Colorectal gastrointestinal stromal tumor

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.

Different Medical Features and Strategies of Large Rectal Gastrointestinal Stromal Tumor: A Multi-Central Pooling Analysis

Purpose

The rectum is a rare site for gastrointestinal stromal tumors (GISTs). Tumors in this critical anatomical site are prone to develop local recurrence, and this occurs at a high level even in low-risk tumors. Previous studies found that high-risk was the most common category in rectal gastrointestinal stromal tumors (RGISTs), and size was the most important factor affecting the long-term prognosis. We aimed to find out the most influential factor on clinical outcomes, and describe demographics, oncological differences, and surgical procedures in patients with poor prognosis.

Patients and Methods

Data on consecutive patients with RGIST, who were diagnosed at Peking University People’s Hospital, Shandong Province Hospital, and The First Affiliated Hospital of Shandong First Medical University from 2010 to 2020, were retrospectively evaluated. Further, a literature search was conducted by retrieving data from PubMed, EMBASE, and the Cochrane Library databases from inception up to March 20, 2020.

Results

In all, 50 patients were diagnosed with RGIST at three medical centers, and 86 published records were finally included in the literature review. Combined analysis of the whole individual patient data showed that 5.5 cm was deemed an appropriate cut-off value for L-RGIST, and that patients usually showed a male predominance (67.59%), younger age at onset (56.61 years), higher operative difficulty, and poorer prognosis.

Conclusion

Separation of patients with large RGIST from general patients may contribute to the recognition of the oncological characteristics and clinical management of this rare type of tumor.

The prognostic factors of primary colorectal sarcoma and the clinical outcomes of negative lymph node dissection

Background

Primary colorectal sarcoma is an extremely rare malignancy that is associated with poor patient outcomes. The aim of this study was to identify the prognostic factors of primary colorectal sarcoma and evaluate the clinical outcomes associated with these prognostic factors.

Methods

Between January 1, 2000 and December 31, 2016, the clinical data of 315 patients with primary colorectal sarcoma were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Cancer-specific survival (CSS) was analyzed by the Kaplan-Meier method and by log-rank test. The prognostic factors were identified by univariate and multivariate Cox regression analysis and hazard ratio (HR) and 95% confidence interval (CI) of covariates were also estimated. The optimal cutoff value for NLN count at dissection was identified using X-tile software and validated by univariate Cox regression analysis.

Results

Of the 315 patients with primary colorectal sarcoma identified, 88.6% received surgery. The median follow-up time was 34 months with an interquartile range (IQR) of 9-79 months. The 5-year rate of CSS was 76.73% and 27.8% for the surgery group and the non-surgery group, respectively (P<0.0001). Univariate and multivariate Cox regression analysis performed on the data of nonmetastatic patients demonstrated that sex, race, radiotherapy, and chemotherapy had no effect on patient CSS, with age, tumor site, tumor grade, and NLN dissection being independent prognostic factors. A significant correlation was found between advanced age (>80 years old) and poor CSS (HR 1.964; 95% CI: 1.005-3.839; P=0.048). There were also significant correlations between colonic tumors and poor CSS (HR 2.903; 95% CI: 1.348-6.250; P=0.006) and grade IV tumors and poor CSS (HR 3.431; 95% CI: 1.725-6.823; P<0.001), while NLN dissection was associated with improved CSS (HR 0.946; 95% CI: 0.911-0.983; P=0.004). X-tile software analysis was used to determine that the optimal cutoff value for NLN count was 13. Patients who received NLN dissection with a cutoff value of 13 or more displayed better CSS than those who did not (P=0.016).

Conclusions

Primary colorectal sarcoma patients can benefit significantly from primary tumor surgery. Age, tumor site, grade and NLN dissection are independent prognostic factors for CSS in nonmetastatic patients. Importantly, nonmetastatic patients treated with NLN dissection with an NLN count of 13 or more have significantly better CSS.

Colonic Gastrointestinal Stromal Tumor: A Population-Based Analysis of Incidence and Survival

Objectives

The incidence of gastrointestinal stromal tumors (GISTs) located in the colon is rare. Current studies mainly focus on case reports for colonic GISTs. Therefore, a population-based analysis was useful to guide the clinical treatment strategy.

Methods

The patients were selected from 2000 to 2015 based on Surveillance, Epidemiology, and End Results (SEER) database. Patients' demographics, tumor characteristics, incidence, treatment, and survival were retrieved for analysis.

