Eros Ferrazzi

Altered tissue electric properties in lung cancer patients as detected by bioelectric impedance vector analysis

Modifications of body composition are frequent in cancer patients. Bioelectric impedance analysis can specifically detect changes in tissue electric properties, which may be associated with outcome. We evaluated the distribution of the impedance vectors from 63 adult male patients with lung cancer, stages IIIB (33 patients) and IV (30 patients), in supportive therapy. Body weight change over the previous 6 m.o. was the same in both groups (stable/increased 36% and decreased in 62%). Patients were compared with 56 healthy subjects matched for gender, age, and body mass index (25 kg/m2). Impedance measurements (standard tetrapolar electrode placement on the hand and foot) were made with 50-kHz alternating currents. The resistance and reactance of the vector components were standardized by the height of the subjects and were plotted as resistance/reactance graphs. The impedance vector distribution was the same in patients with either stage IIIB or IV cancer. The mean vector position differed significantly between cancer patients and control subjects (Hotelling T2 test, P < 0.01) because of a reduced reactance component (i.e., a smaller phase angle) with preserved resistance component in both cancer groups. Patients with a phase angle smaller than 4.5 degrees had a significantly shorter, i.e., 18 m.o., survival. Body weight loss was not significantly associated with survival. In conclusion, impedance vectors from lung cancer patients were characterized by a reduced reactance component. The altered tissue electric properties were more predictive than weight loss of prognosis.

Predictors of survival and toxicity in patients on adjuvant therapy with 5-fluorouracil for colorectal cancer

The present study aimed at investigating whether the simultaneous evaluation of pharmacokinetic, pharmacogenetic and demographic factors could improve prediction on toxicity and survival in colorectal cancer patients treated with adjuvant 5-fluorouracil (5FU)/leucovorin therapy. One hundred and thirty consecutive, B2 and C Dukes stage colorectal cancer patients were prospectively enrolled. 5FU pharmacokinetics was evaluated at the first cycle. Thymidylate synthase (TYMS) 5′UTR and 3′UTR polymorphisms and methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms were assessed in peripheral leukocytes. Univariate and multivariate analyses were applied to evaluate which variables could predict chemotherapy-induced toxicity, disease-free survival (DFS) and overall survival (OS). Multivariate analysis showed that: (a) low 5FU clearance was an independent predictive factor for severe toxicity (OR=7.32; P<0.0001); (b) high-5FU clearance predicted poorer DFS (HR=1.96; P=0.041) and OS (HR=3.37; P=0.011); (c) advanced age was associated with shorter DFS (HR=3.34; P=0.0008) and OS (HR=2.66; P=0.024); (d) the C/C genotype of the MTHFR C677T polymorphism was protective against grade 3–4 toxicity (P=0.040); (e) none of the TYMS polymorphisms could explain 5FU toxicity or clinical outcome.

Bioimpedance vector pattern in cancer patients without disease versus locally advanced or disseminated disease

OBJECTIVE Bioelectrical impedance vector analysis allows non-invasive evaluation of soft tissue hydration and mass through pattern analysis of vector plots as height, normalized resistance, and reactance measurements. METHODS Whole-body impedance measurements were made with a single frequency (50 kHz) analyzer (BIA-101, Akern/RJL Systems) in 148 adult, white, male subjects 45 to 85 y old: 56 healthy control subjects, 31 cancer patients after surgical procedure (without disease), and 61 patients with locally advanced (30 patients) or disseminated (31 patients) disease with the same body mass index and age. All patients were free from antineoplastic treatment and active nutritional intervention. RESULTS Mean vectors of cancer groups without disease and locally advance disease versus the control group were characterized by a comparable normalized resistance component with a reduced reactance component (separate 95% confidence limits, P < 0.05), indicating a comparable ionic conduction (hydration) with loss of dielectric mass (cell membranes and tissue interfaces) of soft tissues. Overlapping 95% confidence limits of their mean vectors indicated comparable electrical tissue properties in less versus more advanced disease. CONCLUSION Monitoring vector displacement trajectory toward the reference target vector position may represent useful feedback in support therapy planning of individual patients.

Pharmacokinetics of intraperitoneal hyperthermic perfusion with mitoxantrone in ovarian cancer.

