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Biomedical subjects

G Milano

Publications and source records attributed to G Milano.

At least 37 records · Page 2Linked to original sources

Dihydropyrimidine dehydrogenase circadian rhythm in mouse liver: comparison between enzyme activity and gene expression.

Dihydropyrimidine dehydrogenase (DPD) is the rate-limiting enzyme of 5-fluorouracil (FU) catabolism. The relevance of the measurement of DPD activity for identifying DPD-deficient patients is lessened by circadian variability in DPD activity. Our purpose was to determine whether or not DPD mRNA is sustained by a circadian rhythm. Synchronised mice (male B6D2F1) were sacrificed at 3, 7, 11, 15, 19 or 23 Hours After Light Onset (HALO; eight mice per time-point). Liver DPD activity was determined by a radio-enzymatic assay and liver DPD expression by a reverse transcriptase-polymerase chain reaction (RT-PCR) enzyme-linked immunosorbent assay (ELISA) method. Mice synchronisation was controlled by leucocyte and neutrophil counts. Individual DPD activity ranged from 555 to 1575 pmol/min/mg prot; mean DPD activity was highest at 3 HALO (mean+/-standard error of the mean (S.E.M.); 1105+/-70) and lowest at 15 HALO (889+/-71). Individual liver DPD expression varied from 761 to 3481 units (DPD/beta actin ratio); the mean was lowest at 3 HALO (1406+/-112) and highest at 15 HALO (2067+/-214). Cosinor analysis indicated that respective double amplitudes of DPD activity and expression were 21 and 30% of the 24-h mean. The acrophases for activity and expression were 6:40 and 14:10 HALO, respectively, meaning that maximum activity occurred 16 h after the maximum observed expression. These results, revealing the existence of a circadian rhythm in DPD expression, should stimulate further studies to enhance our understanding of the molecular mechanisms involved in the circadian regulation of the DPD enzyme.

Animals↗

Fas/FasL expression in tumor biopsies: a prognostic response factor to fluoropyrimidines?

Various studies suggested that cytotoxicity induced by 5-fluorouracil (5-FU) is an apoptotic mechanism possibly mediated by the Fas/FasL system. In this preliminary work, we studied retrospectively the role the Fas/FasL expression as a predictive response factor with fluoropyrimidine-based chemotherapies. We developed a real-time PCR method for measuring Fas and FasL expression in various biopsies from patients treated with a FUFOL-like protocol. No correlation was found between Fas or FasL expression and overall survival or partial response. However, the PCR assay was simple and convenient to use for quantitation of Fas/FasL in tumor biopsies.

Adult↗

Pharmacokinetics of low-dose carboplatin and applicability of a method of calculation for estimating individual drug clearance.

BACKGROUND: Carboplatin is the only cancer drug for which conventional doses are individually adjusted according to estimated clearance and target area under the curve (AUC). The aim of this prospective study was (i) to evaluate intra- and interpatient variability of ultrafilterable (UF) carboplatin AUC(0-)(infinity) and (ii) to test whether the prediction of carboplatin clearance according to the Chatelut formula established for conventional carboplatin doses was accurate for low carboplatin doses. MATERIALS AND METHODS: Thirty-one head and neck cancer patients (29 men, two women, mean age 55.9 years) received concomitant radiotherapy (Rgamma 2 Gy/day) and chemotherapy (carboplatin 50 mg/m(2)/day i.v.) for 7 weeks: Rgamma was administered 5 days/week (days 1-5) and carboplatin 2 days/week (days 1 and 4). Pharmacokinetics was performed once per week. A limited sample strategy based on Bayesian analysis was first validated and blood was subsequently taken 1 and 4 h after the end of carboplatin administration. RESULTS: A total of 143 cycles was analyzed. Ultrafilterable carboplatin AUC(0-)(infinity) ranged from 0.360 to 4.200 mg.min/ml (mean 0.830, median 0.670). As a corollary, UF carboplatin clearance ranged from 19.1 to 244.7 ml/min. Ultrafilterable carboplatin concentrations were very stable over time: AUC(0-)(infinity) variability due to treatment duration contributed to <1% of the total variance, while interpatient variability contributed to 68.6%. Accordingly, intrasubject effect was not significant (P = 0.38) whereas intersubject effect was highly significant (P <0.001). These results suggest that optimal dosage for targeting a given AUC may vary within a 13-fold range between patients. The Chatelut formula, based on creatininemia, body weight, age and sex, over estimates carboplatin clearance by 40% on average (bias 95% CI 29.6% to 51.1%). No significant relationship was observed between either bone marrow toxicity or creatinine clearance decrease and carboplatin pharmacokinetics. CONCLUSIONS: The Chatelut carboplatin clearance model established for conventional carboplatin dosages (>100 mg/m(2)) is not applicable for targeting low AUC (<1 mg x min/ml).

