Neoadjuvant Imatinib Therapy Research Articles

Neoadjuvant Imatinib in Gastrointestinal Stromal Tumors (GIST): The First Analysis of a Mexican Population.

Introduction Gastrointestinal stromal tumors (GISTs) are neoplasms originating from the interstitial cells of Cajal, pacemaker cells responsible for intestinal motility. Patients with locally advanced GISTs and those with borderline resections due to the proximity of vital anatomical structures, which could result in unacceptable post-surgical morbidity, require special therapeutic consideration. Imatinib, a tyrosine kinase inhibitor, has demonstrated significant successin the non-surgical management of metastatic GIST, and its favorable impact on overall survival in the adjuvant setting makes it logical to speculate on the benefit it could provide as a neoadjuvant medication in patients with locally advanced disease. Methods Patients aged 18-90 years with a diagnosis of GIST confirmed by immunohistochemistry (CD117 positivity) who were treated at the Oncology Hospital of Centro Médico Nacional Siglo XXI in Mexico City from January 2012 to December 2016 were included in the study. It is a retrospective study with a duration of four years. Clinical data were collected from the medical records, which included sex, age, tumor location, initial resectability, reason for unresectability, initial tumor size, and mitotic rate. In the case of unresectable disease, patients who were evaluated by medical oncology and who had received treatment with 400 mg of imatinib daily were evaluated. Results A total of 312 patients diagnosed with GIST were analyzed. One hundred thirty-one were men (42%) with a mean age of 57 years, and 181 were women (58%) with a mean age of 59 years. The most frequent anatomical location was the stomach (n=185, 59.2%). At the time of diagnosis, 210 patients (67.3%) presented with resectable disease, while n=102 patients (32.7%) had unresectable disease. A total of 102 patients with unresectable disease received therapy with 400 mg of imatinib per day. Sixteen patients (15.7%) presented a reduction in tumor dimensions and underwent surgery. Conclusion The study highlights the importance of complete surgical resection and the potential benefit of neoadjuvant imatinib therapy in converting unresectable to resectable disease. The results suggest that imatinib can be effective in converting unresectable GISTs to resectable ones, allowing for a complete resection to be performed and obtaining an R0 resection in 93.7% of these cases.

A pure endoscopic full-thickness resection of a large non-metastatic GI stromal tumor >5 cm of the stomach after neoadjuvant imatinib therapy

A pure endoscopic full-thickness resection of a large non-metastatic GI stromal tumor >5 cm of the stomach after neoadjuvant imatinib therapy

Short-term and long-term outcomes after robotic radical surgery for rectal gastrointestinal stromal tumor

BackgroundThe optimal approach for ensuring both complete resection and preservation of anal function in rectal gastrointestinal stromal tumor (GIST) remains unknown. The aim of this study was to clarify short-term and long-term outcomes after robotic radical surgery for rectal GIST.MethodsA total of 13 patients who underwent robotic radical surgery for rectal GIST between December 2011 and April 2022 were included. All robotic procedures were performed using a systematic approach. A supplemental video of robotic radical surgery for rectal GIST is attached. The short-term outcome was the incidence of postoperative complications during the first 30 days after surgery. Surgical outcomes were retrieved from a prospective database. Long-term outcomes, including overall survival and recurrence-free survival, were determined in all patients.ResultsMedian distance from the tumor to the anal verge was 4.0 cm. Surgical margins were negative in all patients. Two patients underwent neoadjuvant imatinib therapy. All patients underwent sphincter-preserving surgery. None underwent conversion to open or laparoscopic surgery. The incidence of postoperative Clavien-Dindo grade II and grade ≥ III complications was 7.7% and 0%, respectively. The median postoperative hospital stay was 7 days. Twelve patients (92.3%) underwent stoma closure within 5 months of the initial surgery. Median follow-up time was 76 months. The 5-year overall survival and recurrence-free survival rates were both 100%. None of the patients had recurrence.ConclusionShort-term and long-term outcomes after radical robotic surgery for rectal GIST were favorable. Robotic surgery might be a useful surgical approach for rectal GIST.

