Diagnosis and surgical treatment of esophageal gastrointestinal stromal tumors

AIM: To retrospectively evaluate our experience with the diagnosis and surgical resection of esophageal gastrointestinal stromal tumors(GISTs).METHODS: Between January 2003 and August 2014, five esophageal GIST cases were admitted to our hospital. In this study, the hospital records, surgery outcomes, tumor recurrence and survival of these patients were retrospectively reviewed.RESULTS: The median age of the patients was 45.6 years(range: 12-62 years). Three patients presented with dysphagia, and one patient presented with chest discomfort. The remaining patient was asymptomatic. Four patients were diagnosed with esophageal GISTs by a preoperative endoscopic biopsy. Three patients underwent esophagectomy, and two patients underwent video-assisted thoracoscopic surgery. The mean operating time was 116 min(range: 95-148 min), and the mean blood loss was 176 m L(range: 30-300 m L). All tumors were completely resected. The mean length of postoperative hospital stay was 8.4 d(range: 6-12 d). All patients recovered and were discharged successfully. The median postoperative follow-up duration was 48 mo(range: 29-72 mo). One patient was diagnosed with recurrence, one patient was lost to follow-up, and three patients were asymptomatic and are currently being managed with close radiologic and clinical follow-up.CONCLUSION:Surgery is the standard,effective and successful treatment for esophageal GISTs.Longterm follow-up is required to monitor recurrence and metastasis.

Perforation of the colon by invading recurrent gastrointestinal stromal tumors during sunitinib treatment

The molecular targets of sunitinib are receptor tyrosine kinases (RTKs),and this drug has also been known to exert blocking effects on the activation of KIT,which is similar to the mechanism of action of imatinib. Moreover,sunitinib has an additional anti-angiogenic effect through its inhibition of the vascular endothelial growth factor receptor activation. We report here a 70-year-old patient diagnosed with a recurrent gastrointestinal stromal tumor (GIST),which invaded the transverse colon and led to a perforation during sunitinib treatment. A computed tomography scan and 3-dimensional reconstruction showed necrosis of the recurrent hepatic mass and perforation of the invaded transverse colon. After percutaneous drainage of the intraperitoneal abscess,antibiotic treatment and restricted diet,the condition of the patient improved. The present case is the first to report that sunitinib,which is administered to treat GIST resistant to imatinib,can cause unexpected colon perforation and subsequent peritonitis.

Prognostic Factors of Gastrointestinal Stromal Tumors： A Single Institutional Retrospective Experience with Surgical Management over 20 Years

OBJECTIVE To analyze the pathological features and prognosis factors of gastrointestinal stromal tumor （GIST） after primary resection. METHODS Medical records of the diagnosis, surgery, and follow-up of 327 patients with GISTs who underwent surgery between 1988 and 2007 were retrospectively reviewed. The predic-tive factors for the survival of these patients were identi. ed using multivariate analysis. RESULTS In the 327 tumors, 152 （46.5%） were located in the stomach, 89 （27.2%） in the small intestine, 33 （10.1%） in the colon and rectum, and 43 （13.1%） in other sites including the omentum and mesentery. The 3-year and 5-year overall survival rates of the 327 GIST patients were 74.4% and 62.7%, respectively, and univariate survival analysis demonstrated that factors, such as tumor size, mitotic index, NIH categories, Ki-67 index, tumor location, surgical margins, tumor bleeding, and tumor necrosis have significant effect on survival of the patients （P 〈 0.05）. Multivariate analysis demonstrated that the NIH categories, surgical margins, and Ki-67 index were independent prognostic factors for the survival rate. In the group of patients with postoperative recurrence or metastasis, the median survival time of patients who did not receive imatinib treatment was 30 months and that of patients who received imatinib treatment was 59 months. Their 5-year survival rates were 16.4% and 39.4%, respectively, and the difference was statistically significant （P = 0.017）. CONCLUSION Complete resection is the .rst choice of treat-ment for GISTs. It is reasonable to evaluate the prognosis of resect-able GISTs and guide the adjunctive therapy with NIH categories and Ki-67 index. Imatinib treatment can signi.cantly increase the survival rate of patients with recurrent and metastatic GISTs.