Adult↗

Phase I and pharmacokinetic study of the association of capecitabine-cisplatin in head and neck cancer patients.

The combination of cisplatin and 5-fluorouracil (5-FU) is considered to be the standard treatment in induction chemotherapy for patients with squamous cell carcinoma of the head and neck. Capecitabine (Xeloda) is an oral fluoropyrimidine that is preferentially activated at the tumoral level, exploiting the higher thymidine phosphorylase activity in tumoral tissue. This phase I trial was conducted in patients with locally recurrent or metastatic head and neck carcinoma. The treatment plan included cisplatin on day 1 every 21 days, followed by capecitabine twice daily from day 2 to day 15, with a 1-week rest period. Pharmacokinetic investigations concerned plasma measurement of unchanged capecitabine, 5'-deoxy-5-fluorocytidine, 5'-doxifluridine and 5-FU using an optimized high performance liquid chromatography method, and cisplatin measurement in plasma using a limited sampling procedure. Twenty-one patients were included (mean age 61 years, range 46-76 years). Dose (mg/m(2)) increments for cisplatin and capecitabine (b.i.d.), respectively, were as follows: level 1, 80 and 1000 (three patients); level 2, 100 and 1000 (12 patients); and level 3, 100 and 1125 (five patients). Dose-limiting toxicities occurring during the first cycle (grade >/= 3) were observed on level 2 (one patient with diarrhea, nausea, vomiting, hand-foot syndrome, one toxic death due to renal failure and neutropenia, one patient with neutropenia) and on level 3 (one patient with diarrhea, one patient with hand-foot syndrome and one patient with neutrothrombocytopenia). Due to delayed side-effects, 14 patients (67%) had repeated cycles every 28 days instead of 21 days as initially planned. Objective response was obtained in seven patients (three complete responses and four partial responses). There was no evidence of pharmacokinetic-pharmacodynamic relationships with the drugs and metabolites investigated. Combination of capecitabine and cisplatin is feasible, with a very promising response rate. The recommended doses for further phase II studies are those of level 2 with cisplatin 100 mg/m(2) on day 1 and capecitabine 1000 mg/m(2) b.i.d. on days 1-14, every 28 days.

Administration, Oral↗

Influence of epidermal growth factor receptor (EGFR), p53 and intrinsic MAP kinase pathway status of tumour cells on the antiproliferative effect of ZD1839 ("Iressa").

of ZD1839 ("Iressa") is an orally active, selective epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), which blocks signal transduction pathways implicated in proliferation and survival of cancer cells, and other host-dependent processes promoting cancer growth. Permanent downstream activation of the mitogen-activated protein kinase pathway can theoretically bypass the upstream block of epidermal growth factor receptor-dependent mitogen-activated protein kinase activation at the epidermal growth factor receptor level. We investigated the impact of epidermal growth factor receptor content, p53 status and mitogen-activated protein kinase signalling status on ZD1839 sensitivity in a panel of human tumour cell lines: seven head and neck cancer cell lines and two colon cancer cell lines (LoVo, HT29) with derivatives differing only by a specific modification in p53 status (LoVo p53 wt + p53 mut cells, HT29 p53 mut + p53 wt rescued cells). The antiproliferative activity of ZD1839 was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide test. ZD1839 concentrations ranged from 0.2-200 microM (48 h exposure). Epidermal growth factor receptor expression, p53 status and p42/p44 (for testing a constitutively active mitogen-activated protein kinase pathway status) were determined by competition analysis (Scatchard plots), denaturing gradient cell electrophoresis and Western blot, respectively. Epidermal growth factor receptor levels ranged from 388 to 33794 fmol mg(-1) protein, a range that is similar to that found in head and neck tumours. The IC(50) values for cell sensitivity to ZD1839 ranged from 6 to 31 microM and a significant inverse correlation (P=0.022, r=0.82) between IC(50) values and epidermal growth factor receptor levels was observed. There was no influence of p53 status on the sensitivity to ZD1839. In two head and neck cancer cell lines with comparably elevated epidermal growth factor receptor expression, a two-fold higher ZD1839 IC(50) value was found for the one with a constitutively active mitogen-activated protein kinase. In conclusion, ZD1839 was active against cells with a range of epidermal growth factor receptor levels, although more so in cells with higher epidermal growth factor receptor expression. Activity was unaffected by p53 status, but was reduced in cells strongly dependent on epidermal growth factor receptor signalling in the presence of an intrinsically activated mitogen-activated protein kinase pathway.

