The role of adjuvant and neoadjuvant therapy in gastrointestinal stromal tumors

Gastrointestinal stromal tumors are the most common sarcoma of the gastrointestinal tract. A decade ago, the only therapy for gastrointestinal stromal tumors was surgery. Treatment paradigms changed with the discovery that gastrointestinal stromal tumor cells express KIT, a tyrosine kinase growth factor receptor, which is mutated in 85% of cases. Imatinib and sunitinib are tyrosine kinase inhibitors with activity against advanced gastrointestinal stromal tumors. This review will discuss the available data on the use of imatinib in the adjuvant setting and the role of imatinib and sunitinib in the neoadjuvant setting.

Retrospective series and prospective studies have demonstrated the benefit of adjuvant imatinib. Randomized data show improved recurrence free survival in patients receiving imatinib for 1 year postoperatively. Ongoing studies are further defining the length of adjuvant therapy. Neoadjuvant treatment decreases tumor size to allow for surgical resection with less morbidity. The use of neoadjuvant imatinib therapy in a prospective randomized study was safe with encouraging outcomes. This approach for palliating advanced disease also appears to be safe following imatinib, sunitinib, or other tyrosine kinase inhibitors therapy.

Treatment for gastrointestinal stromal tumors, formerly limited to surgery, now is a combination of surgery and tyrosine kinase inhibitors therapy. Combination therapy is safe and improves outcomes, particularly in the adjuvant setting.