Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0598934 (tumor growth)
 58,965 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cachexia is a common problem in the clinical management of cancer patients, particularly those with solid tumors. Cachexia is most obviously manifested as weight loss with massive depletion of both adipose tissue and muscle mass, and death is probably due to loss of lean body tissue. Not only is the survival time shorter in patients with cachexia, but the frequency of response to chemotherapy is also significantly reduced. Although anorexia frequently accompanies cachexia, attempts to halt or reverse cachexia by nutritional repletion have not been successful. This suggests that cachexia is due to metabolic abnormalities produced by the tumor in addition to the underlying anorexia. In some patients weight loss is associated with an increased relative energy expenditure possibly through an elevated adrenergic state. Several factors have been postulated as mediators of cancer cachexia and can be divided into two groups. (i) Materials with hormone-like characteristics which result in direct catabolism of host tissues. (ii) Cytokines which cause alterations in host metabolism indirectly. Included in group (i) are the conventional catabolic hormones and a lipid mobilizing factor (LMF) produced by tumors, which causes direct breakdown of adipose tissue. Included in group (ii) are tumor necrosis factor-alpha, interleukin-6, interferon-gamma and leukaemia inhibitory factor. The materials appear to influence adipose tissue indirectly through an inhibition of lipoprotein lipase. Reversal of cachexia has been achieved by two groups of agents. (i) Those stimulating food intake, e.g. megestrol acetate. (ii) Those directly inhibiting the LMF, e.g. eicosapentaenoic acid. While agents in group (i) can cause tumor growth stimulation, those in group (ii) act as tumor growth inhibitors. This latter results suggests that the products of catabolism of host tissues may be important for tumor growth and provides a new avenue for chemotherapeutic intervention.
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PMID:Cancer cachexia. 849 Jan 91

Tumors often cause declines in food intake and body weight, a condition referred to as tumor anorexia. A macrophage-derived peptide known as tumor necrosis factor (TNF) has been proposed as an important mediator of cancer anorexia and cachexia. Our work with an animal model of this condition indicates that strong learned aversions to the available diet arise in rats bearing implanted tumors and that these aversions contribute significantly to depressions in food intake and body weight. Lesions of the area postrema and nearby caudal medial nucleus of the solitary tract (APcmNTS) markedly attenuate both the learned aversions and the anorexia induced by tumor growth. A strikingly similar pattern of effects on tumor-induced aversions and anorexia was seen after subdiaphragmatic vagotomy and after capsaicin treatments. The similarity in the effects of all three treatments suggest that they involve interruption of the same system, presumably afferent signals conveyed by the vagus nerve to the nucleus of the solitary tract. The extent to which peripheral TNF administration generates symptoms similar to those produced by tumor growth was also examined. TNF administration was associated with the development of strong aversions to a novel but not a familiar diet. Area postrema lesions were found to significantly attenuate the effects of TNF on novel diet intake and preference. These observations provide parallels between the effects of TNF and the effects of tumor growth on diet aversions and food intake.
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PMID:Neutral mediation of food aversions and anorexia induced by tumor necrosis factor and tumors. 862 25

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.
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PMID:Cachexia and anorexia in malignancy. 881 1

During tumor growth, anorexia and reduced food intake markedly contribute to the development of malnutrition, thus worsening overall patients' survival. A better understanding of the pathophysiology of eating behavior may lead to new and more effective therapies, aiming at counteracting the detrimental effects of anorexia and reduced food intake on nutritional status and survival in cancer patients. Brain tryptophan and serotonin concentrations seem to play a pivotal role in the regulation of eating behavior. Increased brain serotonin activity is indeed associated with a reduction of food intake. It has been recently hypothesized that increased availability of tryptophan to the brain and the consequent increased serotonin activity may represent the pathogenic mechanism for cancer-associated anorexia. According to this hypothesis, the modulation of brain serotonin activity may result in an improvement of anorexia. Reducing brain tryptophan availability represents a possible mechanism to restore brain serotonin activity to normal. There is evidence that the oral administration of neutral amino acids competing with tryptophan for brain entry results in a significant improvement of cancer anorexia. The same treatment may also be effective in improving secondary anorexia, which is associated with other chronic illnesses, including renal and liver failure, sepsis, and so forth, sharing a similar pathogenic mechanism.
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PMID:Cancer anorexia: new pathogenic and therapeutic insights. 885 Feb 21