Antineoplastic Agents↗

Impact of the oxaliplatin-5 fluorouracil-folinic acid combination on respective intracellular determinants of drug activity.

The combination of 5-fluorouracil-folinic acid and oxaliplatin has led to a significant improvement of chemotherapy efficacy in advanced pretreated colorectal cancer. The objective of the present study was, considering the oxaplatin-5-fluorouracil-folinic acid combination, to examine the impact of one given drug on the cellular determinants of cytotoxic activity of the other drug. These cellular factors were analysed on the human colon cancer cell line WiDr in clinically relevant conditions of drug exposure ('De Gramont' schedule) with oxaliplatin-folinic acid during 2 h followed by 5-fluorouracil 48 h. The DNA binding of oxaliplatin was significantly reduced by the presence of 5-fluorouracil but this effect was time-dependent and after 50 h the platinum incorporated into DNA was identical in controls and in the drug combination. In the presence of oxaliplatin, there was less formation of FUH(2) which is the first catabolite produced in the cascade of 5-fluorouracil metabolic degradation. The effects of drugs on cell cycle were quite different from one drug to the other with oxaliplatin inducing a shift towards G(2) accumulation and 5-fluorouracil-folinic acid to a greater proportion of cells in G(1)-S. When oxaliplatin and 5-fluorouracil-folinic acid were combined the cell cycle effects were very similar to that of the 5-fluorouracil-folinic acid sequence alone. Oxaliplatin was able to reduce thymidylate synthase activity with a marked impact 28 h after the beginning of cell exposure to the drug. The 5-fluorouracil-folinic acid drug sequence led to a profound reduction in thymidylate synthase activity and this decrease was not markedly enhanced by the presence of oxaliplatin. Regarding apoptosis, changes in mitochondrial membrane permeability were observed in the presence of the tested drugs and the impact of 5-fluorouracil-folinic acid was greater than that of oxaliplatin. The addition of oxaliplatin did not amplify the action of 5-fluorouracil-folinic acid upon mitochondrial membrane permeability change. The presence of oxaliplatin itself did not modify the intracellular concentration of total reduced folates. The fact that oxaliplatin may reduce 5-fluorouracil catabolism could be central in explaining the supra-additive interaction between these drugs.

Antineoplastic Combined Chemotherapy Protocols↗

Sequence-dependent effects of ZD1839 ('Iressa') in combination with cytotoxic treatment in human head and neck cancer.

Elevated levels of epidermal growth factor receptor in head and neck cancer have been extensively reported, and are correlated with poor prognosis. The combination of cisplatin and 5-fluorouracil is a standard treatment regimen for head and neck cancer, with radiation representing another therapeutic option. Six head and neck cancer cell lines were used to study the cytotoxic effects of combining ZD1839 ('Iressa'), a new selective epidermal growth factor receptor tyrosine kinase inhibitor, and radiation. Two of the cell lines were also used to study the combination of ZD1839 and cisplatin/5-fluorouracil. Cytotoxic effects were assessed by the MTT test. The results indicated that ZD1839 applied before radiation gave the best effects (P=0.002); an effect that was strongest in those p53-mutated cell lines that express the highest epidermal growth factor receptor levels. The effects of ZD1839 with cisplatin and/or 5-fluorouracil were sequence dependent (P<0.003), with the best results achieved when ZD1839 was applied first. For the triple combinations, ZD1839 applied before cisplatin and 5-fluorouracil resulted in a slight synergistic effect (P=0.03), although the effect was greater when ZD1839 was applied both before and during cytotoxic drug exposure. In conclusion, ZD1839 applied before radiation and before and/or during cisplatin/5-fluorouracil may improve the efficacy of treatment for head and neck cancer.

