High-resolution melting assay (HRMA) is a simple and sensitive stool-based DNA Test for the detection of mutations in colorectal neoplasms.

BACKGROUND: Stool-based DNA testing for colorectal cancer is becoming a favored alternative to existing DNA screening tests. However, current methods of analysis often become more complicated and costly with increased sensitivity. The high-resolution melting assay (HRMA) is a simple and rapid mutation scanning method with low cost and superb accuracy. In this study, we verified the accuracy of HRMA for screening KRAS/TP53 mutations in stool-isolated DNA from patients with colorectal cancer. MATERIALS AND METHODS: Comparing to direct DNA sequencing, the accuracy of HRMA was verified by detecting KRAS/TP53 mutations in 2 independent stages. In study stage I, both tissue and stool samples from colorectal neoplasm patients were analyzed. In study stage II, stool samples from patients with colorectal neoplasms, and normal controls in clinical screening settings were examined. RESULTS: In study stage I, the HRMA identified 14 of 17 target mutations (82.4%) in stools from cancer patients, and 4 of 5 (80.0%) target mutations in stools from advanced adenoma patients. The mutation detection rate in fecal samples (45.0%; 18/40) and referred tissue samples (55.0%; 22/40) was highly consistent (κ = 0.79). The HRMA detected 1% mutant DNA in a background of wild type DNA. In study stage II, the HRMA assay detected 58.8% (20/34) mutations in tumor samples, 41.5% (17/41) in advanced adenomas samples, and 3.33% (2/60) in age-matched normal control samples. The results from HRMA and DNA sequencing revealed 100% sensitivity and specificity in both tissue and stool samples. CONCLUSION: HRMA is a simple, reliable, and sensitive method for detecting DNA mutations in the stool samples from patients with colorectal neoplasms.

[Screening of high-risk group with colorectal cancer].

OBJECTIVE: To measure the rate of high-risk group and the detection rate of colorectal cancer (CRC) in communities in Guangdong province and to provide scientific rationales for formulating mass screening plans in high-risk group. METHODS: Mass survey was conducted by questionnaire combined fecal occult blood test (FOBT) in Huizhou region, Guangdong Province, to sort out the high-risk population of CRC. Then the high-risk population was screened by colonoscopy and pathology to identify CRC. The differences were compared by direct expenditure which was used to calculate screening cost. RESULTS: A total of 68,953 people were surveyed. There were 940 people in high-risk group (detection rate: 1.36%), 3118 in immunity FOBT positive group (detection rate: 4.52%), Merging aforementioned two groups, there were 3870 in population at risk (detection rate: 5.61%). The CRC detection rate in high-risk group, immunity FOBT positive group, population at risk and average-risk group was 506.3/10(5), 314.3/10(5), 315.9/10(5) and 17.7/10(5) respectively. The positive predictive value of CRC screening scheme by high-risk group questionnaire-colonoscopy was 0.43% while CRC screening scheme by FOBT-colonoscopy 0.22%. In terms of direct expenditure of CRC per case in high-risk group and immunity FOBT positive group was 47,834.5 yuan and 82,303.6 yuan. The latter was 1.7 times than that of the former. CONCLUSIONS: The scheme of questionnaire combined FOBT for CRC is an effective way in mass survey. The scheme by high-risk group questionnaire-colonoscopy has a much better cost-effectiveness than that of the scheme by FOBT-colonoscopy so that it should be one of the preferred methods for individual screening in high-risk group.

Colorectal cancer in Guangdong Province of China: a demographic and anatomic survey.

