Maria Rita Lusso

Serum levels of leptin and proinflammatory cytokines in patients with advanced-stage cancer at different sites

Leptin is a recently identified hormone produced by the adipocyte ob gene which acts as a negative feedback signal critical to the normal control of food intake and body weight. A number of proinflammatory cytokines, such as interleukin (IL) 1α, IL-6, tumor necrosis factor (TNF) α and interferon (IFN) γ, have been proposed as mediators of cancer cachexia. These data suggest that abnormalities in leptin production/release or in its feedback mechanism play a role in cancer patients. To elucidate this we studied the relationship between total serum leptin and serum cytokines IL-1α, IL-6, TNFα as well as the production of leptin and cytokines by peripheral blood mononuclear cells (PBMC) isolated from cancer patients. Sixteen advanced cancer patients (mainly stage IV) with tumors at different sites were included in the study. The serum levels of leptin in cancer patients were significantly lower than those of healthy individuals at all times (7 a.m., noon, 3 p.m.). No significant differences were found in circadian rhythm between patients and controls. Serum levels of IL-1α, IL-6, and TNFα were significantly higher in cancer patients than in healthy individuals. An inverse correlation between serum levels of leptin and IL-6 was found in cancer patients. The production in culture of leptin by unstimulated PBMCs and those stimulated by phytohemagglutinin M or by phorbol myristate acetate isolated from cancer patients was very low; no differences were observed in comparison with leptin production by PBMCs from healthy individuals.

Quantitative evaluation of oxidative stress, chronic inflammatory indices and leptin in cancer patients: correlation with stage and performance status.

In advanced cancer patients, the oxidative stress could take place either at the onset of disease or as a function of disease progression. To test this hypothesis, the following parameters were investigated: the erythrocyte activity of the enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx), the serum activity of glutathione reductase (GR) and the serum total antioxidant status (TAS). The total antioxidant capacity of plasma LMWA was evaluated by the cyclic voltammetry methodology. We further determined the serum levels of proinflammatory cytokines (IL‐6 and TNFα), IL‐2, leptin and C‐reactive protein (CRP). All of these parameters have been correlated with the most important clinical indices of patients such as Stage of disease, ECOG PS and clinical response. Eighty‐two advanced stage cancer patients and 36 healthy individuals used as controls were included in the study. Our findings show that SOD activity was significantly higher in cancer patients than in controls and GPx activity was significantly lower in cancer patients than in controls. Serum values of IL‐6, TNFα and CRP were significantly higher in patients than in controls. Serum leptin values of cancer patients were significantly lower than controls. SOD activity increased significantly from Stage II/ECOG 0‐1 to Stage IV/ECOG 0–1, whereas it decreased significantly in Stage IV/ECOG 3. GPx activity decreased significantly in Stage IV/ECOG 2–3. An inverse correlation between ECOG PS and serum leptin levels was found. Serum levels of IL‐2 decreased from Stage II/ECOG 0–1 to Stage IV/ECOG 2–3. A direct correlation between Stage/ECOG PS and serum levels of both IL‐6 and CRP was observed. Cisplatin administration induced a significant increase of GPx after 24 hr. In conclusion, this is the first study that shows that several “biological” parameters of cancer patients such as antioxidant enzyme activity, cytokines, leptin and CRP strictly correlate with the most important clinical parameters of disease such as Stage and ECOG PS.

A Phase II Study with Antioxidants, Both in the Diet and Supplemented, Pharmaconutritional Support, Progestagen, and Anti-Cyclooxygenase-2 Showing Efficacy and Safety in Patients with Cancer-Related Anorexia/Cachexia and Oxidative Stress

Purpose: To test the efficacy and safety of an integrated treatment based on a pharmaconutritional support, antioxidants, and drugs, all given orally, in a population of advanced cancer patients with cancer-related anorexia/cachexia and oxidative stress. Patients and Methods: An open early-phase II study was designed according to the Simon two-stage design. The integrated treatment consisted of diet with high polyphenols content (400 mg), antioxidant treatment (300 mg/d α-lipoic acid + 2.7 g/d carbocysteine lysine salt + 400 mg/d vitamin E + 30,000 IU/d vitamin A + 500 mg/d vitamin C), and pharmaconutritional support enriched with 2 cans per day (n-3)-PUFA (eicosapentaenoic acid and docosahexaenoic acid), 500 mg/d medroxyprogesterone acetate, and 200 mg/d selective cyclooxygenase-2 inhibitor celecoxib. The treatment duration was 4 months. The following variables were evaluated: (a) clinical (Eastern Cooperative Oncology Group performance status); (b) nutritional [lean body mass (LBM), appetite, and resting energy expenditure]; (c) laboratory [proinflammatory cytokines and leptin, reactive oxygen species (ROS) and antioxidant enzymes]; (d) quality of life (European Organization for Research and Treatment of Cancer QLQ-C30, Euro QL-5D, and MFSI-SF). Results: From July 2002 to January 2005, 44 patients were enrolled. Of these, 39 completed the treatment and were assessable. Body weight increased significantly from baseline as did LBM and appetite. There was an important decrease of proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-α, and a negative relationship worthy of note was only found between LBM and IL-6 changes. As for quality of life evaluation, there was a marked improvement in the European Organization for Research and Treatment of Cancer QLQ-C30, Euro QL-5DVAS, and multidimensional fatigue symptom inventory-short form scores. At the end of the study, 22 of the 39 patients were “responders” or “high responders.” The minimum required was 21; therefore, the treatment was effective and more importantly was shown to be safe. Conclusion: The efficacy and safety of the treatment have been shown by the study; therefore, a randomized phase III study is warranted. (Cancer Epidemiol Biomarkers Prev 2006;15(5):1030–4)