Efficacy and safety of neoadjuvant imatinib therapy for patients with locally advanced rectal gastrointestinal stromal tumors: A multi-center cohort study.

Background: Several issues on neoadjuvant imatinib therapy remain controversial despite its widespread application for rectal gastrointestinal stromal tumors (GIST). We aimed to describe the clinicopathological characteristics of this specific population, and compare the surgical and oncologic outcomes between patients with or without neoadjuvant imatinib therapy. Patients and methods: A cohort of 58 consecutive locally advanced rectal GIST patients receiving surgical treatment between January 2007 and July 2019 at Sun Yat-sen University Cancer Center and Yunnan Cancer Hospital was retrospectively analyzed. Recurrence-free survival (RFS) and overall survival (OS) were estimated using Kaplan-Meier method. Results: There were 33 (56.9%) patients who received neoadjuvant imatinib therapy. Among them, 20 (60.6%) patients had partial response (PR) as their best response, 11 (33.3%) patients had stable disease (SD), and 2 (6.1%) patients had progressive disease (PD). The median tumor size reduced from 5.2 to 4.0 cm after treatment (p < 0.001), and an attained “maximal response” was primarily achieved (32/33) on the 12th month after treatment. The most common adverse event was anemia. There were 27 adverse events occurred, most of which were grade 1 (19/27). With respect to intraoperative and postoperative surgical outcomes, no significant difference was found between patients with or without neoadjuvant Imatinib therapy except that patients with neoadjuvant treatment had a significant higher rate of preventive ileostomy (p = 0.004). Patients received neoadjuvant treatment had a superior 2-years RFS outcome than those without, though the difference was no significant (91.7% vs. 78.9%, p = 0.203). There were no significant differences in the 2-years OS rates (95.2% vs. 91.3%, p = 0.441). Conclusion: Neoadjuvant imatinib therapy is an effective and safe treatment for locally advanced rectal GISTs. Further studies are warranted to validate the long-term prognostic benefit for patients with rectal GISTs receiving neoadjuvant imatinib therapy.

Effect of skeletal muscle loss during neoadjuvant imatinib therapy on clinical outcomes in patients with locally advanced GIST

BackgroundCurrently, the effect of skeletal muscle loss during neoadjuvant imatinib therapy on clinical outcomes in patients with locally advanced gastrointestinal stromal tumors (LA-GIST) remains unclear. This study aims to investigate the relationship between changes in skeletal muscle and postoperative complications, survival and tumor response in patients with LA-GIST during neoadjuvant therapy with imatinib.MethodsWe retrospectively analyzed pre- and post-treatment computed tomography images of 57 GIST patients who underwent radical surgery after neoadjuvant therapy with imatinib from January 2013 to March 2019. Skeletal muscle index (SMI) was measured at the L3 vertebral level in all patients. A cut-off value (SMI < 52.3 cm2/m2 and < 38.6 cm2/m2 for men and women, respectively) published in a previous study was used to define sarcopenia. Based on gender, we defined ΔSMI (%)/250 days above 9.69% for men and ΔSMI (%)/250 days above 7.63% for women as significant muscle loss (SML). Factors associated with postoperative complications and tumor response were analyzed using logistic regression, and predictors affecting patient prognosis were analyzed using Cox regression.ResultsOf the 57 patients, sarcopenia was present before and after neoadjuvant therapy in 20 (35.09%) and 28 (49.12%) patients, respectively. It was not associated with immediate or long-term clinical outcomes. However, patients with SML during neoadjuvant therapy had a higher incidence of postoperative complications (60.00% vs. 25.00%, p = 0.008), worse pathological regression (44.00% vs. 75.00%, p = 0.017) and worse 3-year survival (Male, 68.75% vs. 95.45%, p = 0.027; Female, 66.67% vs. 100.00%, p = 0.046) than patients without SML.ConclusionThe development of SML during neoadjuvant therapy in LA-GIST patients, rather than pre- and post-treatment sarcopenia, is a major prognostic factor for the long-term prognosis and is also associated with recent postoperative complication rates and pathological regression.