AIM: To determine the basic demographic features of colorectal cancer (CRC) in five hospitals located in four different areas of Guangdong Province, China. METHODS: A review of patient records from 1986 to 2006 from five hospitals was conducted. Patient data was obtained, including age, gender, location of lesions, staging and histological type of CRC. The Chi-square test was used to assess differences in rates and a significance level of 0.05 was used. Univariate comparisons were made via Fisher's exact tests. RESULTS: Analysis was carried out on 8172 CRC patents, 6.1% (499/8172) of the patients were aged < or = 30 years. The peak incidence was between the ages 61-70 years (27.8%). The mean age at CRC diagnosis increased from 52 years (1986-1988) to 60 years (2004-2006) and the proportion of young CRC patients decreased from 8.0% to 5.9% over the same period. Of 8172 lesions, 4434 (54.3%) were located in rectum and 3738 (45.7%) in colon. The incidence of rectal cancer decreased significantly from 59.4% (1989-1991) to 51.8% (2004-2006) and right sided colon cancer increased from 40.6% to 48.2%. The mean age, anatomic distribution, histological type and differentiation degree were significantly different among the four geographical areas (P < 0.05). CONCLUSION: The hospitalization rate for CRC has increased in Guangdong in recent years. The characteristics of CRC from the five hospitals located in the four different areas of Guangdong Province are also different. Further studies are needed to assess more recent trend in the incidence and prevalence of CRC as well as the respective roles of genetic and environmental factors in CRC.

[Epidemiology investigation of colorectal cancer on community group in Guangdong province].

OBJECTIVE: To explore the epidemiology characteristics of colorectal cancer on community group in Guangdong province. METHODS: Huidong was took as the research spot to investigate the sickness and incidence of colorectal cancer among a whole community group in Guangdong province, and two projects were used simultaneously: "screening of colorectal cancer in high risk group" and "screening project using fecal occult blood test". The numeration time for population of 10 towns was set at July 1, 2005. Five towns were sampled out from Huidong with 100,859 persons. Meanwhile, the diseases and death cause registering system was established. RESULTS: The incidence of colorectal cancer in Huidong community group was 15.2/100,000 (male 17.2/100,000, female 13.0/100,000), the age-adjusted incidence was 17.6/100,000 (male 19.5/100,000, female 16.7/100,000). The morbidity was 41.9/100,000 (male 46.5/100,000, female 37.2/100,000), the age-adjusted morbidity was 49.0/100,000 (male 54.1/100,000, female 45.6/100,000). The mortality was 5.0/100,000 (male 5.9/100,000, female 4.0/100,000) and the age-adjusted morbidity was 6.4/100,000 (male 7.2/100,000, female 5.7/100,000). CONCLUSION: The incidence of colorectal cancer in Huidong community group is lower than that of high incidence area in China, but gets close to the normal incidence area of China and general level of the world.

[Value and economic analysis of emergency endoscopy in the diagnosis and treatment of massive upper gastrointestinal hemorrhage].

OBJECTIVE: To study the application value of emergency endoscopy in the diagnosis and treatment of massive upper gastrointestinal hemorrhage, and to evaluated by the economic analysis whether the emergency endoscopy was safe and effective,or shorten the hospitalization days and reduced the medical costs. METHODS: Ninety-one patients with massive upper gastrointestinal hemorrhage were randomly divided into emergency endoscopy group (group A) and non-emergency endoscopy group (group B). The patients in group A underwent endoscopy as soon as the blood pressures were normal and the patients of group B underwent endoscopy at 24-48 hours after hospitalization. They would be treated depending on the conditions by endoscopy. Then the correct diagnosis rates, rebleeding rates, complication rates, mean hospitalization days, the endoscopy costs, the blood transfusion costs, the drugs costs and the total hospitalization costs of two groups were evaluated and the cost-effect ratio (C/E) was calculated. RESULTS: The correct diagnosis rates and the endoscopy costs of group A were higher than the group B (100.0 percent vs.90.2 percent, P<0.05; (714.78+/-263.54) yuan vs. (383.57+/-251.72) yuan, P<0.01), and the rebleeding rates, the mean hospitalizations days, the blood transfusion costs and the drugs costs and the total hospitalization costs were all lower compared to the group B (6.1 percent vs. 26.8 percent, P<0.05; (5.42+/-1.70) days vs. (8.51+/-2.30) days, P<0.01; (791.80+/-258.35) yuan vs. (1270.29+/-569.21) yuan, P<0.01; (945.22+/-125.82) yuan vs. (1223.81+/-254.44) yuan, P<0.01; (2785.76+/-353.26) yuan vs. (3 527.76+/-555.62)yuan, P<0.01. The C/E of group A was lower than the group B (2785.76 yuan per patient vs. 3527.76 yuan per patient, P<0.01). CONCLUSION: Emergency endoscopy is not only safe and effective but also economical in the diagnosis and treatment of massive upper gastrointestinal hemorrhage.