Antineoplastic Agents↗

Activation of nuclear factor kappaB through the IKK complex by the topoisomerase poisons SN38 and doxorubicin: a brake to apoptosis in HeLa human carcinoma cells.

The transcription factor nuclear factor (NF) kappaB is involved in the regulation of cell survival. NFkappaB is activated in many malignant tumors and seems to play a role in the resistance to cytostatic treatments and escape from apoptosis. We have studied the effects on NFkappaB activation of two topoisomerase poisons and DNA damaging agents that are used in chemotherapy: SN38 (7-ethyl-10-hydroxycamptothecin), the active metabolite of CPT11, and doxorubicin. In HeLa cells, both drugs activate NFkappaB using a preexisting pathway that requires a functional IkappaB-specific kinase complex, IkappaB-specific kinase activation, IkappaB-alpha phosphorylation, and degradation. Blocking NFkappaB activation by stable expression of a mutant super-repressor IkappaB-alpha molecule sensitized HeLa cells to the apoptotic actions of drugs and tumor necrosis factor. RNase protection assay analysis demonstrate that NFkappaB is involved in the regulation of a complex pattern of gene activation and repression during the cellular response of HeLa cells to topoisomerase poisons. The blockade of NF-kappaB activation seems to shift the death/survival balance toward apoptosis.

Antibiotics, Antineoplastic↗

High-performance liquid chromatographic assay with ultraviolet detection for quantification of dihydrofluorouracil in human lymphocytes: application to measurement of dihydropyrimidine dehydrogenase activity.

The anticancer drug 5-fluorouracil (5FU) undergoes extensive biotransformation to 5-dihydrofluorouracil (5FUH2) by the enzyme dihydropyrimidine deshydrogenase (DPD). A new HPLC method with direct UV detection for the determination of 5FUH2 in peripheral lymphocytes has been developed to detect DPD deficiency in patients treated with 5FU-based therapy. The method has been shown to be valid over the 5FUH2 concentration range of 1.14-37.88 nmol/ml. Optimal enzymatic conditions for DPD activity measurement were studied: incubation time, protein and 5FU concentrations. The assay was successfully cross-validated with the existing method using HPLC with radiochemical detection.

Chromatography, High Pressure Liquid↗

Impact of thymidine phosphorylase surexpression on fluoropyrimidine activity and on tumour angiogenesis.

Tumoral thymidine phosphorylase (TP) appears to play a dual role by being involved in neoangiogenesis and by activating 5FU prodrugs at the tumoral target site. The aim of the study was to investigate more thoroughly these potential physiological and pharmacological roles of TP. A rat carcinoma cell line (PROb) was transfected with TP/PD-ECGF in order to study the effect of the overexpression of this enzyme (1) on the sensitivity of cells to 5'DFUR and 5FU in vitro and (2) on tumour growth in vivo by using a syngenic tumour model in the BDIX rat (hepatic tumours, sub-cutaneous tumours). Cytotoxic effects of 5'DFUR, and to a lesser extent those of 5FU, were enhanced in TP clones as compared to control cells: there was a highly significant correlation between TP activity and in vitro sensitivity to 5'DFUR (r2= 0.91, P = 0.0002, n = 8) and, to a lesser extent, to 5FU (r2= 0.49, P = 0.053, n = 8). The impact of TP transfection on tumour growth was relatively modest and concerned only the initial stages of tumour expansion. Staining of TP tumours for endothelial (factor VIII) cells was always higher than controls. The staining ratio (TP/controls) tended to be reduced as tumours increased in size. The stability of TP expression was checked both in vitro (TP activity measurement) and in vivo (RT-PCR determinations) and there was no loss of TP expression over time which could be advanced to explain the progressive weakening of the impact of TP overexpression on both tumour growth and neoangiogenesis.

