Increased hepatic gluconeogenesis: the secret of Lance Armstrong's success.

Enormous amounts of lactic acid are produced during endurance sport by muscle cells. This metabolite is thought responsible for the muscle pain and the fatigue during sport. Its internal removal from the body by enzymatic conversion depends mainly on the capacity of the hepatic gluconeogenesis that converts lactic acid to glucose. The extraordinary sportive results of the racing cyclist Lance Armstrong did us realize that a high capacity of hepatic gluconeogenesis was the basis of his success, because it might have provided him with less pain complaints caused by lactic acid and with an extra source of energy from lactic acid. This enhanced gluconeogenesis can be due to his heavy training program. At the age of 12-13 years he daily swam 10,000m and cycled 32km. In later years as cyclist his training labour was also more than normal. A constitutional increased gluconeogenesis cannot be excluded, because as a boy of 12 years he became already fourth in 1500m free style swimming in a contest for swimmers from whole Texas. The last argument for an increased gluconeogenesis is that Armstrong in October 1996 suffered from an extensively disseminated testicular tumour. This large tumour load caused that in the tumour the oxidative (=aerobic) energy generation changed into a fermentative (=anaerobic) one. This resulted in a high increase of lactic acid that putted up the gluconeogenesis in the liver. We think that this stimulated, high level gluconeogenesis remained high in the following years, when Armstrong restarted cycling, that it provided him with extra energy from lactic acid and with fewer complaints due to the exercise, and that thus this was the basis of his success.

In vitro modulation of cisplatin cytotoxicity by sparsomycin inhibition of protein synthesis.

Inhibition of protein synthesis can alter cellular responsiveness to the classical anticancer drugs. The in vitro response of Chinese hamster ovary (CHO) cells to cisplatin with or without sparsomycin (Sm) was studied with the use of [3H]leucine and [methyl-3H]thymidine incorporation and clonogenic assay. Pretreatment of exponentially growing CHO cells with 1 microgram Sm/ml for 3 or 5 hours decreased [3H]leucine incorporation by 20% and resulted in significant resistance to cisplatin (P = .005). Sm in a concentration of 10 micrograms/ml reduced [3H]leucine and [methyl-3H]thymidine incorporation after 3 hours by 92 and 84%, respectively, and resulted in potentiation of the cisplatin cytotoxicity (P = .004). This effect was the same in the case of nonproliferating cells (P = .005), while protection due to Sm (1 microgram/ml) was seen only during cell proliferation. Simultaneous incubation and postincubation with Sm proved to have much less or no potentiating effect on cisplatin. The mechanisms of both protection and potentiation are still not clear, but our data indicate that Sm is a promising drug for further studies on the modulation of the cancer cell response to classical anticancer drugs.

Effect of modulators on 5-fluorouracil metabolite patterns in murine colon carcinoma determined by in vitro 19F nuclear magnetic resonance spectroscopy.

High-resolution 19F nuclear magnetic resonance spectroscopy at 7 T was used to study the effect of modulators on the metabolism of 5-fluorouracil (5-FUra, 115 mg/kg i.p.) in C38 murine colon tumors grown in C57BL/6 mice. Distinct 5-FUra metabolite patterns were found in perchloric acid extracts of these tumors after treatment. The 19F nuclear magnetic resonance spectra exhibited resonances representing 5-FUra, the catabolites alpha-fluoro-beta-ureidopropionic acid and alpha-fluoro-beta-alanine, as well as four distinct fluoronucleotide anabolites. Using this model system the effect of several modulators on 5-FUra tumor metabolite patterns was investigated: methotrexate (300 mg/kg); alpha-interferon (10(5) IU/animal); N-(phosphonacetyl)-L-aspartate (100 and 250 mg/kg); and leucovorin (300 and 750 mg/kg). A significant increase in the anabolite:catabolite ratio was observed for the groups treated with 5-FUra in combination with the modulators methotrexate (n = 8), alpha-interferon (n = 7), and high-dose leucovorin (n = 14), but not for low-dose leucovorin (n = 7). Cotreatment with high-dose N-(phosphonacetyl)-L-aspartate (n = 8) resulted in a significant decrease in the anabolite: catabolite ratio compared to treatment with 5-FUra alone (n = 16). Possible correlations of metabolite profiles with therapy response are discussed.

