Gastrointestinal tumors of the colon and rectum

Local excision and radical excision for rectal gastrointestinal stromal tumors: a meta-analysis protocol

Background

To date, several studies have compared the surgical and oncological outcomes of local excision (LE) and radical excision (RE) for rectal gastrointestinal stromal tumors (GISTs), but some have limited numbers of small series. This protocol outlines the planned scope and methods for a systematic review and meta-analysis that will compare the surgical and oncological outcomes of LE and RE in patients with rectal GISTs.

Methods

This protocol is presented in accordance with the PRISMA-P guideline. PubMed, Embase, Web of Science, Cochrane Library and Wanfang database will be systematically searched. Furthermore, reference lists of all included articles will be screened manually to add other eligible studies. We will include randomized controlled trials (RCTs) and non-randomized studies (NRS) in this study. The primary outcomes evaluated will be R0 resection rate and disease-free survival, while the secondary outcomes will contain overall survival, length of stay, tumor rupture rate and complications. Two reviewers will independently screen and select studies, extract data from the included studies, and assess the risk of bias of the included studies. Preplanned subgroup analyses and sensitivity analyses are detailed within this protocol. The strength of the body of evidence will be assessed using GRADE.

Discussion

This review and meta-analysis will provide a comprehensive evaluation of the current evidence concerning the application of LE and RE in patients with rectal GISTs. The findings from this review will serve as a foundation for future research and emphasize the implications for clinical practice.

Systematic review registration

PROSPERO (CRD42017078338), https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=387409, PROSPERO CRD42017078338.

Rectal Gastrointestinal Stromal Tumors

Rectal gastrointestinal stromal tumors (GISTs) are rare types of tumors, but the incidence is increasing, and we now know more about the pathogenesis and management of rectal GIST. The main goal is to resect the tumor with negative microscopic margins. With the development of neoadjuvant Imatinib therapy, preoperative reduction in tumor size has become possible, thus introducing the chance for anus-preserving surgery, with better quality of life. We present a case of a 55-year-old female who presented to the emergency department with complaints of bleeding per rectum, abdominal pain, and pain on defecation. A 6-cm mass was detected during the rectal examination and a biopsy confirmed the diagnosis of GIST. The patient was given neoadjuvant imatinib chemotherapy for four months followed by trans-anal resection of the mass. The procedure was done successfully, and she received further adjuvant imatinib for a course of three years. Follow-up by magnetic resonance imaging and a colonoscopy after two years showed no recurrence. The patient is living healthily and doing well.

Clinicopathological features and prognosis of colonic and rectal gastrointestinal stromal tumors: A propensity score matching analysis

Background

Colonic gastrointestinal stromal tumor (cGIST) and rectal gastrointestinal stromal tumor (rGIST) are two rare subtypes of gastrointestinal stromal tumor (GIST). The view that colonic and rectal carcinoma are different is generally accepted; however, whether there is a difference between cGIST and rGIST is still unknown. Here, we aimed to provide evidence for future clinical management and research by comparing the differences between the two types of GIST in the above-mentioned aspects.

Methods

Patients were enrolled from three medical centers in China and published literature was collected following the inclusion and exclusion criteria. Propensity score matching was used to eliminate differences between cohorts.

Results

Between cGIST and rGIST patients, significant differences were observed in age, tumor size, mitotic index, NIH risk category, growth pattern, and symptoms. Adjuvant therapy is used in a high proportion of cGIST patients, and neoadjuvant therapy is used in a high proportion of rGIST patients. Although local resection is the main surgical method in both cohorts, the proportion is higher in cGIST patients. The overall survival of rGIST patients was better than that of the cGIST patients before propensity score matching (PSM). Interestingly, no significant differences in prognosis were observed after PSM.

Conclusions

Although there were significant differences between cGIST and rGIST patients in baseline characteristics, clinicopathological features, treatment choice, and overall survival rate before PSM, no significant differences in long-term survival were observed between the two groups after PSM. In our study, there may be no differences in the tumor entity between cGIST and rGIST.

Prognostic Factors and Management of Colorectal Gastrointestinal Stromal Tumors

Introduction The gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm of the gastrointestinal tract. Even though it can be found in any location of the digestive tract, the colorectal GIST is rare. With this study, we aim to review the current knowledge regarding the prognosis and management of colorectal GIST.

Methods A literature search was conducted in PubMed, and 717 articles were collected. After analyzing these studies, 60 articles were selected to use in this review.

Results The mitotic index, as well as tumor size and location were identified as good discriminators of prognosis in various studies. Surgery remains the only curative therapy for potentially resectable tumors. However, even after surgical resection, some patients develop disease recurrence and metastasis, especially those with high-risk tumors. Therefore, surgical resection alone might be inadequate for the management of all colorectal GISTs. The discovery of GIST's molecular pathway led to a shift in its therapy, insofar as tyrosine kinase inhibitors became part of the treatment schemes for this tumor, revolutionizing the treatment's outcome and prognosis.

