), and 4.5 x 10(8) (n = 30) plaque-forming units intradermally every other week for 8 weeks. Patients with stable or responding disease received monthly boost injections. Biopsies of vaccine sites were obtained 48 h after vaccination to evaluate leukocytic infiltration and CEA expression. Induction of CEA-specific T-cell precursors was assessed by an ELISPOT assay looking for the production of IFN-gamma. Therapy was well tolerated, without significant toxicity attributable to vaccine. All patients had evidence of leukocytic infiltration and CEA expression in vaccine biopsy sites. Six patients with elevated serum CEA values at baseline had declines in their levels lasting 4-12 weeks. These patients all had stable disease after four vaccinations. After four vaccinations, patients who were HLA-A-2-positive demonstrated increases in their CEA-specific T-cell precursor frequencies to a CEA-A2-binding peptide from baseline. The number of prior chemotherapy regimens was inversely correlated with the ability to generate a T-cell response. ALVAC-CEA B7.1 is safe in patients with advanced, recurrent adenocarcinomas that express CEA, and it is associated with the induction of a CEA-specific T-cell response.

Adenocarcinoma↗
PubMed1999

Constructing meiotic maps with known error probability.

We propose methods to construct meiotic gene maps while controlling the probability of a decision-error. First, a single step gene ordering procedure is presented whose decision-error probability is bounded above by a prespecified threshold. The bound for the error probability is valid under quite general circumstances. The ordering procedure is optimal in the sense of having maximal predictive probability of correct ordering among all procedures subject to the same bound on the error probability. Second, to reduce the number of hypotheses to be tested, a stepwise ordering procedure is presented. A Monte Carlo simulation study demonstrated the integrity of the proposed error bound for the stepwise procedure under a wide variety of situations, including data coming from different laboratories and marker typing errors. The stepwise procedure was applied to version 2 of the public database maintained by the Cooperative Human Linkage Center and maps of the 23 chromosomes were generated such that the probability that the order of the markers in a given chromosome is incorrect is less than 1%.

Algorithms↗
PubMed1999

Allelic instability as a predictor of survival in Egyptian breast cancer patients.

This work was designed with the purpose of determining whether the presence of allelic imbalances (AI) such as microsatellite instability (MSI) and loss of heterozygosity (LOH) in chromosomes 2, 11, 13, and 17 in primary breast cancer could be used as prognostic indicators of patient survival. The DNA from breast cancers removed from 29 patients who were followed-up for up to five years was analyzed for MSI and LOH using a panel of 24 markers located at chromosome 2 (TPO, D2S131, D2S144, D2S171, D2S177, D2S119, D2S123, D2S147 and D2S136), chromosome 11 (C-RAS, Int-2, D11S940, D11S912), chromosome 13 (D13S289, D13S260, D13S267, D13S218, D13S263, D13S155, and D13S162), and chromosome 17 (D17S513, TP53, D17S855, and D17S785). The frequency of AI in the markers studied ranged from 30-55%, being highest for D11S912, D2S171, TP53 and D17S855. Univariate analysis showed association between overall survival rate and AI in 9 out of the 24 markers tested. Five of them were located at the area of the mismatch repair gene (MMR)-2 gene, two at 11p, one at 13q and one at 17p. Using multivariate analysis, it was observed that only pathological and clinical stage (defined as stage II or not) and AI at D2S171, D11S912, or D17STP53 generated significant predictive models for survival.

Adult↗
PubMed1999

Exploring family relationships in cancer risk counseling using the genogram.

OBJECTIVES: The genogram is a tool that has facilitated counseling in family therapy and social work for many years. It is hypothesized that genograms may also be useful in genetic counseling, because they help the counselor to acquire more objective and consistent information from the client, as well as to incorporate family dynamics and psychosocial issues into the counseling approach. MATERIALS AND METHODS: A pilot study of genograms used as an adjunct to genetic counseling was performed at Fox Chase Cancer Center's Family Risk Assessment Program. A questionnaire was developed to elicit genograms from 38 women at risk for familial breast and/or ovarian cancer. After standard pedigree expansion, a series of questions was asked about the consultand's relationship with other family members, communication patterns within the family, attitudes toward genetic testing, family reactions to cancer, roles individuals play in the family, and significant historical or anniversary events. Relationships were defined by the consultand as close, very close, conflictual, fused and conflictual, distant, or estranged. RESULTS: The majority of relationship types reported by 38 individuals was "very close" or "close." Eighty-one % reported having close/very close relationships with their spouses, 83% reported close/very close relationships with their mothers, and 70% reported close/very close relationships with their fathers. The degree of familial cohesion as depicted by the genogram correlates positively with scores obtained on the standardized Social Adjustment Scale Self-Report (P = 0.01). CONCLUSIONS: Given the family-wide implications of genetic testing, the genogram may offer important guidance in family-targeted interventions.

