Abstract for: Dynamics of Colorectal Cancer Screening in Low and Middle-Income Countries: A Modeling Analysis from Thailand

Early Colorectal Cancer (CRC) detection is critical to reducing CRC progression and mortality rates. However, low and middle-income countries often face CRC detection constraints, including restricted access to care and low colonoscopy capacity. Considering these two constraints, we aim to identify the best strategies for increasing access to CRC detection and colonoscopy capacity to minimize CRC progressions and deaths in Thailand. We developed Colo-Sim (Colorectal cancer Simulation model) and analyzed increased access to 1) screening, 2) symptom evaluation, and 3) their combination on two primary outcomes: prevented CRC deaths and progressions. Projecting the baseline from 2023-2032, annual deaths increased from 88 to 115 people/year (per 100K people), and annual CRC progressions rose from 132 to 160 people/year (per 100K people). Improving screening access prevents 7K CRC deaths and 9K CRC progressions; improving symptom evaluation access prevents 35K CRC deaths and no CRC progressions; and the combined strategy prevents 41K CRC deaths and 7K CRC progressions. The combined strategy would prevent more deaths than each strategy alone; however, there is a tradeoff. Increasing the current capacity (200K) can reduce the tradeoff and improve all outcomes. With sufficient capacity (681K), the combined strategy achieves the best results across all primary outcomes.