Important Role of Health Surveillance Systems in Community‐Based Colorectal Cancer Screening

Abstract

This commentary discusses a recent report on the planning, implementation, and outcomes of a community‐based colorectal cancer screening program in Shanghai, China, as well as important components of a successful cancer screening program.

Colorectal cancer is an important cause of morbidity and mortality globally, with incidence increasing substantially in populations that previously reported low incidence rates, including in urban and economically developed areas of People's Republic of China [1], [2]. Screening for colorectal cancer has been shown to be effective in preventing death and reducing morbidity due to colorectal cancer; low‐ and middle‐income countries and communities are increasingly implementing organized or opportunistic screening programs and sharing their experiences to improve program quality assurance [3], [4], [5], [6].

In this issue of The Oncologist, Gong, Peng, and colleagues from the Shanghai Municipal Center for Disease Control and Prevention (Shanghai CDC) report on the planning, implementation, and outcomes of the first round of a community‐based colorectal cancer program in Shanghai, People's Republic of China [7]. The report illustrates the importance of fundamental components of public health surveillance and health service delivery systems needed to support a community‐based screening program. It describes the process of using evidence from the surveillance system to justify and make sound public health investments and policies. The report details the careful preparatory steps taken to ensure the availability of trained personnel, referral system, diagnostic and treatment facility capacity, and establishing a screening database prior to implementing the screening program. Building upon well‐developed health surveillance and service delivery systems, the comprehensive approach enabled data linkage for analysis and evaluation of results, and to inform areas for improvement in future rounds of the screening program. Moreover, the report highlights the significant challenges faced by screening programs to ensure that patients who screen positive are followed up to complete colonoscopy and subsequent care, even in a well‐resourced setting such as the Shanghai municipality. Strategies to overcome such challenges are needed urgently in the implementation of organized screening programs for colorectal and other cancers, particularly in resource‐constrained settings.

The analysis and reporting of Shanghai vital and cancer registry data clearly indicated increased colorectal cancer burden over time in the population and provided convincing evidence to justify government investment to initiate the colorectal cancer screening program. The Shanghai municipality began death registration in 1954 and cancer registration in 1963, enacting legislation over time to require reporting to achieve coverage of the entire population of the municipality [8]. Data from the periodic population‐based risk factor surveillance survey were useful to show low reported use of colorectal cancer screening modalities in the general population. The Shanghai government further invested in a dedicated, web‐based colorectal cancer screening registry and information management system [7], linked to cancer outcomes in the vital and cancer registries via unique personal identifying number. These data resources enable the Shanghai CDC to optimally evaluate the costs, operations, and impact of the screening program in reducing colorectal cancer mortality and morbidity in the defined target population.

Shanghai serves as an important model for other urban municipalities in low‐ and middle‐income countries and demonstrates the value and crucial role of government investment in building health surveillance and service delivery systems and in leading community‐based cancer screening programs. Components of such a system include accurate and timely cause‐specific death registration, population‐based cancer registration, and a screening database to capture key indicators of cancer screening and outcomes. Linkage of various databases using unique personal identifying numbers is needed to monitor and evaluate operation of the screening program and to measure the impact of the screening program in achieving its goals. The information management system dedicated to the cancer screening program [7] enabled listing of the population eligible for screening, tracking of the initial screening using the risk assessment questionnaire and the immunological fecal occult blood test (FIT), tracking of initial screening outcomes, subsequent referrals, and completion of diagnostic testing and treatment, all with reminder systems for program providers and participants.

The Shanghai report details the careful preparatory steps taken and policy considerations necessary prior to program implementation, including defining the eligible population, screening protocol, financing, ensuring the availability of trained personnel, a referral system for follow‐up services, and ensuring adequate capacity of the diagnostic and treatment facilities that serve the community health centers where the initial screening took place. These are consistent with recent recommendations and essential elements identified for population‐based cancer screening programs in low‐ and middle‐income countries [9], based on shared experience of International Cancer Screening Network members (ICSN). Sharing best practices can benefit all entities considering similar investments and programs and help set data standards and quality assurance measures, as encouraged by the International Colorectal Cancer Screening Network [6] and the ICSN [9]. The Shanghai experience will be especially informative as more nations and large municipalities initiate and strengthen health surveillance and service delivery systems and consider colorectal cancer screening programs.

The Shanghai report is noteworthy in that it highlights the elements that contributed to the success of the screening program [7]. The health surveillance system enabled the availability and use of local vital and cancer registry data, collected over decades, to make sound public health decisions. Based upon evidence, policy and guidance on colorectal cancer screening were jointly issued by government agencies in multiple sectors, thus ensuring authority, commitment, and success of the program. A lead agency was designated to be responsible for program management, protocol development, use of unique personal identifying number to link data, data management, training, quality control, and program evaluation. Standardized training was provided to personnel on an annual basis. The government took responsibility for bulk purchasing of the screening test, thus streamlining procedures, reducing cost, and increasing efficiencies. Importantly, prior to implementation, the lead agency identified hospitals for patient referral, diagnosis, and treatment, and engaged surgical, endoscopy, and pathology specialists to check the quality of diagnosis and treatment of colorectal neoplasia.