EP-262 Neoadjuvant imatinib for Resectable Gastrointestinal Stromal Tumors. A State-of-the-art

Abstract Aims Surgical removal remains the cornerstone of primary GIST treatment and complete surgical resection offers prognostic value toward risk of relapse. However, primary tumors, particularly of the stomach, are of advanced size when detected, and multivisceral resection seems to be the treatment of choice. Existing results of recent clinical trials have established the feasibility of neoadjuvant imatinib therapy mainly in unresectable GISTs. Yet, proof of the survival effectiveness of neoadjuvant imatinib therapy in borderline resectable tumors has not been sufficiently demonstrated. Methods A review of the literature was performed to identify the current evidence for preoperative treatment of large GISTs with Imatinib regarding R0 resection and oncological outcome. Results Data supporting benefit of neoadjuvant imatinib are available from several case reports and small retrospective series, most of which include a mix of patients with borderline resectable and unresectable primary disease. In addition, a single-phase II United States Intergroup trial and an Asian phase II trial of neoadjuvant therapy in large stomach tumors, concluded that Neoadjuvant imatinib therapy is preferred for marginally resectable tumors. Progressive disease after neoadjuvant treatment was a rare event, and partial response was achieved in 40–80% of all patients. Conclusion Neoadjuvant therapy with imatinib is safe and recommended for patients with resectable, locally advanced GIST. It may also enable less invasive and organ-sparing surgery, increase the complete resection rate, and avoid the surgical rupture by decreasing the tumor size. Clinical questions still remain about the most appropriate period of pre- and post-operative imatinib administration in the neoadjuvant protocol.

Recent Advancements in the Treatment of Rectal Gastrointestinal Stromal Tumor: In Era of Imatinib.

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumor of the gastrointestinal tract, with an annual incidence of 10–15 cases per million. However, rectal GIST has a low incidence, accounting for approximately 0.1% of all rectal tumors. The treatment of rectal GISTs is still controversial and the relative unified guidelines and consensus opinions are inadequate. Treatment is based primarily on the clinical experience of the physician. The widespread application of neoadjuvant imatinib therapy allows diversification of treatment, especially in the choice of surgical methods. Herein, we reviewed the most recent literature and summarized the new progress in rectal tumor treatment, with the aim of providing patients with more systematic and individualized therapeutic strategies.

Robotic-assisted surgery for esophageal submucosal tumors: a single-center case series

Esophageal submucosal tumors (SMTs) are rare heterogenous clinical entities. The surgical resection can be performed in different surgical approaches. However, the robotic surgical strategy is poorly documented in the treatment of SMTs. We present our series of operated esophageal SMTs approached via robotic-assisted surgery. Six patients with symptomatic esophageal submucosal tumors underwent robotic surgery within a 3-year period. The performed procedures were robotic-assisted enucleation, robotic esophagectomy (RAMIE) and reverse hybrid robotic esophagectomy. Patients’ clinical data, intra/postoperative outcomes, and histopathological features were retrieved from the institution’s prospective database. Five of six patients were scheduled for upfront surgery: four underwent robotic enucleation (three leiomyoma and one suspected GIST) and one underwent reverse hybrid robotic esophagectomy (suspected GIST). One patient, diagnosed with GIST, was treated with neoadjuvant Imatinib therapy, before undergoing a RAMIE. No major intra-operative complications were recorded. Median length of stay was 7 days (6–50), with a longer post-operative course in patients who underwent esophagectomy. Clavien–Dindo > 3a complications occurred in two patients, aspiration pneumonia and delayed gastric emptying. The final histopathological and immuno-histochemical diagnosis were leiomyoma, well-differentiated GIST, low-grade fibromyxoid sarcoma and Schwannoma. Robotic-assisted surgery seems to be a promising option for surgical treatment strategies of benign or borderline esophageal submucosal tumors.

