Gastrointestinal stromal tumours: ESMO-EURACAN Clinical Practice Guidelines for diagnosis, treatment and follow-up
Abstract
Gastrointestinal stromal tumours (GISTs) are rare tumours, with an estimated unadjusted incidence of around 1/100 000/year. This only covers clinically relevant GISTs, since, if investigated, a much higher number of lesions LESS-THAN OR EQUAL TO 1 cm in diameter (microGISTs) can be found at histopathological examination of stomach tissue in middle-aged and elderly individuals.
There is a slight prevalence in males. The median age is around 60-65 years, with a wide range.
Occurrence in children is very rare. Paediatric GIST represents a clinically and molecularly distinct subset, marked by female predominance, absence of KIT/platelet-derived growth factor alpha (PDGFRA) mutations, frequent mutations or silencing of the four genes that encode the subunits of the succinate dehydrogenase (SDH) enzyme complex, gastric multicentric location and possible lymph node metastases.
Some syndromes are linked to GISTs: The Carney triad syndrome, marked by gastric GISTs, paraganglioma and pulmonary chondromas (these may occur at different ages); Carney-Stratakis syndrome, marked by a dyad of GIST and paraganglioma; and Neurofibromatosis type 1(NF1), possibly leading to wild-type (WT), often multicentric GIST, predominantly located in the small bowel. Families with germline autosomal dominant mutations of KIT are an extremely rare finding, presenting with multiple GISTs at an early age, possibly along with other associated features such as pigmented skin macules, urticaria pigmentosa and diffuse hyperplasia of the interstitial cells of Cajal in the gut wall.