Sequential high-dose methotrexate and fluorouracil combined with doxorubicin--a step ahead in the treatment of advanced gastric cancer: a trial of the European Organization for Research and Treatment of Cancer Gastrointestinal Tract Cooperative Group.

In a prospective phase III multicenter trial, 213 patients with advanced measurable or nonmeasurable gastric cancer were randomized to receive methotrexate (MTX), fluorouracil (5-FU), and Adriamycin (doxorubicin; Farmitalia Carlo Erba, Milan, Italy) (FAMTX) or 5-FU, Adriamycin, and mitomycin (FAM). The results show a significantly superior response rate (41% v 9% [P less than .0001]), and survival (median, 42 weeks v 29 weeks [P = .004]) for FAMTX. There was a cumulative thrombocytopenia in FAM and not in FAMTX. The FAMTX protocol should be the reference treatment in future clinical trials that seek to improve the therapeutic outcome in advanced gastric cancer.

Enhanced myelotoxicity due to granulocyte colony-stimulating factor administration until 48 hours before the next chemotherapy course in patients with small-cell lung carcinoma.

PURPOSE: To evaluate the impact of granulocyte colony-stimulating factor (G-CSF) priming on peripheral-blood cell counts during standard-dose chemotherapy. PATIENTS AND METHODS: Twelve patients with relapsed small-cell lung carcinoma (SCLC) were treated with two chemotherapy courses. Six patients received G-CSF priming only before the first course (group A) and the other six patients only before the second course (group B). Each patient served as his own control. Patients were treated with cyclophosphamide, epirubicin, and etoposide (CEE), or with vincristine, ifosfamide, mesna, and carboplatin (VIMP) every 4 weeks. G-CSF was administered subcutaneously 5 microg/kg/d for 6 days until 48 hours before the first or second chemotherapy course. RESULTS: Priming caused a lowering of the WBC nadir, with a median value of 0.95 x 10(9)/L (P = .004), and of absolute neutrophil nadir, with a median value of 0.48 x 10(9)/L (P = .03). There was a trend for a lower platelet (PLT) nadir after G-CSF priming (P = .09). G-CSF priming resulted in a prolonged duration of WBC count less than 3.0 x 10(9)/L of +4.25 days (P = .04), and of WBC count less than 1.0 x 10(9)/L of +0.50 days (P = .03). The duration of neutropenia less than 0.5 x 10(9)/L seemed longer in primed courses (+3.75 days, P = .18). The duration of PLT counts less than 100 x 10(9)/L was prolonged by 1.5 days (P = .04). Hemoglobin (Hgb) levels were not influenced by G-CSF priming. CONCLUSION: G-CSF administration until 48 hours before the next chemotherapy course increases chemotherapy-associated leukocytopenia and thrombocytopenia. This may be of special concern when G-CSF is administered during dose-densified chemotherapy.

Phase II trial of vinorelbine in metastatic squamous cell esophageal carcinoma. European Organization for Research and Treatment of Cancer Gastrointestinal Treat Cancer Cooperative Group.

PURPOSE: To evaluate the response rate and toxic effects of vinorelbine (VNB) administered as a single agent in metastatic squamous cell esophageal carcinoma. PATIENTS AND METHODS: Forty-six eligible patients with measurable lesions were included and were stratified according to previous chemotherapy. Thirty patients without prior chemotherapy and 16 pretreated with cisplatin-based chemotherapy were assessable for toxicity and response. VNB was administered weekly as a 25-mg/m2 short intravenous (i.v.) infusion. RESULTS: Six of 30 patients (20%) without prior chemotherapy achieved a partial response (PR) (95% confidence interval [CI], 8% to 39%). The median duration of response was 21 weeks (range, 17 to 28). One of 16 patients (6%) with prior chemotherapy had a complete response (CR) of 31 weeks' duration (95% CI, 0% to 30%). The overall response rate (World Health Organization [WHO] criteria) was 15% (CR, 2%; PR 13%; 95% CI, 6% to 29%). The median dose-intensity (DI) was 20 mg/m2/wk. VNB was well tolerated and zero instances of WHO grade 4 nonhematologic toxicity occurred. At least one episode of grade 3 or 4 granulocytopenia was seen in 59% of patients. A grade 2 or 3 infection occurred in 16% of patients, but no toxic deaths occurred. Other side effects were rare, and peripheral neurotoxicity has been minor (26% grade 1). CONCLUSION: These data indicate that VNB is an active agent in metastatic esophageal squamous cell carcinoma. Given its excellent tolerance profile and low toxicity, further evaluation of VNB in combination therapy is warranted.