Postpartum Diagnosis of a Recurrent Metastatic Gastrointestinal Stromal Tumor

Background: Gastrointestinal stromal tumors are rare in pregnancy, and typically present in the second trimester with size-greater-than-dates, abdominal pain, or nonspecific symptoms. Case: A 31-year-old gravida 1 female presented in the postpartum period with weight loss, cachexia, an abdominal mass, and persistent unexplained tachycardia. She was found to have a recurrent metastatic gastrointestinal stromal tumor and pulmonary emboli. She was anticoagulated and treated with neoadjuvant imatinib therapy with excellent initial response. Unfortunately, she died one year later due to complications of her disease and treatment. Conclusion: Malignancy should be considered in a pregnant woman with size-greater-than-dates or with an abdominal mass, especially when associated with unexplained weight loss and a history of a gastrointestinal stromal tumor, as the recurrence rate is high without continued maintenance therapy. Delivery at 35 to 37 weeks is recommended, and involvement of a multidisciplinary team improves outcomes.

Postpartum diagnosis of a recurrent metastatic gastrointestinal stromal tumor

Background: Gastrointestinal stromal tumors are rare in pregnancy, and typically present in the second trimester present with size-greater-than-dates, abdominal pain, or nonspecific symptoms. Case: A 31-year-old gravida 1 female presented in the postpartum period with weight loss, cachexia, an abdominal mass, and persistent unexplained tachycardia. She was found to have a recurrent metastatic gastrointestinal stromal tumor and pulmonary emboli. She was anticoagulated and treated with neoadjuvant imatinib therapy with excellent initial response. Unfortunately, she died one year later due to complications of her disease and treatment. Conclusion: Malignancy should be considered in a pregnant woman with size-greater-than-dates or with an abdominal mass, especially when associated with unexplained weight loss and a history of a gastrointestinal stromal tumor, as the recurrence rate is high without continued maintenance therapy. Delivery at 35 to 37 weeks is recommended, and involvement of a multidisciplinary team improves outcomes.

Transanal endoscopic microsurgery with alternative neoadjuvant imatinib for localized rectalgastrointestinal stromal tumor: a single center experience with long-term surveillance.

Transanal endoscopic microsurgery (TEM) is widely used in the treatment of local rectal lesions and helps avoid radical surgery. This study evaluated the management and outcome in a long-term followed cohort of patients with localized rectal GIST underwent TEM with alternative neodajuvant imatinib (nIM). A retrospective cohort study was undertaken of patients identified from a case database at Department of General Surgery, Peking Union Medical College Hospital (PUMCH) over a continuous period, from January 2006 to December 2017. Over 12years, 42 patients presented with a primary rectal GIST in PUMCH. Median age was 49 (range 27-77) years. Neoadjuvant imatinib (nIM) therapy was used in 16 patients, significantly reducing mean tumor size from 4.41 to 2.46cm (p < 0.001) and mitotic index (p = 0.041). All of these patients underwent TEM with no tumor rupture, nIM therapy enabled sphincter-preserving surgery to be undertaken in 16 (16/42) patients who would otherwise have required abdominoperineal resection or pelvic exenteration for tumor clearance and all patients (42/42) achieve R0 resection and negative margin. Imatinib was also used as postoperative adjuvant treatment in 15 patients with high-risk GIST. Median follow-up was 77 (range 14-144) and overall survival is 100%. In 42 patients, Local recurrence (LR) occurred in 3 of 42 patients and 1 of 42 patients developed distant metastasis (DM) in 112months after TEM. In the univariate analysis, mitotic index (p = 0.028), NIH risk categories (p = 0.047) were predictive feature of local relapse. The application of nIM significantly decreased tumor size in large localized rectal GIST, which permitted TEM to preserve sphincter. The TEM procedure with alternative neoadjuvant imatinib therapy is a practicable treatment for patients with rectal GIST to preserve anus and have satisfied anal function.

