Adenoma detection rates in an opportunistic screening colonoscopy program in Iran, a country with rising colorectal cancer incidence

Colorectal Cancer Screening Pilot Project in Tehran-Iran, a Feasibility Study

BACKGROUND

Colorectal cancer (CRC) is the third most common cancer in Iran, where there is no organised CRC-screening programme. This study aimed to evaluate feasibility of CRC screening using a qualitative fecal immunochemical test (FIT) among Iranian average-risk adults.

METHODS

In this feasibility study, 7039 individuals aged 50-75 years were invited by community health workers (CHWs) in southern Tehran and its suburban districts between April 2018 and November 2019. The CHWs performed a qualitative FIT with cut-off level 50 ng Hb/mL buffer and referred those with positive-FIT for colonoscopy to the endoscopy center of Shariati hospital in Tehran. Outcomes included acceptance rate, FIT positivity rate, colonoscopy compliance, detection rates and positive predictive values (PPVs) with 95% confidence interval for CRC and advanced adenomas (AAs).

RESULTS

Acceptance rate at initial invitation was 71.7%. From 4974 average-risk adults (1600 males and 3374 females) who were offered FIT, 96.8% (n=4813) provided valid samples, of whom 471 (9.8%) tested positive. Among FIT-positive participants, 150 (31.8%) underwent colonoscopy; CRC was detected in 2.0% (n=3) and adenomas in 27.3% (n=41). Detection rate of CRC and AAs per 1000-FIT-screened participants was 0.6 (0.1-1.8) [males: 0.7 (0.01-3.6), females: 0.6 (0.07-2.0)] and 4.2 (2.5-6.4) [males: 5.9 (2.6-11.0), females: 3.4 (1.7-6.0)], respectively. PPVs were 2.0% (0.4-5.7) for CRC and 13.3% (8.3-19.8) for AAs. There was no association between gender and the studied outcomes.

CONCLUSION

Our results partially support the feasibility of scaling up organized CRC-screening through the existing healthcare system in Iran; it remains to be discussed carefully to ensure the capacity of healthcare system for adequate colonoscopy services.

Opportunistic Colonoscopy Cancer Screening Pays off in Romania-A Single-Centre Study

Colorectal cancer (CRC) is the third most diagnosed cancer in men (after prostate and lung cancers) and in women (after breast and lung cancer). It is the second cause of cancer death in men (after lung cancer) and the third one in women (after breast and lung cancers). It is estimated that, in EU-27 countries in 2020, colorectal cancer accounted for 12.7% of all new cancer diagnoses and 12.4% of all deaths due to cancer. Our study aims to assess the opportunistic colorectal cancer screening by colonoscopy in a private hospital. A secondary objective of this study is to analyse the adenoma detection rate (ADR), polyp detection rate (PDR), and colorectal cancer (CRC) detection rate. We designed a retrospective single-centre study in the Gastroenterology Department of Saint Mary Hospital. The study population includes all individuals who performed colonoscopies in 2 years, January 2019-December 2020, addressed to our department by their family physician or came by themselves for a colonoscopy. One thousand seven hundred seventy-eight asymptomatic subjects underwent a colonoscopy for the first time. The mean age was 59.0 ± 10.9, 59.5% female. Eight hundred seventy-three polyps were found in 525 patients. Five hundred and twenty-five had at least one polyp, 185 patients had two polyps, 87 had three polyps, and 40 patients had more than three polyps. The PDR was 49.1%, ADR 39.0%, advanced adenomas in 7.9%, and carcinomas were found in 5.4% of patients. In a country without any colorectal cancer screening policy, polyps were found in almost half of the 1778 asymptomatic patients evaluated in a single private center, 39% of cases adenomas, and 5.4% colorectal cancer. Our study suggests starting screening colonoscopy at the age of 45. A poor bowel preparation significantly impacted the adenoma detection rate.