Purpose: Theoretical data and experimental assumptions indicate that intraperitoneal hyperthermic chemotherapy may play a role in the treatment of peritoneal carcinomatosis. The feasibility, tolerability and pharmacokinetics of intraperitoneal hyperthermic perfusion with mitoxantrone were studied in patients with pretreated ovarian cancer. Methods: After cytoreductive surgery, 11 patients underwent intraperitoneal hyperthermic perfusion with mitoxantrone. A heated (42–43 °C) solution of the drug (28 mg/m2) was recycled through a perfusion apparatus into the abdominal cavity for 90 min. Treatment was repeated every month for two to four cycles. In six patients blood and peritoneal perfusate samples were collected at 0.5, 1, 1.5, 2, 4, 8, 16 and 24 h after drug administration and mitoxantrone was assayed by an HPLC method. Results: Although treatment was generally well tolerated, all patients developed transient intestinal subocclusion. Maximal mitoxantrone plasma concentrations (Cmax), times to Cmax (Tpeak) and area under the curves (AUC) were highly variable between subjects (Cmax 14–337 ng/ml; Tpeak 0.5–8 h; AUC 222–4130 ng · ml−1 · h). The plasma to peritoneal fluid AUC ratio was significantly higher during the second (0.177) than during the first cycle (0.066), suggesting a cycle-dependent increase in systemic bioavailability. Furthermore, when comparing present data with those reported previously, hyperthermic perfusion may have lowered the mitoxantrone levels in the peritoneal fluid without greatly influencing plasma levels. Conclusions: Intraperitoneal mitoxantrone administered under hyperthermia to advanced ovarian cancer patients is feasible and well tolerated. Mitoxantrone pharmacokinetics may be altered by repeated intraperitoneal administration (increased bioavailability) and by hyperthermic perfusion (possibly, increased peritoneal tissue uptake).

A novel G/C single-nucleotide polymorphism in the double 28-bp repeat thymidylate synthase allele.

Thymidylate synthase (TYMS) is the main molecular target for fluoropyrimidine anticancer drugs, and its expression has been correlated with the number of repeats of a 28-bp sequence in the 5′-untranslated region of the TYMS gene and with the presence of a G → C single-nucleotide polymorphism in the second repeat of 3R alleles. Based on this double polymorphism, three main TYMS alleles have so far been identified: TYMS 2R, TYMS 3RC and TYMS 3RG. During genetic analysis of TYMS polymorphisms in 100 colorectal cancer patients, three patients revealed an unexpected 113-bp band after electrophoresis of the restriction fragment length polymorphism analysis. Subsequent sequencing revealed two 28-bp repeats in the 5′-untranslated region and the presence in both repeats of cytosine instead of guanine at the 12th nucleotide. This allele variant (TYMS 2RC) has not been previously described in man. All three patients were heterozygotes for TYMS 2RC and experienced grade 2–3 chemotherapy-related toxicity.

New Limited Sampling Strategy for Determining 5-fluorouracil Area Under the Concentration-time Curve After Rapid Intravenous Bolus

All limited sampling models so far proposed to determine the area under the concentration-time curve (AUC) of anticancer drugs can be applied only to the dosing/sampling schedule used to obtain the model. The authors have developed a new method to predict the AUC of 5-fluorouracil (5-FU) after rapid intravenous bolus administration of various doses, using as few as two plasma drug concentrations. The 5-FU AUC (AUCtrue) was first determined in 20 patients receiving adjuvant therapy for colorectal cancer, based on nine plasma drug concentrations obtained at 0, 2.5, 5, 10, 15, 20, 30, 45, and 60 minutes after drug administration. Ten patients received 375 mg/m2 5F-U + 100 mg/m2 leucovorin and 10 received 425 mg/m2 5-FU + 20 mg/m2 leucovorin. The kinetics of 5-FU was described by either a one- or two-compartment linear model, as needed. The AUC was then recalculated (AUCapprox) using a reduced number of plasma concentrations and a simple one-compartment model. The time combinations tested were 2.5, 5, 10, and 20; 2.5, 10, and 20; 5, 10, and 20; 5 and 20; and 2.5 and 20 minutes. The accuracy and precision of the method in predicting the AUCtrue were measured by calculating the mean prediction error (MPE%) and the mean absolute error (MAE%) of the AUCapprox. MPE% ranged between −0.8% and −8.3% and MAE% between 6.1% and 9.5%, depending on the time combination used. In general, all limited sampling models tested tended to underestimate the AUCtrue slightly, particularly when 5-FU kinetics followed a two-compartment model, but bias was still within acceptable limits. The best results were obtained with plasma concentrations measured at 2.5 and 20 minutes after drug bolus (MPE%, −0.8%; MAE%, 6.1%). Although 5-FU kinetics was dose-dependent, MPE% and MAE% were not significantly different between the two groups. These data show that 5-FU AUC can be reliably predicted by using just two plasma concentrations and a one-compartment model, even when different doses are used and plasma concentration decay is biexponential.

