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Query: UMLS:C0699790 (colon cancer)
 28,837 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Researchers have investigated green tea as a potential protectant against cancer. This review focuses on studies of green tea in humans. Green tea contains polyphenols, chemicals that act as powerful antioxidants. Epidemiological and human studies have shown varying results. Thirty-one human studies and four reviews were examined. Among five studies reporting on colon cancer, three found an inverse association and one reported a positive association. For rectal cancer, only one of four studies reported an inverse association; increased risks were seen in two of the studies. An inverse association is suggested for urinary bladder cancer in two of two studies. Of 10 studies examining the association of green tea and stomach cancer, 6 suggest an inverse and 3 a positive association. The most comprehensive of these studies supports an inverse association of green tea and stomach cancer. Pancreatic cancer studies hint at an inverse association in two of three studies. A strong inverse effect was found with green tea and esophageal cancer. Lung cancer studies have shown an inverse effect with Okinawan tea, yet tentatively increased risk was shown in another study. Although human studies have their limitations, the research has warranted a further look into the effects of green tea and cancer.
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PMID:Green tea and cancer in humans: a review of the literature. 979 66

In various types of human malignant tumors, the presence or absence of expression of apoptosis-associated gene products (p53 protein and Bcl-2 protein) and the tumor proliferation activity-related factor (Ki-67) was assessed by immunohistochemical staining and the correlation between this expression and chemosensitivity to anticancer drugs was investigated. Study subjects comprised 55 preoperative patients with untreated malignant tumors (9 with esophageal cancer, 11 with stomach cancer, 11 with colon cancer, 13 with hepatic cancer and 11 with breast cancer). A chemosensitivity test was carried out with the histoculture drug response assay (HDRA) method using 4 drugs, mitomycin C (MMC), 5-fluorouracil (5-FU), doxorubicin hydrochloride (ADM), and cisplatin (CDDP). Immunohistochemical staining was used to assess expression of p53 protein, Bcl-2 protein and Ki-67. The tumor growth inhibition index (I.I.) of the 4 drugs was significantly lower in a group of the patients with p53 protein overexpression-type (mutant p53 protein positive expression-type) tumors than in a group with p53 protein negative expression-type tumors (p<0.05). No significant correlation was found between the expression of the Bcl-2 protein by and the I.I. of any drug studied in any type of cancer. A negative correlation was found between the labeling index (L.I.) for Ki-67 in all cases and I.I. for MMC and ADM and thus, chemosensitivity of the tumors with high growth activity was lower. Furthermore, a positive correlation existed between the L.I. for Ki-67 and that for p53 protein. The patients with p53 protein overexpression-type (mutant p53 protein positive) tumors showed low chemosensitivity. In addition, overexpression of p53 protein is suggested to be one of the factors involved in the lowered chemosensitivity of the tumors with high growth activity. Summarizing these findings, the p53 protein can play an important role in cancer therapy.
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PMID:Usefulness of p53 protein, Bcl-2 protein and Ki-67 as predictors of chemosensitivity of malignant tumors. 1020 14

R. Mayer (USA), summarizing the data presented during the three-day conference, stressed the importance of the development of new cytotoxic drugs and -- particularly -- biological therapies as forms of treatment for patients with gastrointestinal malignancies. He also acknowledged the increasing application of molecular biology to gastrointestinal cancer through the identification of genetically-defined high-risk patients who merit costly screening techniques and the increased use of molecular 'markers' to serve as prognostic indicators and criteria for stratification in future clinical trials. Dr Mayer cautioned against allowing long-term frustration over poor surgical outcomes in patients with T3-4 esophageal cancer and enthusiasm derived from uncontrolled (i.e., phase II) trials to lead to the premature acceptance of preoperative chemoradiation therapy as standard treatment for such patients in the absence of properly controlled, adequately powered randomized studies. Dr Mayer reinforced the progress that has been made in the adjuvant treatment of colon cancer and noted the increasing number of new randomized studies that have been proposed to further enhance the likelihood for cure, particularly in patients with stage III disease. Dr Mayer concluded by presenting a series of hypothetical agenda items for the Fourth International Conference on Biology, Prevention, and Treatment of Gastrointestinal Malignancies to be held in the new millennium which he hoped would demonstrate the incorporation of biological agents into clinical trials, would document more concerted efforts to study the biology and improve the treatment for pancreatic cancer, and would begin to consider the use of 'risk-adapted' management strategies into clinical trials, based on such preclinical biological markers as intratumoral thymidylate synthase levels, apoptotic indices, allelic deletions, and the like.
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PMID:Third International Conference on Biology, Prevention and Treatment of Gastrointestinal Malignancies. Cologne, 23-26 September 1998. 1035 71

