Gastrointestinal Stromal Tumors Research Articles

Prediction of Ki-67 expression and malignant potential in gastrointestinal stromal tumors: novel models based on CE-CT and serological indicators.

To identify more reliable imaging and serological indicators for predicting Ki-67 expression and malignant potential in gastrointestinal stromal tumors, as well as to develop a preoperative prediction model with clinical utility. This study retrospectively analyzed patients with gastrointestinal stromal tumors (GIST) diagnosed at the First Affiliated Hospital of Jinzhou Medical University between May 2018 and May 2024. Univariate logistic analyses, two-way stepwise regression, P-value stepwise regression, and LASSO regression were employed to screen for Ki-67 high expression and high malignant potential risk factors associated with GIST. Models were established using various regression methods; Nomograms, calibration curves, and clinical decision curves were generated for the two best prediction models. Two-way stepwise regression analysis revealed that diameter (P=0.037; OR=1.22; 95% CI: 1.01 - 1.46), growth pattern (extraluminal type: P=0.028; OR=3.54; 95% CI: 1.14 - 10.94), enhancement model (P=0.099; OR=0.39; 95% CI: 0.12 - 1.20), EVFDM (P=0.069; OR=0.43; 95% CI: 0.17 - 1.07), PLR (P=0.099; OR=3.06; 95% CI: 0.81 - 11.59), and OPNI (P=0.058; OR=2.38; 95% CI: 0.97 - 5.84) are identified as independent risk factors for Ki-67 expression. Utilizing the two-way stepwise regression model to predict Ki-67 expression, the area under the curve (AUC) for the training group was 0.865 (95% CI: 0.807-0.922), while for the validation group it was 0.784 (95% CI: 0.631-0.937). The Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC) for the training group were 153.360 and 174.619, respectively. Two-way stepwise regression analysis revealed that volume (P < .001, OR = 1.06; 95% CI: 1.03 - 1.09), contour (P = 0.066; OR = 0.17; 95% CI: 0.05 - 0.62), ulcer (P = 0.094; OR = 0.16; 95% CI: 0.03 - 0.98), IBSC (P = 0.008; OR = 5.27; 95% CI: 1.57 - 17.69), and OPNI (P = 0.045; OR = 0.22; 95% CI: 0.05 - 0.96) are independent risk factors for malignant potential. Utilizing the two-way stepwise regression model to predict malignant potential, the AUC for the training group was 0.950 (95% CI: 0.920 - 0.980), while for the validation group it was 0.936 (95% CI: 0.867 - 1.000). The AIC and BIC values for the training group were 96.330 and 114.552, respectively. Diameter, growth pattern, enhancement pattern, EVFDM, PLR, and OPNI are independent risk factors for GIST with high Ki-67 expression. Additionally, volume, contour, ulceration, IBSC, and OPNI serve as independent risk factors for GIST with high malignant potential. The preoperative models developed using CT images can predict the malignant potential and Ki-67 expression status of GIST to a certain extent. When combined with serological indicators, these models' predictive performance can be further enhanced.

Radiomics-based predictive model for preoperative risk classification of gastrointestinal stromal tumors using multiparametric magnetic resonance imaging: aretrospective study.

