Molecular Characteristics of Colorectal Cancer, Associated Epidemiological Risk Factors, and Challenges to Introducing Screening in Oman: A Mixed-Approach Study

Background Cancer is the leading cause of death in developed and developing countries alike. The early detection of cancer is associated with decreased mortality and improved prognosis; in addition, prompt recognition reduces the need for extensive treatment. Colorectal cancer (CRC) is one of the most common types of cancer diagnosed in Oman after breast and thyroid cancers. Various molecular and genetic pathways have been linked to the development of CRC; furthermore, certain risk factors have been found to be associated with an increased risk of CRC, including diabetes mellitus, obesity, type of diet, smoking and alcohol consumption, and certain sociodemographic factors. Moreover, the absence of screening programs and certain sociodemographic and economic characteristics have also been reported as factors which can potentially lead to delays in cancer diagnosis or treatment. To the best of our knowledge, no previous studies have yet been conducted in Oman to investigate the molecular characteristics of CRC in this country or to identify their regional distribution in order to ascertain the prevalence of specific subtypes in different regions of Oman. Also, to our knowledge, no previous studies conducted in Oman have sought to examine relationships between the sociodemographic and economic factors, and co-existing morbidities with the development of various subtypes of CRC, as well as factors affecting access to medical care, screening programs, and the challenges or barriers to introducing a screening program for CRC in Oman. Aims and objectives The aims of the study are: 1.To determine the prevalence of molecular characteristics of CRC in various regions of Oman. 2.To identify associations between molecular characteristics of CRC and various causative factors in the Omani population, such as diabetes mellitus, ischaemic heart disease, obesity, smoking and alcohol consumption, and sociodemographic factors. 3.To evaluate barriers and identify challenges related to the introduction of a national CRC screening program among members of the public and policymakers in Oman. The objectives of the study are: 1.To assess the prevalence of molecular subtypes of CRC in various regions of Oman. 2.To determine associations between molecular characteristics of CRC and various factors, such as diabetes mellitus, ischaemic heart disease, obesity, smoking and alcohol consumption, and sociodemographic factors. 3.To evaluate awareness of and to identify barriers toward CRC screening among members of the public. 4.To explore the knowledge, attitude, and perceived barriers toward CRC screening among health care professionals (HCPs). 5.To identify barriers toward introducing a CRC screening program in Oman. Methods: Three different studies will be conducted. Study one will be a prospective cohort study aiming to address aim one. A total of 305 newly-diagnosed CRC patients will be recruited from the Sultan Qaboos University Hospital (SQUH) and Royal Hospital (RH) over a three-year period. The prevalence of various molecular characteristics of CRC in different regions of Oman will be identified and a registry of CRC cases established. Study two will consist of a case-control study aiming to address aim two. A total of 338 subjects (169 per group) will be recruited, of which half will consist of CRC patients recruited from the registry established in study one. Non-cancer patients in the control group will be matched to the case group based on important potential confounding factors, such as age and gender. The main outcome will be the determination of risk factors associated with different molecular subtypes of CRC. Study three will comprise a mixed-design study aiming to address aim three. This study will target three groups: general Omani population with average risk for CRC, HCPs working in primary health centres (PHCs) and endoscopy service centres (including both nurses and physicians), and policymakers in Oman. A cross-sectional study will be conducted of 2,178 members of the public recruited from different healthcare centres located in Muscat Governorate. Data regarding the participants? knowledge, attitude, and barriers toward CRC screening will be collected. In addition, approximately 336 HCPs (including both nurses and physicians) will be recruited from various healthcare centres within Muscat Governorate and endoscopy services in Oman to identify potential and facilitators toward implementing CRC screening in Oman. Finally, individual interviews will be conducted with a group of 18 administrative personnel and policymakers from the Ministry of Health (MOH) in Oman in order to collect qualitative data regarding their views on the challenges with implementing CRC screening in Oman. Statistical analysis: For study one, descriptive statistics will be used to describe the basic sociodemographic and clinical characteristics of newly-diagnosed CRC patients. Prevalence rates of different subtypes of CRC will be identified and compared according to sociodemographic and clinical data using Fisher?s exact test and analysis of variance (ANOVA). For study two, descriptive statistics will be used to describe the basic sociodemographic and clinical characteristics of CRC cases and controls. A univariate analysis will be conducted to identify factors associated with CRC cases overall, as well as different subtypes of CRC, compared with the controls. Multivariate logistic regression will be employed to explore which risk factors are associated with the development of CRC and its specific subtypes. For study three, a regression (linear or logistic) model will be used to examine factors (e.g., sociodemographic factors) contributing to knowledge, attitude, and barrier scores among members of the public. Descriptive statistics will be used to describe the basic sociodemographic characteristics of the HCPs recruited. The HCPs? knowledge and barrier scores or percentages related to CRC screening will be compared with their sociodemographic data. A regression (linear or logistic) model will be used to examine factors contributing to knowledge or barrier scores for each professional group. Finally, the qualitative data collected during the personal interviews with HCPs and policymakers from the MOH will be analysed through content and thematic analysis. All quantitative and qualitative data analysis in the three studies will be performed using the software Statistical Package for the Social Sciences (SPSS), version 23 (IBM Corp., Armonk, NY) and NVivo, version 12 (QSR International, Doncaster, Australia), respectively, and levels of statistical significance will be set at 5%.