Phase I and pharmacologic study of oral (PEG-1000) 9-aminocamptothecin in adult patients with solid tumors.

PURPOSE: 9-Amino-20(S)-camptothecin (9-AC) is a specific inhibitor of topoisomerase-I. Recently, a bioavailability of approximately 48% for the oral PEG-1000 formulation was reported. We conducted a phase I and pharmacokinetic study of the oral PEG-1000 formulation of 9-AC to define the maximum-tolerated dose, toxicity profiles, pharmacokinetic-dynamic relationships, and preliminary antitumor activity in patients with solid tumors. PATIENTS AND METHODS: Patients were treated with oral (PEG-1000) 9-AC given once a day for 7 or 14 days at doses ranging from 0.25 to 1.1 mg/m(2)/d; cycles were repeated every 21 days. For pharmacokinetic analysis, plasma sampling was performed on days 1 and 6 or 8 of the first course using a validated high-performance liquid chromatographic assay. RESULTS: Thirty patients were entered onto the study; three patients were not assessable for toxicity and response. Twenty-seven patients received a total of 89 courses. The dose-limiting toxicities (DLTs) were myelosuppression and diarrhea at a dose of 1.1 mg/m(2)/d for 14 days. Pharmacokinetics showed a substantial interpatient variation of the area under the plasma concentration-time curve (AUC) of 9-AC. The intrapatient variability was extremely small. A significant correlation was observed between the percentage decrease in WBC count and the AUC of 9-AC lactone (r(2) = 0.86). One partial response was noted in a patient with metastatic colorectal cancer. CONCLUSION: DLTs in this phase I study of oral 9-AC daily for 14 days every 21 days were myelosuppression and diarrhea. The recommended dose for phase II studies is 0.84 mg/m(2)/d. In view of the substantial interpatient variability in AUC and the availability of a limited sampling model, a pharmacokinetic guided phase II study should be considered.

Effect of carbogen breathing on the pharmacodynamics of 5-fluorouracil in a murine colon carcinoma.

To determine whether carbogen breathing has an effect on 5-fluorouracil (5-FU) uptake, retention and metabolism in C38 murine colon tumours grown in C57Bl/6 mice, we used in vivo 19F nuclear magnetic resonance (NMR) spectroscopy. Eleven tumour-bearing mice were treated with 150 mg/kg of 5-FU given intraperitoneally (i.p.). Five mice received carbogen gas (95% O(2) and 5% CO(2)) for 9.5 min, starting 1 min before 5-FU administration. We found increased levels of 5-FU and its anabolites and catabolites by sequential ¿19F NMR spectroscopy in the group treated with 5-FU in combination with carbogen compared with the group treated with 5-FU alone. The maximum of normalised values of 5-FU and its metabolites, reached after carbogen breathing, was almost 2-fold higher than after treatment with 5-FU alone. Despite these increased concentrations no significant effect of carbogen on growth inhibition of the tumour by 5-FU was observed, which may be related to the size as well as the well vascularised and perfused conditions of the tumours studied.

Phase II trial of cisplatin for adenocarcinoma of unknown primary site. IKZ/IKO Clinical Research Group.

The activity of cisplatin against advanced metastatic adenocarcinoma of unknown primary site (ACUP) was evaluated in 21 patients. Cisplatin (100 mg/m2) was given as a 4-h continuous infusion every 3 weeks, with appropriate fluids and diuretics. The overall response rate was 19% with 1 complete remission for 12 months and 3 partial remissions lasting from 4 to 7 months. 7 patients achieved stable disease and in 9 patients the disease was progressive. The median duration of response was 6.5 months. The median survival 7.5 months. The median survival of the total patient group was 5 months (range 1-18 months). Toxicity comprised mainly nausea and vomiting, mild creatinine elevation and leukocytopenia. Slight ototoxicity was observed in 6 patients.