The colorectal cancer screening program in Shanghai used FIT and a risk assessment questionnaire to capture information on symptoms, personal history of polyps, appendicitis, and cancer, as well as family history of colorectal cancer, for initial screening. Individuals were referred for diagnostic colonoscopy based on positive FIT result, positive risk assessment by questionnaire, or both. Interestingly, although the overall proportion of screened positives who completed colonoscopy was 40%, this proportion was significantly higher among persons with positive FIT result (46%) or both positive FIT and risk assessment questionnaire (53%), compared with those with positive risk assessment questionnaire only (30%). The report stated that the initial FIT and risk assessment questionnaire results were generated by computer and communicated to participants via notification letters; positive‐result letters were used as referral letters for colonoscopy. The contents of the positive‐result letter, and the use of a computer‐generated letter to communicate risk, may warrant review and revision to increase compliance to completing colonoscopy, as are improved ways to communicate the increased risk of colorectal cancer to persons with family history of colorectal cancer or adenoma. Lowery and colleagues suggest four strategies for reducing colorectal cancer among persons with a positive family history of colorectal cancer, including improving the collection of family cancer history, establishing consensus on screening guidelines by family history, improving provider‐patient knowledge of guidelines and communication about colorectal cancer risk, and encouraging colorectal cancer survivors to promote screening within their families [10]. In addition to financial and other considerations suggested in the Shanghai report, better education and communication of the increased risk may help to improve colonoscopy completion rate in persons with a positive family history.

Although fifty hospitals in Shanghai were officially designated as treatment facilities after screening, 70% of them tier‐II hospitals, 35% of the participants who completed a colonoscopy chose a nondesignated higher‐tier hospital [7]. This led to the program's inability to capture outcome information on all colonoscopies performed and polyps detected. This limitation of having incomplete outcome information yields an underestimated polyp detection rate and highlights the challenges and importance of complete ascertainment of outcomes from all potential diagnostic and treatment facilities where participants may seek care after screening. Further, it suggests the potential to utilize patient navigation and similar interventions as an approach to link screen‐positive individuals to colonoscopy and care, as well as to obtain outcome data [11]. Such interventions could make use of the reminder system already established for program providers and participants in Shanghai. Better understanding of patient preferences and patterns in care‐seeking behaviors and interactions with patient navigators might inform health service planning in Shanghai, as well as the need to raise public awareness and change public perception and behavior about the quality of designated tier‐II hospitals. The Shanghai cancer registry will eventually identify colorectal cancer cancers diagnosed and treated in the nondesignated hospitals, at which time it will be possible to estimate the false‐negative rate of initial screening. Nevertheless, having complete data from all hospitals and persons screened is necessary for accurate assessment of test performance characteristics of FIT and the risk assessment questionnaire, and estimation of the rate of false‐positive test results.

Future analyses of data from colorectal cancer screening programs should include detection rates of all polyps and not only adenomas, due to increased understanding of the molecular heterogeneity and malignant potential of serrated polyps [12]. Data from linked screening and cancer registries will enable reporting and investigating initial screening false‐negative rates to inform adjustments needed in the screening program. Data from risk assessment questionnaires are useful to inform the design of colorectal cancer screening guidelines stratified by family history of colorectal cancer and polyps in the screened population. The wealth of data found in screening registries, linked with cancer and vital registry data, can serve as a platform from which to conduct research on the continuum of colorectal cancer care, prevention, and control. Such research could include investigating operational research questions on implementing screening programs in the general population and linking screening‐positive persons with care and treatment, as well as a range of questions on colorectal cancer early detection, diagnosis, treatment, survival, and palliation. An example of innovative research conducted alongside a public health program is the study of fecal microbiota profiling conducted by Shanghai CDC and U.S. National Cancer Institute researchers during the pilot phase of the Shanghai colorectal cancer screening program [13]. Study results, if confirmed in larger populations, suggest the potential value of fecal microbiota analysis to further improve colorectal cancer screening to reduce colorectal cancer mortality.

The Shanghai colorectal cancer screening program demonstrates the important role of government leadership and investment in essential elements of mass cancer screening efforts. These include the ability to identify and recruit eligible members of the population, link screen‐positive individuals to care and treatment, engage high‐quality treatment centers, as well as establishing accurate health surveillance systems to measure, monitor, and evaluate outcomes. These elements are currently not available in many low‐ and middle‐income countries, and, as such, mass screening for colorectal cancer is not recommended in such settings [14]. Although the Shanghai colorectal cancer screening program is fully appropriate for the Shanghai municipality, this intervention may not be generalizable to other settings lacking such fundamental components.

Disclosures

The authors indicated no financial relationships.