Discussion/Conclusion The controversy concerning colorectal GIST prognosis and treatment can be, in part, attributed to the limited number of studies in the literature. In this review, we gathered the most recent knowledge about the prognosis and management of GIST in this rare location and propose two algorithms for its approach. Lastly, we highlight the importance of an individualized approach in the setting of a multidisciplinary team.

Transvaginal Resection of a Rectal Gastrointestinal Stromal Tumor: A Case Report

Gastrointestinal stromal tumors (GISTs) are a type of mesenchymal tumors. They are rare in rectum. This location is a surgical challenge due to the high morbidity after aggressive surgeries. We present the case of an 81-year-old female with a high-grade GIST treated with transvaginal excision and adjunctive therapy with imatinib. The postoperative period was uneventful without anal dysfunction. Within the types of surgical treatment available, transvaginal excision is an acceptable procedure in lesions located in the rectovaginal region.

Multifocal gastrointestinal stromal tumor: A case report with CT, surgical, and histopathologic correlation

Mutifocal gatrointestinal stromal tumors (GISTs) are rare conditions that are usually associated with other syndromes or reported in pediatric cases. The sporadic form represents only 11% of GISTs. The imaging features on a contrast-enhanced computed tomography examination, surgery and histopathology of a rare case of a sporadic multifocal small bowel GISTs in an emergency setting are described. This case highlights how GISTs appearances on an imaging computed tomography may vary. Radiologists can have difficulty in defining the point of origin of large lesions. In our case, laparotomy open surgery was mandatory to figuring out the correct diagnosis.

Management of low rectal gastrointestinal stromal tumor with neoadjuvant therapy and transanal excision: a rare case report and review of the literature

Background

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. However, rectal GISTs represent only 5% of this category. We report a case of a rectal GIST treated with local excision after neoadjuvant therapy.

Case presentation

A 41-year-old male patient presented with anal bleeding. Colonoscopy revealed a mass located 5 cm from the anal verge. Histological examination showed a GIST with immunohistochemical positivity for CD117 and CD34. Transanal local excision was performed after neoadjuvant therapy.

Conclusion

Neoadjuvant immunotherapy for GISTs with unfavorable localization may facilitate local excision and avoid complications of more demanding operations.

DNA damage response and repair in colorectal cancer: Defects, regulation and therapeutic implications

DNA damage response, a key factor involved in maintaining genome integrity and stability, consists of several kinase-dependent signaling pathways, which sense and transduce DNA damage signal. The severity of damage appears to determine DNA damage responses, which can include cell cycle arrest, damage repair and apoptosis. A number of recent studies have demonstrated that defection in signaling through this network is thought to be an underlying mechanism behind the development and progression of various types of human malignancies, including colorectal cancer. In this review, colorectal cancer and its molecular pathology as well as DNA damage response is briefly introduced. Finally, the involvement of key components of this network in the initiation/progression, prognosis, response to treatment and development of drug resistance is comprehensively discussed.

Management of rectal gastrointestinal stromal tumor

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm of the gastrointestinal tract. However, rectal GIST is rare, the incident rate of it is approximately 5% of all GISTs. Rectal GIST symptoms generally include bleeding and/or pain and occasionally, urinary symptoms. Immunohistochemical evaluation finds that most rectal GIST tumors are CD117 (KIT) positive, and are sometimes CD34, platelet-derived growth factor receptor alpha (PDGFRA), smooth muscle actin, S-100, or vimentin positive. The National Institutes of Health (NIH) classifies rectal GIST as very-low risk, low risk, intermediate risk, or high risk, and the frequencies have been estimated as 0-23.8% for very-low risk, 0-45% for low risk, 0-34% for intermediate risk, and 21-100% for high risk tumors. The first-line treatment for localized GIST is curative resection, but is difficult in rectal GIST because of anatomical characteristics such as the deep, narrow pelvis and proximity to the sphincter muscle or other organs. Several studies noted the efficacy of the minimally invasive surgery, such as trans-anal, trans-sacral, trans-vaginal resection, or laparoscopic resection. The appropriate surgical procedure should be selected depending on the case. Imatinib mesylate (IM) is indicated as first-line treatment of metastatic or unresectable GIST, and clinical outcomes are correlated with KIT mutation genotype. However, the KIT mutation genotypes in rectal GIST are not well known. In this review, as in other GISTs, a large proportion (59-100%) of rectal GISTs carry exon 11 mutations. Although curative resection is indicated for localized rectal GIST, a high rate of local recurrence is a problem. Multimodal therapy including perioperative IM may improve postoperative outcomes, contributing to anus-preserving surgery. Moreover, KIT mutation analysis before IM treatment is important. This review summarizes current treatment strategies for rectal GIST.