During tumor growth, anorexia and reduced food intake are among the major causes leading to malnutrition and eventually cachexia, which negatively affect patients' outcome. Consistent evidence from our laboratories in rats and humans indicates a key role for ventromedial hypothalamic (VMH) serotonergic system in the development of cancer anorexia. Thus, we postulated that during cancer, increased plasma tryptophan levels (the precursor of serotonin) lead to increased cerebrospinal fluid tryptophan concentrations and increased VMH serotonin synthesis, which then mediates the occurrence of anorexia. However, recent data strongly suggest that factors other than tryptophan supplied to the central nervous system might be involved in the pathogenesis of reduced food intake during tumor growth. Particularly, a significant role appears to be played by interleukin-1 (IL-1). We recently showed that IL-1 infusion in normal rats causes changes in food intake and its determinants, meal number and meal size, similar to those characterizing cancer anorexia, thus supporting the involvement of this cytokine in the development of anorexia. Interestingly, IL-1 and the VMH serotonergic system appear to be closely linked: peripherally infused IL-1 increases brain tryptophan and serotonin concentrations, while intracerebrally infused IL-1 increases neuronal firing rate and serotonin release. We therefore hypothesize that during tumor growth, increased production/secretion of IL-1 occurs, which facilitates the tryptophan supply to the brain. IL-1 can then also act on the VHM itself, where IL-1 receptors exist, to increase its neuronal activity and serotonin release. In other words, we believe that centrally acting IL-1 increases hypothalamic neuronal firing rate and serotonin release, while peripherally acting IL-1 is critical in supplying the hypothalamus with the precursor, tryptophan, in order to maintain the high rate of serotonin synthesis. Also, additional factors recently proposed as mediators of anorexia (including neuropeptide Y and nitric oxide) appear to be part of the hypothesized pathogenic mechanism.
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PMID:Cracking the riddle of cancer anorexia. 893 95

The child with a malignancy frequently will have associated cachexia with significant weight loss and malnutrition. The reasons for this are multifactorial and may be related directly to the tumor, such as increased metabolic rate, circulating peptides leading to anorexia, and decreased intake due to poor appetite or gut involvement. There appears to be other reasons involved, including increased whole body protein breakdown, increased lipolysis, and increased gluconeogenesis. Release of certain cytokines, such as tumor necrosis factor, interleukin-1, interleukin-6, and others may increase the cancer cachexia. Malnutrition in these children leads to intolerance of chemotherapy and radiotherapy as well as increased local and systemic infections. For many years, oncologists were hesitant to provide nutrition support to cancer patients for fear that tumor growth would be enhanced. Pediatric oncologists learned early that starvation plays no positive role in cancer therapy. Adjunctive nutritional support, either enterally or parenterally, supports the patient during therapy with surgery, chemotherapy, or radiation. Many studies have now shown that the nutritionally replete patient tolerates therapy better and in some pediatric malignancies may enhance survival.
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PMID:Nutritional support of the pediatric oncology patient. 943 98

Our previous experience has demonstrated that growth of gastric cancer during the waiting period for surgery cannot be neglected, and some patients hope to receive prophylactic treatment to inhibit the growth of tumor until surgery. The present study was designed to assess the clinical benefits of preoperative chemotherapy with oral UFT for gastric cancer during the waiting period for surgery. Fifty patients with gastric cancer (24 early, 25 advanced and 1 recurrent cancers) were treated with oral UFT at 300-600 mg/day for 7-36 days before surgery and the objective responses and the postsurgical survivals were evaluated. In 42 of 50 patients objective responses of primary lesions were assessed by endoscopy or upper gastrointestinal series examination, and 2 CRs, 15 PRs and 25 NCs were seen (40% response). The histological effect was evaluated in 50 patients and the following classifications were made: grade 3 (complete disappearance or necrosis of tumor cells), 2; grade 2 (necrotic changes > 2/3 area), 4; grade 1b (> 1/3 area), 7; grade 1a (< 1/3 area), 15; and grade 0 (no histological changes), 22. A longer period of UFT administration was associated with CR or PR. All the patients underwent gastrectomy (38 curative and 12 palliative gastrectomies): all patients with Stage I-III primary gastric cancer are alive after surgery, and the 50% survival period of the patients with Stage IV cancer was 20 months. The side effects were not serious, including slight myelotoxicity, liver dysfunction and anorexia. It is concluded that preoperative chemotherapy for gastric cancer with oral UFT on outpatient basis may result in down-staging as well as the prevention of tumor growth during the waiting period for surgery without serious side effects.
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PMID:Neoadjuvant chemotherapy of gastric cancer with oral UFT (a mixture of uracil and fturafur) during the waiting period for surgery. 956 72

