Cancer Cachexia Syndrome Research Articles

Pancreatic cancer as a model: inflammatory mediators, acute-phase response, and cancer cachexia.

Patients with pancreatic cancer frequently develop the syndrome of cancer cachexia. Pro-inflammatory cytokines have been strongly implicated in the pathogenesis of this syndrome. In patients with pancreatic cancer an acute-phase response (an index of pro-inflammatory cytokine activity) is associated with accelerated weight loss, hypermetabolism, anorexia, and a shortened duration of survival. However, little is known about the primary significance of the acute-phase response in terms of altered hepatic export protein synthesis rates and its potential impact on the body's nitrogen economy. In a recent series of studies on weight-losing pancreatic cancer patients with hypoalbuminemia we have demonstrated albumin synthesis to be unaltered whereas fibrinogen synthesis is increased two- to threefold compared with healthy controls. Because of the mismatch in amino acid composition between the body's main labile amino acid reserve (skeletal muscle) and that of acute-phase proteins, these results lend support to the concept that in pancreatic cancer the reprioritization of body protein metabolism during an acute-phase response may well be a significant factor in the loss of lean tissue in these patients.

Tumor growth and food intake in interleukin-6 gene knock-out mice

Interleukin (IL)-6 has potential antitumor activity and at the same time is responsible for tumor-derived cachexia. Using IL-6 gene knock-out (GKO) mice, we investigated the effect of IL-6 deficiency on the survival time, tumor growth and daily food intake of mice inoculated with Ehrlich ascites carcinoma. IL-6 GKO mice gained weight due to tumor growth more rapidly than the wild-type mice. The daily food intake of wild-type mice declined on day 2 after tumor inoculation and was only 37% on day 8. In contrast, the daily food intake of IL-6 GKO mice was constant for the first 7 days after tumor inoculation. Although wild-type mice suffered from cachexia, their survival time was significantly longer than that of IL-6 GKO mice. We propose that both IL-6 secretion and cancer cachexia syndrome may be involved in the defense mechanism against tumor progression.

Carnitine palmitoyltransferase II activity is decreased in liver mitochondria of cachectic rats bearing the Walker 256 carcinosarcoma: effect of indomethacin treatment.

The syndrome of cancer cachexia is accompanied by several alterations of lipid metabolism, especially that in the liver. In this study we have investigated a possible mechanism whereby the presence of the Walker 256 carcinosarcoma affects hepatic fatty acid oxidative capacity in tumour-bearing rats. Hepatic mitochondrial outer membrane carnitine palmitoyltransferase I (CPT I), generally accepted as the main site of regulation of fatty acid oxidation, was unaffected by the presence of the extra-hepatic tumour. However, mitochondrial inner-membrane carnitine palmitoyltransferase II (CPT II) activity was markedly decreased in mitochondria isolated from the liver of tumour-bearing rats. Immuno-detection by Western blotting using a CPT II-specific antibody identified two bands (corresponding to M(r) 69,000 and 54,000) in tumour-bearing rats whereas only the normal-sized CPT II was present (at the expected M(r) 69,000) in mitochondria from control rats. It is suggested that the emergence of the second, smaller protein may represent a catalytically less active protein that arises in vivo, since its appearance was not affected by the inclusion of proteolysis inhibitors in the mitochondrial preparation buffers. Treatment of the tumour-bearing rats with indomethacin, a prostaglandin (including PGE2) synthesis inhibitor, increased CPT II activity to levels even higher than those found in the control animals. It is suggested that PGE2 may play a role in the control of CPT II expression in the liver of tumour-bearing rats. Indomethacin treatment did not affect either of the two CPT activities of the mitochondria isolated from tumour tissue.

Toxohormones responsible for cancer cachexia syndrome in nude mice bearing human cancer cell lines.

Toxohormones are tumor-derived factors that induce cancer cachexia syndrome in tumor-bearing animals. Nude mice bearing tumors induced by eight human cancer cell lines with this activity were studied for cytokine production and expression of a newly identified gene, ob, which has the ability to control body weight. A melanoma cell line, SEKI, and a neuroepithelioma cell line, NAGAI, produced a large amount of the cytokine, leukemia-inhibitory factor (LIF). A uterine carcinoma cell line, Yumoto, produced a large amount of interleukin 6 (IL-6), and an oral cavity carcinoma cell line, OCC-1C, concomitantly produced LIF, IL-6, and IL-11. Reverse transcription polymerase chain reaction studies revealed that ob gene mRNA was not expressed in any of these cell lines, suggesting that the gene does not have a role as a tumor product responsible for cancer cachexia in this model. These findings suggest that in four of eight animal models in which cancer cachexia syndrome developed, LIF, IL-6, or possibly IL-11 produced by cancer cells may be toxohormones, but in the remaining four cancer cell lines the mechanism responsible for cachexia syndrome remains unknown.