Adult↗
PubMed1998

Cancer phase I clinical trials: efficient dose escalation with overdose control.

We describe an adaptive dose escalation scheme for use in cancer phase I clinical trials. The method is fully adaptive, makes use of all the information available at the time of each dose assignment, and directly addresses the ethical need to control the probability of overdosing. It is designed to approach the maximum tolerated dose as fast as possible subject to the constraint that the predicted proportion of patients who receive an overdose does not exceed a specified value. We conducted simulations to compare the proposed method with four up-and-down designs, two stochastic approximation methods, and with a variant of the continual reassessment method. The results showed the proposed method effective as a means to control the frequency of overdosing. Relative to the continual reassessment method, our scheme overdosed a smaller proportion of patients, exhibited fewer toxicities and estimated the maximum tolerated dose with comparable accuracy. When compared to the non-parametric schemes, our method treated fewer patients at either subtherapeutic or severely toxic dose levels, treated more patients at optimal dose levels and estimated the maximum tolerated dose with smaller average bias and mean squared error. Hence, the proposed method is promising alternative to currently used cancer phase I clinical trial designs.

Antineoplastic Agents↗
PubMed1997

Utility of linked markers in genetic counseling: estimation of carrier risks in X-linked ocular albinism.

We apply a method proposed by Rogatko et al. [1995: Am J Med Genet 59:24-32] to estimate carrier risks using genetic linkage data. The method is illustrated for X-linked ocular albinism. Linkage data from pedigrees were combined with genome mapping data to compute carrier risks for individuals with unknown carrier status based on pedigree data alone. We considered two situations. First, a linkage map with some ambiguity in the gene order was considered. This analysis allows us to examine the effect of incomplete genetic map information on risk computations. Second, published physical and meiotic mapping information was used to derive a linkage map that could be assumed known without ambiguity. In both situations, the mean and median estimate of carrier risk differed significantly from that obtained using pedigree relationships only, in that the computed risk was significantly different from the a priori value of 0.5. The 95% CI's associated with point estimates of risk made using the known map or an map with ambiguity did not overlap in some cases. These results suggest that the risk estimate and the confidence with which a risk estimate can be imparted may depend on the genetic map and marker data used in the risk estimation procedure. We conclude that the method presented here can be used to estimate genetic risk under a variety of analytical conditions.

Albinism, Ocular↗
PubMed1996

Evaluation of carboplatin pharmacokinetics in the absence and presence of paclitaxel.

In a clinical trial of paclitaxel (Taxol) and carboplatin in combination, the severity of thrombocytopenia was less than would be expected with an equivalent dose of carboplatin alone. To determine whether a pharmacokinetic interaction was responsible for this observation, the effect of pretreatment with Taxol on the pharmacokinetics of carboplatin was examined in 11 patients. Each patient was randomized to one of two treatment groups that determined the order of drug treatments. The treatments were carboplatin as a 30-min infusion alone or immediately following 175 mg/m2 Taxol administered as a 3-h i.v. infusion. The treatments were separated by 1 week. The carboplatin dose was chosen to produce a target area under the concentration-time curve (AUC) of 3.75 mg-min/ml according to a previously published formula (A. H. Calvert et al., J. Clin Oncol., 7: 1748-1756, 1989). The mean administered dose of carboplatin was 338 mg. Serial blood samples were collected over 24 h and analyzed for total and free platinum, and, in some patients, Taxol. The pharmacokinetics of carboplatin (i.e., total clearance and volume of distribution at steady state), was not significantly affected by pretreatment with Taxol. Total clearances of carboplatin were 67.2 +/- 28.8 ml/min and 64.6 +/- 27.9 ml/min in the absence and presence of Taxol, respectively (P = 0.56). The AUC of free carboplatin (3.45 mg-min/ml) obtained in the absence of Taxol was not significantly different from that measured in the presence of Taxol (3.27 mg-min/ml). The AUC of carboplatin in both the absence and presence of Taxol agreed with the projected target AUC of 3.75 mg-min/ml. In conclusion, the application of an individualized dosing strategy is valid for the calculation of the carboplatin dose in this combination. The pharmacokinetics of carboplatin is not altered by pretreatment with Taxol at a standard dose, and a pharmacokinetic interaction is not responsible for the altered toxicity of the combination.