Results

249 cases of colonic GISTs were collected. The male-female ratio was close to 1 : 1 (male 51.41%, female 48.59%). Most cases were Caucasians (70.28%), and African Americans accounted for 19.68%. Age of diagnosis ranged from 21 to 93 years with a median (mean) age of 67.5 (65.56). The incidence was rare, only 0.018 per 100,000. It had an annual percentage change (APC = -0.7728) without statistical significance (P = 0.5127) while the incidence of other GISTs increased from 2000 to 2015, with an annual percentage change of 3.9% (P = 0.0001). Surgery was associated with better prognosis whereas chemotherapy did not impact the survival rate.

Conclusion

Colonic GIST is a rare solid tumor, and the incidence is stable. The entity has a poorer prognosis than other GISTs. Surgery improved the survival rate, while chemotherapy did not.

Colorectal sarcoma: more than a gastrointestinal stromal tumor

Primary colorectal sarcomas have been defined as a rare and diverse group of mesenchymal cancers distinct from gastrointestinal stromal tumors (GISTs). Primary colorectal sarcomas have been recognized as a distinct entity from GISTs due to the dramatically worse prognosis these sarcomas carry. Also, primary colorectal sarcomas when compared to the more common colorectal adenocarcinoma, demonstrate more aggressive biology, present at a younger age and carry worse outcomes. At this time, surgery remains the mainstay of treatment and adjuvant chemotherapy has an unclear role in treatment of primary colorectal sarcoma. This paper attempts to review the available data regarding primary colorectal sarcomas.

Gastrointestinal stromal tumors: A multidisciplinary challenge

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors located in the alimentary tract. Its usual manifestation is gastrointestinal bleeding. However, small asymptomatic lesions are frequently detected as incidental finding. Characteristically, most GISTs (> 95%) are positive for the KIT protein (CD117) by IHC staining and approximately 80%-90% of GISTs carry a mutation in the c-KIT or PDGFRA genes. Mutational analysis should be performed when planning adjuvant and neoadjuvant therapy, due to its possible resistance to conventional treatment. The arise of tyrosine kinase inhibitor has supposed a revolution in GISTs treatment being useful as adjuvant, neoadjuvant or recurrence disease treatment. That is why a multidisciplinary approach to this disease is required. The correct characterization of the tumor at diagnosis (the diagnosis of recurrences and the evaluation of the response to treatment with tyrosine kinase inhibitors) is fundamental for facing these tumors and requires specialized Endoscopist, Radiologists and Nuclear Medicine Physician. Surgery is the only potentially curative treatment for suspected resectable GIST. In the case of high risk GISTs, surgery plus adjuvant Imatinib-Mesylate for 3 years is the standard treatment. Neoadjuvant imatinib-mesylate should be considered to shrink the tumor in case of locally advanced primary or recurrence disease, unresectable or potentially resectable metastasic tumors, and potentially resectable disease in complex anatomic locations to decrease the related morbidity. In the case of Metastatic GIST under Neoadjuvant treatment, when there are complete response, stable disease or limited disease progression, complete cytoreductive surgery could be a therapeutic option if feasible.

Clinicopathological features and prognosis of colonic gastrointestinal stromal tumors: evaluation of a pooled case series

Background

Due to the extremely rare incidence, data about colonic GISTs are limited. Therefore, aim of the present study was to explore clinicopathological characteristics and prognosis of colonic GISTs.

Patients and Methods

Colonic GISTs cases were obtained from our center and from case report and clinical studies extracted from MEDLINE. Clinicopathological features and survivals were analyzed.

Results

There were 79 colonic GISTs patients with a female predominance. The median age was 66 years (range 0.17-84). The median tumor size was 5.8 cm (range 0.5-29). The most common location was sigmoid colon (45.8%), followed by transverse colon (19.5%). The majority of colonic GISTs were high risk (70.8%). Mitotic index was correlated with gender (P = 0.002) and tumor size (P = 0.005), and tumor location was correlated with age (P = 0.017). The five year DFS and DSS were 57.4% and 61.6%, respectively. Mitotic index and NIH risk classification were associated with prognosis of colonic GISTs. However, mitotic index was the only independent risk factor. The distribution of tumor size and NIH risk classification were significantly different between colonic and gastric GISTs (both P = 0.000). The DFS and DSS of colonic GISTs were significantly lower than that of gastric GISTs (P = 0.012 and P = 0.002, respectively).

Conclusions

The most common location for colonic GISTs was sigmoid colon. Most tumors were high risk. Mitotic index was the only independent risk factor for prognosis of colonic GISTs. Colonic GISTs differ significantly from gastric GISTs in respect to clinicopathological features. The prognosis of colonic GISTs was worse than that of gastric GISTs.

