The effect of neoadjuvant Imatinib therapy on outcome and survival after rectal gastrointestinal stromal tumour

Aim The study aimed to characterize the pathological and clinical response of rectal gastrointestinal stromal tumours (GISTs) to neoadjuvant Imatinib. Method The medical records of patients with rectal GISTs who were diagnosed and treated in five medical centres in Israel between January 2002 and January 2009 were retrospectively examined. Twelve patients who fulfilled the inclusion criteria of nonmetastatic rectal GIST for which preoperative neoadjuvant treatment with Imatinib was considered were suitable for enrollment. Results Of the 12 patients, nine received neoadjuvant treatment with Imatinib. The three patients who had immediate surgery were excluded. There were five men and four women with a median age of 63 years and a median follow up of 32 months. All tumours were located in the lower two-thirds of the rectum. One patient had a complete clinical response, six had a partial response and two had stable disease. Seven patients subsequently underwent surgery; six had an R0 resection and one had an R1 resection. Three patients had recurrence. There was no disease-related mortality. The reduction in both tumour size and mitotic activity during preoperative Imatinib therapy was significant. Conclusion Preoperative Imatinib therapy can shrink large rectal GISTs, improving the chances of successful radical surgery and decreasing the risk of considerable morbidity.