One Biopsy, Several Readings: Checking an AI RNA-Sequencing Cancer-Origin Result Against the Sequencing Chain's Own Settings

An AI test reads the RNA sequencing of a tumour biopsy and gives a probability for each of many cancer types. It is especially useful when the doctor cannot tell where a cancer began. Today the answer is usually shown as a top choice, or a top three. This note describes a simple check that can sit on top of any such test. From the data of one biopsy, several versions are made by changing the settings that the sequencing chain itself allows, within the range it permits. The AI model reads every version. If the answers stay together, the biopsy supports the answer firmly. If they spread out, the answer depends on a setting and deserves a closer look. Other methods shake the data with invented changes, such as artificial noise. This method uses the settings the sequencing chain itself allows, so the uncertainty it measures is real. One number, the spread value, tells which case it is. A computer-decided shunting action then moves the case that needs care to a specialist's list, while all other cases carry on. The words used for the patient stay calm. It needs the data of only one biopsy, no second sample and no new device, and the model itself is not changed. Patent pending.