Figure 1

Markov process for disease natural history and prognosis of colorectal cancer (CRC).* * The ovals represent Markov states; the solid arrows represent the direct transition between states, and the dotted arrows represent the transition toward competing cause of death. Abbreviations: Small adenoma, adenoma smaller than 1 cm in size; large adenoma, adenoma larger than 1 cm in size; early CRC, Dukes' stage A and B colorectal cancer, late CRC, Dukes' stage C and D colorectal cancer; OCD, other cause of death.