Surgical Management of Gastrointestinal Stromal Tumours: A Large Single Centre Experience

Abstract

Introduction: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract, accounting for 1-3% of all gastrointestinal malignancies. The most common site of origin within the gastrointestinal tract is the stomach, followed by the small bowel. The clinical presentations of GISTs are highly variable according to the site of origin and the and size, but none of them is pathognomonic. GISTs are indeed often diagnosed incidentally during investigations performed for other reasons. The preoperative radiological diagnosis of GISTs is complicated by their varied macroscopic morphology. Moreover, the precision of preoperative histopathological diagnostics is reduced by the submucosal localization of the lesion. Surgical resections is the ‘gold standard’ therapeutic choice of primary GISTs. Recently, a targeted therapy with inhibitors of tyrosine kinase receptors (imatinib) has been introduced for the management of advanced and metastatic tumors. Aim of the study: The present study was designed in order to assess the survival of GIST-diagnosed patients after surgical resection, to identify factors that could have a prognostic impact and finally evaluate the role of Imatinibmesylate as therapeutic option in this group of individuals. Materials and methods: We retrospectively collected 88 consecutive patients who were diagnosed with GIST and surgically resected in our center (Department of General Surgery, ‘San Matteo’ Hospital, Pavia) in the last 15 years (January 2000-December 2014). General and clinical data were reviewed from patients’ medical reports: symptoms at presentation, clinical course, histopathological features, type of surgery, post-surgical complications and disease-free survival. Results: 45 (51.13%) out of 88 patients were male, 43 (48.86%) were female. The median age of our study population was 55 years. Most tumors originated in the stomach (63.63%, 56), 22.72% (20) were isolated from the small intestine, duodenum (3.4%, 3), colon (3.4%, 3), esophagus (2.27%, 2) or elsewhere (4.54%, 4) with an average diameter of 9.1 cm (range 0.5-19 cm). Tumor size was less than 2.0 cm in 22.72% (20) of patients, between 2.0 and 5.0 cm in 38.63% (34) of patients, between 5.0 and 10.0 cm in 25% (22) of patients, and greater than 10.0 cm in 13.63% (12). Twenty-one patients presented with gastrointestinal bleeding (23.86%), 17 patients with intestinal obstruction (19.3%), 8 with intraperitoneal haemorrhage (9.09%) and 4 with perforation and peritonitis (4.5%). Thirtyeight patients were asymptomatic (43.01%) and diagnosed incidentally during investigations performed for other reasons. Complete macroscopic resection (Wedge+Partial organ resection) was performed in 74 patients (84.1%), total organ resection and peritoneal biopsy were chosen for 9 patients (10.22%), while 5 patients (5.685) received “en-bloc” resection. Fourty-six (52.27%) out of 88 patients underwent postoperative (adjuvant) treatment with Imatinib and only one isolated case received a combination of Imatinib and Sunitinib. 23 (26.14%) patients did not need any adjuvant therapy but only a close follow up with Computed Tomography (CT) and blood tests monitoring every 3/6 months. We were not able to collect data from 18 (20.45%) patients who did not presented at the follow-up visits. Conclusion: GISTs constitute an interesting chapter of oncological pathologies. Surgery is still the gold standard treatment in localized primary GIST. Still a little number of cases with low risk disease can be treated with radical surgery. The prognosis is strictly related to the size and completeness of the surgical resection. Large size, high mitotic rate, high risk group, and adjacent organ involvement all contribute to bad outcome of GISTs. Imatinib therapy significantly improves survival of patients with intermediate-high risk or advanced staging.