Animals↗

Determination of microsatellite instability, p53 and K-RAS mutations in hepatic metastases from patients with colorectal cancer: relationship with response to 5-fluorouracil and survival.

In vitro and clinical studies have suggested that high-frequency microsatellite instability (MSI-H) phenotype, p53 and K-ras mutations might influence the response to chemotherapy in a variety of tumors, including primary colorectal cancers (CRC). Unresectable hepatic metastases from CRC are commonly treated with 5-fluorouracil (5FU) and folinic acid. Since several new active drugs are now used for treating CRC, molecular determinants predictive to response to 5FU would thus be crucial for optimizing indications of chemotherapy to those patients. MSI-H phenotype, p53 and K-ras status were characterized in a prospective study of 56 patients with CRC metastatic to the liver and treated with 5FU-based chemotherapy. The objective response rate after a 3-month treatment was 32.1%. The prevalence of p53 mutations, K-ras mutations and MSI-H phenotype was 62.5%, 30.3% and 1.8%, respectively. No significant association was found between response to chemotherapy and p53 mutations (78% mutated tumors in responders vs. 55% in nonresponders; p = 0.10) and K-ras mutations (39% mutated tumors in responders vs. 26% in nonresponders; p = 0.34). Survival was longer for patients with p53-mutated metastases than for patients with unresected wild-type p53 metastases (median survival 15 months vs. 17 months; p = 0.06). The determination of the MSI-H phenotype, p53 and K-ras status in hepatic metastases from CRC does not discriminate a group of patients that should preferentially benefit from 5FU-based chemotherapy. The prognosis of patients with treated liver metastases is better when p53 is mutated.

Adult↗

Patellar tendon healing after removal of its central third. A morphologic evaluation in rabbits.

The central third of the patellar tendon of the right knee was removed in 40 adult New Zealand White (NZW) rabbits. The animals were divided into two groups of 20 animals each. In group 1 the tendon defect was left open and in group 2 the tendon defect was closed. The peritenon was closed in all cases. The animals were killed after 2 weeks, 1, 3, 6 and 9 months. Operated and contralateral normal tendons of each knee underwent a gross, histologic, immunohistochemical and morphometric analysis. Gross examination revealed that in the closed group there was a greater shortening of the patellar tendon but the difference between the two groups was not statistically significant. The width, thickness and cross-sectional area increased progressively in both groups and were greater in the closed group. Histological examination showed that at 1 month in both groups the harvest site was filled with a loose unoriented fibrovascular tissue. In group 1, large fatty inclusions could be seen in the deep layer, that were still present in the 3-, 6- and 9-month samples. At 3 months in group 1 the newly formed tissue was immature and rich in elastic fibres, as confirmed by immunohistochemical analysis, whereas in group 2 it was more compact and oriented. In group 1 there was in many cases an ossification on the lower pole of the patella, which was not seen in group 2. At 9 months a well-organized fibrous tissue could be seen in both groups at the harvest site. Histomorphometric analysis confirmed the better orientation and the greater density of the newly formed tissue in the closed group as compared to the open group, and the greater number of elastic fibres in the open group, even after 9 months.

Animals↗

Clinical and radiographic results of ACL reconstruction: a 5- to 7-year follow-up study of outside-in versus inside-out reconstruction techniques.

This study compared the clinical outcome of anterior cruciate ligament (ACL) reconstruction between the inside-out and the outside-in techniques and assessed radiographically whether surgical technique affects the position and direction of the bone tunnels. A patellar tendon ACL reconstruction was performed in 141 patients with inside-out (group I, n = 78) and outside-in technique (group II, n = 63). Clinical results were evaluated using the International Knee Documentation Committee (IKDC) form; radiographic study was performed in anteroposterior, lateral, and notch views. Overall results in group I were normal in 23% of cases, nearly normal in 55%, and abnormal in 22%; in group II there were normal results in 19% of cases, nearly normal in 57%, abnormal in 19%, and severely abnormal in 5%. Radiographic examination identified important differences between the two groups. The main differences between the two surgical techniques were related to the positioning of the femoral tunnel. With the inside-out technique the femoral tunnel was significantly more vertical, both in the frontal and the sagittal planes. Moreover, the femoral tunnel was higher when drilled from the inside, but the difference between the two techniques was not statistically significant. The differences found between the two techniques regarding the tibial tunnel were not significant, although in the inside-out group the tibial tunnel seemed slightly more lateral, vertical, and posterior. Moreover, we observed a greater risk of bone-screw divergence on the femur in the inside-out group. This divergence was greatest in the sagittal plane. However, we observed no effect of this bone-screw divergence on the stability of the knee at follow-up.