Activity of cisplatin in adenocarcinoma of the pancreas.

The activity of cisplatin in metastatic adenocarcinoma of the pancreas was assessed in 33 patients. Cisplatin was administered in a dose of 100 mg/m2, every 4 weeks. There were 2 complete responses and 5 partial responses (a response rate of 21%). The median duration of response was 5 months (range, 2+ to 15 months). Cisplatin is a modestly active drug in advanced pancreatic cancer.

Significance of cell proliferation measurement in gastric cancer.

Cell kinetic data may be important indicators of clinical behaviour in many types of cancer. Recently, several antibodies to cell-cycle associated antigens have been characterised. This overview summarises the advantages and disadvantages of different methods for the assessment of cell proliferation. Moreover, the prognostic value of proliferative activity in gastric cancer is discussed and suggestions for future research are given.

Phase II study of nimustine in metastatic soft tissue sarcoma. European Organization for Research and Treatment of Cancer Soft Tissue and Bone Sarcoma Group.

The EORTC Soft Tissue and Bone Sarcoma Group has conducted a phase II trial in 33 eligible patients with metastatic soft tissue sarcoma with nimustine 100 mg/m2 every 6 weeks. In 31 evaluable patients there were 3 (10%) partial responses lasting 4.5, 6 and 7.5 months, and 5 cases of stable disease. 12 patients had progressive disease and 11 patients early progressive disease. Toxicity consisted mainly of leukopenia and thrombocytopenia and nausea and vomiting. It is concluded that nimustine has only minor activity in soft tissue sarcoma.

Antitumour activity and retinotoxicity of ethyldeshydroxy-sparsomycin in mice.

The colony formation in agar of human tumour xenografts was used as a test system to study the cytostatic activity of ethyldeshydroxy-sparsomycin (EdSm) at the cellular level. EdSm was additionally studied in vivo in human tumour xenografts and murine tumour models. EdSm showed a clear dose-response effect in vitro. At continuous exposure with 0.01 micrograms/ml, 2 out of 11 of the tumours responded (a gastric and a small cell lung carcinoma). At 0.1 mu/ml EdSm, the tumour response was 5/11 tumours and at 1 microgram/ml the compound was active in all tumours. The maximal tolerable doses of EdSm in vivo have been determined in non-tumour bearing CDF1 mice. In the intraperitoneally (i.p.) given multiple dose schedules the respective LD10 doses indicated that the tolerable cumulative dose increases when lower doses are given more frequently. This also enhances the antitumour activity in L1210 leukaemia to 172% T/C. On the other hand, continuous infusion strongly diminished the tolerable dose as well as the antitumour activity. EdSm was also active against i.p. inoculated P388 leukaemia (150% T/C), B16 melanoma (156% T/C), and RC carcinoma (197% T/C), and the subcutaneously (s.c.) inoculated L1210 (139% T/C) and RC (138% T/C). Absence of tumour responses was found in the following s.c. implanted murine tumours: M5076 sarcoma, osteosarcomas C22LR and CP369, and the LL carcinoma, as well as in the human tumour xenografts: LXFG 529, a non-small cell lung carcinoma; GXF 251, a gastric carcinoma; and FMa, an ovary carcinoma. Possible long-range retinotoxic effects of EdSm were investigated in tumour-bearing mice, cured after surviving treatment with LD50 doses of EdSm, by assaying the protein biosynthetic capacity of the retinal by assaying the ocular rhodopsin and opsin levels as parameters. In none of these cases could a significant reduction in either opsin or rhodopsin levels be measured and no changes were seen histologically.

Weekly high-dose 5-fluorouracil and folinic acid in metastatic pancreatic carcinoma: a phase II study of the EORTC GastroIntestinal Tract Cancer Cooperative Group.

