Distribution trends of colorectal adenoma and cancer: a colonoscopy database analysis of 11,025 Chinese patients

Background and Aim: A left‐to‐right shift of colorectal cancer (CRC) has been reported in Western studies. However, few Asian studies have investigated the anatomic distribution of colorectal adenoma and CRC. We aimed to describe the time trends in the distribution of colorectal adenoma and CRC in a Chinese population. Methods: A colonoscopy database was reviewed, and all consecutive patients with lower gastrointestinal symptoms who underwent colonoscopy from 1998 to 2009 were identified. Data, including patients' sex, age, symptoms, and the number and anatomic locations of colorectal adenoma and CRC, were documented. Results: A total of 11 025 patients were included in the final analysis; 1012 and 363 patients were diagnosed with colorectal adenoma and CRC, respectively. Overall, there were more distal than proximal adenomas (54.4% vs 37.9%), and the proportion of proximal adenomas remained stable from 1998–2006 to 2007–2009 (38.2% vs 37.6%). Similarly, there were more distal than proximal CRC (56.5% vs 42.4%), and the proportion of proximal CRC declined from 45.8% in 1998–2006 to 38.4% in 2007–2009. Colorectal adenoma and CRC were equally distributed among both sexes. For elderly patients (> 50 years), there was a non‐significant trend towards more proximal adenoma and CRC. Conclusions: The present study suggests no distal‐to‐proximal shift of colorectal adenoma and CRC among the Chinese population in Shanghai over the past 12 years. The distribution pattern of colorectal adenoma and CRC of Chinese patients is different from that of Western patients, who had more colorectal lesions located in the distal part.     

Depressed‐type submucosal invasive colorectal cancer in a patient with Lynch syndrome diagnosed using short‐interval colonoscopy

Although regular colonoscopy surveillance is recommended for patients with Lynch syndrome (LS) who underwent partial colectomy, the appropriate interval has not been determined. We report a case of colorectal cancer (CRC) detected by short‐interval surveillance colonoscopy (SC) in a patient with LS having a past history of partial colectomy. A 65‐year‐old man underwent sigmoidectomy for advanced CRC. His family history revealed that his two younger brothers had CRC in their twenties and thirties, respectively, and the patient met with the criteria in the Revised Bethesda Guidelines. After confirming the loss of MSH2 protein expression in the primary tumor, subsequent genetic testing showed germline mutation with a large deletion of exon 7–14 in the MSH2 gene, indicating a diagnosis of LS. After the diagnosis of LS, the patient underwent annual SC. Three years after the initial surgery, superficial submucosal invasive cancer was detected. Subsequently, SC after a 6‐month interval revealed a deep submucosal invasive cancer (7 mm in diameter). Although additional surgery was recommended, considering his comorbidities, regular SC rather than colectomy was selected. Even shorter‐interval SC carried out within a year is not sufficient to detect endoscopically resectable tumors in some high‐risk LS cases.     

Screening colonoscopy in asymptomatic average-risk Koreans: analysis in relation to age and sex

BACKGROUND AND AIMS: Although the incidence of colorectal cancer is rising in Asian countries, there are no guidelines for its screening in this region due in part to the lack of epidemiological data regarding colorectal neoplasms. This study aimed to evaluate the prevalence of colorectal neoplasms in average-risk Koreans and to assess the effectiveness of screening colonoscopy in Korea. METHODS: The prevalence of colorectal neoplasms was assessed by primary screening colonoscopy in 5,086 consecutive asymptomatic adults (males 70.5%; age 20-84 years) with no risk factors for colorectal cancer. RESULTS: The overall prevalence of colorectal neoplasms in the 5,086 subjects was 21.9% and this increased linearly with age. Among the 2,435 subjects aged >or=50 years (males 66.7%; mean age 57.7 years), the prevalence of all colorectal neoplasms was 30.2% (males 35.9% vs females 18.7%; P < 0.001), while advanced neoplasms accounted for only 4.1% (males 5.1% vs females 2.0%; P < 0.001). The prevalence of advanced neoplasms in Korean men of a specific age group was similar to that of Korean women in the 10-years older age group. Also, Koreans in a specific age group showed a prevalence of advanced neoplasms similar to that of Westerners in the 10-years younger age group. CONCLUSIONS: Colonoscopy is a useful modality for colorectal cancer screening in Korea, as established in Western countries. However, the screening colonoscopy may begin at an older age for Koreans than for Westerners. Similarly, the optimal starting age for screening in Korean women may be higher than that in men by 10 years.     

