Modeling historic incidence trends implies early field cancerization in esophageal squamous cell carcinoma
Fig 2
Functional regularization of period (year) trends on the field-defect rate νFD.
The parameters s0, y0, w1, w2 and ν0 are estimated from the data. Note, νFD approaches the background rate ν0 smoothly at the reference point y0 and is assumed to remain constant for y > y0. Here s refers to age, B to birth year, y to period. For illustration, we also show some randomly generated νFD trajectories with the attenuating term log(s/s0) included (solid lines) and with this term omitted (dotted lines).