The aim of the study was to assess the response rate and toxicity of high-dose 24 h infusion of 5-fluorouracil (5FU) in metastatic adenocarcinoma of the pancreas. Patients with measurable disease, performance status 0-2, and no prior chemotherapy were registered to receive cycles of leucovorin (LV) 500 mg/m2 (or l-LV 250 mg/m2 over 1 h followed by 5FU 2.6 g/m2 over 24 h, weekly for 6 weeks, followed by a 2-week rest. The main endpoints were the response rate and toxicity. From 37 patients, 36 were the analysed for toxicity, and 33 were eligible and analysed for response. The median age was 59 years (range 28-74 years), and the median performance status was 1. Partial response was observed in three patients (9%) (95% Confidential Interval (CI): [2-24]%). Main grade 3/4 National Cancer Institute (NCI) common toxicity criteria toxicities (patients) were diarrhoea (n = 3), vomiting (n = 2) and hand-foot syndrome (n = 5). Median time to progression was 7 weeks (95% CI: [6.4-11.7] weeks) and median survival 19 weeks (95% CI: [12-35] weeks). In conclusion, high-dose 5FU and folinic acid is well tolerated, but has only modest activity in pancreatic cancer.

Effects of doxorubicin on maturation of human monocytes in adherent and non-adherent cultures.

Purified human monocytes were cultured for 2 h, 88 h, and 10 days in plastic tubes (adherent) and for 10 days in Teflon foil bags (non-adherent). Monocytes were incubated with doxorubicin by two short-term exposures (750 or 1500 ng/ml) for 1 h or by continuous exposure (75 ng/ml). Maturation was monitored by measuring the intracellular activity of three metabolic enzymes and two acid hydrolases. Expression of receptors for the Fc moiety of immunoglobulin G (FcRI, FcRII, FcRIII), CD14, and HLA-DR was assayed by indirect immunofluorescence with monoclonal antibodies. In the presence of doxorubicin, the adherent capacity, the yield, and the enzyme activities reflecting growth and intermediary metabolism were similar to the control groups. However, doxorubicin reduced the expression of FcRI (32-45%), FcRII (10-26%), CD14 (20-37%), and HLA-DR (25-34%) on the monocyte-derived macrophages. Expression of FcRIII was not detectable after 10 days of culture.

Results of a randomised phase II study of cisplatin plus 5-fluorouracil versus cisplatin plus 5-fluorouracil with alpha-interferon in metastatic pancreatic cancer: an EORTC gastrointestinal tract cancer group trial.

A randomised phase II study of 5-fluorouracil (5-FU) plus cisplatin (CDDP) with or without alpha-interferon 2b was performed in patients with pancreatic cancer with measurable metastatic disease outside the pancreas. The treatment in arm A consisted of cisplatin (100 mg/m(2)) on day 1, followed by a continuous infusion of 5-FU 1000 mg/m(2) for 4 days and in arm B the same treatment was given plus alpha-interferon 2b in a dose of 3 million Units/day subcutaneously (s.c.) from day 1 for 5 days. 36 patients were entered in the trial, 18 in each arm. In arm B only 15 patients were eligible. No responses were observed in the 5-FU/CDDP arm and only 2 partial responses were achieved in the interferon-arm, lasting 27 and 32 weeks, respectively. Both treatment arms showed considerable toxicity. It has to be concluded that both treatment regimens have little activity and cannot be recommended.

Results of a phase II trial of epirubicin and cisplatin (EP) before and after irradiation and 5-fluorouracil in locally advanced pancreatic cancer: an EORTC GITCCG study.