Development of an innovative nomogram of risk factors to predict postoperative recurrence of gastrointestinal stromal tumors

BACKGROUND There are many staging systems for gastrointestinal stromal tumors(GISTs),and the risk indicators selected are also different;thus,it is not possible to quantify the risk of recurrence among individual patients.AIM To develop and internally validate a model to identify the risk factors for GIST recurrence after surgery.METHODS The least absolute shrinkage and selection operator(LASSO)regression model was performed to identify the optimum clinical features for the GIST recurrence risk model.Multivariable logistic regression analysis was used to develop a prediction model that incorporated the possible factors selected by the LASSO regression model.The index of concordance(C-index),calibration curve,receiver operating characteristic curve(ROC),and decision curve analysis were used to assess the discrimination,calibration,and clinical usefulness of the predictive model.Internal validation of the clinical predictive capability was also evaluated by bootstrapping validation.RESULTS The nomogram included tumor site,lesion size,mitotic rate/50 high power fields,Ki-67 index,intracranial necrosis,and age as predictors.The model presented perfect discrimination with a reliable C-index of 0.836(95%CI:0.712-0.960),and a high C-index value of 0.714 was also confirmed by interval validation.The area under the curve value of this prediction nomogram was 0.704,and the ROC result indicated good predictive value.Decision curve analysis showed that the predicting recurrence nomogram was clinically feasible when the recurrence rate exceeded 5%after surgery.CONCLUSION This recurrence nomogram combines tumor site,lesion size,mitotic rate,Ki-67 index,intracranial necrosis,and age and can easily predict patient prognosis.

Gastrointestinal stromal tumor solitary distant recurrence in the left brachialis muscle

Gastrointestinal stromal tumors(GISTs) are mesenchymal tumors of the gastrointestinal tract that are most commonly found in the stomach. Although GISTs can spread to the liver and peritoneum, metastasis to the skeletal muscle is very rare and only four cases have previously been reported. These cases involved concurrent skeletal metastases of primary GISTs or liver metastases. Here, we report the first case of a distant recurrence in the brachialis muscle after complete remission of an extra-luminal gastric GIST following a wedge resection of the stomach, omental excision, and adjuvant imatinib therapy for one year. Ten months after therapy completion, the patient presented with swelling and tenderness in the left arm. Magnetic resonance imaging revealed a large mass in the brachialis muscle, which showed positivity for c-kit and CD34 upon pathologic examination. This is the first reported case of a solitary distant recurrence of a GIST in the muscle after complete remission had been achieved.

Impact of tumour rupture risk on the oncological rationale for the surgical treatment choice of gastrointestinal stromal tumours

Tumour rupture of gastrointestinal stromal tumours(GISTs)has been considered to be a remarkable risk factor because of its unfavourable impact on the oncological outcome.Although tumour rupture has not yet been included in the current tumor-node-metastasis classification of GISTs as a prognostic factor,it may change the natural history of a low-risk GIST to a high-risk GIST.Originally,tumour rupture was defined as the spillage or fracture of a tumour into a body cavity,but recently,new definitions have been proposed.These definitions distinguished from the prognostic point of view between the major defects of tumour integrity,which are considered tumour rupture,and the minor defects of tumour integrity,which are not considered tumour rupture.Moreover,it has been demonstrated that the risk of disease recurrence in R1 patients is largely modulated by the presence of tumour rupture.Therefore,after excluding tumour rupture,R1 may not be an unfavourable prognostic factor for GISTs.Additionally,after the standard adjuvant treatment of imatinib for GIST with rupture,a high recurrence rate persists.This review highlights the prognostic value of tumour rupture in GISTs and emphasizes the need to carefully take into account and minimize the risk of tumour rupture when choosing surgical strategies for GISTs.

Two different mutational types of familial gastrointestinal stromal tumors:Two case reports

BACKGROUND Gastrointestinal stromal tumors(GISTs)are the most common mesenchymal tumors of the gastrointestinal(GI)tract,and cases of GISTs tend to be of the disseminated type,with a global incidence of 10 to 15 cases/million each year.The rarer familial GISTs,which often represent a population,differ in screening,diagnosis,and treatment.Familial GISTs include primary familial GISTs with predominantly KIT/PDGFRA mutations and wild-type GISTs.However,whether the same genetic family has different phenotypes has not been reported.CASE SUMMARY We report two cases of rare GISTs in the same family:A male patient with the V561D mutation in exon 12 of the PDGFRA gene,who has been taking the targeted drug imatinib since undergoing surgery,and a female patient diagnosed with wild-type GIST,who has been taking imatinib for 3 years since undergoing surgery.The favorable prognosis of these patients during the 7-year follow-up period validates the accuracy of our treatment strategy,and we have refined the entire process of diagnosis and treatment of familial GISTs in order to better manage this rare familial disease.CONCLUSION Different mutation types of familial GISTs in the same family are very rare,thus it is very important to make the correct diagnosis and treatment strategies according to the results of molecular detection for the management of familial GISTs.