The efficacy of adjuvant imatinib therapy in improving the prognosis of patients with colorectal gastrointestinal stromal tumours

INTRODUCTION

Although it has now been accepted that imatinib is a valid treatment for gastrointestinal stromal tumour (GIST) patients in the adjuvant setting, information on its clinical efficacy in improving the prognosis for patients with colorectal GISTs is limited.

METHODS

The clinical and follow-up records of 42 colorectal GIST patients who underwent surgical resection at our institution between January 2004 and December 2013 were reviewed retrospectively. The effect of postoperative imatinib treatment on recurrence free survival and overall survival time was analysed with the Kaplan-Meier method and the multivariate Cox proportional hazards model.

RESULTS

Sixteen patients were assigned to imatinib treatment (imatinib group) after surgical tumour resection while twenty-six patients did not receive any adjuvant treatment (control group). The one, three and five-year recurrence free survival rates were 100%, 90% and 77% respectively. This was significantly higher than in the control group (92%, 53% and 36%) (logrank test, p=0.012). The one, three and five-year overall survival rates were 100%, 91% and 68% in the imatinib group compared with 96%, 77% and 39% in the control group (logrank test, p=0.021). Analysis with the multivariate Cox regression model yielded similar results on the efficacy of adjuvant imatinib in prolonging both recurrence free survival (hazard ratio [HR]: 0.23, 95% confidence interval [CI]: 0.07-0.80) and overall survival (HR: 0.20, 95% CI: 0.05-0.91).

CONCLUSIONS

Adjuvant imatinib therapy seems to be effective in decreasing the risk of tumour occurrence and prolonging the overall survival time in colorectal GIST patients.

Sphincter sparing resection of a large obstructive distal rectal gastrointestinal stromal tumour after neoadjuvant therapy with imatinib (Glivec)

Gastrointestinal stromal tumours (GISTs) are generally rare but are known to be the most common mesenchymal tumours of the gastrointestinal tract. We present a case of a patient who presented with persistent obstructive gastrointestinal and urological symptoms, a sense of incomplete evacuation and bleeding per rectum. A colonoscopy was performed and a biopsy was taken of a submucosal mass in the distal rectum that revealed a GIST with positive KIT immunostaining. A positron emission tomography (PET)/CT scan showed a large metabolically active distal rectal tumour of 8 cm with macroscopic invasion of surrounding structures. Neoadjuvant therapy with receptor tyrosine kinase inhibitor imatinib (400 mg orally daily) was initiated and an excellent partial response consisting of a significant decrease in the size of the tumour with complete metabolic resolution was observed within 3 months. Six months after initiation of the neoadjuvant therapy a rectum resection with manual side-to-end coloanal anastomosis was performed. Pathology showed a GIST of 5 cm located 0.1 cm from the distal section plane. Our case shows that in patients with a large invasive distal rectal GIST, neoadjuvant imatinib therapy can facilitate anal sphincter sparing surgery.

Robot-assisted excision of a pararectal gastrointestinal stromal tumor in a patient with previous ileal neobladder

Gastrointestinal stromal tumors (GISTs) are the most frequent mesenchymal tumors of the gastrointestinal tract with surgical resection remaining the cornerstone of therapy. Pararectal lesions are considered to be technically difficult and pose in some cases a challenge. We report, to the best of our knowledge, the first robotic-assisted pararectal GIST excision. A 43-year-old man was referred to our center with pararectal GIST recurrence, despite treatment with targeted therapy. Eleven years ago, he underwent extensive abdominal surgery including cystoprostatectomy with ileal neobladder diversion due to GIST resection in the rectoprostatic space. Robot-assisted surgical resection was successfully performed without the need for temporary colostomy. The postoperative course of the patient was uneventful, and the pathology report confirmed a GIST recurrence with negative surgical margins and pelvic lymph nodes free of any tumor. Robotic-assisted pelvic surgery can be extended to incorporate excision of pararectal GISTs, as a safe, less invasive surgical alternative with promising oncological results and minimal injury to adjacent structures.

