Knowledge of the Molecular Signaling Pathways Improves the Chances of Treatment of Gastrointestinal Stromal Tumors

Abstract

Gastrointestinal Stromal Tumors (GISTs) are the most common mesenchymal (nonepithelial)
tumors of the gastrointestinal tract. A better molecular understanding of this entity,
as Christopher L. Cordless in Modern Pathology in 20141 demonstrated, GISTs mainly a result
from two-level changes in two Oncogenes: KIT oncogene (75%) and PDGFRA oncogene (α
receptor platelet-derived growth factor) which occurs in about 10% of cases; the remaining
15% are designated wild type tumors. Having knowledge of the oncogenic pathways of this condition, allows the possibility
of creating models that stratify the risk of recurrence of GIST after surgery. This risk is
determined by analyzing three factors (size, mitotic index and tumor location) in very low risk
patients, low risk, medium and high risk, according to the model of “NIH” (National Institutes
of Health). Patients with very low risk and low-risk tumors can perform only surgery; the intermediate
risk and high risk may be indicated for adjuvant treatment. Emphasis on tumors where
rupture of the tumor capsule occurs, always have indication for adjuvant treatment.