Adolescent↗

The relationship of epidermal growth factor receptor levels to the prognosis of unresectable pharyngeal cancer patients treated by chemo-radiotherapy.

The aim of this study was to analyse prognostic factors for time to treatment failure (TTF) and overall survival (OS) in patients with unresectable cancer of the pharynx. A twice daily (b.i.d.) radiotherapy with concomitant cisplatin-5-fluorouracil chemotherapy was administered to 77 consecutive patients (68 males, 9 females; median age: 56 years). The studied factors were: age, gender, tumour differentiation, tumour volume, initial hemoglobin level, karnofsky index (KI), primary tumour location, T, N, epidermal growth factor receptor (EGFR) level in the tumour (fmol/mg protein). KI and EGFR level were significant predictors in a multivariate analysis for TTF (P=0.004 and P=0.0001) and OS (P=0.004 and P=0.0001). In order to select subgroups with different outcomes, a stratification of patients was performed based on the EGFR value: patients with tumour EGFR levels <35 fmol/mg protein, between 35 and 275 fmol/mg protein and >275 fmol/mg protein had 95%, 51% and 16% 3 year OS rates, respectively (log rank test; P=0.0001). Interestingly, for patients exhibiting a complete response (CR) after concomitant b.i.d. chemo-radiotherapy, patients with EGFR levels <35 fmol/mg protein were all alive at 3 years; in contrast, there was only 70 and 13% 3 year survival rates for patients with EGFR tumour levels between 35 and 275 fmol/mg protein and above 275 fmol/mg protein, respectively. EGFR determination appears to be a powerful prognostic parameter in unresectable pharyngeal cancer patients treated by concomitant chemo-radiotherapy.

Adult↗

[Concomitant bifractionated radiotherapy and chemotherapy with cisplatin and 5-fluorouracil in locally progressive, non-resectable epidermoid carcinomas of the pharynx: ten years experience at the Antoine Lacassagne center].

PURPOSE: Patients suffering from locally advanced unresectable squamous cell carcinoma of the oropharynx and hypopharynx treated with radiotherapy alone have a poor prognosis. More than 70% of patients die within 5 years mainly due to local recurrences. The aim of this study was to evaluate retrospectively the Antoine Lacassagne Cancer Center's experience in a treatment by concomitant bid radiotherapy and chemotherapy. Evaluation was based on analysis of the toxicity, the response rates, the survival, and the clinical prognostic factors. PATIENTS AND METHODS: From 1992 to 2000, 92 consecutive patients were treated in our single institution. All of them had stage IV, unresectable squamous cell carcinoma of the pharynx and they received continuous bid radiotherapy (two daily fractions of 1.2 Gy, 5 days a week, with a 6-h minimal interval between fractions). Total radiotherapy dose was 80.4 Gy on the oropharynx and 75.6 Gy on the hypopharynx. Two or three chemotherapy courses of cisplatin (CP)-5-fluorouracil (5FU) were given during radiotherapy at 21-day intervals (third not delivered after the end of the radiotherapy). CP dose was 100 mg/m2 (day 1) and 5-FU was given as 5-day continuous infusion (750 mg/m2/day at 1st course; 430 mg/m2/day at 2nd and 3rd courses). Special attention was paid to supportive care, particularly in terms of enteral nutrition and mucositis prevention by low-level laser energy. RESULTS: Acute toxicity was marked and included WHO grade III/IV mucositis (89%, 16% of them being grade IV), WHO grade III dermatitis (72%) and grade III/IV neutropenia (61%). This toxicity was significant but manageable with optimised supportive care, and never led to interruption of treatment for more than 1 week, although there were two toxic deaths. Complete global response rate at 6 months was 74%. Overall global survival at 1 and 2 years was 72% and 50% respectively, with a median follow-up of 17 months. Prognostic factors for overall survival were the Karnofsky index (71% survival at 3 years for patients with a Karnofsky index of 90-100% versus 30% for patients with a Karnofsky index of 80% versus 0% for patients with a Karnofsky index of 60-70%, p = 0.0001) and tumor location (55% at 3 years for oropharynx versus 37% for panpharynx versus 28% for hypopharynx, p = 0.009). CONCLUSION: These results confirm the efficacy of concomitant bid radiotherapy and chemotherapy in advanced unresectable tumor of the pharynx. The improvement in results will essentially depend on our capacity to restore in a good nutritional status the patients before beginning this heavy treatment.