A germline sequence alteration at codon 1307 of the APC gene (I1307K) has been reported in 6-7% of the Ashkenazi Jewish population in the United States. This alteration is believed to predispose the APC gene to a secondary mutation at the same locus, resulting in an increased risk of colorectal carcinoma. There is an increased risk of colorectal carcinoma in patients with inflammatory bowel disease (IBD), a relatively large proportion of whom are Ashkenazi Jews. We therefore sought to determine whether the I1307K sequence variant occurred in the germline DNA of IBD patients. To our surprise, we found this sequence in only two of 267 patients with IBD (0.7%), occurring in only 1.5% of Jewish IBD patients. The I1307K sequence variant was not found in 67 patients with esophageal cancer, 53 patients with gastric carcinoma (13 MSI-H and 44 MSI-negative), or ten patients with sporadic MSI-H colon cancer. These findings suggest that the I1307K sequence is relatively rare in the germline of Jewish as well as non-Jewish IBD patients. It does not appear to contribute to the increased colorectal cancer risk present in these patients.
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PMID:Low prevalence of the APC I1307K sequence in Jewish and non-Jewish patients with inflammatory bowel disease. 1044 54

Vascular endothelial growth factor (VEGF) is a most potent angiogenic molecule. In this article, we demonstrated that VEGF is participated in the tumor angiogenesis of hepatocellular carcinoma, esophageal cancer, and pancreatic cancer. Furthermore, we revealed that VEGF is one of the molecules which are responsible for metastasis and prognosis in esophageal cancer and colon cancer. Although the mechanism on the induction of VEGF gene is still unclear in human cancer tissue, we obtained the informative evidence indicating that p53 mutation is involved in VEGF expression of esophageal cancer. Our experimental study with stable transfectant of VEGF gene provided the confirmative results showing that VEGF gene induces neovascularization in and around tumor and that VEGF augment metastastic potential by accelerating proliferative activity after reaching the target organ.
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PMID:Implication of vascular endothelial growth factor in the development and metastasis of human cancers. 1045 2

The occurrence of multiple primary cancers in the aerodigestive tract is a well known phenomenon that has been explained by the concept of 'field carcinogenesis'. Metachronous or synchronous esophageal cancer has usually been identified in patients with head and neck cancer, gastric cancer or colon cancer. The incidence of multiple primary cancers of the esophagus and thyroid gland is very low. We treated four patients with synchronous cancers of the cervical esophagus and the thyroid gland. Histologically, all of the esophageal cancers were squamous cell carcinomas. Thyroid cancers were evaluated as papillary carcinoma or follicular carcinoma. Both the esophageal cancer and the thyroid cancer frequently metastasized to lymph nodes. All patients had multiple lymph nodes metastasis from the esophageal or the thyroid cancer. In one patient, both the esophageal and the thyroid cancers were detected in the same lymph node. Three of four patients died from recurrence of esophageal cancer. The prognosis of these patients was poor. In the treatment of esophageal carcinoma, cancers of other organs including the thyroid gland should be carefully investigated.
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PMID:Multiple primary cancers of the esophagus and thyroid gland. 1047 Jun 60

Dietary factors were analyzed for the regional difference of GI tract cancer mortality rates in China. Sixty-five rural counties were selected among a total of 2,392 counties to represent a range of rates for seven most prevalent cancers. The dietary data in the selected 65 counties were obtained by three-day dietary record of households in 1983. The four digestive cancer mortality rates (annual cases per 100,000 standardized truncated rates for ages 35-64) and per capita food consumption were analyzed by the principal components factor analysis. Esophageal cancer associated with poor area, dietary pattern rich in starchy tubers, and salt, lack of consumption of meat, eggs, vegetables and rice. Stomach cancer seemed to be less associated with diet in this study because of its small model Kaiser-Meyer-Olkin (KMO) measure of sampling adequacy, suggesting some other carcinogenic factors would play more important role in the development of this cancer in China. The colon and rectal cancer showed close relation to diet; rich in sea vegetables, eggs, soy sauce, meat and fish, while lack in consumption of milk and dairy products. Rapeseed oil was more important risk factor for colon cancer than that of rectum. Rice, processed starch and sugar were closely associated with colon cancer, supporting the insulin/colon cancer hypothesis.
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PMID:Factor analysis of digestive cancer mortality and food consumption in 65 Chinese counties. 1051 May 86