The objective of the present study was to define the role of chemotherapy, in the form of the EP regimen, consisting of epirubicin (E) and cisplatin (P) in addition to irradiation in combination with 5-fluorouracil (5-FU) for treatment of pancreatic cancer. 53 eligible patients with histologically or cytologically proven locally advanced pancreatic cancer were treated with three cycles of E 60 mg/m2 (if this dose was well tolerated then the dose of E was increased by 10 mg/m2 in the next cycle; 80 mg/m2 was the maximum dose for the following cycles) and P 100 mg/m2 once every 3 weeks, followed after 4 weeks by a split course of irradiation of 40 Gy with 5-FU 500 mg/m2 on each of the first 3 days of each 20 Gy treatment segment. This was followed by another three cycles of EP in patients who achieved stable disease (SD) or a better response after the first three cycles. The treatment given with standard anti-emetics was moderately tolerated. The chemotherapy related toxicity consisted mainly of myelosuppression and the chemoradiotherapy related toxicity of gastrointestinal side-effects. However, due to the long duration of treatment which made the whole treatment difficult to endure, only 18/53 (34%) actually completed the full treatment regimen. Responses were evaluated after the first three cycles and 4 weeks after the completion of the treatment by serial CT-scans using standard criteria. The results in 53 evaluable patients after the first three cycles of EP were as follows: 1 patient achieved a clinical complete response (CR), 7 a partial response (PR) (CR + PR: 15%; 95% confidence interval (CI): 11-33%), 36 patients (68%) had stable disease (SD) and 6 patients progressive disease (PD). There was 1 early PD, 1 toxic death and 1 patient could not be evaluated. The response at the end of the treatment was 3 CR, 11 PR (CR + PR: 14/53 (26%); 95% CI: 15-40%), 30 SD and 6 PD. The median time to progression was 8.9 months and the median duration of response 13.1 months. The median survival of all treated patients was 10.8 months (range 7 days to 41.5 months), of responders 15.1 months and, of the patients with SD 10.3 months. These results are comparable to other combined modality regimens reported in the literature for locally advanced disease. The addition of the systemic treatment with E and P offers no additional advantage to combined modality treatment alone.

Fluorouracil continuous infusion plus alfa interferon plus oral folinic acid in advanced colorectal cancer.

Several reports on fluorouracil (5-FU) and alfa interferon (IFN-alpha) combination therapy in patients with advanced colorectal cancer have been published. In our study high-dose continuous infusion 5-FU (60 mg/kg per 48 hours), oral folinic acid (FA) (8 x 90 mg during 5-FU), and IFN-alpha three times weekly were combined. Because the addition of IFN-alpha has not been tested before, and serious toxicity of 5-FU plus IFN-alpha therapy has been reported, the IFN-alpha dose was escalated from 3 to 10 million units (MU)/dose in the first 11 patients. Grade 3 toxicity was noted in four patients, and consisted mainly of oral mucositis. No grade 4 toxicity occurred. Three partial responses were noted. Preliminary results of a phase II study, in which all patients received IFN-alpha at 10 MU/dose, show grade 3 and 4 toxicities in 24% and 4% of patients, respectively. This compares favorably with other trials in which 5-FU and IFN-alpha was used without FA.

Non-selective lymphocyte isolation from human blood by nylon wool filtration and density centrifugation.

A new method was employed to isolate lymphocytes from human peripheral blood. Continuous flow filtration through a nylon wool filter, at a flow rate of 1.4 ml/min, produced a lymphocyte yield of 90.5% and a purity of 96% without any shift in the B-T cell ratio. Ficoll-Isopaque with a specific gravity of 1.085 g/ml instead of 1.077 g/ml could be used to remove the erythrocytes. An overall recovery, including defibrination, filtration, Ficoll-Isopaque centrifugation and washing step, of 74.5% was achieved.

Monocyte purification with counterflow centrifugation monitored by continuous flow cytometry.

Continuous monitoring of cell light scatter during counterflow centrifugation of a mononuclear cell suspension allows counting and size recognition of the cell types elutriated. With this method an optimal separation point between monocytes and lymphocytes, determined for each individual donor, may be established. With a constant flow of 15 ml/min this separation point is found at centrifugal velocities ranging from 2348 to 2444 rpm (n = 10). From 50 ml venous blood, 84.1% +/- 4.1% (15.7 +/- 8.6 x 10(6)) of all elutriated monocytes, with a purity of 92.4% +/- 1.4%, is collected in a volume of 50 +/- 1 ml. In the same run, 92% +/- 4.3% of the lymphocytes is gathered in one fraction with a purity of 98.9% +/- 0.7%. After counterflow centrifugation, 91.6 +/- 10.5% of the cells loaded is recovered; viability exceeds 98%.