Comparative clinical features and short-term outcomes of gastric and small intestinal gastrointestinal stromal tumours: a retrospective study

The impact of gender on survival outcomes in patients with small intestinal stromal tumors: a comprehensive analysis using the SEER database

BACKGROUND

Small intestinal stromal tumors (SISTs) are a rare type of mesenchymal tumor. Gender is known to influence the incidence and prognosis of various tumors, but its role on the survival of SISTs at the population level remains unclear. Therefore, we aim to explore the relationship between gender and the prognosis of SISTs using the Surveillance, Epidemiology, and End Results (SEER) database.

METHODS

Data on SISTs patients from 2000 to 2019 were derived from the SEER database. Multiple imputation was used to address missing data. Kaplan-Meier analyses and Cox proportional hazard models were applied to evaluate the impact of demographic and clinical characteristics on overall survival (OS) and cancer-specific survival (CSS).

RESULTS

A total of 3513 patients with SISTs were analyzed, including 1921 males and 1592 females. Kaplan-Meier analysis coupled with log-rank testing demonstrated a significantly higher mortality rate among male patients compared to females (P < 0.001). Notably, female patients exhibited superior OS (hazard ratio [HR] 0.808, 95% confidence interval [CI] 0.724-0.902, P < 0.001) and CSS (HR 0.801, 95% CI 0.692-0.927, P = 0.003) compared to male patients. While the mean 1-year CSS rates were comparable between genders (95.3% for males vs. 96.0% for females, P = 0.332), male patients consistently showed lower mean survival rates at 3-, 5-, and 10-year intervals. Surgical intervention significantly boosted 5-year OS and CSS rates in both male and female patients (P < 0.001). Multivariate Cox regression analysis identified age, sex, grade, TNM stage, surgery, and mitotic rate as independent risk factors for OS and CSS in patients with SISTs.

CONCLUSIONS

Our findings suggest that male patients with SISTs have a higher risk of mortality compared to female patients, indicating that gender may serve as a predictive indicator for survival in this patient population.

Incidence Trends and Main Features of Gastro-Intestinal Stromal Tumours in a Mediterranean Region: A Population-Based Study

Gastro-Intestinal Stromal Tumours (GISTs) are a kind of neoplasm whose diagnosis in common clinical practice just started in the current century, implying difficulties for proper registration. Staff from the Cancer Registry of Murcia, in southeastern Spain, were commissioned by the EU Joint Action on Rare Cancers into a pilot study addressing GIST registration that also yielded a population-based depiction of GISTs in the region, including survival figures. We examined reports from 2001 to 2015 from hospitals as well as cases already present in the registry. The variables collected were sex, date of diagnosis, age, vital status, primary location, presence of metastases, and risk level according to Joensuu's Classification. In total, 171 cases were found, 54.4% occurred in males, and the mean age value was 65.0 years. The most affected organ was the stomach, with 52.6% of cases. Risk level was determined as "High" for 45.0%, with an increment of lower levels in recent years. Incidence for the year 2015 doubled that of 2001. Overall, the 5-year net survival estimation was 77.0%. The rising incidence magnitude is consistent with trends in other European countries. Survival evolution lacked statistical significance. A more interventional approach in clinical management could explain the increase in the proportion of "Low Risk GISTs" and the first occurrence of "Very Low Risk" in recent years.

Distinctive characteristics of granulation tissue in laparotomy wounds with underlying oncological processes

This study aimed to investigate the effects of malignant neoplasms on the morphological characteristics of laparotomy wound granulation tissue in the muscular-aponeurotic layer. The study involved a sample of 34 deceased individuals who had undergone abdominal organ surgery. Biopsy samples were taken from the muscular-aponeurotic layer of the anterior abdominal wall and subjected to histological examination, including staining with hematoxylin and eosin and methylene blue/Chromotrope 2B using N.Z. Slinchenko's method. Descriptive methods and morphometry were used to evaluate pathomorphological changes. The results suggest that malignant neoplasms significantly impede and decelerate the maturation of laparotomy wound granulation tissue. Surgeries performed at the late stages of abdominal organ malignant neoplasms result in an uneven and slow maturation of the tissue, characterized by a higher prevalence of lymphoid cells, increased blood vessel volume, reduced optical density of stained collagen fibers, and pronounced chromotropophilia of collagen fibers. These distinct features should be considered to prevent postoperative eventration, a complication that is more likely to occur in this patient group. Clinicians should be aware of the possible consequences of malignant neoplasms on laparotomy wound granulation tissue, which may require additional measures to prevent postoperative complications in these patients.

Prognostic significance of hemoglobin, albumin, lymphocyte, platelet in gastrointestinal stromal tumors: A propensity matched retrospective cohort study

BACKGROUND

The combined index of hemoglobin, albumin, lymphocyte, and platelet (HALP) can reflect systemic inflammation and nutritional status simultaneously, with some evidence revealing its prognostic value for some tumors. However, the effect of HALP on recurrence-free survival (RFS) in patients with gastrointestinal stromal tumors (GISTs) has not been reported.

AIM

To investigate the prognostic value of HALP in GIST patients.

METHODS

Data from 591 untreated patients who underwent R0 resection for primary and localized GISTs at West China Hospital between December 2008 and December 2016 were included. Clinicopathological data, preoperative albumin, blood routine information, postoperative treatment, and recurrence status were recorded. To eliminate baseline inequivalence, the propensity scores matching (PSM) method was introduced. Ultimately, the relationship between RFS and preoperative HALP was investigated.