The aim of this study was to develop and assess aradiomics model utilizing multiparametric magnetic resonance imaging (MRI) for the prediction of preoperative risk assessment in gastrointestinal stromal tumors (GISTs). An analysis was performed retrospectively on agroup of 121 patients who received ahistological diagnosis of GIST. They were then divided into two sets, with85 in the training set and 36 in the validation set through random partitioning. Radiomics features from five MRI sequences, totaling 600 per patient, were extracted and subjected to feature selection utilizing arandom forest algorithm. The discriminatory efficacy of the models was evaluated through receiver operating characteristic (ROC) and precision-recall (P-R) curve analyses. Model calibration was assessed via calibration curves. Subgroup analysis was performed on GISTs with apathological maximum diameter equal to or less than 5 cm. Furtherly, Kaplan-Meier (K-M) curves and log-rank tests were used to compare the differences in survival status among different groups. Cox regression analysis was employed to identify independent prognostic factors and to construct aprognostic prediction model. The clinical model (ModelC) displayed limited predictive efficacy in the context of GIST. Conversely, aradiomics model (ModelR) incorporating five parameters exhibited robust discriminative capabilities across both the training and validation sets, yielding area under the ROC curve (AUC) values of 0.893 (95% confidence interval [CI]: 0.807-0.949) and 0.855 (95% CI: 0.732-0.978), respectively. The F1max scores derived from the P‑R curves were 0.741 and 0.842 for the training and validation sets, respectively. Noteworthy was the exclusion of the two-dimensional tumor diameter and tumor location when constructing ahybrid model (ModelCR) that amalgamated radiomics and clinical features. ModelR demonstrated asubstantially enhanced discriminative capacity in the training set compared with ModelC (p < 0.005). The net reclassification improvement (NRI) corroborated the superior performance of ModelR over ModelC, thereby enhancing diagnostic accuracy and clinical applicability. Patients in the high-risk group had significantly worse recurrence-free survival (RFS, p < 0.001) and overall survival (OS, p = 0.004), and the radiomics signature is an independent risk factor for RFS. The extended model incorporating the radiomics signature outperformed the baseline model in terms of risk assessment accuracy (p < 0.001). Our investigation underscores the value of integrating radiomics analysis in conjunction with machine learning algorithms for prognostic risk stratification in GIST, presenting promising implications for informing clinical decision-making processes as well as optimizing management strategies.

Appendiceal neurofibroma after resection of multiple gastrointestinal stromal tumors of the small intestine in a patient with neurofibromatosis type 1: a case report.

Neurofibromatosis type 1 (NF1), also known as von Recklinghausen disease, is an autosomal dominant disorder that can affect multiple organs. Although gastrointestinal manifestations, such as neurofibromas and gastrointestinal stromal tumors (GISTs), can occur, appendiceal neurofibromas are extremely rare, with no documented cases of their occurrence following other gastrointestinal lesions. Herein, we report a case of an appendiceal neurofibroma following the resection of multiple small intestinal GISTs. A 68-year-old man with NF1 presented with melena and was diagnosed with anemia due to bleeding from multiple small intestinal GISTs. Laparoscopic three partial resection of the small intestine was performed to control the bleeding. Histopathologic examination revealed the proliferation of spindle cells that are positive for c-kit and Discovered on GIST-1, confirming the diagnosis of GIST. Two years later, a follow-up computed tomography (CT) scan revealed a progressively enlarging mass in the appendix with suspected invasion into the small intestine. Positron emission tomography/CT showed fludeoxyglucose accumulation in the tumor. Therefore, considering the possibility of malignancy, laparoscopic ileocecal resection with lymph node dissection was performed. Postoperatively, melena was observed, but the anemia did not progress and improved with fasting and hemostatic therapy. The patient was eventually discharged on postoperative day 8. Histopathologic examination revealed spindle cell proliferation with positivity for S-100, confirming the diagnosis of neurofibroma. Patients with NF1 can develop a variety of gastrointestinal lesions. Appendiceal neurofibroma can be difficult to diagnose preoperatively and differentiate from malignancy. Hence, surgical resection should be considered.

Anatomic and Reconstructive Considerations During Gastric GIST Resection

Gastric gastrointestinal stromal tumors (GISTs) are the most common type of GISTs in the gastrointestinal tract. Gastric GISTs may present in a wide variety of sizes and locations in the stomach. The goal of the surgical and/or endoscopic treatments is a complete R0 resection with free margins, and combined methods to accomplish this resection are available. This manuscript will review the various surgical and/or endoscopic techniques available and the technical considerations for appropriate gastric GIST resections.

An additional gastrojejunostomy may reduce the incidence of moderate and severe delayed gastric emptying after distal segmental duodenectomy for gastrointestinal stromal tumors.