Adult↗
PubMed1995

Risk prediction with linked markers: theory.

A Bayesian method to predict disease recurrence risks based on distance information between loci and allowing for uncertain gene location is presented. The methodology allows derivation of the posterior distribution of recurrence risks, from which point estimates and associated precision measures can be calculated. The resulting risk distribution accounts for all available information concerning location and relative distance, and can be updated as additional data become available.

Bayes Theorem↗
PubMed1995

Risk prediction with linked markers: pedigree analysis.

Rogatko [1995: Am J Med Genet 59:14-23] has proposed a method for risk prediction with linked markers. The actual implementation of this method required that the analytical forms of likelihood and risk functions be specified. It is impractical to obtain the explicit analytical form of these functions in large phase unknown pedigrees. When large phase unknown pedigrees are encountered, the compound risk can be approximated by a transformation of the discrete distribution obtained by computing the likelihood and risk functions over a grid of points. We propose a method to compute genetic risks when the functional form of the pedigree likelihood is unknown. The method was evaluated using a simple pedigree by comparing the results when functional forms were and were not known. This method was also applied to estimate genetic risks for a single pedigree with nonsyndromal X-linked mental retardation using 3 genetic markers linked to the putative disease gene. Linkage data from an extended pedigree were combined with genome mapping data, and recurrence risk distributions were calculated for members of the pedigree. The results suggest that the proposed method provides accurate risk estimate for genetic diseases. Computer programs are available to apply this method whenever genetic markers are suspected of being linked to a disease gene.

Female↗
PubMed1995

Phase I study of phosphonacetyl-L-aspartate, 5-fluorouracil, and leucovorin in patients with advanced cancer.

Low-dose phosphonacetyl-L-aspartate (PALA) may potentiate both 5-fluorouracil (5-FU) incorporation into RNA and thymidylate synthase inhibition by 5-fluorodeoxyuridylate (5-FdUMP). The gastrointestinal toxicity of 5-FU is not increased by PALA administration. Exogenous leucovorin, on the other hand, which enhances thymidylate synthase inhibition, appears to increase the clinical toxicity of 5-FU in a dose-dependent manner. As a result, the clinical use of high-dose leucovorin requires a marked dose reduction of 5-FU. Extracellular leucovorin levels of 1 microM suffice to maximize the enhancement of thymidylate synthase inhibition in several models. We conducted a trial to add leucovorin to the PALA/5-FU regimen. We chose a leucovorin dose that was predicted to yield end-infusion total reduced folate concentrations of 1 microM. The major endpoint was to determine the maximum tolerated dose of 5-FU in this combination. The regimen consisted of 250 mg/m2 PALA given on day 1 and, 24 h later, escalating 5-FU doses ranging from 1,850 to 2,600 mg/m2 admixed with 50 mg/m2 leucovorin and given by 24-h infusion. Courses were repeated weekly. A total of 24 patients with a median performance status of 1 were entered at three dose levels. Diarrhea was dose-limiting; 6/13 patients had grade II or worse diarrhea at 2,600 mg/m2. Dose modification resulted in a mean dose intensity of 2,300 mg/m2 at both the 2,600- and 2,300-mg/m2 dose levels. The 2,300-mg/m2 dose is suitable for phase II testing of this regimen. Three patients (two with breast cancer and 1 with sarcoma) had a partial remission. We measured steady-state concentrations (Css) of 5-FU in 23 patients. The mean Css increased with dose from 0.738 to 1.03 micrograms/ml. Total body clearance did not vary with dose in this range. Patients with grade II or worse diarrhea had a higher mean Css (1.10 +/- 0.19) than those with grade O or I toxicity (0.835 +/- 0.25, P < 0.02). Total bioactive folates (bound and free) were measured using a biological assay. Pretreatment values ranged from 2 to 52 nM and were not predictive of toxicity. End-infusion (23-h) values were somewhat lower than predicted and ranged from 400 to 950 nM. The risk of diarrhea was positively correlated with end-infusion total folate values. In a logistic regression analysis, total folate values obtained at 23 h were a more powerful predictor of diarrhea than were 5-FU Css values.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