Table 2 Model Assumptions For An Average Repair Proficient Colorectal Cancer
From: A simple algebraic cancer equation: calculating how cancers may arise with normal mutation rates
Parameter | Assumptions | Comments |
|---|---|---|
driver mutations or rate-limiting stages (k) | the same for all cancers, transformation or growth does not occur until all driver mutations accumulate | value is unknown and is inferred to fit the epidemiology, growth is likely to precede transformation but most mutations likely accumulate in normal stem cells |
number of crypts (m) | does not change during life | crypt number may vary between individuals |
stem cells per crypt (n) | does not change during life | value is unknown (minimum of one per crypt), inferred to fit the epidemiology. |
mutation rate (u) | does not change during life | value may differ between genes but is ~10-10 to 10-9 per base per division |
stem cell divisions since birth (d) | constant division rate during life | value is unknown but may be as high as once per day [13] |
probability of cancer (p) | no significant time between transformation and diagnosis | data from cancer epidemiology, lag time may vary between patients |