To investigate whether an additional gastrojejunostomy reduces the incidence of delayed gastric emptying (DGE) following a distal segmental duodenectomy for duodenal and proximal jejunal gastrointestinal stromal tumors (GIST). This retrospective review of the GIST database at Peking University Cancer Hospital included 50 patients who underwent distal segmental duodenectomies for primary GIST in the duodenum or proximal jejunum within 20cm of Treitz's ligament between January 2008 and December 2023. The patients were divided into two groups: non-bypass (without gastrojejunostomy) and bypass (with gastrojejunostomy and Braun's jejunojejunostomy). Perioperative characteristics and postoperative complications were analyzed. Among the 50 patients, 27 underwent duodenojejunostomies without gastrojejunostomies and 23 with gastrojejunostomies and Braun's jejunojejunostomies. The incidence of grade B-C DGE was significantly lower in the bypass group (43.5% vs. 74.1%, p = 0.028). In addition, non-bypass surgery was an independent risk factor for increased grade B-C DGE (OR 3.67, 95% CI 1.07-12.64, p = 0.039). The bypass group showed a trend towards a shorter postoperative hospital stay (median: 14 days, range: 10-56) compared to the non-bypass group (median: 28 days, range: 6-75), but this difference did not reach statistical significance (p = 0.070). Operative time (min) was significantly longer in the multi-visceral resection group (381.0 ± 108.8 vs. 227.3 ± 87.6, p < 0.001), for tumors ≥ 6.3cm compared to < 6.3cm (337.0 ± 116.4 vs. 228.3 ± 99.8, p = 0.002), and in patients with positive preoperative symptoms versus asymptomatic patients (319.9 ± 118.0 vs. 210.2 ± 90.3, p = 0.031). The addition of gastrojejunostomy and Braun's jejunojejunostomy in distal segmental duodenectomy can reduce the incidence of grade B-C DGE, potentially facilitating timely adjuvant imatinib therapy. Future multicenter studies are needed to confirm these findings.

Prognostic Significance of C-MYC and EGFR Overexpression in Gastrointestinal Stromal Tumors: An Immunohistochemical Study

Introduction: In addition to mutations in KIT and PDGFRA, many other genetic alterations have been described in gastrointestinal stromal tumors (GISTs), including amplifications of C-MYC and EGFR, which are often associated with increased protein expression. The main of this study was to investigate the prognostic significance of C-MYC and EGFR expression in GISTs using immunohistochemistry (IHC). Methods: We collected all GIST cases over a 16-year period. These cases were tested using antibodies against C-MYC (Leica, clone EP121) and EGFR (Leica, clone 113). C-MYC staining was assessed using the H-score method for nuclear, cytoplasmic, and combined staining. For EGFR staining (either cytoplasmic or nuclear), the intensity was graded as follows: 0 (no staining), 1 (weak staining), 2 (moderate staining), and 3 (strong staining). The percentage of positive cells was evaluated using a semiquantitative approach. Statistical analysis was performed using SPSS24. Results: A total of 37 cases were included in our study. Nuclear expression of C-MYC was observed in 43% of the cases, with a high H-score in 43%. A statistically significant association was found between a high nuclear H-score for C-MYC and mitotic rate (P=0.046), as well as a high Ki-67 proliferation rate (P=0.046). However, no statistically significant associations were identified between the nuclear H-score of C-MYC and other clinical, pathologic, or survival data. Cytoplasmic expression of C-MYC was noted in 22% of cases, but no significant correlations were found with the clinicopathological data. EGFR staining was observed in 86% of cases, with a high score of 51%. EGFR expression was significantly associated with the mitotic index (P=0.012) and Ki-67 proliferation rate (P=0.046). Conclusions: Our findings suggest that both C-MYC and EGFR may be overexpressed and/or amplified in GISTs, indicating their potential prognostic role. This could also pave the way for therapeutic strategies targeting these proteins.

BN SO55 - Rare case of Ectopic pancreatitis in stomach and its Surgical Management

Abstract Background This presentation covers the case of Mr. D, a 38-year-old male who presented with upper abdominal pain and vomiting, initially treated as gastritis but later developing more complex symptoms. This case highlights the diagnostic challenges and management of ectopic pancreatitis, a rare condition characterized by pancreatic tissue located outside its usual anatomical position.Mr. D, a personal trainer with a history of asthma and Meckel's diverticulum excision, experienced recurring epigastric pain, bloating, and early satiety. His pain was particularly related to eating, fasting and often disrupted his sleep. Despite treatment with proton pump inhibitors (PPIs), his symptoms persisted, prompting further investigation Method Initial investigations including ultrasound, chest X-ray, and ECG showed no significant abnormalities. However, subsequent gastroscopy and CT scans suggested a gastrointestinal stromal tumor (GIST), leading to referral for endoscopic ultrasound (EUS) and biopsy. The findings indicated a highly vascular, mixed echogenic lesion in the submucosa, likely a GIST, but initial biopsies were inconclusive Results Following conservative treatment, Mr. D's inflammation significantly reduced, though he experienced recurrent pain necessitating surgical intervention. Diagnostic laparoscopy and gastroscopy revealed extensive adhesions and an inflammatory mass. The patient underwent a pyloric-preserving sleeve gastrectomy, with histology confirming pancreatic heterotopia with inflammation and cystic degeneration. Post-operatively, Mr. D initially struggled with dietary intake but improved over time, tolerating a solid diet by the last follow-up. Conclusion This case underscores the complexity of diagnosing and managing rare conditions like ectopic pancreatitis. It highlights the importance of a multidisciplinary approach and the potential need for surgical intervention when conservative management fails. The presentation aims to provide valuable insights into the diagnostic process, the role of MDT discussions, and the therapeutic challenges associated with ectopic pancreatitis.

