Gastrointestinal Stromal Tumor (GIST)


Gastrointestinal stromal tumors (GISTs) comprise less than 1% of all gastrointestinal tumors and are rare compared with other types of gastrointestinal tumors due to the type of tissue where they originate.1,2 Despite overall rarity, GISTs are the most common nonepithelial or mesenchymal tumors of the gastrointestinal tract (80%), and they represent 5% of all sarcomas.3 In the US, approximately 4000 to 6000 adults are diagnosed with GIST per year.1 Globally, the incidence of GIST is approximately 1.5 in every 100,000 people.4 In 2015, researchers in Sweden conducted a systematic review of population-based cohort studies from 19 countries to approximate the global incidence of GIST. Most studies reported a 10-15 per million incidence of GIST.5

Race

GIST is more common in individuals of non-Hispanic origin compared with Hispanics (RR, 1.23).6 It is also more common in individuals of African descent (RR, 2.07), as well as individuals of Asian or Pacific Island origin (RR, 1.50), compared with Caucasians.6 

Age

GIST can occur in individuals of any age; however, GIST is rarely diagnosed in infants, young children, adolescents, or young adults.7,8 Sporadic GIST is primarily found in adults who are between 50 and 70 years of age.2,8 Median age at diagnosis is 60 years.3 Familial GIST is most common among individuals between 25 and 45 years of age. If GIST were to occur in individuals younger than 25 years, there is most likely a familial inheritance.2

Between 2001 to 2011, annual age-adjusted incidence increased from 0.55/100,000 to 0.78/100,000, demonstrating an increasing trend with age. Incidence peaks in individuals over 70 years of age (3.06/100,000).6

Sex

While some sources report that there is an equal gender distribution of GIST3,4, others report that GIST is slightly more common in men compared with women (rate ratio (RR), 1.35).6  

Prevalence of Types of GIST

Mutations in the KIT gene cause 80% of GIST, while mutations in the PDGFRA gene account for 10% of GIST.8 Succinate dehydrogenase gene (SDH) and neurofibromatosis type 1 gene (NF1) mutations comprise the rarest forms of GIST that are usually present within the Carney triad, Carney-Stratakis syndrome, and neurofibromatosis Type 1 syndrome.9,10,11

The Carney triad, caused by mutation of the SDH gene, is a rare, nonhereditary condition characterized by the presence of 3 different types of tumors: GISTs, pulmonary chondromas, and extra-adrenal paragangliomas. The Carney triad is most prevalent in young women with a mean onset at 20 years of age. There are less than 100 cases reported worldwide.12

Carney-Stratakis syndrome, caused by mutations in the SDHB, SDHC, and SDHD subunits of the SDH gene, is characterized by the presence of GISTs and paragangliomas. It presents in individuals at a young age (median age = 19 years). Carney-Stratakis syndrome, also known as Carney-Stratakis dyad, is an extremely rare, autosomal dominant, inherited syndrome, reported in less than 20 unrelated families worldwide. The prevalence is <1/1,000,000.13 

Neurofibromatosis type 1, caused by mutations in the NF1 gene, is an autosomal dominant genetic disorder, characterized by the presence of neurofibromas and café-au-lait macules.   Neurofibromatosis type 1 has an incidence of approximately 1:2600 to 1:3000 individuals, and half are familial in mode of inheritance.14  

Prevalence of GIST Based on Location

Studies show that 60% to 65% of GISTs primarily develop in the stomach, while 25% to 35% of GISTs are found in the small intestine. Less than 5% of GISTs develop in the esophagus, and the remainder are rarely found in the colon, rectum, and abdominal cavity.1,4 GISTs have the potential to become cancerous and metastasize to other regions of the body, so in individuals with widespread disease, primary GISTs have been found to metastasize primarily to the liver and intraperitoneal cavity, while less than 5% of metastatic cases involve the lungs, lymph nodes, subcutis, and bones.4

Detection of GIST

Between the years 1983 and 2000, researchers analyzed the manner of GIST diagnosis of 1460 individuals in Sweden. They found that 90% of GISTs were detected clinically, 69% due to symptoms, and 21% due to incidental findings during surgical procedures. The remaining 10% were discovered only on autopsy. Of the 90% clinically detected GISTs, 29% were categorized as high-risk, resulting in a 63% patient mortality within an average of 40 months, and 15% were categorized as malignant, with an 83% patient mortality within an average of 16 months.15 Early detection is critical to improving the survival rates of individuals with GIST. 

References

  1. Gastrointestinal stromal tumor (GIST): statistics. Cancer.Net. Published June 25, 2012. Accessed June 15, 2021.
  2. Familial GIST. Cancer.Net. Published January 15, 2016. Accessed June 16, 2021.
  3. Gastrointestinal stromal tumor. Union for International Cancer Control. Accessed June 15, 2021.
  4. Gastrointestinal stromal tumor (GIST): solid tumor model for cancer therapy. Medscape. Accessed June 15, 2021. 
  5. Søreide K, Sandvik OM, Søreide JA, Giljaca V, Jureckova A, Bulusu VR. Global epidemiology of gastrointestinal stromal tumours (GIST): a systematic review of population-based cohort studies. Cancer Epidemiol. 2016;40:39-46. doi:10.1016/j.canep.2015.10.031
  6. Ma GL, Murphy JD, Martinez ME, Sicklick JK. Epidemiology of gastrointestinal stromal tumors in the era of histology codes: results of a population-based study. Cancer Epidemiol Biomarkers Prev. 2015; 24(1):298-302. doi:10.1158/1055-9965.EPI-14-1002
  7. Gastrointestinal stromal tumor (GIST): risk factors. Cancer.Net. Published June 25, 2012. Accessed June 16, 2021.
  8. Gastrointestinal stromal tumor: frequency. MedlinePlus Genetics. Accessed June 16, 2021.
  9. SDH-deficient GIST. GIST Support International. Accessed June 14, 2021.
  10. Carney stratakis syndrome – GIST gastrointestinal stromal tumor – surgical pathology criteria. Stanford University School of Medicine. Accessed June 14, 2021.
  11. Valencia E, Saif MW. Neurofibromatosis type 1 and GIST: is there a correlation? Anticancer Res. 2014;34(10):5609-5612.
  12. Carney triad. Genetic and Rare Diseases Information Center. Accessed June 16, 2021.
  13. Carney stratakis syndrome. Orphanet. Accessed June 16, 2021.
  14. Neurofibromatosis type 1 (NF1): pathogenesis, clinical features, and diagnosis. UpToDate. Accessed June 16, 2021.
  15. Nilsson B, Bümming P, Meis-Kindblom JM, et al. Gastrointestinal stromal tumors: The incidence, prevalence, clinical course, and prognostication in the preimatinib mesylate era. Cancer. 2005; 103(4):821-829. doi:10.1002/cncr.20862

Article reviewed by Eleni Fitsiou, PhD, on July 1, 2021.

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