The Tyrer-Cuzick model does not have a strict minimum age for a calculation, although the per annum baseline risk for women under 30 is very small. This basically means that a woman essentially has the same lifetime risk at 20 as she does at 30 as long as the other risk factors are the same. As Tyrer Cuzick is based on IBIS trial participants, one might think that the patient should be in her 30’s. However, the calculator accepts any age between 1 and 84.
The Claus model starts at 30, and the Gail model starts at 35.
BRCPAPRO, like T/C does not have a strict age minimum.