OGC O01 - Stomach Cancer Elective Surgery Morbidity and Mortality at 90-Days (HOLD Study): A Prospective, International Collaborative Cohort Study

Abstract Background Data on multinational 90-day mortality and morbidity rates after surgery for gastric cancer is limited in the literature. This study aimed to understand the 90-day mortality and morbidity outcomes according to GASTRODATA Registry for elective gastric cancer surgery patients and identify risk factors. Method We conducted an international prospective study on ≥18 years patients undergoing elective surgery for gastric cancer with curative intent from 01 April 2022 to 30 September 2022. Known metastatic disease, concurrent secondary cancers, gastrointestinal stromal tumour (GIST) and Siewert type I/II oesophagogastric junction malignancies were excluded. Univariate and multivariate logistic regression was used to identify variables associated to 90-day outcome. Results 380 collaborators from 47 countries submitted data on 1538 patients. Mean age was 64.2 years and 58.5% were males. 90-day morbidity rate was 38.2% (n=587) and mortality rate was 2.9% (n=45). Pre-operative higher CCI or ASA score, pre-operative weight loss &amp;gt;10%, and surgical determinants such as type of gastric resection, positive specimen margin, number of harvested lymph nodes, longer surgery duration and post operative pathological IV staging (p value&amp;lt;0.05) were identified as predictors of postoperative severe complications and mortality. Conclusion Elective gastric cancer surgery has a 90-day morbidity of 38.2% and 90-day mortality of 2.9%, globally. This study identified several factors associated with higher morbidity and exemplified the importance of a unified language on surgical morbidity, pre-habilitation and ongoing audits to enhance patient outcomes.

OGC SO12 - Extended Venous Thromboembolism Prophylaxis in Postoperative Oesophagogastric Cancer Patients: A Completed Audit

Abstract Background Venous thromboembolism (VTE) is a life-threatening complication for cancer patients undergoing oesophagogastric surgery. The NICE recommends extending pharmacological VTE prophylaxis to 28 days for patients undergoing major abdominal cancer surgery. While the effectiveness of in-hospital VTE prophylaxis is well-documented, the optimal duration for postoperative VTE prophylaxis remains a subject of debate. This study aims to evaluate the prescribing compliance, effectiveness, and safety of extending VTE prophylaxis to 28 days following hospital discharge (HD), a policy adopted trust-wide since 2014. Method This is an 11-year retrospective study from July 2012-2022, followed by a complete audit cycle conducted between January 2023-2024. The study included all patients who underwent cardio-esophagectomy or gastrectomy for oesophagogastric cancers. Exclusion criteria comprised patients who died during the index admission, those who underwent benign oesophagogastric surgery or local excision of gastrointestinal stromal tumours (GIST), and patients with peripherally inserted central catheter (PICC) line-associated VTE. The primary outcome measured was the prescribing compliance of 28-day VTE prophylaxis post-hospital discharge. Secondary endpoints included the incidence of VTE and bleeding complications necessitating hospital readmission within 28 days of discharge. Results Our study included 582 patients, showing that post-2014, 423 out of 490 patients (86.3%) were discharged with 28-day VTE prophylaxis, compared to 13 out of 92 patients (14.1%) pre-2014, indicating a significant improvement (p&amp;lt;0.05). Only one patient (0.17%) developed VTE more than 28 days post-discharge, and no readmissions due to bleeding complications. In the subsequent audit, 63 out of 68 patients (92.6%) received the prophylaxis, further increasing prescribing compliance. Comparing the two periods, compliance improved from 86.3% to 92.6%, though not statistically significant (p=0.145). Overall, VTE incidence was minimised from 0.17% to 0%, with no readmissions due to bleeding complications. Conclusion Routine extended VTE prophylaxis for 28 days post-hospital discharge should be recommended for cancer patients undergoing oesophagogastric surgery. This practice has significantly improved prescribing compliance rates, reduced post-hospital discharge VTE incidence, and demonstrated safety, with no hospital readmissions due to bleeding complications.