The role of laparoscopy in the care of patients with cancer is currently evolving. Numerous experimental and clinical studies have attempted to elucidate the nature and cause of port-site metastases--particularly to discern whether they simply are a marker of advanced disease, or if they are a result of the laparoscopic intervention. Laparoscopy has a role in establishing the diagnosis of cancer in some situations by allowing biopsy of intraperitoneal and retroperitoneal masses, lymph nodes, and visceral lesions, as well as examination of abdominal contents under direct vision or with ultrasound probes. Laparoscopy is useful in the staging of established malignancies such as pancreatic cancer, hepatic lesions, lymphoma, and esophageal cancer. Laparoscopy also has a role in the surgical treatment of a variety of malignancies, including gastric carcinoma, pancreatic cancer, splenic malignancies, adrenal cancers, and colon cancer. The safety of laparoscopy for the definitive resection of colon cancer has not yet been proven, and until the results of a randomized prospective trial currently underway are known, should be performed only in the context of a clinical trial. Lastly, laparoscopy can play an important role in the palliative care of the cancer patient in performing procedures such as feeding-tube placement or intestinal stoma creation. It is imperative that using laparoscopy in the care of patients with malignancies be carefully and thoroughly evaluated since this technique can either benefit or adversely affect survival or quality of life.
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PMID:The role of laparoscopy in the treatment of intra-abdominal malignancies. 1080 31

A prospective ecological evaluation of mortality from common malignancies with dietary risk factors and alcohol consumption was carried out among 10 state capitals of Brazil. Regression analysis was used to examine the association of dietary intake with mortality rates of the most common cancers among adults age 30 years and older. Age-adjusted cancer mortality rates varied 2.4 to 3.3 fold across the state capitals. A positive relationship was observed between energy intake and colon, lung, and esophageal cancer (p</=0.02 for each). Colon cancer mortality was positively associated with consumption of total fat, eggs, alcohol, mate tea, cereals, and vegetables (p</=0.01). Lung cancer was positively associated with mate and cereal intake (p<0.05). Stomach cancer was associated with consumption of eggs (p=0.04); and negatively associated with consumption of high fiber foods, fruits, and vitamin A and C (p</=0.05). Esophageal cancer was positively associated with fat intake, mate and cereals (p</=0.05) and negatively associated with vitamin A (p=0.02); prostate cancer was negatively associated with vitamin C (p=0.007). Breast cancer was not associated with any of the factors studied. The marked variation in cancer mortality rates in Brazil may be partially related to the high variation in dietary components or other diet associated factors.
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PMID:Diet and mortality from common cancers in Brazil: an ecological study. 1090 7

Fas (CD95/APO-1) is a cell surface "death receptor" that mediates apoptosis upon engagement by its ligand, FasL. Fas-mediated apoptosis of lymphocytes normally serves immunoregulatory roles, including tolerance acquisition, immune response termination, and maintenance of immune privilege in certain organs. Colon tumors can exploit this lymphocyte death program by expressing FasL. This may enable colon tumors to mount a "Fas counterattack" against antitumor lymphocytes, impairing antitumor immune responses. FasL-expressing colon tumor-derived cell lines can trigger Fas-mediated apoptosis of cocultured T cells in vitro. FasL expressed in esophageal cancer has been significantly associated with apoptosis and depletion of tumor-infiltrating lymphocytes (TIL) in vivo. FasL may also facilitate metastatic colonization of Fas-sensitive organs such as the liver, by inducing apoptosis of target organ cells. Normal colonic epithelial cells express Fas and are relatively sensitive to Fas-mediated apoptosis. By contrast, colon tumor-derived cell lines are usually resistant to induction of Fas-mediated apoptosis, and colon cancer cells frequently coexpress Fas and FasL. The mechanisms allowing resistance to Fas-mediated apoptosis are complex, and defects have been identified at several levels of Fas signal transduction. The "Bcl-2 rheostat" may be pitched against apoptosis in colon cancer, inasmuch as overexpression of Bcl-2, downregulation of Bak, and mutation of Bax are common defects in colon tumors. Caspase-1 is also downregulated in colon cancer. The high frequency of p53 mutations in late-stage cancers may also inhibit Fas signaling. Fundamental defects in apoptosis signaling may contribute to both immuno- and chemoresistance in colon cancer and allow expression of FasL to counterattack antitumor lymphocytes.
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PMID:Altered mechanisms of apoptosis in colon cancer: Fas resistance and counterattack in the tumor-immune conflict. 1091 13


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