Laparoscopic resection of a gastrointestinal stromal tumor of the lower rectum in a patient with coronary artery disease following long-term neoadjuvant imatinib treatment and anticoagulation therapy

Surgery is the mainstay of treatment for gastrointestinal stromal tumors (GISTs). However, complete resection of rectal GISTs is sometimes difficult because of bulkiness and/or anatomical reasons. Neoadjuvant imatinib therapy has gained attention as an alternative treatment to increase the chance of en bloc resection of rectal GISTs, although it usually takes several months. In this case report, we first demonstrated that neoadjuvant imatinib therapy can be performed safely not only to downsize tumors, but also to allow adequate time for the effective treatment of major comorbid illnesses. A 74-year-old man was diagnosed with a 45 mm GIST of the lower rectum. He also had severe stenosis in the proximal segment of the left anterior descending coronary artery. Following the implantation of a drug-eluting stent, the patient received imatinib together with dual anti-platelet therapy for 12 months without obvious side effects. Follow-up image studies revealed tumor shrinkage as well as stent patency. En bloc resection of the GIST was performed laparoscopically, which preserved the anus. The patient is currently alive without any evidence of relapse for 12 months after surgery.

Laparoscopic local excision and rectoanal anastomosis for rectal gastrointestinal stromal tumor: modified laparoscopic intersphincteric resection technique

BACKGROUND

Rectal GI stromal tumor is uncommon. Local excision with free resection margins provides adequate treatment, but extended surgery such as abdominoperineal resection has been frequently performed because of technical difficulties in the confined pelvic space.

OBJECTIVE

We aimed to report the technical details of a new method of local excision for rectal GI stromal tumor: the modified laparoscopic intersphincteric resection technique.

DESIGN

This study was a retrospective analysis.

SETTING

This study was performed at a single institute.

PATIENTS

We included 3 patients with rectal GI stromal tumor who underwent this procedure following neoadjuvant imatinib therapy.

INTERVENTION

Medial-to-lateral retroperitoneal dissection was begun near the sacral promontory, and rectal dissection while preserving autonomic nerves was performed down to the pelvic floor into the anal canal without dividing the inferior mesenteric artery. Dissection between the tumor and prostate was meticulously performed under laparoscopic magnified view. Next, circumferential connection between the laparoscopic and transanal dissections was performed through a transanal approach, and the rectum was extracted through the anus. Circular full-thickness local excision of the rectum and handsewn straight rectoanal anastomosis was performed.

MAIN OUTCOME MEASURES

The safety and feasibility of this procedure were the primary outcomes measured by this study.

RESULTS

The median operative time was 180 minutes, and the median estimated blood loss was 115 mL. There were no conversions or intraoperative complications, and there was 1 postoperative intestinal obstruction that recovered with conservative therapy. All patients had negative resection margins (R0), including 1 pathological complete response.

LIMITATIONS

The study was limited by the small number of patients.

CONCLUSIONS

This modified laparoscopic intersphincteric resection technique is a novel and safe method for local excision of rectal GI stromal tumors located very close to the anus (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A139).

Rare tumors of the rectum. Narrative review

Most rectal neoplasms are adenocarcinomas, but there is a small percentage of tumors which are of other histological cell lines such as neuroendocrine tumors, sarcomas, lymphomas and squamous cell carcinomas, which have special characteristics and different treatments. We have reviewed these rare tumors of the rectum from a clinical and surgical point of view.

Clinicopathologic factors predicting outcomes in patients with gastrointestinal stromal tumors of the rectum and colon

Limited information is available concerning the clinicopathologic profile of colorectal gastrointestinal stromal tumors (GISTs), which are relatively rare, as well as survival rates following surgical resection. The present study was designed to describe the clinicopathologic characteristics of patients with colorectal GISTs and identify potential factors that may predict postoperative survival outcomes. We reviewed the medical records of 67 patients with colorectal GISTs who underwent surgical resection between January 2000 and December 2012. Clinicopathologic factors affecting overall survival were assessed using the Kaplan-Meier method and multivariate Cox proportional hazards models. The median age at diagnosis was 57 years (range, 32-79 years), with a male-to-female ratio of 1.68. Tumor size varied from 0.2 to 11 cm, with a median size of 5.7 cm. Sixty-two tumors (93%) were positive for CD117, 53 (79%) for CD34, 6 (9%) for PDGFRA, 15 (22%) for SMA, 5 (8%) for S100, and 39 (58%) for vimentin. The overall median survival time was 54 months (95% confidence interval, 32-59 months), and the 1-, 3-, and 5-year overall survival rates were 89.6, 63.9, and 34.4%, respectively. High-risk tumors (determined by histologic grade, size, and other histologic variables) were associated with poor prognosis (hazard ratio, 1.83; 95% confidence interval, 1.21-2.78), and patients who received adjuvant treatment with imatinib had significantly longer median overall survival times than patients who did not (hazard ratio, 0.43; 95% confidence interval, 0.24-0.80). In patients with colorectal GISTs, high-risk tumor histologic grade can predict poor prognosis, and patients may benefit from adjuvant treatment with imatinib. Findings from the present study may provide information to establish evidence-based management strategies for colorectal GISTs.