Prevalence and risk of colorectal adenoma in asymptomatic Koreans aged 40–49 years undergoing screening colonoscopy

Background and Aim: Colorectal cancer screening is recommended for average‐risk persons beginning at age 50. However, information about the incidence and risk factors of precursor adenoma in preceding decades is limited. The aim of this study was to determine the prevalence and risk factors of colorectal adenoma in persons aged 40–49 years and to compare the data with those aged 30–39 years and 50–59 years. Methods: A cross‐sectional study of 5254 asymptomatic subjects who underwent screening colonoscopy was conducted. Data were stratified by age into three groups: 608 aged 30–39 years, 1930 aged 40–49 years, and 2716 aged 50–59 years. Results: Prevalence of overall adenomas was 10.4% in the 30–39 years age group, 22.2% in the 40–49 years age group, and 32.8% in the 50–59 years age group. Advanced adenoma was found in 0.7% of the 30–39 years age group, 2.7% of the 40–49 years age group, and 4.1% of the 50–59 years age group. In the 40–49 years age group, male sex and current smoking habits showed associations with low‐risk adenoma after multiple adjustments. Moreover, male sex (odds ratio [OR] = 1.55, 95% confidence interval [CI]: 1.02–3.23), current smoking (OR = 1.58, 95%CI: 1.06–3.50), and family history of colorectal cancer (OR = 2.54, 95%CI: 1.16–5.56) were independent predictors of advanced adenoma in this age group. Conclusions: Prevalence of adenoma in subjects aged 40–49 years was higher than in previous studies. Male sex and current smoking habits along with a family history of colorectal cancer were associated with advanced adenoma in this age group.     

Emerging next‐generation robotic colonoscopy systems towards painless colonoscopy

Advances in the field of robotics have allowed modern technology to be integrated into medicine and that can minimize patients suffering from the side effects that are inherent to procedures for improving their quality of life. Conventional devices that are used for colonoscopies are rigid and require a high level of expertise from endoscopists to perform the procedure. Advances in robot‐assisted colonoscopic systems now produce softer, more slender, automated designs that no longer require the operator to use forceful pushing to advance the colonoscope inside the colon, reducing risks to the patient of perforation and pain. It is challenging to reprocess these scopes for reuse as the materials used can be damaged during decontamination, leading to the possible risks of cross‐infection by pathogenic microorganisms when reused by patients. An ideal solution is to eliminate these contamination risks to patients by adopting sterile, single‐use scopes straight from the manufacturer's package to the patient. With this idea in mind, emerging developments that push the boundaries in this area will benefit patients and encourage the public to participate in and adhere better to colonoscopy screening to reduce the development of colorectal cancer. Thus, in light of these concerns and challenges, to encourage patients undergoing colorectal screening to comply with colonoscopy procedures that they are less invasive, changes in the design and materials are necessary. One of the more promising technological advances in this area is the advent of robotic colonoscopy.     

The role of colonoscopy in screening persons with family history of colorectal cancer

Abstract First-degree relatives of colorectal cancer patients are at increased risk for developing colorectal neoplasms. In order to assess the potentiality of colonoscopy screening in this high-risk population, 213 asymptomatic family members (age range 30-69 years, mean 42.8 years) of those patients with colorectal cancer received colonoscopic examination at Chang-Gung Memorial Hospital from April 1992 to May 1994. Twenty-eight persons with 42 lesions (polyps or cancer) were identified, including 28 adenomas, nine hyperplastic polyps and five adenocarcinomas. The positive detection rate was 9.9% for adenoma and 2.3% for cancer. Colorectal neoplasms afflicted males more frequently than females (16.7 vs 5.7%, P < 0.05) and occurred less frequently in those < 40 years of age (5.5 vs 17.2%, P < 0.05). Forty-two per cent of the detected neoplastic lesions were beyond the reach of 60 cm flexible sigmoidoscopy and 36% of adenomas were < 0.5 cm in size and would be missed if patients were screened by air contrast barium enema. Cost analysis revealed that the charges of both screening colonoscopy and screening flexible sigmoidoscopy/air contrast barium enema were approximate. Colonoscopy also has a high acceptability and safety. It appears appropriate to use colonoscopy, rather than flexible sigmoidoscopy or air contrast barium enema, as an initial screening procedure for persons with a family history of colorectal cancer, especially those > 40 years of age.