Figure 1.

Approximate distribution of MGMT methylation in GISTs, according to pathogenetic type. The pie chart illustrates the distribution of GISTs according to the molecular trigger.¹ The shaded area, representing GISTs featuring MGMT methylation, involves about two thirds of SDH-deficient GISTs, one fifth of NF1-associated GISTs, two fifths of the other KIT/PDGFRA-WT GISTs, and slightly more than one twentieth of KIT mutant GISTs; no MGMT-methylated cases have been reported so far among PDGFRA mutant GISTs.

Source: Data from Ricci et al.¹⁹

GIST, gastrointestinal stromal tumor; MGMT, O⁶-methylguanine-DNA methyltransferase; SDH, succinate dehydrogenase.