Treatment Option Overview
The management of patients with gastrointestinal stromal tumors (GIST) is a multidisciplinary effort involving close collaboration between pathologists, medical oncologists, surgeons, and imaging experts.
Treatment may involve surgery and/or the use of tyrosine kinase inhibitors (TKI) depending on the extent of disease and tumor sensitivity to TKI. Although recurrence is common for patients with high-risk tumors (see Table1), complete resection of localized tumors may be associated with long-term disease-free survival (DFS).[Level of evidence: 3iiiDii] Standard chemotherapy is not used because of the insensitivity of GIST to chemotherapeutic agents.[3,4,5,6] Radiation therapy rarely has a role in the management of patients with GIST; it may occasionally be used for pain control in patients with limited, bulky hepatic metastases or with a single, large metastatic lesion fixed to the abdominal or pelvic wall.[Level of evidence: 2Div] Whether tumors 2 cm or smaller with a mitotic index of 5 or less per 50 high-power fields require surgery is controversial. Such tumors appear to have low rates of progression and metastasis, but the absolute rates are not known with precision. Endoscopic surveillance is an option.
Surgery is typically the initial therapy for the following types of patients:
- Those with primary GIST who do not have evidence of metastasis.
- Those with tumors that are technically resectable if the risks of morbidity are acceptable.
In the surgical treatment of GIST, the goal is complete gross resection with an intact pseudocapsule and negative microscopic margins. Because lymph node metastasis is rare with GIST, lymphadenectomy of clinically uninvolved nodes is not necessary.
Although a prospective, randomized trial studying the role of laparoscopic surgery in the management of GIST has not been performed, several studies, listed below, indicate a role for this surgical approach with gastric tumors:
- In one retrospective study involving 33 patients with gastric tumors ranging in size from 0.5 cm to 10.5.cm, all gross tumors could be successfully removed by laparoscopic surgery, with short hospitalizations and low morbidity. There were no recurrences observed with a mean follow-up of 13 months.[Level of evidence: 3iiDii]
- In another retrospective study involving 60 patients, laparoscopic or laparoscopy-assisted resections of GIST measuring 2 cm to 5 cm were associated with a 5-year DFS of 100% for very low-risk groups and low-risk groups versus a 5-year DFS of 89.9% for intermediate-risk groups and high-risk groups; no local or distant recurrences were observed for tumors smaller than 4 cm in size.[Level of evidence: 3iiDi]
- In another study involving 50 consecutive patients undergoing laparoscopic or laparoendoscopic resection of gastric GIST (mean tumor size = 4.4 cm) who were identified in a prospectively collected database, 46 (92%) patients were found to be disease free at a mean follow-up of 36 months.[Level of evidence: 3iiDi]