Growth Rate Sensitivity Explorer

Hold a cross-sectional tumor-size distribution fixed and watch the implied natural-history timescale swing wildly as the assumed growth rate changes.

sensitivity analysis
natural history
tumor growth
assumption dependence

Implied years from initial lesion to observed size

Growth trajectory with observed tumor volumes

Summary statistics

Statistic	Value
Tumors (n)	298.000
Median implied years	4.701
IQR (years)	2.9–7.1
Assumed growth rate	0.40 cm/yr
Initial diameter	1.0 cm

The data didn't change — only the assumption did

Every histogram above is generated from the same fixed cross-sectional tumor sizes. Sliding the assumed growth rate from 0.2 to 1.0 cm/year moves the median implied age of these tumors by more than a decade. Reporting a natural-history timescale from cross-sectional imaging without stating (and justifying) the growth-rate assumption is a hidden modeling choice dressed up as a measurement.

Preparing the simulation…