Figure 2

Regression tree to evaluate the features predictive of MSI-H. In the Amsterdam group 81% of right-sided vs 26.3% of left sided CRC were MSI-H (p = 0.0005) whereas in the subgroup without Amsterdam II criteria only 11.1% of the right-sided vs 1.7% of the left sided CRC were MSI-H (p = 0.13). To confirm and evaluate (analyze) these results, we built a Regression Tree which revealed that by using a combination of the two features “No Amsterdam Criteria” and “left sided CRC” to exclude MSI-H the accuracy was 89.7% (84.2-95.2).