Prevalence, diagnosis, and treatment of primary hepatic gastrointestinal stromal tumors

Gastrointestinal stromal tumors(GIST), which is the most common mesenchymal tumor of the digestive tract, account for 1%-3% of gastrointestinal tumors. Primary stromal tumors outside the gastrointestinal tract are collectively referred to as extra GISTs, and stromal tumors in different regions often have different prognoses. A primary hepatic GIST is a rare tumor with an unknown origin, which may be related to interstitial Cajal-like cells. Although primary hepatic GIST has certain characteristics on imaging, it lacks specific symptoms and signs;thus, the final diagnosis depends on pathological and genetic evidence. This review summarizes all cases of primary hepatic GIST described in the literature and comprehensively analyzes the detailed clinical data of all patients. In terms of treatment, local resection alone or with adjuvant therapy was the prioritized choice to obtain better disease-free survival and longer survival time. For advanced unresectable cases, imatinib mesylate was applied as the first-line chemotherapy agent. Moreover, transcatheter arterial chemoembolization,/by-nc/4.0/Manuscript source: Unsolicited manuscript radiofrequency ablation, and microwave ablation were shown to improve overall survival for selected patients. Liver transplantation was a final treatment option after resistance to chemotherapy developed.

Postoperative retroperitoneal desmoid tumor mimics recurrent gastrointestinal stromal tumor:A case report

Desmoid tumor is a locally invasive,myofibroblastic,nonmetastatic tumor.Its pathogenesis remains unclear and it may involve genetic abnormalities,sex hormones and traumatic injury,including surgery.Postoperative intra-abdominal desmoid tumor is rare,especially in the retroperitoneum.We report a case of postoperative retroperitoneal desmoid tumor that developed 29 mo after the first excision of a gastrointestinal stromal tumor.Sporadic trauma-related intraabdominal desmoid tumors reported in the English literature are also reviewed.Despite an extremely low incidence,postoperative desmoid tumor should be considered in the differential diagnosis when a recurrent neoplasm is found at least one year after operation.However,it is a clinical challenge to distinguish recurrent malignant neoplasms from desmoid tumors,and surgical resection is the treatment option depending on the anatomic location.

Examining the impact of early enteral nutritional support on postoperative recovery in patients undergoing surgical treatment for gastrointestinal neoplasms

BACKGROUND Patients with gastrointestinal tumors often suffer from poor nutritional status during treatment.Surgery is the main treatment for these patients,but the long postoperative recovery period is often accompanied by digestive and absorption dysfunction,leading to further deterioration of the nutritional status.Early enteral nutrition support is hypothesized to be helpful in improving this situation,but the exact effects have yet to be studied in depth.AIM To observe the effect of early enteral nutritional support on postoperative recovery in patients with surgically treated gastrointestinal tract tumors,with the expectation that by improving the nutritional status of patients,the recovery process would be accelerated and the incidence of complications would be reduced,thus improving the quality of life.METHODS A retrospective analysis of 121 patients with gastrointestinal tract tumors treated in our hospital from January 2020 to January 2023 was performed.Fifty-three of these patients received complete parenteral nutrition support as the control group for this study.The other 68 patients received early enteral nutritional support as the observation group of this study.The clinical indicators comparing the two groups included time to fever,time to recovery of postoperative bowel function,time to postoperative exhaustion,and length of hospital stay.The changes in immune function and nutritional indexes in the two groups were compared.Furthermore,we utilized the SF-36 scale to compare the changes in the quality of life between the two groups of patients.Finally,the occurrence of postoperative complications between the two patient groups was also compared.RESULTS The postoperative fever time,postoperative bowel function recovery time,postoperative exhaustion time,and hospitalization time were all higher in the control group than in the observation group(P<0.05).The levels of CD3+,CD4+,immunoglobulin(Ig)A,IgM,and IgG in the observation group were significantly higher than those in the control group at 1 d and 7 d postoperatively,while CD8+was lower than in the control group(P<0.05).Total protein,albumin,prealbumin,and transferrin levels were significantly higher in the observation group than in the control group at 7 d postoperatively(P<0.05).The SF-36 scores of patients in the observation group were significantly higher than those in the control group(P<0.0001).The overall incidence of adverse reactions after the intervention was significantly lower in the control group than in the observation group(P=0.021).CONCLUSION We found that patients with gastrointestinal tumors are nutritionally vulnerable,and early enteral nutrition support programs can improve the nutritional status of patients and speed up postoperative recovery.This program can not only improve the immune function of the patient and protect the intestinal function,but it can also help to improve the quality of life of the patient.However,this program will increase the incidence of complications in patients.Caution should be taken when adopting early enteral nutrition support measures for patients with gastric cancer.The patient's condition and physical condition should be comprehensively evaluated and closely monitored to prevent possible complications.

