Gastrointestinal cancer occurrence in East Azarbaijan: a five year study from North Western Iran.
(73/276)
BACKGROUND AND AIMS: Regardless of the fact that neoplasms of the GI tract have been reported as the most common fatal cancers in east Azerbaijan, there is a serious lack of population based studies in this region. The aim of this pathology-based cancer registry report is to document epidemiologic aspects of gastrointestinal tract cancers in East Azerbaijan for further medical programs for treatment and screening of high-risk groups and study changes over time. METHODS: A survey team reviewed and collected all records of cancer cases from all referral and valid pathology laboratories, hospitals and out patient public and private clinics of East Azerbaijan province during a five year period (September 1999 to 2004). RESULTS: 5,417 new cases of histologically confirmed GI tract cancers were registered, 61.7% of the subjects being male. The mean (+/- SD) ages were 63.25+/-12.79 and 59.45+/-13.39 yr for men and women, respectively . Gastric cancer was the most common GI tract cancer with an annual ASR of 21.3 per 10(5) for males and 8.2 for females . The annual ASRs for esophagus and colorectal cancers were 9.4 and 6 in males and 7.1 and 9.2 in females. Gastric cancer was significantly more common among men although women were more likely to develop cancer in younger age. Some 14% of our subjects with colorectal cancer were under the age of 40. CONCLUSION: This first report from East Azarbaijan, suggests a need for further evaluations to map out the risk factors and interventions. (+info)
Frequency and spectrum of mutations at codons 12 and 13 of the c-K-ras gene in human tumors.
(74/276)
The frequency of point mutations at codons 12 and 13 of the c-K-ras gene has been determined in a panel of more than 400 human tumors. Mutant c-K-ras genes were detected in about 75% of adenocarcinomas of the pancreas (n = 84); 40% of adenomas (n = 72) and carcinomas (n = 244) of the colon end rectum; 30% of carcinomas of the bile duct (n = 19); 25% of carcinomas of the lung (n = 92), and in lower frequency in other carcinomas, including liver, stomach, and kidney. No mutations were found in carcinomas of the breast, prostate, esophagus, and gall bladder, among others. Comparative analysis of the spectrum of mutations show that while G to A transitions were the most frequent mutations in pancreatic and colo-rectal tumors, G to T transversions were more prevalent in lung carcinomas. The aspartic acid mutation at codon 13 (GGC----GAC) was relatively frequent in colo-rectal tumors but rare in pancreatic and lung carcinomas. The differences in the mutation spectrum of the c-K-ras gene in cancers of the gastrointestinal and respiratory tracts are suggestive of differential exposure to genotoxic agents. (+info)
Correlation between expression of major histocompatibility complex class I and that of antigen presenting machineries in carcinoma cell lines of the pancreas, biliary tract and colon.
(75/276)
To elicit a tumor immune response, tumor antigens represented by major histocompatibility (MHC) class I complex on the cell surface is indispensable. Some investigators demonstrated that many cancer cells reduce expression of beta2-microglobulin, a transporter of antigen presenting (TAP) or low molecular protein (LMP), due to the deletion mutant or point mutation. We investigated gene expression levels of antigen presenting machineries in 13 cell lines of the pancreas, biliary tract and colon cancer by using real-time quantitative PCR. We also evaluated the correlation between expression of MHC class I and that of antigen-processing molecules in these gastrointestinal cancer cell lines. Flow cytometric analysis showed that expression of MHC class I for the pancreatic cancer cell lines was generally lower than that for the biliary tract or colon cancer cell lines. It was further found that the colon cancer cell lines HCT-15/DLD-1 showed no MHC class I expression and lack of protein expression for beta2-microglobulin. Transfection of the wild-type beta2-microglobulin gene restored MHC class I antigen expression on the cell surface for DLD-1. Quantitative real-time PCR demonstrated lower expression for TAP1, TAP2, LMP2 and LMP7 gene in five cancer cell lines. Partial correlation analysis demonstrated that LMP2 was the only antigen presenting machinery which was significantly associated with MHC class I expression. Our results suggest that beta2-microglobulin and LMP2 are important for the expression of MHC class I in 13 gastrointestinal cancer cell lines, while the combined but complex expression of antigen presenting mechanisms was related to MHC class I expression level on the surface of cancer cells. (+info)
Carcinoid tumors.
(76/276)
Carcinoid tumors are rare, slow-growing neuroendocrine neoplasms that often are indolent and may not become clinically apparent until there has been metastatic spread or evidence of carcinoid syndrome. Recent evidence has revealed that the overall incidence of carcinoid tumors has been steadily increasing, and although the disease was thought to be relatively benign, it is now considered one of increasing malignancy. Carcinoid tumors derive from different embryonic divisions of the gut: foregut carcinoid tumors commonly originate in the lungs, bronchi, or stomach; midgut carcinoid tumors in the small intestine, appendix, or proximal large bowel; and hindgut carcinoid tumors in the distal colon or rectum. Carcinoid syndrome, although rare, is most associated with midgut carcinoid tumors. The diagnosis of a carcinoid tumor often is coincidental with surgery performed for another reason. Treatment and prognosis are dependent on the location of the primary tumor and the degree and extent of metastasis at the time of diagnosis. (+info)
Can fluorodihydroxyphenylalanine PET replace somatostatin receptor scintigraphy in patients with digestive endocrine tumors?
