Development of a simulation model of colorectal cancer

Abstract

Colorectal cancer (CRC) is deadly if not found early. Any protocols developed for screening and surveillance and any policy decisions regarding the availability of CRC resources should consider the nature of the disease and its impact over time on costs and quality-adjusted life years in a population. Simulation models can provide a flexible representation needed for such analysis; however, the development of a credible simulation model of the natural history of CRC is hindered by limited data and incomplete knowledge. To accommodate the extensive modeling and remodeling required to produce a credible model, we created an object-oriented simulation platform driven by a model-independent database within the .NET environment. The object-oriented structure not only encapsulated the needs of a simulation replication but created an extensible framework for specialization of the CRC components. This robust framework allowed development to focus modeling on the CRC events and their event relationships, conveniently facilitating extensive revision during model construction. As a second-generation CRC modeling activity, this model development benefited from prior experience with data sources and modeling difficulties. A graphical user interface makes the model accessible by displaying existing scenarios, showing input variables and their values, and permitting the creation of new scenarios and changes to its input. Output from the simulation is captured in familiar tabbed worksheets and stored in the database. The eventual CRC model was conceptualized through a series of assumptions that conformed to beliefs and data

Using simulation-optimization to construct screening strategies for cervical cancer

“…Harper and Jones [15] and Roberts et al [16] develop a detailed simulation model for colorectal cancer that focuses on cancer event relationships and could be applied to other forms of cancer or disease. Evenden et al [17] examine screening for Chlamydia using simulation that takes high-risk subgroups and their geographic dynamics into account, which results in a more holistic screening Chlamydia framework.…”

“…Cancer Death: Death due to cervical cancer. 16. All Cause Death: Death due to causes other than cervical cancer.…”

Probability model for estimating colorectal polyp progression rates

“…In this section, we first present our method for estimating incidence rates, followed by the probability model for estimating the progression rates. The probability model was developed based on the assumptions that nonpolyp pathway accounts for 15% of the cancers and 70% of the cancers with polyps arise from pathway 1 (based on expert opinions cited in [15] and [6]). All notation used in the model presented in this section are summarized in Table 1.…”

“…The literature contains a considerable number of simulation and mathematical models for CRC screening strategies ( [4][5][6][7][8][9][10][11][12] and CISNET models [13]). All of these models have a natural history component for the incidence and progression of polyps, most of which are modeled using variants of Markovian techniques.…”

Probabilistic cost-effectiveness comparison of screening strategies for colorectal cancer

“…We employ the Vanderbilt/NC State (V/NCS) stochastic discrete-event simulation model of the natural history of CRC, which is capable of modeling a population over time and may include a mixture of patients with different birth years, races, genders, and family histories of colorectal neoplasia [Cubbage 2003;Roberts et al 2008]. Exploiting the object-oriented structure of the model, a screening structure was added to perform deterministic and probabilistic costeffectiveness analyses of the screening strategies recommended by the clinical guidelines provided by the American Gastroenterological Association (AGA) [Winawer et al 2003] and some potential strategies employing more recently developed screening modalities.…”