Role of Ki-67 as a prognostic factor in gastrointestinal stromal tumors

AIM:To investigate primarily the prognostic value of Ki-67,as well as other parameters,in gastrointestinal stromal tumors(GISTs).METHODS:Ki-67,c-KIT,platelet-derived growth factor receptor-alpha(PDGFRα),smooth muscle actin(SMA),CD34,S100 were stained for immunohistochemistry which was performed on formalin-fixed,paraffinembeded sections on representative block from each case.Proliferation index counted by Ki-67 antibody was calculated as a number of positive nuclear reaction over 100 cells.Immunoreactivity for c-KIT and PDGFRα was evaluated semiquantitatively(weak,intermediate,strong) and for c-KIT type of reactivity was analyzed(cytoplasmic,membrane and "dot-like" staining).Immunoreactivity for SMA,CD34 and S100 were was evaluated as positive or negative antigen expression.Pathologic parameters investigated in this study included tumor size,cell type(pure spindle,pured epitheloid mixed spindle and epitheloid),mitotic count,hemorrhage,necrosis,mucosal ulceration.Clinical data included age,gender,primary tumor location and spread of disease.χ 2 test and Student's t-test were used for comparisons of baseline characteristics.The Cox's proportional hazard model was used for univariable and multivariable analyses.Survival rates were calculated by Kaplan-Meier method and statistical significance was determined by the log-rank test.RESULTS:According to the stage of disease,there were 36 patients with localized disease,29 patients with initially localized disease but with its recurrence in the period of follow up,and finally,35 patients had metastatic disease from the very beginning of disease.Tumor originated most commonly in the stomach(41%),small intestine was the second most common location(36%).The mean size of primary tumors was 6.5 cm.The mean duration of follow-up was 60 mo.Multiple parameters were analyzed for their effect on overall survival,but no one reached statistical significance(P = 0.06).Analysis of time to progression/relapse in initially localized disease(univariate analysis),tumor size,mitotic count,Ki-67 and type of d-KIT distribution(cytoplasmic vs membrane/"dot-like") showed statistically significant correlation.In multivariate analysis in the group of patients with localized disease,there were only 2 parameters that have impact on relapse,Ki-67 and SMA(P < 0.0001 and P < 0.034,respectively).Furthermore,Ki-67 was analyzed in localized diseasevs localized with recurrence and metastatic disease.It was shown that there is a strict difference between these 2 groups of patients(median value was 2.5 for localized disease vs 10.0 for recurrent/metastatic disease,P < 0.0001).It was also shown that the cut-off value which is still statistically significant in terms of relapse on the level of 6%.The curves for survival on that cut-off level are significantly different(P < 0.04,Cox F).CONCLUSION:Ki-67 presents a significant prognostic factor for GIST recurrence which could be of great importance in evaluating malignant potential of disease.

Esophagogastric junction gastrointestinal stromal tumor:Resection vs enucleation

Esophageal gastrointestinal stromal tumors(GISTs) are extremely uncommon,representing approximately 5% of GISTs with the majority of esophageal GISTs occurring at the esophagogastric junction(EGJ).The treatment options available for these GISTs are fairly controversial.Many different options are nowadays at our disposal.From surgery to the target therapies we have the possibility to treat the majority of GISTs,including those which are defined as unresectable.The EGJ GISTs represent a stimulating challenge for the surgeon.The anatomical location increases the possibility of postoperative complications.As the role of negative margins in GIST surgery is still controversial and the eff icacy of target therapy has been demonstrated,why not treat EGJ GISTs with enucleation and,where indicated,adjuvant target therapy?

