Loading
Whether a gastrointestinal stromal tumour will come back after surgery is read from three things on the pathology report, its size, how many cells are dividing in a 5 square millimetre field, and where it started (stomach is safer than small bowel or rectum), plus whether it ruptured; high-risk patients get three years of imatinib and the others get none.
What is measured: the probability that a resected GIST will recur. How: tumour size in centimetres, mitotic count per 5 mm² (about 50 high-power fields; 5 or fewer against more than 5), the site of origin and rupture before or during surgery, read against the Miettinen and Lasota (AFIP, 2006) tables (a gastric tumour of 5 cm or less with 5 or fewer mitoses has a 0 to 2 percent risk; a small-bowel tumour over 10 cm or with more than 5 mitoses a 50 to 90 percent risk), the modified NIH criteria (Joensuu 2008) that add rupture as high risk, and nomograms and contour maps. The genotype is read alongside: KIT exon 11 deletions involving codons 557 and 558 are worse, PDGFRA D842V tumours are indolent and imatinib-insensitive, SDH-deficient tumours follow their own course; KIT (CD117) and DOG1 immunohistochemistry make the diagnosis. What a result changes: high risk or rupture means three years of adjuvant imatinib (SSG XVIII: five-year survival 92 against 82 percent with one year; five years against three is being tested), with the dose and the decision informed by genotype (no adjuvant imatinib for D842V); intermediate risk is discussed case by case; low and very low risk get follow-up only, with imaging intensity set by risk. Where it matters: GIST and its KIT exon 11, PDGFRA D842V and imatinib-resistant pages.
The glossary entry explains the word; the readout page carries the scoring rule, the thresholds approvals use, the companion diagnostics and the tests.
Shares PDGFRA exon 18 mutation (D842V), Avapritinib, KIT, Gastrointestinal stromal tumour (GIST).
Shares PDGFRA D842V-mutant GIST, KIT exon 11-mutant GIST, Imatinib-resistant GIST, Gastrointestinal stromal tumour (GIST).
Shares KIT exon 11-mutant GIST, Imatinib-resistant GIST, Gastrointestinal stromal tumour (GIST).
Shares PDGFRA, KIT exon 11-mutant GIST, Imatinib-resistant GIST, KIT.
Shares PDGFRA D842V-mutant GIST, Avapritinib, Gastrointestinal stromal tumour (GIST).
Shares KIT exon 11-mutant GIST, Imatinib-resistant GIST, KIT, Gastrointestinal stromal tumour (GIST).
Shares KIT exon 11-mutant GIST, Imatinib-resistant GIST, KIT.
Shares PDGFRA D842V-mutant GIST, Avapritinib.