Case report: a rare clinical presentation of a difficult diagnosis of dedifferentiated liposarcoma showing leiomyosarcoma phenotype in the ileocecal region

Dedifferentiated liposarcoma is a malignant lipomatous tumor that rarely occurs in the gastrointestinal tract, including the ileocecal region. In this case, computed tomography and magnetic resonance imaging showed no fatty mass located in the mesenteric or submucosal lesion, and positron emission tomography–computed tomography showed a high maximum standardized uptake value, collectively indicating the gastrointestinal stroma tumor and lymphoma. The pathological findings resemble leiomyosarcoma; the immunohistochemistry findings including mouse double minute 2 homolog and cyclin D-dependent kinase-4 and amplification of mouse double minute 2 homolog in fluorescence in situ hybridization just favored the diagnosis of dedifferentiated liposarcoma with leiomyosarcoma phenotype and not leiomyosarcoma. Recently, a new inhibitor for mouse double minute 2 homolog and cyclin D-dependent kinase-4 has been developed, and clinical trials for dedifferentiated liposarcoma are currently ongoing. This could change the treatment strategy drastically compared with other soft tissue sarcomas. Hence, a correct diagnosis of dedifferentiated liposarcoma is required.

Mean platelet volume/platelet count ratio can predict the recurrence-free survival rate of patients after complete resection of gastrointestinal stromal tumors

PurposeThe aim of this study is to compare mean platelet volume/platelet count ratio (PVPR) and other indicators’ predictive abilities. Simultaneously, a new nomogram for predicting recurrence-free survival (RFS) after gastrointestinal stromal tumors (GISTs) R0 resection was developed.MethodsFrom January 2010 to July 2019, 295 patients with GIST who were operated on at Harbin Medical University Cancer Hospital were retrospectively reviewed. With a 4-year RFS as the end point, using the Kaplan–Meier methods and log rank test, and then conducting Cox regression analysis, we compared and identified meaningful indicators for predicting prognosis. Finally, a nomogram was developed and validated using calibration curves.ResultsThe receiver operating characteristic curve indicated that a cutoff point of 0.044 was the ideal threshold for PVPR, and patients were divided into a high-PVPR group (≤0.044) and a low-PVPR group (&amp;gt;0.044). Kaplan–Meier curves suggested that PVPR&amp;gt;0.044 had obvious associations with better RFS (p &amp;lt; 0.001). In accordance with multivariate analysis, PVPR (&amp;gt;0.044 vs. ≤0.044) (p = 0.005), National Institutes of Health (NIH) risk category (p &amp;lt; 0.001), and Ki-67 (p = 0.005) were the independent prognostic indicators of RFS. Tumor size, gastrointestinal bleeding, mitotic index, NIH risk category, CD34, and Ki-67 all exhibited an obvious correlation with PVPR (all p &amp;lt; 0.05). The nomogram’s probability of concordance was 0.823, indicating that the nomogram predictions were well calibrated.ConclusionIn GISTs, RFS can be independently predicted by PVPR. Patients with higher PVPR have better RFS. The nomogram including PVPR could be used to assist clinical treatment decision-making.

Mesocolic schwannoma mimicking gastrointestinal stromal tumor: A case report and review of literature.

