Prevalence of colorectal cancer and its precursor lesions in symptomatic patients under 55 years of age undergoing total colonoscopy: results of a large retrospective, multicenter, controlled endoscopy study

Purpose Colorectal cancer (CRC) is the second most common cancer in Germany. Around 60,000 people were diagnosed CRC in 2016 in Germany. Since 2019, screening colonoscopies are offered in Germany for men by the age of 50 and for women by the age of 55. It is recently discussed if women should also undergo a screening colonoscopy by the age of 50 and if there are any predictors for getting CRC. Methods Colonoscopies of 1553 symptomatic patients younger than 55 years were compared with colonoscopies of 1075 symptomatic patients older than 55 years. We analyzed if there are any significant differences between those two groups in the prevalence of CRC and its precursor lesions or between symptomatic men and women. We evaluated if there is a correlation between abdominal symptoms and the prevalence of CRC. Results In 164/1553 symptomatic patients, 194 (12.5%) polyps were detected. In total, six colorectal carcinomas (0.4%) were detected. There were no significant differences between men and women. In symptomatic patients ≥ 55 years, significantly more polyps were found (p<0.0001; 26.6% vs. 12.5%). Totally, 286 polyps (26.6%) were removed in 1075 symptomatic patients older than 55 years. Anorectal bleeding was the only abdominal symptom being a significant indicator for the prevalence of the occurrence of colon and rectum cancer in both groups (p=0.03, OR=2.73 95%-CI [1.11;6.70]), but with only low sensitivity (44%). Conclusion Due to no significant differences in men and women, we recommend screening colonoscopies also for women by the age of 50.

The results of colorectal cancer screening in the Republic of Kazakhstan during the period from 2013 to 2018.

e13074 Background: Colorectal cancer (CRC) remains one of the actual problems in oncology. In 2017, in the structure of oncopathology of the Republic of Kazakhstan (RK), CRC took the 3rd place in terms of incidence - 17.5, and in mortality - 8.2 per 100 thousand people. The population screening of CRC has been introduced in the Republic of Kazakhstan since 2011, among the population aged 50 to 70 years, with a survey interval every 2 years. Fecal immunochemical test (FIT) and total colonoscopy (TC) were introduced in 2013. Methods: For the period 2013 - 2018, 5133602 subjects were examined. The analysis of screening indicators was carried out: the number of positive results of FIT, completion rate of follow-up colonoscopy and CRC detection rate. The analyzed groups were divided into regions with: A - high (26 - 30.7 per 100 thousand people), B - medium (13.2-21.8), C - low (5.9 - 10.8) incidence. Results: The positive FIT for the study period was found on average, in 1.23% (62971) positive results in the Republic of Kazakhstan, in group A it was 1.50% (27675), in group B - 1.26% (17178), and in group C - 0.94% (18118). The number of TC: in group A - 76.1% (21067), in group B - 75.8% (13016), in group C was 66.7% (12080), in total - 46163 cases in the Republic of Kazakhstan, which is 73.3% of indications. During the period of study 2480 patients with colorectal cancer were identified: in group A - 0.07% (1236), in group B - 0.05% (638), in group C - 0.03% (606) people. Conclusions: For regions with different incidence rates is necessary to define performance indicators to improve the quality assurance in CRC screening.

Dietary Carcinogens and Cancer Risk: Findings From Japanese Studies

Background: Red meat and processed meat consumption are established risk factors for colorectal cancer. One hypothesized mechanism for this association is through exposure to heterocyclic aromatic amines (HAAs), which are formed when meat is cooked at high temperature for a long duration. Although they are mutagenic and carcinogenic in nonhuman primates, the findings of epidemiologic studies that have specifically examined the association between HAA intake and colorectal cancer risk have been inconsistent. Moreover, since N-acetyltransferase 2 (NAT2) has been shown to play a critical role in the bioactivation of HAAs, an interaction between HAA intake and NAT2 on colorectal cancer has been hypothesized and the findings in the previous studies have been inconsistent. Aim: To investigate the association of meat- and fish-derived HAA intake, which were estimated by our validated food frequency questionnaire and population-specific data on HAA contents in meat and fish items with the risk of colorectal adenoma, precursor of colorectal cancer, among middle-aged and elderly Japanese in Japan and Japanese Brazilians in Sao Paulo. In addition, to test the modifying effect of NAT2 on the association of HAA intake on colorectal adenoma risk. Methods: Tokyo adenoma study includes 738 patients with adenoma and 697 controls who underwent total colonoscopy in National Cancer Center, Japan. Brazil adenoma study includes 316 patients with adenoma and 403 controls who underwent total colonoscopy in 2 hospitals in Sao Paulo. HAA intake was estimated from meat and fish intake based on an HAA database that was validated against 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) values measured in human hair. NAT2 acetylation genotype was inferred using 2 SNPs in the NAT2 gene. Logistic regression models were used to calculate odds ratios (ORs) and 95% confidence interval (CI) for the association between HAA intake and colorectal adenoma risk after adjusting for potential confounders. Results: Tokyo adenoma study showed that high intake of 2-amino-3,4-dimethylimidazo[4, 5-f]quinoline (MeIQ) and total HAA was significantly associated with an increased risk of colorectal adenoma in women but not in men. No clear association with PhIP or 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) intakes and no effect modification by NAT2 genotype was observed. Brazil adenoma study found no association for HAAs and no effect modification by NAT2 genotype. Conclusion: Tokyo Adenoma Study suggests that high MeIQ and total HAA intakes are positively associated with colorectal adenoma risk among Japanese women in Japan. However, Brazil adenoma study failed to observe positive associations. The possible explanations of inconsistent findings and the difficulty of the studies will be discussed.

Haptic feedback is useful in remote manipulation of flexible endoscopes

Background and study aims We developed the Endoscopic Operation Robot (EOR) version 3, offering built-in haptic feedback and manipulation of the entire scope with one hand. Manipulation of the flexible endoscope is done entirely remotely. However, inclusion of haptic feedback places a huge burden on the system. Our purpose in this study was to determine whether haptic feedback is needed in remote manipulation of a flexible endoscope. Methods Five endoscopists performed total colonoscopy using a colonoscopy training model. A trial was conducted in which the endoscope was inserted up to the cecum five times with haptic feedback and five times without haptic feedback. Insertion time, maximum and mean haptic force, and incidence of sigmoid colon overstretching were compared between groups. Results Insertion time was significantly shorter with haptic feedback than without, and overstretching of the sigmoid colon was less frequent. Insertion could thus be performed without using excessive force. Conclusion Haptic feedback is useful for remote control manipulation of flexible endoscopes.