Analysis of CD117-negative gastrointestinal stromal tumors

AIM: To identify the gastrointestinal stromal tumors(GISTs) that are negative for CD117 expression by immunohistochemistry and to characterize their malignant potential.METHODS: A total of 108 primary mesenchymal tumors of the gastrointestinal tract were screened to select CD117-negative tumors, from which KIT(exons 9, 11, 13, and 17)and PDGFRA (exons 10, 12, 14, and 18) were sequenced to identify GISTs. Tumor recurrence and distant metastasis were used as the criteria of malignancy.RESULTS: The result showed that approximately 25%(29/108) of the gastrointestinal mesenchymal tumors were negative for CD117 and approximately 6% (7/108)of the tumors were CD117-negative GISTs. All these CD117-negative tumors had a mutated KITand a wildtype PDGFRA. All CD117-negative GISTs with mutations at codons 557/558 of KIThad mitotic counts ＞10/50 high power field, and 75% (3/4) of them showed multiple recurrence or distant metastasis.CONCLUSION: CD1 17-negative KITmutated GISTs account for approximately 6% of the gastrointestinal mesenchymal tumors. Tumor recurrence or distant metastasis correlates to both theKITmutations at codons 557/558 and the mitotic counts, but not to the tumor size.

Gastrointestinal stromal tumors:Thirty years experience of an Institution

AIM:To report our experience of gastrointestinal stromal tumors (GISTs) during the last 29 years. METHODS:Thirty two cases of GIST referred to our Institution from the 1st January 1981 to the 10th June 2010 were reviewed. Metastases,recurrence and survival data were collected in relation to age,history,clinical presentation,location,size,resection margins and cellular features. RESULTS:Mean age was 63.7 years (range,40-90) and incidence was slightly higher in males (56%). R0 resection was performed in 90.7% of cases,R1 in 6.2% (2 cases) and R2 in 3.1% (one case). Using Fletcher's classification 8/32 (25%) had high risk,9/32 (28%) intermediate and 15/32 (47%) low risk tumors. Follow-up varied from 1 mo to 29 years,with a median of 8 years; overall survival was 75% (24/32),disease-free survival was 72% and tumor-related mortality was 9.3%. Three patients with high risk GIST were treated with imatinib mesylate:one developed a recurrence after 36 mo,and 2 are free from disease at 41 mo. CONCLUSION:Surgical treatment remains the gold standard therapy for resectable GISTs. Pathological and biological features of the neoplasm represent the most important factors predicting the prognosis.

Comparison between air and carbon dioxide insufflation in the endoscopic submucosal excavation of gastrointestinal stromal tumors

AIM:To evaluate the safety and efficacy of CO2 insufflation compared with air insufflation in the endoscopic submucosal excavation(ESE) of gastrointestinal stromal tumors.METHODS:Sixty patients were randomized to undergo endoscopic submucosal excavation,with the CO2 group(n = 30) and the air group(n = 30) undergoingCO2 insufflation and air insufflation in the ESE,respectively.The end-tidal CO2 level(pETCO2) was observed at 4 time points:at the beginning of ESE,at total removal of the tumors,at completed wound management,and 10 min after ESE.Additionally,the patients' experience of pain at 1,3,6 and 24 h after the examination was registered using a visual analog scale(VAS).RESULTS:Both the CO2 group and air group were similar in mean age,sex,body mass index(all P > 0.05).There were no significant differences in PetCO2 values before and after the procedure(P > 0.05).However,the pain scores after the ESE at different time points in the CO2 group decreased significantly compared with the air group(1 h:21.2 ± 3.4 vs 61.5 ± 1.7;3 h:8.5 ± 0.7 vs 42.9 ± 1.3;6 h:4.4 ± 1.6 vs 27.6 ± 1.2;24 h:2.3 ± 0.4 vs 21.4 ± 0.7,P < 0.05).Meanwhile,the percentage of VAS scores of 0 in the CO2 group after 1,3,6 and 24 h was significantly higher than that in the air group(60.7 ± 1.4 vs 18.9 ± 1.5,81.5 ± 2.3 vs 20.6 ± 1.2,89.2 ± 0.7 vs 36.8 ± 0.9,91.3 ± 0.8 vs 63.8 ± 1.3,respectively,P < 0.05).Moreover,the condition of the CO2 group was better than that of the air group with respect to anal exsufflation.CONCLUSION:Insufflation of CO2 in the ESE of gastrointestinal stromal tumors will not cause CO2 retention and it may significantly reduce the level of pain,thus it is safe and effective.

