Clinical and histological indicators of proximal and distal gastric cancer in eight provinces of Iran.

BACKGROUND AND AIM: Gastric cancer is the second most common cancer worldwide. In this study the clinical and histological features of gastric cancer in the cardia and distal stomach were evaluated. METHOD: Proximal and distal gastric cancer diagnosed and treated in eight provinces of Iran from 2010-2011 were reviewed in all collected cases. The age standardized incident rates were calculated and tumor location and histological type were recorded. RESULTS: The age-standardized incidence rate for the eight centers was 40.6 per 100,000 populations per year with an upper and lower range of 22.1 and 102.4 per 100,000 population per year. Thirty four percent of the tumors were located in the cardia, 3% in fundus, and 63% in the distal stomach. In 7 provinces the prevalence of distal tumors was significantly greater than proximal tumors (p=0.006). A significant relationship was observed between diffuse form of gastric cancer and distal gastric tumors (p=0.007) and between poor tumor differentiation and distal gastric tumors (p<0.001). CONCLUSIONS: the result of this study shows that distal gastric cancer is more common than proximal gastric cancer in Iran.

Lymphocyte telomere dynamics and telomerase activity in inflammatory bowel disease: effect of drugs and smoking.

BACKGROUND: The chromosome instability observed in peripheral blood lymphocytes in ulcerative colitis could be a biomarker of cancer susceptibility. AIM: To determine whether accelerated telomere shortening could explain chromosome instability and assess the effect of drugs and smoking on telomere dynamics in these cells. METHODS: Peripheral blood lymphocytes were isolated from ulcerative colitis, Crohn's disease and non-inflammatory bowel disease control patients. Telomere lengths were measured by quantitative real-time polymerase chain reaction. After activation and cell separation, telomerase activity and human telomerase reverse transcriptase messenger ribonucleic acid were measured by telomerase repeat amplification protocol enzyme-linked immunosorbent serological assay and quantitative real-time polymerase chain reaction, respectively. RESULTS: Age-related telomere loss in peripheral blood lymphocytes was similar in ulcerative colitis, Crohn's disease and control patients. Telomerase activity decreased with age in all groups and correlated positively with telomere length (r = 0.489, P = 0.006). Among Crohn's disease patients, azathioprine was associated with decreased telomerase activity (0.66 vs. 1.54, P = 0.026, P < 0.05) and smoking was associated with decreased human telomerase reverse transcriptase mRNA expression (10.5 vs. 33.3, P = 0.036, P < 0.05). CONCLUSIONS: Telomere shortening is not accelerated and therefore cannot be the cause of the chromosome instability observed in ulcerative colitis peripheral blood lymphocytes. Azathioprine and cigarette smoking modify telomerase expression in these cells.