Assessment of quality benchmarks in adenoma detection in Mexico

Background and study aims  Several Latin American countries, including Mexico, have reported an increase in colorectal cancer (CRC) mortality. The effectiveness of a colonoscopy in preventing CRC depends on the quality of the procedure, for which the adenoma detection rate (ADR) is one of the most trusted indicators. Awareness of ADR can improve the quality of colonoscopies through proper feedback and training of the specialists. The goal of this study was to estimate the ADR among Mexican endoscopists with experience in CRC screening and to compare it with previously reported data from this country. Methods  We carried out a retrospective study to analyze ADR data in Mexico. The information was obtained from a group of certified endoscopists and compared with the former published data from Mexico. Results  We found a current ADR of 24.6 % (95 %CI, 22.4 %-26.8 %) from 1,478 colonoscopies performed by eight endoscopists in two third-level private hospitals. The average ADR reported in previous publications was 15.2 % (95 %CI, 13.3 %-17.1 %). Statistical analysis showed differences between our results and those from previous studies (24.6 % vs. 15.2 %, P  < 0.001). Conclusions  The actual ADR in Mexico is higher than previously reported. Previous low ADR values could be explained by poorly performed colonoscopies rather than by low adenoma and CRC incidence in our country.

Determination of withdrawal times in individualized opportunistic screening colonoscopies

To investigate effects of bowel preparation, experience level of colonoscopists, and colonoscopy withdrawal time (CWT) on the quality of an individual opportunistic screening colonoscopy, according to adenoma detection rate (ADR).Data were retrospectively analyzed from opportunistic screening colonoscopies (n = 16,951) at 4 hospitals of various care levels in China.The ADR positively correlated with the experience level of the colonoscopist. The individualized CWT varied, depending on the quality of bowel preparation and the number of colonoscopies performed previously by the colonoscopist. In a setting of adequate bowel preparation, the mean CWT decreased with the increased experience of the colonoscopist. With poor and inadequate bowel preparation, no colonoscopist at any level of experience could obtain a satisfactory ADR.For adequately prepared colonoscopies, minimum CWTs have been determined. Repeat colonoscopy is strongly recommended for patients with poor bowel preparation, regardless of the colonoscopist's experience.

Cancer Screening Awareness and Practice in a Middle Income Country; A Systematic Review from Iran

Objective: Ageing population and noticeable changes in lifestyle in developing countries like Iran caused an increase in cancer incidence. This requires organized cancer prevention and screening programs in population level, but most importantly community should be aware of these programs and willing to use them. This study explored existing evidence on public awareness and practice, as well as, adherence to cancer screening in Iranian population. Methods: Major English databases including Web of Science, PubMed, Scopus, and domestic Persian databases i.e., SID, Magiran, and Barakat search engines were searched. All publications with focus on Iranian public awareness about cancer prevention, screening, and early detection programs which were published until August 2015, were explored in this systematic review. For this purpose, we used sensitive Persian phrases/key terms and English keywords which were extracted from medical subject headings (MeSH). Taking PRISMA guidelines into considerations eligible documents, were evaluated and abstracted by two separate reviewers. Results: We found 72 articles relevant to this topic. Screening tests were known to, or being utilized by only a limited number of Iranians. Most Iranian women relied on physical examination particularly self-examination, instead of taking mammogram, as the most standard test to find breast tumors. Less than half of the average-risk adult populations were familiar with colorectal cancer risk factors and its screening tests, and only very limited number of studies reported taking at least one time colonoscopy or FOBT, at most 5.0% and 15.0%, respectively. Around half of women were familiar with cervical cancer and Pap-smear test with less than 45% having completed at least one lifetime test. The lack of health insurance coverage was a barrier to participate in screening tests. Furthermore some people would not select to be screened only because they do not know how or where they can receive these services. Conclusion: Low awareness and suboptimal use of screening tests in Iran calls for effective programs to enhance intention and compliance to screening, improving the patient-physician communication, identifying barriers for screening and providing tailored public awareness and screening programs.

Assessment of Bone Morphogenetic Protein 3 Methylation in Iranian Patients with Colorectal Cancer

BACKGROUND

Colorectal cancer (CRC) is a common cancer that results in outstanding morbidity and mortality worldwide. DNA methylation is one of the most important epigenetic events that is thought to occur during the early stages of oncogenic transformation especially in CRC. The aim of this study was to investigate whether hypermethylation of bone morphogenetic protein 3 (BMP3) in tissue samples is implicated in Iranian patients with CRC.

METHODS

From fresh frozen tissue samples of 30 patients with CRC, the DNA was isolated, treated with sodium bisulfite and analyzed by methylation-specific polymerase chain reaction with primers specific for methylated or unmethylated promoter sequences of the BMP3 gene. Demographic characteristics of the patients including age, sex, tumor grade, location, stage, and TNM classification were evaluated and the relationship between hypermethylation of the gene and clinicopathological features was analyzed.

RESULTS

Methylation of the BMP3 promoter was often present in the DNA extracted from the tumoral tissues. A sensitivity of 56.66% and specificity of 93.3% were attained in the detection of colorectal neoplasia.