Effectiveness and safety of endoscopic resection for duodenal gastrointestinal stromal tumors:A single center analysis

BACKGROUND Endoscopic resection for duodenal gastrointestinal stromal tumors(GISTs)is still considered a great challenge with a high risk of complications,including perforation,bleeding,tumor rupture,and residual tumor.AIM To assess the effectiveness and safety of endoscopic resection for duodenal GISTs.METHODS Between January 2010 and January 2022,11 patients with duodenal GISTs were treated with endoscopic resection.Data were extracted for the incidence of complete resection,bleeding,perforation,postoperative infection,recurrence,and distant metastasis.RESULTS The incidence of successful complete resection of duodenal GISTs was 100%.Three cases(27.3%)had suspected positive margins,and the other 8 cases(72.7%)had negative vertical and horizontal margins.Perforation occurred in all 11 patients.The success rate of perforation closure was 100%,while 1 patient(9.1%)had suspected delayed perforation.All bleeding during the procedure was managed by endoscopic methods.One case(9.1%)had delayed bleeding.Postoperative infection occurred in 6 patients(54.5%),including 1 who developed septic shock and 1 who developed a right iliac fossa abscess.All 11 patients recovered and were discharged.The mean hospital stay was 15.3 d.During the follow-up period(14-80 mo),duodenal stenosis occurred in 1 case(9.1%),and no local recurrence or distant metastasis were detected.CONCLUSION Endoscopic resection for duodenal GISTs appears to be an effective and safe minimally invasive treatment when performed by an experienced endoscopist.

Intra-abdominal desmoid tumors mimicking gastrointestinal stromal tumors——8 cases: A case report

BACKGROUND Intra-abdominal desmoid tumors(DTs) can mimic recurrence or progression of gastrointestinal stromal tumors(GISTs). Differential diagnosis is important to avoid unnecessary or inappropriate treatment.CASE SUMMARY All 8 patients experienced surgical resection of GIST, and median time to diagnosis of DT was 1.8 years after surgical resection. All sites of DT were in the peritoneum around the surgical sites of GIST. The following clinical suspicion coupled with radiological findings contributed to the suspicion of intraabdominal DTs:(1) Occurrence of a new single lesion in the peritoneum around the surgical sites of GIST;(2) uncontrolled lesion with imatinib while other lesions being controlled with imatinib;(3) well-defined ovoid shaped lesion with delayed or mild enhancement and absence of necrosis, hemorrhage, and cystic change on computed tomography; and(4) a lesion showing mild or no hypermetabolic activity on 18 fluorodeoxyglucose-positron emission tomography,contrary to initially hyperactive lesion of GIST. All DTs were surgically removed except for one unresectable DT and only one DT recurred at another site of peritoneum, which was also surgically removed.CONCLUSION Intra-abdominal DT should be a differential diagnosis for a new single lesion in patients with GIST.

Characterizing gastrointestinal stromal tumors and evaluating neoadjuvant imatinib by sequencing of endoscopic ultrasound-biopsies