Adult↗

Epidermal growth factor receptor expression in 780 breast cancer patients: a reappraisal of the prognostic value based on an eight-year median follow-up.

PURPOSE: Because new therapeutic approaches target tumors expressing epidermal growth factor receptor (EGFR), the aim was to undertake a thorough analysis of the expression profile of EGFR in breast cancer and to reassess its prognostic value. PATIENTS AND METHODS: Tumor EGFR levels were determined by a specific ligand binding assay in 780 consecutive breast cancer patients followed in our institute between 1980 and 1993. Mean age was 61 years (25-85 years). All patients had undergone tumor resection with axillary lymph node dissection: 373 patients (47.8%) underwent mastectomy, 37 (5%) subcutaneous mastectomy and 370 (47.2%) tumorectomy. RESULTS: EGFR levels ranged between non-detectable up to 789 fmol/mg protein. EGFR median value was 9 fmol/mg protein and only a small proportion of patients exhibited a relatively marked EGFR expression. There was no link between tumor size, grade, node status and EGFR tumoral levels. There was a constant and significant decrease in EGFR tumoral levels according to patient age. A significant inverse relationship was found between estradiol receptors (ER) and EGFR. Median follow-up was 97 months with a minimum at 4 months and a maximum at 228 months. From univariate analysis it was found that histological grade, tumor size, node status and ER status were all significant predictors of survival, considering metastasis-free as well as overall survival. Using multivariable analysis, only histological grade, tumor size and node status remained independent predictors of survival. CONCLUSION: EGFR determination is of limited value as a prognostic indicator in breast cancer.

Adult↗

Tolerance of isolated rat hearts to low-flow ischemia and hypoxia of increasing duration: protective role of down-regulation and ATP during ischemia.

We tested the hypothesis that down-regulated hearts, as observed during low-flow ischemia, adapt better to low O2 supply than non-down-regulated, or hypoxic, hearts. To address the link between down-regulation and endogenous ischemic protection, we compared myocardial tolerance to ischemia and hypoxia of increasing duration. To that end, we exposed buffer-perfused rat hearts to either low-flow ischemia or hypoxia (same O2 shortage) for 20, 40 or 60 min (n = 8/group), followed by reperfusion or reoxygenation (20 min, full O2 supply). At the end of the O2 shortage, the rate-pressure product was less in ischemic than hypoxic hearts (p < 0.0001). The recovery of the rate-pressure product after reperfusion or reoxygenation was not different for t = 20 min, but was better in ischemic than hypoxic hearts for t = 40 and 60 min (p < 0.02 and p < 0.0002, respectively). The end-diastolic pressure remained unchanged during low-flow ischemia (0.024 +/- 0.013 mmHg x min(-1)), but increased significantly during hypoxia (0.334 +/- 0.079 mmHg x min(-1)). We conclude that, while the duration of hypoxia progressively impaired the rate-pressure product and the end-diastolic pressure, hearts were insensitive of the duration of low-flow ischemia, thereby providing evidence that myocardial down-regulation protects hearts from injury. Excessive ATP catabolism during ischemia in non-down-regulated hearts impaired myocardial recovery regardless of vascular, blood-related and neuro-hormonal factors. These observations support the view that protection is mediated by the maintenance of the ATP pool.

Adenosine Triphosphate↗