Quality of treatment and surgical approach for rectal gastrointestinal stromal tumour (GIST) in a large European cohort

BackgroundRectal gastrointestinal stromal tumours (GISTs) are rare tumours. Variability in the management may influence outcome, but there is a lack of understanding regarding contemporary variance in care. A multicenter, international, retrospective cohort study was performed to elucidate characteristics and outcomes of rectal GIST in European practice, with particular reference to surgical approach. MethodsAll rectal GIST patients diagnosed between 2009 and 2018 were identified from five European databases. Recurrence free survival (RFS) and overall survival (OS) were estimated using Kaplan-Meier method. Possible confounders were identified using Cox regression analyses. ResultsFrom 210 patients, 155 patients had surgery. The three main types of surgery were local tumour resection (LTR, n = 46), low anterior resection (LAR, n = 31) and abdomino-perineal resection (APR, n = 32). Most patients received neoadjuvant (65%) and/or adjuvant imatinib therapy (66%). Local recurrence rate after surgery was 15% and overall recurrence rate 28%. No significant differences were found in terms of RFS nor OS between LTR, LAR and APR. However, locally resected tumours were smaller, while LAR and APR patients more often received perioperative imatinib. General hospitals treated smaller GISTs, offered imatinib less frequently, and had a higher tumour rupture rate. In the multivariate analysis in the group having LTR, APR or LAR, the only significant prognostic factor for local recurrence was higher age (HR 1.06, CI 1.00–1.12, p = 0.048). ConclusionsIn European clinical practice for rectal GIST, LTR, LAR and APR have comparable local control. Multimodal approach is higher and tumour rupture less frequent in specialist centres compared to general hospitals.

Laparoscopic Multivisceral Resection of Gastrointestinal Stromal Tumor Post Neoadjuvant Imatinib Therapy: A Series Of Two Cases.

Title: Laparoscopic Multivisceral Resection of Gastrointestinal Stromal Tumor Post Neoadjuvant Imatinib Therapy: A Series Of Two Cases. Introduction: Gastrointestinal stromal tumor is the most common mesenchymal tumor of gastrointestinal tract. Surgery is the cornerstone of management. Targeted chemotherapy viz. Imatinib, sunitinib, regorafenib had reported to be useful in locally advanced cases for downstaging. Here we are presenting two cases, one was arising from the stomach another from tail of the pancreas. Both were successfully managed by laparoscopic multivisceral resection of gastrointestinal stromal tumor after downstaging of tumors. Case report 1: A 47 years old male presented with postprandial fullness and early satiety for 8 months associated with on an off episode of melena. His general, physical and abdominal examination was unremarkable. Endoscopy revealed, normal gastric mucosa with an extrinsic bulge. USG abdomen and CECT revealed a heterogeneously enhancing lesion probably arising from the greater curvature of the stomach and abutting spleen and pancreas. Neoadjuvant therapy started in view of locally advanced disease. He underwent laparoscopic sleeve resection of gastric GIST with distal pancreatico-splenectomy. After a year follow up, no signs of recurrence seen. Case report 2: A 64 years old male presented with dyspepsia and postprandial fullness for 2 years with no history of melena. He also had a loss of appetite and weight. UGI endoscopy revealed extrinsic compression with normal mucosa. USG abdomen and CECT revealed a 17.2 x 11 x 10.5 cm solid cystic lesion abutting greater curvature of the stomach and extending up to splenic hilum and effacing pancreas. In view of locally advanced disease he received imatinib for 1 year followed by laparoscopic distal pancreaticosplenectomy. On six months follow up he is doing well. Conclusion: Gastrointestinal stromal tumor is a rare mesenchymal tumor that has metastatic potential. Open surgery is the preferred view to avoid spill and positive resection margins. Here both patients were managed by multivisceral resection, laparoscopically. Though there is a dearth of literature regarding laparoscopic surgery. However, it is feasible in experienced hands.

Prospective Evaluation of Neoadjuvant Imatinib Use in Locally Advanced Gastrointestinal Stromal Tumors: Emphasis on the Optimal Duration of Neoadjuvant Imatinib Use, Safety, and Oncological Outcome.