CACHEXIA AND ANOREXIA IN MALIGNANCY

The cancer cachexia syndrome may be present in up to 80% of patients with cancer. Malnutrition resulting from cancer cachexia is a significant cause of morbidity and mortality. Anorexia, tissue wasting, and weight loss appear to be the result of metabolic abnormalities caused by host cytokine production in response to the tumor. The host cytokines include TNF-alpha, IL-1, IL-6, IFN-gamma, and D-factor. Nutritional support in the patient with cancer has been controversial, with the belief that tumor growth may be augmented; however, human studies fail to confirm that tumor growth occurs in excess of normal tissue growth. The efficacy of nutritional support in the cancer has not been adequately studied. Considerable interest exists in providing nutritional support pharmacologically to modify the response to malignancy.

Hormonal treatment in advanced non-small cell lung cancer: fact or fiction?

In patients with advanced non-small cell lung cancer, cachexia is an important cause of morbidity and mortality. The pathogenic mechanism of this finding, usually referred to as "cancer anorexia and cachexia syndrome" (CACS), is complex and far from completely understood, but a disturbed equilibrium between possible food intake and metabolic needs seems to be fundamental. The literature data on the treatment options in advanced non-small cell lung cancer (NSCLC) with cachexia are reviewed. Based on the clinical studies on cancer cachexia, some recommendations for the therapeutic approach of this disorder in patients with advanced NSCLC can be given. Metoclopramide is easily administered, can alleviate gastric disturbances, but probably does not correct the catabolic spiral of CACS. There are not enough data to advise the use of parenteral nutritional support, hydrazine, cyproheptadine, tetrahydrocannabinol or nandrolone decanoate. Corticosteroids are useful in additional analgesia and fast palliation of very weak and debilitated patients in the final episode of their disease. Recent data in non-small cell lung cancer patients are in favour of the use of high-dose progestagens to improve both appetite and weight.

Cytokine production in five tumor cell lines with activity to induce cancer cachexia syndrome in nude mice.

To identify the so‐called toxohormone, which is a tumor‐derived factor with activity to induce cancer cachexla syndrome in tumor‐bearing animals, 5 human cancer cell lines with this activity were studied for cytokine production. Tumor cell products with activity to inhibit lipoprotein lipase (LPL) were shown to play an important role in the development of the cancer cachexia syndrome. All culture media conditioned by the 5 cell lines possessed LPL‐inhibitory activity. However, the activity differed with the cell line. In order to characterize the activity, we examined whether the cultured cells produced cytokines with activity to inhibit LPL. A melanoma cell line, SEKI, and a neuroepithelioma cell line, NAGAI, were found to express a large amount of leukemia inhibitory factor (LIF) mRNA. Furthermore, both of these cell lines were demonstrated to produce a large amount of LIF protein, and plasma levels of LIF were extremely elevated in SEKI‐ and NAGAI‐bearing nude mice, indicating that LIF produced by the tumor cells induced cancer cachexia syndrome in the animals. Thus, LIF fulfills the requirements for a toxohormone, except for suppressive activity on liver catalase. In contrast, the mechanisms responsible for cachexia in the MKN‐1‐, LX‐1‐ and LS180‐bearing mice remain unknown. These findings suggest that various types of bioactive substances produced by cancer cells could be toxohormones.

ANOREXIA IN PATIENTS WITH CANCER WITH SPECIAL REFERENCES ON ITS ASSOCIATION WITH EARLY CHANGES IN FOOD-INTAKE BEHAVIOR CHEMOTHERAPEUTIC TREATMENT AND ADJUVANT ENTERAL NUTRITION (REVIEW)

Anorexia defined as decreased appetite resulting in fatigue, change of body image and weight loss is stated to be fundamental to the syndrome of cancer cachexia. Weight loss is the most apparent symptom of anorexia and cachexia, and occurs quite frequently in patients with cancer. Interest in the pathogenetic mechanisms, is due to the strong association between weight loss and lower duality and quantity of life. This review discusses anorexia in the pathogenesis of cancer cachexia, particularly the effect of taste alterations and chemotherapy; and the long-term acceptability and effect of oral nutritional support and drug therapy.

Leukemia inhibitory factor induces changes in lipid metabolism in cultured adipocytes.