Nutritional therapy for cancer patients includes various objectives such as improvement of cachexia, elucidation of the mechanism of malnutrition, development of therapy for anorexia, nutrition support during chemotherapy or radiotherapy, and inhibition of tumor growth under controlled caloric intake. This review describes recent remarkable developments in nutritional therapy for cancer patients. Cytokines such as interleukin (IL)-1, IL-6, and tumor necrosis factor which induce proteolysis and lipolysis are involved in the cause of malnutrition and cachexia in cancer patients. IL-1 also plays a significant role in the development of cancer anorexia via direct action in the brain. For anorexia therapy, progestogens have been shown to improve appetite and food intake in cancer patients. Moreover, glutamine supplementation improves the host protein metabolism without enhancement of tumor growth during chemotherapy. Among the effects of caloric intake on anticancer therapy, AO-90, a methionine-free intravenous amino acid solution, has been shown to increase the antitumor effect of 5-fluorouracil in clinical studies. From these observations, recent progress in nutritional therapy for cancer patients has been remarkable. Further study of nutritional therapy is required in order to maintain or improve the quality of life of cancer patients in the future.
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PMID:[Nutrition and cancer patients]. 961

Although reduced biological activity of the obese gene product, leptin, has been associated with obesity, little information is available concerning leptin alterations during anorexia. Therefore, we measured circulating leptin concentrations and hypothalamic leptin binding in anorectic tumor-bearing and pair-fed control rats. Plasma concentrations of leptin decreased in tumor-bearing rats early in the course of tumor growth, and fell to nearly non-detectable levels during severe anorexia. The pair-fed control rats that ate the same amount of food as did the anorectic tumor-bearing rats exhibited a 50% decrease in plasma leptin concentration. Concentrations of free fatty acids were elevated in both tumor-bearing and pair-fed groups, while circulating levels of triglycerides were increased only in anorectic tumor-bearing rats. Leptin receptor density was doubled in the hypothalamus of tumor bearing rats, while binding affinity was decreased by 50%. These results suggest that peripheral leptin production is down-regulated, perhaps due to increased lipolysis in tumor-bearing rats. It appears that hypothalamic leptin systems up-regulate receptor numbers in response to decreased blood leptin level, however, the decrease in binding affinity may compensate for these alterations. Therefore, the influence of leptin on hypothalamic neuropeptide Y feeding systems may be minimal in anorectic tumor-bearing rats.
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PMID:Reciprocal changes in hypothalamic receptor binding and circulating leptin in anorectic tumor-bearing rats. 972 52

Most cancers in children are acute diseases. Therefore, the incidence of malnutrition, in general, is not different from the incidence in the referral population. Some specific tumors, such as neuroblastoma and those resulting in the diencephalic syndrome, can be exceptions. By contrast, malnutrition is a frequent problem during modern intensive cancer treatment as the result of the associated anorexia, altered taste sensations and catabolic effects of drugs. In addition, there are psychogenic factors and metabolic consequences associated with the tumor itself. Nutritional support does improve the feeling of well-being and performance status, while maintaining or improving the immune competence, thereby potentially affecting survival by limiting infectious episodes. There is no convincing evidence to date that nutritional support has an antineoplastic effect per se, but deficiency of a specific nutrient might be beneficial because of a differential requirement between tumor and normal cells. Theoretically, nutritional support might enhance tumor growth but also susceptibility to chemotherapy. In either case, nutrition is a support modality that must be given with appropriate tumor-directed therapy if curative intent is the goal of treatment. Nutrition remains a consideration after therapy is completed. This generates different challenges. If further tumor-directed therapy is futile, the decision to continue nutritional support is difficult, but if the child is well, nutritional rehabilitation must be pursued. Finally, the cured child continues to benefit from dietary advice. Nutrition should be viewed for what it is: supplying the most basic need of children.
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PMID:Benefits of nutritional intervention on nutritional status, quality of life and survival. 987 82


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