Phase I–II intraperitoneal mitoxantrone in advanced pretreated ovarian cancer

36 previously treated patients (25 with anthracyclines) with advanced epithelial ovarian cancer have been treated with intraperitoneal (i.p.) mitoxantrone (M) at increasing doses. The response was evaluated through repeated laparoscopy with multiple biopsies and serial measurement of Ovarian Cancer Antigen 125 (CA 125); 11/36 patients had a complete (6 patients) or partial (5 patients) response. Toxicity (both local and general) was observed starting from 25 mg/m2 of M per cycle. The amount of drug reaching systemic circulation was monitored by measuring M plasma value after i.p. treatment. This study showed wide variations in serum levels obtained after i.p. doses ranging from 23 to 36 mg/m2. The area under the curve (AUC) of mitoxantrone plasma samples, did not correlate with the i.p. administered dose. Conversely, a correlation seems to exist between the plasma AUC and the responder status. Patients who showed clinical responses to i.p. treatment with mitoxantrone had AUCs and plasma peak levels of the drug that were significantly higher than those in non-responders (P = 0.03, Fishers exact test).

Quantitative analysis of ribonucleoside triphosphates in human lymphoid cells by micellar electrokinetic capillary chromatography

Micellar electrokinetic capillary chromatography (MECC) was applied to develop an analytical method for quantitation of ribonucleoside triphosphates (rNTPs) in human lymphoid cells obtained from patients with B-chronic lymphocytic leukaemia (B-CLL) and cutaneous lymphomas. The results of this analysis showed a significant depression of intracellular rNTPs in patients with B-CLL, compared with rNTPs of healthy controls. These data are in agreement with other studies in which rNTP separations were performed with traditional high-performance liquid chromatography. MECC has proved to be a useful tool for intracellular rNTPs determination, revealing possible new applications in the study of the metabolic state of human cells. In addition, this method can be useful in monitoring the effect of many drugs (antiviral, antineoplastic) which interfere with nucleotide metabolism.

Classification of thymidylate synthase gene enhancer region polymorphisms

Dear Sir, Gusella et al. and Lincz et al. have recently identified a new single nucleotide polymorphism in the enhancer region of the 2R allele of the thymidylate synthase gene (TYMS), consisting in a G>C base change at the 12th nucleotide of the first 28-bp repeat. This finding enlarges the number of possible TYMS allelic variants and calls for a revision of the present classification. Lincz et al. designated the new allele 2RCC to indicate the SNPs present in the first and second repeats of the 2R allele and in order to maintain consistency, they adopted this notation for the 3R alleles as well, so that the alleles formerly quoted in most literature as 3RG and 3RC became 3RGGC and RGCC, respectively. Since the latter structurebased nomenclature seemed to the authors themselves somewhat cumbersome and at risk of becoming more complex if similar SNPs would be identified in all TYMS alleles, at present consisting of 1–9 repeats, they proposed a new, simplified functional classification system, integrating the variable number of tandem repeat (VNTR) polymorphism with the new acquisitions regarding the allied G>C polymorphism, and based on the number of the E-box consensus elements for the upstream stimulatory factor-1 (USF-1). In fact, it was demonstrated that the G>C change abolishes the ability of the USF-1 to bind the E-box and to increase the TYMS transcriptional activity. Considering the allelic variants identified so far, the new functional notation ranges from 0 for a homozygous 2RCC to a maximum of 4 for a homozygous 3RGGC individual. However, the authors suggest that if a C>G SNP will be identified in the first repeat of the 3R allele, then the possibility of 6 putative functional repeats would exist (i.e., 3RGGG/ 3RGGG) and could be easily accommodated by this system.