Gastrointestinal stromal tumors (GISTs) at uncommon locations: a large population based analysis

INTRODUCTION

Sparse information is available about GISTs in uncommon locations. Our large database analysis aims to determine the characteristics of GISTs in the esophagus, colon and rectum and compare to gastric GISTs.

METHODS

The Surveillance Epidemiology and End Results (SEER) database was queried from 1990 to 2009 using CS SCHEMA v0203. Characteristics of each location were compared to gastric GISTs.

RESULTS

4411 GIST (29 esophageal, 2658 stomach, 1463 small intestine, 126 colonic, and 135 rectal) from 1990 to 2009 were identified. Univariate and multivariate predictors of worse disease specific survival in both the entire cohort and surgical resection group include older age, male gender, tumor size > 5 cm, no surgical intervention and anatomical location. Although less likely to undergo surgical resection, esophageal GIST (all patients and resected) had a comparable survival to gastric GIST. A higher proportion of colonic GISTs presented with distant disease and had a worse disease specific survival when compared to rectal GISTs.

CONCLUSION

Our results show a rising incidence in GISTs and highlight the characteristics of GISTs based on anatomical location. In addition, this is the first study to demonstrate that colonic GISTs behave differently when compared to rectal GISTs and warrants further prospective evaluation.

Rectal gastrointestinal stromal tumors: Imaging features with clinical and pathological correlation

AIM: To investigate computed tomography (CT) and magnetic resonance imaging (MRI) manifestations of rectal gastrointestinal stromal tumors (GISTs) in order to enhance the recognition of these rare tumors.

METHODS: Fourteen patients with pathologically proven rectal GISTs were retrospectively reviewed. Patient histories were retrospectively reviewed for patient age, gender, presenting symptoms, endoscopic investigations, operation notes and pathologic slides. All tumors were evaluated for CD117, CD34 expression, and the tumors were stratified according to current criteria of the National Institutes of Health (NIH). In all cases the first pre-operation imaging findings (CT and MRI, n = 3; MRI only, n = 8; CT only, n = 3) were analyzed by two experienced radiologists by consensus, which include: tumor size, shape, CT density (hypodense, isodense and hyperdense), MRI signal intensity (hypointense, isointense and hyperintense), epicenter (intraluminal or extraluminal), margin (well-defined or ill-defined), internal component (presence of calcifications, necrosis, hemorrhage or ulceration), pattern and degree of enhancement, invasion into adjacent structures. After review of the radiologic studies, clinical and pathological findings were correlated with radiological findings.

RESULTS: The patients, 13 men and 1 woman, were aged 31-62 years (mean = 51.5 ± 10.7 years). The most common initial presentation was hematochezia (n = 6). The mean tumor diameter was 5.68 ± 2.64 cm (range 1.5-11.2 cm). Eight lesions were round or oval, and 6 lesions were irregular. Eleven lesions were well-defined and 3 had ill-defined margins. Ten tumors were extraluminal and 4 were intraluminal. The density and MR signal intensity of the solid component of the lesions were similar to that of muscle on unenhanced CT (n = 6) and T1-weighted images (n = 11), and hyperintense on T2-weighted MR images. Calcification was detected in 2 tumors. Following intravenous injection of contrast media, 3 lesions had mild enhancement and 11 lesions had moderate enhancement. Enhancement was homogenous in 3 lesions and heterogeneous in 11. In 1 of 11 patients who underwent both CT and MRI, the tumor was homogenous on CT scan and heterogeneous on MRI. Eight patients were classified as high risk according to the modified recurrent risk classification system of NIH.

CONCLUSION: Rectal GISTs usually manifest as large, well-circumscribed, exophytic masses with moderate and heterogeneous enhancement on CT and MRI. The invasion of adjacent organs, bowel obstruction and local adenopathy are uncommon.

Gastrointestinal Stromal Tumor Masquerading as a Spontaneous Rectal Hematoma

A 78-year-old Caucasian male with a history of atrial fibrillation and anticoagulation with warfarin presented with a change in bowel habits and weight loss. A computed tomography (CT) scan showed a 3.5 cm rectal mass. After biopsy with colonoscopy and endoscopic ultrasonography, the rectal mass was highly suspicious for rectal hematoma. When the rectal mass did not resolve after 1 month of follow-up, surgery showed the patient to have a rectal gastrointestinal stromal tumor. He is being treated with imatinib and follow-up CT scans. This case illustrates the importance of a high level of suspicion for a gastrointestinal stromal tumor when a rectal mass is found.