AIM To evaluate endoscopic ultrasound(EUS)-guided biopsies for the pretreatment characterization of gastrointestinal stromal tumors(GIST) to personalize the management of patients.METHODS All patients with lesions suspected to be GIST who were referred for EUS-sampling at a tertiary Swedish center were eligible for inclusion 2006-2015. During the observational study phase(2006-2011), routine fine-needle-aspiration(EUS-FNA) was performed.In 2012-2015, we converted to an interventional, randomized protocol with dual sampling EUS-FNA and fine-needle-biopsy-sampling(EUS-FNB) for all lesions. c-KIT-and DOG-1-immunostaining was attempted in all samples and a manual count of the Ki-67-index was performed. FNB-sampled tissue and the resected specimens were subjected to Sanger sequencing of the KIT and platelet-derived growth factor alpha(PDGFRA) genes. RESULTS In all, 64 unique patients with GIST were included, and of these, 38 were subjected to pretreatment dual sampling. EUS-FNB had a higher diagnostic sensitivity when compared head-to-head with EUS-FNA(98% vs 58%, P < 0.001) and was more adequate for Ki-67-indexing(Ki-67EUS)(92% vs 40%, P < 0.001). Sequencing of EUS-biopsies was successful in 43/44(98%) patients, and the mutation profiles(KIT-mutation 73%, PDGFRA-mutation 18%, wild-type 7%) were fully congruent with those detected in the corresponding resected specimens. In imatinib-na?ve patients, the Ki-67_(EUS) was comparable with the Ki-67-index in the corresponding surgical specimens(Ki-67_(SURG))(2.7% vs 2.9%, P = 0.68). In patients treated with neoadjuvant imatinib who also carried mutations indicating sensitivity, the Ki-67 EUS was higher than the Ki-67_(SURG)(2.5% vs 0.2%, P = 0.005), with a significant reduction in the Ki-67-index of-91.5%(95%CI:-82.4 to-96.0, P = 0.005). CONCLUSION EUS-guided biopsy sampling is accurate for the pretreatment diagnosis and characterization of GISTs and allows the prediction and evaluation of tumor response to neoadjuvant imatinib therapy.

COVID-19 in patients with gastrointestinal stromal tumors: Recommendations for management and vaccination

The coronavirus disease 2019(COVID-19)pandemic profoundly affected the management and treatment of patients with malignancies.Based on the progress reported in the literature,we reviewed the recommendations for treatment and vaccination in patients with gastrointestinal stromal tumor(GIST)during COVID-19.We focus on whether there is a risk and what could be the possible effects of vaccinating patients with GIST/cancer.Since the situation is quickly changing,and the health services have been severely disrupted,the diagnosis,treatment and recommendations for vaccination of these patients against COVID-19 are still not updated.The approval of vaccines in the pandemic gave hope that we would soon be able to return to a more normal life.However,the oncology community needs to adapt and provide the most effective treatment and care models for patients with rare cancer,such as GIST.Collecting data on the impact of vaccination in patients with GIST/cancer also will be beneficial in expanding knowledge about the future planning of treatment strategies and optimizing care in the event of a subsequent pandemic.

Endoscopic submucosal dissection for the treatment of neoplastic lesions in the gastrointestinal tract

AIM: To investigate the indications, resection rate, and safety of endoscopic submucosal dissection (ESD) for neoplastic lesions in the gastrointestinal tract at a European referral center. METHODS: We carried out a retrospective analysis of the ESD procedures performed in our center for mucosal neoplastic and submucosal lesions of the gastrointestinal tract. The duration of the procedure, en bloc and complete (R0) resection rates, and complication rates were evaluated. Variables were reported as mean ± SD or simple proportions. Univariate analysis and comparisons of procedure times and resection rates were performed using Mann-Whitney U tests, or χ2 tests for dichotomous variables.RESULTS: Between 2007 and 2011, ESD was performed in a total of 103 patients (46.7% male, mean age 64.0 ± 12.7 years). The indications for the procedure were epithelial tumor (n = 54), submucosal tumor (n = 42), or other (n = 7). The total en bloc resection rate was 90.3% (93/103) and R0 resection rate 80.6% (83/103). The median speed of the procedure was 15.0 min/cm2 . The complete resection rate was lower for submucosal tumors arising from the muscle layer (68%, 15/22, P < 0.05). Resection speed was quicker for submucosal tumors localized in the submucosal layer than for lesions arising from the muscularis propria layer (8.1 min/cm 2 vs 17.9 min/cm 2 , P < 0.05). The R0 resection rate and speed were better in the last 24 mo (90.1%, 49/54 and 15.3 min/cm 2 ) compared to the first 3 years of treatment (73.5%, 36/49, P < 0.05 and 22.0 min/cm2 , P < 0.05). Complications occurred in 14.6% (n = 15) of patients, including perforation in 5.8% (n = 6), pneumoperitoneum in 3.9% (n = 4), delayed bleeding in 1.9% (n = 2), and other in 2.9% (n = 3). Only one patient with delayed perforation required surgical treatment. During the mean follow-up of 26 ± 15.3 mo, among patients with R0 resection, recurrence occurred in one patient (1.2%).CONCLUSION: ESD is an effective and safe method for resection of neoplastic lesions with low recurrence. Speed and the R0 resection rate increased after 50 procedures.