(77/276)
The aim of this study was to evaluate whether (18)F-fluorodihydroxyphenylalanine ((18)F-FDOPA) PET is accurate for the diagnosis and follow-up of any type of well-differentiated digestive endocrine tumor and to assess its performance compared with standard somatostatin receptor scintigraphy (SRS) using (111)In-pentetreotide. METHODS: We reviewed the results of 33 evaluable (18)F-FDOPA PET and (111)In-pentetreotide SRS examinations performed between March 2002 and September 2005 in 30 patients referred for documented well-differentiated digestive endocrine tumor. RESULTS: The sensitivity and accuracy of (18)F-FDOPA PET were significantly better for carcinoid tumors (defined according to the World Health Organization 2000 classification) (n = 19) than for noncarcinoid tumors (n = 14)-that is, 93% versus 25% for sensitivity (P < 0.01) and 89% versus 36% for accuracy (P < 0.01), respectively. In contrast, the performances of (111)In-pentetreotide SRS did not differ according to the carcinoid or noncarcinoid type of the primary endocrine tumor-that is, 81% versus 75% for sensitivity and 79% versus 71% for accuracy, respectively. In carcinoid tumors, comparison between (18)F-FDOPA PET and (111)In-pentetreotide SRS showed that (18)F-FDOPA PET more accurately evaluated the extent of disease than (111)In-pentetreotide SRS. (111)In-Pentetreotide SRS did not reveal any additional lesions in any case. Conversely, in noncarcinoid tumors, the extent of the disease was more accurately evaluated in all cases by (111)In-pentetreotide SRS than by (18)F-FDOPA PET. CONCLUSION: This preliminary study emphasizes the importance of a precise histologic characterization of well-differentiated digestive endocrine tumor to select the best radiopharmaceutical. (18)F-FDOPA PET appears to be useful in carcinoid tumors and could become the first-line scintigraphic imaging modality for these tumors, but (111)In-pentetreotide SRS appeared to be a better first-line scintigraphic imaging modality for noncarcinoid digestive tumors. (+info)
TNM staging of foregut (neuro)endocrine tumors: a consensus proposal including a grading system.
(78/276)
The need for standards in the management of patients with endocrine tumors of the digestive system prompted the European Neuroendocrine Tumor Society (ENETS) to organize a first Consensus Conference, which was held in Frascati (Rome) and was based on the recently published ENETS guidelines on the diagnosis and treatment of digestive neuroendocrine tumors (NET). Here, we report the tumor-node-metastasis proposal for foregut NETs of the stomach, duodenum, and pancreas that was designed, discussed, and consensually approved at this conference. In addition, we report the proposal for a working formulation for the grading of digestive NETs based on mitotic count and Ki-67 index. This proposal, which needs to be validated, is meant to help clinicians in the stratification, treatment, and follow-up of patients. (+info)
Socioeconomic and geographic determinants of survival of patients with digestive cancer in France.
(79/276)
Using a multilevel Cox model, the association between socioeconomic and geographical aggregate variables and survival was investigated in 81 268 patients with digestive tract cancer diagnosed in the years 1980-1997 and registered in 12 registries in the French Network of Cancer Registries. This association differed according to cancer site: it was clear for colon (relative risk (RR)=1.10 (1.04-1.16), 1.10 (1.04-1.16) and 1.14 (1.05-1.23), respectively, for distances to nearest reference cancer care centre between 10 and 30, 30 and 50 and more than 90 km, in comparison with distance of less than 10 km; P-trend=0.003) and rectal cancer (RR=1.09 (1.03-1.15), RR=1.08 (1.02-1.14) and RR=1.12 (1.05-1.19), respectively, for distances between 10 and 30 km, 30 and 50 km and 50 and 70 km, P-trend=0.024) (n=28 010 and n=18 080, respectively) but was not significant for gall bladder and biliary tract cancer (n=2893) or small intestine cancer (n=1038). Even though the influence of socioeconomic status on prognosis is modest compared to clinical prognostic factors such as histology or stage at diagnosis, socioeconomic deprivation and distance to nearest cancer centre need to be considered as potential survival predictors in digestive tract cancer. (+info)
Marijuana use and the risk of lung and upper aerodigestive tract cancers: results of a population-based case-control study.
(80/276)
BACKGROUND: Despite several lines of evidence suggesting the biological plausibility of marijuana being carcinogenic, epidemiologic findings are inconsistent. We conducted a population-based case-control study of the association between marijuana use and the risk of lung and upper aerodigestive tract cancers in Los Angeles. METHODS: Our study included 1,212 incident cancer cases and 1,040 cancer-free controls matched to cases on age, gender, and neighborhood. Subjects were interviewed with a standardized questionnaire. The cumulative use of marijuana was expressed in joint-years, where 1 joint-year is equivalent to smoking one joint per day for 1 year. RESULTS: Although using marijuana for > or =30 joint-years was positively associated in the crude analyses with each cancer type (except pharyngeal cancer), no positive associations were observed when adjusting for several confounders including cigarette smoking. The adjusted odds ratio estimate (and 95% confidence limits) for > or =60 versus 0 joint-years was 1.1 (0.56, 2.1) for oral cancer, 0.84 (0.28, 2.5) for laryngeal cancer, and 0.62 (0.32, 1.2) for lung cancer; the adjusted odds ratio estimate for > or =30 versus 0 joint-years was 0.57 (0.20, 1.6) for pharyngeal cancer, and 0.53 (0.22, 1.3) for esophageal cancer. No association was consistently monotonic across exposure categories, and restriction to subjects who never smoked cigarettes yielded similar findings. CONCLUSIONS: Our results may have been affected by selection bias or error in measuring lifetime exposure and confounder histories; but they suggest that the association of these cancers with marijuana, even long-term or heavy use, is not strong and may be below practically detectable limits. (+info)