Schwannomas are common peripheral nerve tumors originating from Schwann cells, primarily occurring in the head and neck, limbs, and trunk. Schwannomas occurring in the mesocolon are rare and often have no specific manifestations. Abdominal schwannomas need to be differentiated from common abdominal tumors such as gastrointestinal stromal tumors. We report a case of a mesocolic schwannoma in a 59-year-old female presenting with gastrointestinal symptoms of acid reflux. At an outside hospital, gastroscopy, colonoscopy, and abdominal computed tomography scans revealed a soft tissue mass adjacent to the greater curvature of the stomach, leading to a suspicion of a gastric mesenchymal tumor. Mesocolic schwannoma. Laparoscopy was performed at our hospital. Intraoperatively, the tumor was found to be closely related to the transverse colon and was initially diagnosed as a mass originating from the transverse colon. Consequently, a resection of the mass along with the adherent portion of the transverse colon was performed. Postoperative pathology and immunohistochemistry confirmed that the tumor was a schwannoma of the mesentery and did not originate from the transverse colon. Schwannomas can be distinguished from gastrointestinal stromal tumors by immunohistochemical staining, and surgical treatment is effective for benign schwannomas.

Successful diagnosis of small gastrointestinal stromal tumor using modified mucosal incision-assisted biopsy with a cold snare.

Successful diagnosis of small gastrointestinal stromal tumor using modified mucosal incision-assisted biopsy with a cold snare.

CT feature of irregular extensive ulceration as a predictor of liver metastasis in gastric gastrointestinal stromal tumours.

This study aimed to investigate whether the computed tomography (CT) finding of irregular extensive ulceration (IEU) can serve as a predictor of liver metastasis (LIM) in patients with gastric gastrointestinal stromal tumours (GISTs). This study retrospectively collected clinical and imaging data from 286 patients diagnosed with low-, intermediate-, or high-risk gastric GISTs, or primary lesions with LIM from three medical institutions. The patients were categorised into non-LIM and LIM groups according to whether they had synchronous or metachronous LIM. Multivariate logistic regression analyses were performed to identify significant predictors of LIM. Additionally, receiver operating characteristic (ROC) curve, subgroup, and pathologic-radiologic correlation analyses were conducted. A total of 124 patients were ultimately enroled. There were significant differences in sex, site, growth pattern, size, shape, ulceration and Ki-67 expression between LIM and non-LIM groups. ROC curve analysis demonstrated that IEU had the highest area under the curve for predicting LIM (AUC = 0.842; 95% CI: 0.760-0.924; p < 0.001). Multivariate analysis indicated that IEU was the most significant independent predictor of high LIM risk (OR = 88.62; 95% CI: 2.80-2803.54; p = 0.011). Subgroup analysis showed that IEU was more frequently associated with male sex, age ≤ 55 years, proximal sites, irregular shapes, mixed growth patterns, and a high Ki-67 expression. The CT feature of IEU serves as an independent predictor of LIM in gastric GISTs and is strongly associated with high Ki-67 expression. Question Accurate assessment of LIM risk in patients with gastric GISTs is crucial, yet current non-invasive predictors remain inadequate. Findings IEU on CT is an independent predictor of LIM, with high diagnostic accuracy and a significant association with elevated Ki-67 expression. Clinical relevance IEU on CT scans enables non-invasive risk stratification for LIM in gastric GISTs. Our study refined the assessment of ulceration types, highlighting significant heterogeneity, which may guide personalised treatment strategies.

Genomic and transcriptomic landscape of human gastrointestinal stromal tumors

Gastrointestinal stromal tumor (GISTs) are clinically heterogenous exhibiting varying degrees of disease aggressiveness in individual patients. We comprehensively describe the genomic and transcriptomic landscape of a cohort of 117 GISTs including 31 low-risk, 18 intermediate-risk, 29 high-risk, 34 metastatic and 5 neoadjuvant GISTs from 105 patients. GISTs have notably low tumor mutation burden but widespread copy number variations. Aggressive GISTs harbor remarkably more genomic aberrations than low-/intermediate-risk GISTs. Complex genomic alterations, chromothripsis and kataegis, occur selectively in aggressive GISTs. Despite the paucity of mutations, recurrent inactivating YLPM1 mutations are identified (10.3%, 7 of 68 patients), enriched in high-risk/metastatic GIST and functional study further demonstrates YLPM1 inactivation promotes GIST proliferation, growth and oxidative phosphorylation. Spatially and temporally separated GISTs from individual patients demonstrate complex tumor heterogeneity in metastatic GISTs. Finally, four prominent subtypes are proposed with different genomic features, expression profiles, immune characteristics, clinical characteristics and subtype-specific treatment strategies. This large-scale analysis depicts the landscape and provides further insights into GIST pathogenesis and precise treatment.