Cytokines induce a number of changes in lipid metabolism that can produce hyperlipidemia. Leukemia inhibitory factor (LIF), a recently discovered cytokine, has been suggested to play a role in the cancer cachexia syndrome through its ability to decrease lipoprotein lipase (LPL) activity. This study explores the mechanism by which LIP decreases LPL activity in cultured adipocytes and determines its effects on fatty acid synthesis and lipolysis to see if it shares the same catabolic effects on fat cells as seen with other cytokines, such as tumor necrosis factor (TNF). LIF decreased LPL activity in cultured adipocytes by 44% compared with an 85% decrease produced by TNF. Although the percent decrease in LPL activity is not as great in LIF-incubated adipocytes as in TNF-incubated adipocytes, the half-maximal doses for both cytokines are similar. LPL messenger RNA levels paralleled LPL activity in the LIF-treated adipocytes, suggesting that the effect of LIF on LPL activity is predominantly mediated through transcriptional regulation. In contrast to TNF, LIF tended to increase the de novo synthesis of fatty acids. Acetyl coenzyme-A carboxylase messenger RNA levels paralleled the changes seen in fatty acid synthesis for both cytokines. LIF caused a small increase in lipolysis, whereas TNF increased lipolysis by greater than 2-fold. These results demonstrate that the catabolic effects of LIF are weaker than those of TNF and are predominantly directed toward decreasing LPL activity, which may contribute to the hyperlipidemia associated with infection, inflammation, and cancer.

Pathophysiology of cancer cachexia.

Patients with advanced cancer and cachexia typically demonstrate modestly increased rates of energy expenditure in the presence of diminished food intake due to anorexia and to gastrointestinal disturbances. Rates of glucose production by the liver, gluconeogenesis and glycolysis to lactate (Cori cycle) are increased, fat mobilisation and oxidation are accelerated. There is a redistribution of body proteins away from muscle towards visceral proteins, resulting in marked muscle protein loss. Cancer cachexia differs from simple starvation and demonstrates metabolic similarities to sepsis or polytrauma. The metabolic response in the patient with cancer is largely due to mediators released by the tumour or by the host; recently the role of cytokines such as tumour necrosis factor alpha (TNF alpha), interleukin-1 (IL-1) and -6 (IL-6) and interferon gamma (INF gamma) has been emphasized. Catabolic hormones such as glucocorticoids and adrenaline have also been implicated. Cytokines have the potential to reproduce experimentally the clinical syndrome of cancer cachexia. There is evidence of increased production of several of them in certain types of cancer. There are overlapping activities of the cytokines TNF alpha, IL-1, IFN gamma and IL-6. The contribution of each of them to cancer cachexia remains unclear. Inhibition of cytokine activity using specific antibodies in cancer-bearing experimental animals demonstrated partial prevention of cachexia. A positive feedback between macrophage-derived IL-1 and tumour-derived IL-6 has been demonstrated recently in experimental cancer cachexia. Cytokines may support tumour growth by acting as growth factors.

Cancer cachexia.

Cancer cachexia describes a syndrome of progressive weight loss, anorexia, and persistent erosion of host body cell mass in response to a malignant growth. Although often associated with preterminal patients bearing disseminated disease, cachexia may be present in the early stages of tumor growth before any signs or symptoms of malignancy. A decline in food intake relative to energy expenditure (which may be increased, normal, or decreased) is the fundamental physiologic derangement leading to cancer-associated weight loss. In addition, abnormalities of host carbohydrate, protein, and fat metabolism lead to continued mobilization and ineffective repletion of host tissue, despite adequate nutritional support. Mediators of cancer anorexia and associated abnormalities are unknown. Cachectin/TNF or other host-derived cytokines (produced as a defense against malignancy) have been implicated as signal molecules in cachexia, based upon similar metabolic derangements produced by these cytokines in other chronic wasting illnesses. Nutritional support is effective in maintaining body weight of cachectic cancer patients, but ineffective in maintaining lean body mass. Although in one study parenteral nutritional support has improved operative morbidity and mortality in cancer patients, it has not yet improved response to chemotherapy or radiation therapy. Because of metabolic derangements seen in cancer cachexia, effective nutritional treatment regimens will probably require manipulation of host intermediary metabolism in addition to feeding. Insulin therapy or exercise are two such methods which appear to preserve host composition by preferential feeding of the host at the expense of the tumor. Future studies which more clearly define the role of signal molecules in producing cancer cachexia syndrome may lead to new treatment strategies, possibly involving modulation of the effects of such molecules on host metabolism.