Antioxidant agents are effective in inducing lymphocyte progression through cell cycle in advanced cancer patients: assessment of the most important laboratory indexes of cachexia and oxidative stress

This study assessed in a wide population of advanced cancer patients the biological parameters relevant to cancer cachexia, such as serum levels of proinflammatory cytokines (IL-1β, IL-6, TNFα), IL-2, acute-phase proteins (C-reactive protein and fibrinogen), leptin, and relevant to oxidative stress (OS), such as ROS, body antioxidant enzymes GPx and SOD. We also studied the ability of effective antioxidant agents α-lipoic acid (ALA), N-acetyl cysteine (NAC), and amifostine (AMI) added into culture to induce lymphocyte progression through the cell cycle, namely to enter into S phase. Additionally, we assessed the most significant clinical indexes of nutritional status such as body mass index and disease progression such as stage and ECOG-PS in the same cancer patient population. Cell cycle analysis of cultured unstimulated or PHA-stimulated PBMCs isolated from 120 cancer patients and 60 controls, with or without ALA, NAC, or AMI, was studied. The biological parameters relevant to cancer cachexia and OS were also studied. The addition of antioxidants ALA, NAC and AMI, enhanced significantly the progression through the cell cycle, namely from G0/G1 to S phase, of PBMCs isolated from cancer patients (+132%, +150% and +141%, respectively). The percentage of PHA-stimulated PBMCs of cancer patients entering S phase, which was significantly lower than that of controls, increased significantly to more than physiological level after coculture with antioxidants. ROS levels were significantly higher and GPx and SOD activities significantly lower in cancer patients than controls. Serum levels of IL-1 β, IL-6, and TNFα were significantly higher and serum levels of IL-2 and leptin significantly lower in cancer patients than controls. Serum levels of C-reactive protein and fibrinogen were significantly higher in cancer patients than controls. A significant correlation was found in laboratory parameters only between serum levels of leptin and body mass index. Patients with advanced cancer thus exhibit both a high-grade OS and a chronic inflammatory condition. Antioxidant agents ALA, NAC, and AMI enhanced significantly the PBMCs progression through the cell cycle, thus providing evidence of their potential role in the functional restoration of the immune system in advanced cancer patients. Our data warrant further investigation with adequate clinical trials.

Reactive oxygen species, antioxidant mechanisms and serum cytokine levels in cancer patients: impact of an antioxidant treatment

Objective. So far, it is not well established whether oxidative stress found in cancer patients results from an increased production of oxidants in the body or from a failure of physiological antioxidant systems. To further investigate this question we have assessed the blood levels of reactive oxygen species as a marker of free radicals producing oxidative stress and the most relevant of the physiological body enzymes counteracting reactive oxygen species, namely glutathione peroxidase and superoxide dismutase. Serum levels of proinflammatory cytokines and IL‐2 were also investigated. All these parameters were studied in relation to the clinically most important index of disease progression, namely Performance Status (ECOG PS). We also tested the reducing ability of different antioxidant agents on reactive oxygen species levels by measuring the increase in glutathione peroxidase activity, and the reduction of serum levels of IL‐6 and TNF. Design, setting and subjects. We carried out an open non randomized study on 28 advanced stage cancer patients (stage III, 10.7%, and stage IV, 89.3%) with tumours at different (8) sites: all were hospitalized in the Medical Oncology Dept, University of Cagliari Interventions. The patients were divided into 5 groups and a different antioxidant treatment was administered to each group. The selected antioxidants were: alpha lipoic acid 200 mg/day orally, N‐acetylcysteine 1800 mg/day i.v. or carboxycysteine‐lysine salt 2.7 g/day orally, amifostine 375 mg/day i.v., reduced glutathione 600 mg/day i.v., vitamin A 30000 IU/day orally plus vitamin E 70 mg/day orally plus Vitamin C 500 mg/day orally. The antioxidant treatment was administered for 10 consecutive days. Results. Our results show that all but one of the antioxidants tested were effective in reducing reactive oxygen species levels and 2 of them (cysteine‐containing compounds and amifostine) had the additional effect of increasing glutathione peroxidase activity. Comprehensively, the “antioxidant treatment” was found to have an effect both on reactive oxygen species levels and glutathione peroxidase activity. The antioxidant treatment also reduced serum levels of IL‐6 and TNF. Patients in both ECOG PS 0‐1 and ECOG PS 2‐3 responded to antioxidant treatment.

Serum values of proinflammatory cytokines are inversely correlated with serum leptin levels in patients with advanced stage cancer at different sites

Leptin is a recently identified hormone produced by the adipocyte ob gene which acts as a negative feedback signal critical to the normal control of food intake and body weight. A number of proinflammatory cytokines, such as interleukin 6, tumor necrosis factor α, and interferon γ, have been proposed as mediators of cancer cachexia; these data suggest that abnormalities in leptin production/release or in its feedback mechanism play a role in cancer patients. We therefore studied the relationship between serum leptin and serum cytokines interleukin 6 and tumor necrosis factor α levels in advanced-stage cancer patients. Twenty-nine advanced stage cancer patients (all but one stage IV) with tumors at various sites were included in the study. A direct correlation between body mass index and serum leptin levels was found both in cancer patients and in healthy individuals. The serum levels of interleukin 6 were significantly higher in cancer patients than in healthy individuals. In cancer patients an inverse correlation was found between serum levels of leptin and proinflammatory cytokines. There was an inverse correlation between the Eastern Cooperative Oncology Group performance status scale and serum levels of leptin. Regarding survival, patients with very high serum levels of proinflammatory cytokines and very low levels of leptin had very short survival. Although obtained in a cancer patient population not overtly cachectic, our results provide further evidence that a simple dysregulation of leptin production and/or release cannot be involved in cancer-associated pathophysiological changes leading to cachexia.