The R.O.A.D. to precision medicine

We propose a novel framework that addresses the deficiencies of Randomized clinical trial data subgroup analysis while it transforms ObservAtional Data to be used as if they were randomized, thus paving the road for precision medicine. Our approach counters the effects of unobserved confounding in observational data through a two-step process that adjusts predicted outcomes under treatment. These adjusted predictions train decision trees, optimizing treatment assignments for patient subgroups based on their characteristics, enabling intuitive treatment recommendations. Implementing this framework on gastrointestinal stromal tumors (GIST) data, including genetic sub-cohorts, showed that our tree recommendations outperformed current guidelines in an external cohort. Furthermore, we extended the application of this framework to RCT data from patients with extremity sarcomas. Despite initial trial indications of universal treatment necessity, our framework identified a subset of patients who may not require treatment. Once again, we successfully validated our recommendations in an external cohort.

MASSIVE GASTROINTESTINAL STROMAL TUMOR OF THE STOMACH. CLINICAL CASE

Gastrointestinal stromal tumors (GIST) are rare overall but the most common malignant mesenchymal tumors in the gastrointestinal tract. The decisive factor for the diagnosis in addition to objective symptoms is the expres­sion of the proto-oncogene KIT (CD117) receptor. The most common treatment is surgical resection, preceded by neoadjuvant therapy. In this clinical case we present a 55 year old patient’s who is diagnosed with a giant gastric GIST, effectiveness of systemic treatment.

Construction of an electrochemical aptamer-based sensors for rapid quantification of the anticancer drug imatinib in blood to improve drug bioavailability at microdoses

Imatinib (Ima), as a commonly used anticancer drug for the clinical treatment of leukemia and gastrointestinal mesenchymal stromal tumour, requires timely monitoring of patients' blood concentration to ensure efficacy while reducing complications and achieving precision medicine due to its narrow therapeutic window (1–5 μM) and the varying sensitivity and resistance of different patients to Ima. However, traditional assays are slow and cumbersome, so improved and innovative platforms for monitoring Ima in the clinic are necessary. In this work, a nanoporous electrochemical aptamer-based (E-AB) sensor was designed for the detection of Ima and imatinib mesylate (Ima-Mes) in blood. Apt-37, a high-affinity and conformationally variable aptamer, was screened by molecular docking simulation calculations and circular dichroism (CD) for the construction of the E-AB sensor. The sensor detected Ima and Ima-Mes in the range of 0.1 μM-1 mM, and the recoveries in spiked blood samples were in the range of 70.7 %-104.6 % and 74.8 %-113.9 %, respectively. The precision and accuracy of the E-AB sensor for measuring Ima-Mes concentration in blood was similar to the standard LC-MS method. These results demonstrate that the developed E-AB sensor is an effective tool for rapid monitoring of Ima and Ima-Mes in blood.

Gastrointestinal stromal tumors: a focus on the impact of interstitial cells of Cajal in disease development

Gastrointestinal stromal tumors: a focus on the impact of interstitial cells of Cajal in disease development

Heterotopic pancreas in the jejunum: highlighting the necessity of excision and histopathological confirmation – a case report

Heterotopic pancreas (HP) is a congenital anomaly characterized by the presence of pancreatic tissue that is anatomically separate from the main pancreatic gland without continuity of the duct system and vascularity. The most frequent locations for this displacement are within the upper gastrointestinal tract, particularly in the stomach, duodenum, and proximal jejunum. Other less common sites include the esophagus, ileum, Meckel diverticulum, biliary tree, mesentery, and spleen. Typically, uncomplicated heterotopic pancreas does not exhibit symptoms, and the lesion is often discovered incidentally during unrelated surgeries, imaging examinations, or autopsy. This report describes a 35-year-old male with a history of corrosive ingestion who presented with dysphagia. During surgical exploration, a tissue measuring 0.7 × 0.5 cm was observed approximately 40 cm from the DJ flexure in the jejunum. The identified tissue was excised and sent in for histopathological examination (HPE). In conclusion, we advise the excision of the ectopic tissue and recommend HPE because the diagnosis of HP cannot be confirmed without a thorough histopathological examination. Despite its rarity, heterotopic pancreas should be included in the differential diagnosis when evaluating gastrointestinal stromal tumors.