CONCLUSION

We assumed that solely BMP3 methylation analysis in our population is not sufficient to select the gene as a screening biomarker and it should be considered in combination with other markers to screen for detection of colorectal cancer.

Advanced colonic neoplasia in the first degree relatives of colon cancer patients: A colonoscopy-based study

We aimed to determine the risk of advanced neoplasms among a cohort of asymptomatic first degree relatives (FDRs) of patients with sporadic colorectal cancer (CRC) compared with matched controls. Data for patients with a diagnosis of CRC made between September 2013 and August 2014 were obtained from a population-based cancer registry system in Tehran. Screening colonoscopies were done for 342 FDRs and the findings were compared to those from 342 age- and gender-matched healthy controls without a family history of CRC. We reported the association as conditional Odds Ratio (OR) using Mantel Hazel and Logistic regression. The prevalence of advanced neoplasia was 13.2% among FDRs and 3.8% in controls (matched OR [mOR], 4.0, 95% confidence interval [CI], 2.1 - 7.6; p < 0.001). In FDRs aged 40-49 years, the prevalence of advanced neoplasia was significantly higher than in their matched controls (mOR, 6.8, 95% CI, 1.5-31.4; p = 0.01). Family history of CRC in at least one FDR was the strongest predictor of advanced neoplasia (adjusted OR, 4.0, 95% CI: 2.1-7.6; p < 0.001). The age of the index case at diagnosis did not predict the presence of advanced colonic neoplasms in their FDRs. Our study indicates a high risk of advanced neoplasia in FDRs of CRC cases, where only eight colonoscopies are needed to detect one advanced neoplasia. Our data suggest that all FDRs, regardless of the age of CRC diagnosis in their index case, should be considered for a targeted early screening.

Bowel Prep Quality in Patients of Low Socioeconomic Status Undergoing Screening Colonoscopy With Patient Navigation

The effectiveness of colonoscopy is directly affected by the quality of the patient's bowel preparation. Patients with lower socioeconomic status (SES) are at increased risk of having suboptimal bowel prep quality. Patient navigators can play a key role in clarifying bowel prep instructions. The aim of the present study was to examine the quality of bowel prep and its predictors among individuals of low SES undergoing screening colonoscopy with patient navigation. Participants (N = 607) were individuals of low SES who completed a screening colonoscopy with patient navigation. Demographic information was collected after the participants received a primary care referral for a screening colonoscopy. After the colonoscopy was completed, medical charts were reviewed to document the colonoscopists' bowel prep quality ratings. A total of 6.8% (41/607) of the sample had poor bowel prep, which significantly correlated with having a colonoscopy that did not reach the cecum. If fair preps were included, approximately 19.3% (117/607) of our cohort would be considered to have suboptimal bowel prep. Our suboptimal bowel prep rates were better than those reported from other low SES samples.

Mean Polyp per Patient Is an Accurate and Readily Obtainable Surrogate for Adenoma Detection Rate: Results from an Opportunistic Screening Colonoscopy Program

BACKGROUND The incidence of colorectal cancer is rising in several developing countries. In the absence of integrated endoscopy and pathology databases, adenoma detection rate (ADR), as a validated quality indicator of screening colonoscopy, is generally difficult to obtain in practice. We aimed to measure the correlation of polyp-related indicators with ADR in order to identify the most accurate surrogate(s) of ADR in routine practice. METHODS We retrospectively reviewed the endoscopic and histopathological findings of patients who underwent colonoscopy at a tertiary gastrointestinal clinic. The overall ADR and advanced-ADR were calculated using patient-level data. The Pearson's correlation coefficient (r) was applied to measure the strength of the correlation between the quality metrics obtained by endoscopists. RESULTS A total of 713 asymptomatic adults aged 50 and older who underwent their first-time screening colonoscopy were included in this study. The ADR and advanced-ADR were 33.00% (95% CI: 29.52-36.54) and 13.18% (95% CI: 10.79-15.90), respectively. We observed good correlations between polyp detection rate (PDR) and ADR (r=0.93), and mean number of polyp per patient (MPP) and ADR (r=0.88) throughout the colon. There was a positive, yet insignificant correlation between advanced ADRs and non-advanced ADRs (r=0.42, p=0.35). CONCLUSION MPP is strongly correlated with ADR, and can be considered as a reliable and readily obtainable proxy for ADR in opportunistic screening colonoscopy programs.