Decision analysis of surveillance for colorectal cancer in ulcerative colitis

Abstract

Background-Patients with long standing, extensive ulcerative colitis have an increased risk of developing colorectal cancer. Aims-To assess the feasibility of surveillance colonoscopy in preventing death from colorectal cancer. Patients-A hypothetical cohort of patients with chronic ulcerative colitis. Methods-The benefits of life years saved were weighted against the costs of biannual colonoscopy and proctocolectomy, and the terminal care of patients dying from colorectal cancer. Two separate Markov processes were modelled to compare the cost-benefit relation in patients with or without surveillance. The cumulative probability of developing colorectal cancer served as a threshold to determine which of the two management strategies is associated with a larger net benefit. Results-If the cumulative probability of colorectal cancer exceeds a threshold value of 27%, surveillance becomes more beneficial than no surveillance. The threshold is only slightly smaller than the actual cumulative cancer rate of 30%. Variations of the assumptions built into the model can raise the threshold above or lower it far below the actual rate. If several of the assumptions are varied jointly, even small changes can lead to extreme threshold values. Conclusions-It is not possible to prove that frequent colonoscopies scheduled at regular intervals are an eVective means to manage the increased risk of colorectal cancer associated with ulcerative colitis. (Gut 2000;46:500-506)

A novel mouse model for colitis-associated colon carcinogenesis induced by 1,2-dimethylhydrazine and dextran sulfate sodium

“…The incidence of colorectal cancer (CRC) has been increasing in patients with ulcerative colitis (UC) and the risk of CRC increases with increased extent and duration [1][2][3][4] . The mechanisms underlying the frequent development of CRC in patients with UC are still unknown.…”

Guia de Practica Clinica. Prevencion del Cancer Colorrectal. Actualizacion 2009

“…Los estudios de coste-efectividad disponibles muestran resultados contradictorios en relación con la vigilancia endoscópica 373,374 . A ello contribuye la escasez de información clínica contrastada 374 .…”

“…A ello contribuye la escasez de información clínica contrastada 374 . Adem as, debe tenerse en cuenta que la efectividad y coste-efectividad de las estrategias de vigilancia puede mejorar con la incorporación de nuevas t ecnicas endoscópicas 375 .…”

Ulcerative Colitis and Colon Cancer: Strategies for Cancer Prevention

“…Others have tried to draw conclusions on the impact on mortality by using mathematical models of hypothetical cohorts of UC patients. Recently, Delco and Sonnenberg [36] used the Markov model and compared cost-benefit outcomes in patients undergoing and those not undergoing a surveillance program. Albeit that such models make strict assumptions that may not be easily extrapolated into realworld populations, this modelling analysis did not find it possible to prove that colonoscopic surveillance was an effective means to manage the increased risk of CRC in UC patients.…”