Background: Neoadjuvant imatinib therapy has been proposed for routine practice with favorable long-term results for patients with locally advanced gastrointestinal stromal tumors (GISTs). However, clarification of the optimal duration, safety, and oncological outcomes of neoadjuvant imatinib use before surgical intervention remains necessary. Methods: We prospectively analyzed the treatment outcomes of 51 patients with locally advanced, nonmetastatic GISTs treated with neoadjuvant imatinib followed by surgery. The optimal duration was defined as the timepoint when there was a <10% change in the treatment response or a size decrease of less than 5 mm between two consecutive computed tomography scans. Results: Primary tumors were located in the stomach (23/51; 45%), followed by the rectum (17/51; 33%), ileum/jejunum (9/51; 18%), and esophagus (2/51; 4%). The median maximal shrinkage time was 6.1 months, beyond which further treatment may not be beneficial. However, the maximal shrinkage time was 4.3 months for the stomach, 8.6 months for the small bowel and 6.9 months for the rectum. The R0 tumor resection rate in 27 patients after neoadjuvant imatinib and surgery was 81.5%, and 70.4% of resection procedures succeeded in organ preservation. However, 10 of 51 patients (19.6%) had complications following neoadjuvant imatinib use (six from imatinib and four from surgery). Conclusion: Our analysis supports treating GIST patients with neoadjuvant imatinib, which demonstrated favorable long-term results of combined therapy. However, careful monitoring of complications is necessary. The optimal duration of neoadjuvant imatinib use before surgical intervention is, on average, 6.1 months.

Aggressive surgical resection following neoadjuvant imatinib therapy for advanced duodenal tumor with hepatic metastasis

Duodenal gastrointestinal stromal tumors (GISTs) are rare tumors which constitute <5% of all cases of GIST. The treatment of locally advanced/inoperable and metastatic GIST is primarily tyrosine kinase inhibitor therapy (TKI), i.e., imatinib mesylate. In some patients, initial TKI therapy may result in significant downstaging of the primary tumor and metastatic disease. The role of aggressive surgical resection in such patients remains controversial. We present a case of advanced duodenal GIST treated successfully by Whipple's procedure with liver wedge resection following neoadjuvant TKI therapy. This case shows that aggressive surgical resection for metastatic duodenal GIST following neoadjuvant imatinib seems to be a feasible treatment option.

Neoadjuvant imatinib therapy in rectal gastrointestinal stromal tumors.

Rectal gastrointestinal stromal tumor (GIST) is a rare entity. Thus, its clinical features have not been well documented, and optimal treatment strategies have not been established. Surgery for rectal GISTs may be difficult because they are often large in size. In addition, rectal GISTs were found to be associated with high rates of local recurrence, regardless of the surgical procedure, before imatinib was introduced in the early 2000s. Since the introduction of imatinib therapy, accumulating evidence suggests that neoadjuvant imatinib therapy may improve the outcomes of rectal GIST treatment. Neoadjuvant imatinib therapy for rectal GISTs offers a number of potential benefits, including tumor downsizing, reduction in mitotic activity, reduced morbidity, and a reduced risk of recurrence. Less radical procedures may allow for the preservation of the anal sphincter and avoidance of a permanent colostomy. This review summarizes the current status and future perspectives of neoadjuvant imatinib therapy for the treatment of rectal GISTs.

Combined computed tomography-measured tumor density and RECIST for evaluating neoadjuvant therapy in locally advanced gastrointestinal stromal tumors

