Table 1.

Main natural history assumptions in the MISCAN-Colon model.

Model parameter	Value	Source
Distribution of risk for adenomas over the general population	Gamma distributed, mean 1, variance 1.98	Fit to multiplicity distribution of adenomas in autopsy studies:[7] Age 60 ≥1: 20% ≥2: 6% ≥3: 2% Age 90: ≥1: 37% ≥2: 17% ≥3: 9%
Adenoma incidence per year	Age and race dependent varying from 0-10% per year	Fit to adenoma prevalence in autopsy studies*, and cancer incidence in SEER registry in 1995.[6]
Probability that a new adenoma is progressive	Dependent on age at onset, varying from 0-89%	Fit to adenoma prevalence in autopsy studies*, and cancer incidence in SEER registry in 1975-1979 (pre-screening era).[6]
Regression of adenomas	No significant regression of adenomas	Expert opinion
Mean duration of preclinical cancer	6.7 years	Estimated from large randomized controlled FOBT trials.[8]
Percent of non-progressive adenomas that stay 6-9mm, or become ≥10mm	25% and 75% respectively	Fit to size distribution of adenomas in colonoscopy trial (percentages corrected for colonoscopy sensitivity): [9] ≤5mm: 73% 6-9mm: 15% ≥10mm: 12%
Percent of cancers that develops from 6-9mm adenoma and from 10≥mm adenoma	30% of CRCs develop from 6-9 mm, 70% from 10≥mm	Expert opinion
Localization distribution of adenomas and cancer	Dependent on state and race:	Directly estimated from SEER in 1995.[6]
10-year relative survival after clinical diagnosis of CRC	Dependent on period, stage, state and race (Supporting material 2)	Directly estimated from SEER in 1995-2008.[6]

SEER: Surveillance, Epidemiology, and End Results; CRC: Colorectal cancer

^*References to autopsy studies provided in Supporting material 1.