Background: Deciding the most appropriate timing for surgical resection of locally advanced gastrointestinal stromal tumors (LAGISTs) has conventionally been challenging, because no well-established clinical guideline is available. In this study, we combined computed tomography (CT)-measured tumor density and Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1) to evaluate the clinical responses in 12 patients with LAGISTs. We aimed to offer alternative approaches that can enhance the surgical resectability evaluation of LAGISTs after neoadjuvant therapy. Methods: This study recruited 12 consecutive patients diagnosed with LAGISTs who had received neoadjuvant imatinib therapy primarily at the study institution from December 2010 to December 2017. They were followed up until December 2017. Tumor responses were simultaneously analyzed by measuring tumor density on CT images and applying RECIST. Clinicopathological features, clinical outcomes, and KIT and PDGFR gene mutation profiles were also evaluated. Results: Analysis of tumor responses using the combined CT-measured tumor density and RECIST method revealed that 10 of 12 patients were considered as partial response (PR). One patient showed stable disease (SD) but was a borderline PR hence all 11 patients were resectable. Three of 7 GISTs patients who underwent resection were considered as stable disease according to RECIST but 2 of 3 were categorized as PR using our combined evaluation approach. The other one patient was a borderline PR with 28% of CT tumor density reduction. Of the 12 patients, five patients had KIT exon 11 deletion, two had KIT exon 11 insertion, three had point mutation and one was wild-type KIT and PDGFRA . However, KIT gene mutation status was not a useful indicator when evaluating surgical resectability in our study. Conclusions: We suggest that our combined CT-measured tumor density and RECIST evaluation method may be beneficial for deciding an appropriate timing for surgical resection of LAGISTs.

Neoadjuvant therapy for gastrointestinal stromal tumor.

Molecular-targeting therapy using tyrosine kinase inhibitor imatinib mesylate is effective for metastasis/recurrent gastrointestinal stromal tumors (GISTs). Likewise, imatinib would be effective in the neoadjuvant therapy for high-risk GIST. Neoadjuvant therapy may have the potential to increase the complete resection rate and to avoid the surgical rupture by decreasing the tumor size. Thereby, it is expected that improvement of recurrence rate and survival rate can be obtained by neoadjuvant therapy. Neoadjuvant therapy is also expected to be favored from the viewpoint of organ/function preservation by tumor shrinkage. The existing results of clinical trials established the feasibility of neoadjuvant imatinib therapy. However, proof of the survival effectiveness of neoadjuvant imatinib therapy has not been sufficiently demonstrated. The aim of this article is to introduce previous evidence and strategies regarding neoadjuvant therapy for GIST.

Surgical intervention of a giant gastric gastrointestinal stromal tumor following neoadjuvant therapy with imatinib

Gastrointestinal stromal tumors (GISTs) treatment has improved remarkably in recent years. However, giant and unresectable lesions could still be challenging, especially from the surgical aspect. We reported a case of a 44-year-old male patient who complained about abdominal pain and distention. Computed tomography scans, upper GI endoscopy, and tissue biopsy proved the diagnosis of a giant GIST which was considered unresectable. With the aid of neoadjuvant imatinib therapy, the tumor shrank tremendously, and we successfully performed en bloc resection with clean margins. Therefore, we suggested combining imatinib therapy and surgery in managing giant and unresectable GIST lesions.

Rectal gastrointestinal stromal tumour: What do we know in 2017? A systematic review protocol

IntroductionGastrointestinal stromal tumour is a pathology that originates from the interstitial cells of Cajal and differentiates from other mesenchymal neoplasm by expression of CD117 oncogene on Immunohistochemistry test. Colon and Rectal GISTs constitutes of approximately 5% of all gastrointestinal GISTs. The past decade has witnessed a dramatic change in the treatment of rectal cancer. Preoperative, perioperative and postoperative, management has changed thanks to new chemotherapy regimens and emergence of novel surgical techniques. Our aim is to investigate if same change can be implemented for rectal GISTs management. Methods and analysisThis protocol is compliant with the Preferred Reporting Items for Systematic Review and Meta-Analysis protocols (PRISMA-P) guidelines. Exclusion and inclusion criteria are outlined within this protocol. Points of interest and objectives are described within this protocol. The search strategy, aims to identify all articles on “Rectal GISTs”. DiscussionThe choice of resection type surgery depends upon the location and size of rectal GIST. Neoadjuvant Imatinib therapy yields tumour shrinkage in at least 50% and is associated with a prolonged disease-free survival for intermediate and high-risk patients. This review will also allow a summary clinicopathological features and prognostic factors of rectal GISTs. Ethics and disseminationThe Centre for Reviews and Dissemination, University of York acknowledged that this systematic review is within the register scope. This review will be published in a peer-reviewed journal and will be presented at various national and international conferences.