RESULTS

The optimal cutoff value for HALP was determined to be 31.5 by X-tile analysis. HALP was significantly associated with tumor site, tumor size, mitosis, Ki67, National Institutes of Health (NIH) risk category, and adjuvant therapy (all P < 0.001). Before PSM, GIST patients with an increased HALP had a significantly poor RFS (P < 0.001), and low HALP was an independent risk factor for poor RFS [hazard ratio (HR): 0.506, 95% confidence interval (95%CI): 0.291-0.879, P = 0.016]. In NIH high-risk GIST patients, GIST patients with low HALP had a worse RFS than patients with high HALP (P < 0.05). After PSM, 458 GIST patients were identified; those with an increased HALP still had significantly poor RFS after PSM (P < 0.001) and low HALP was still an independent risk factor for poor RFS (HR: 0.558, 95%CI: 0.319-0.976, P = 0.041).

CONCLUSION

HALP was significantly correlated with postoperative pathology and postoperative treatment. Furthermore, HALP showed a strong ability to predict RFS in GIST patients who underwent radical resection.

The analysis of prognostic factors of primary small intestinal gastrointestinal stromal tumors with R0 resection: A single-center retrospective study

OBJECTIVE

We aim to assess factors that affect overall survival in patients with primary small intestinal gastrointestinal stromal tumors (GISTs) who had undergone R0 resection.

METHOD

A retrospective analysis reviewed the data of 82 consecutive confirmed GIST patients at a single medical center in China from January 2012 to June 2020. The survival curve was estimated using the Kaplan-Meier method, and independent prognostic factors were confirmed using the Cox regression model.

RESULTS

A total of 82 patients were included in the study: 42 men and 40 women, the mean age was 59 years old (23-83 years old). Tumors were commonly found in the jejunum (46.3%), ileum (20.7%), and duodenum (32.9%). The median tumor size was 6.0 cm (range: 1.0-15.0 cm). The number of mitoses per one 50 high-power field was used to define the mitotic rates. In our present study, 56 patients presented a mitotic rate ≤5 (68.3%) and 26 patients showed a rate >5 (31.7%) at the time of diagnosis. All patients accepted tumor resection without lymph node resection. The positivity rate was 97.6% for CD117, 96.3% for delay of germination 1, 65.9% for CD34, 6.1% for S-100, and 59.8% for smooth muscle actin using immunohistochemistry. Tumor size, tumor rupture, Ki67 index, mitotic index, and postoperative imatinib were independent prognostic factors for small intestinal GISTs.

CONCLUSIONS

In this study, larger tumor size, high Ki67 index, high mitotic index, the occurrence of tumor rupture, and use of imatinib were independent unfavorable prognostic indicators.

Comparison of endoscopic full-thickness resection and cap-assisted endoscopic full-thickness resection in the treatment of small (≤1.5 cm) gastric GI stromal tumors

BACKGROUND AND AIMS

With the increasing incidence of small GI stromal tumors (GISTs), endoscopic full-thickness resection (EFTR) and cap-assisted EFTR (EFTR-C) have been suggested as 2 effective resection methods. We aimed to compare the outcomes of EFTR and EFTR-C for the treatment of small (≤1.5 cm) gastric GISTs.

METHODS

This retrospective study included 67 patients who underwent EFTR and 46 patients who underwent EFTR-C at Nanjing Drum Tower Hospital. Clinicopathologic features, adverse events (AEs), and outcomes were compared between the 2 groups. Univariate and multivariate linear and logistic regressions were used to analyze the effects of the procedure on the therapeutic outcomes of patients and adjusted for covariates in the multivariate analysis.

RESULTS

The tumor size in the EFTR group tended to be larger (P = .005). The resection time in the EFTR-C group was shorter than that in the EFTR group (38.3 ± 20.7 minutes vs 15.0 ± 11.8 minutes, P < .001), which retained statistical significance with adjustment for the covariates (adjusted mean difference, 22.2; 95% confidence interval, 15.0-29.4; P < .001). The R0 resection rate of the EFTR group was 94.0% and of the EFTR-C group 97.8% (P = .355). The EFTR-C group was superior to the EFTR group in terms of perioperative therapeutic outcomes, AEs, and postoperative recovery. No recurrence occurred in the EFTR and EFTR-C groups.

CONCLUSIONS

EFTR-C was found to be the preferable technique for small (≤1.5 cm) gastric GISTs with shorter operation times, lower AEs, faster postoperative recovery, and shorter hospitalization times as compared with EFTR.

CADM1 promotes adhesion to vascular endothelial cells and transendothelial migration in cultured GIST cells

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the human gastrointestinal tract. Small intestinal GISTs appear to be associated with poorer prognosis and higher metastasis rate than gastric GISTs of the same size and mitotic index. Recently, we reported that cell adhesion molecule 1 (CADM1) is expressed specifically in most small intestinal GISTs, but not in most gastric GISTs, suggesting that this difference in CADM1 expression between gastric GISTs and small intestinal GISTs might influence the difference in clinical behavior between them. The aim of the present study was to examine whether high CADM1 expression affected proliferation, migration, invasion, adhesion to endothelial cells and transendothelial migration of cultured GIST cells by comparing original GIST-T1 cells with very low CADM1 expression with GIST-T1 cells with high CADM1 expression induced by CADM1 cDNA transfection (GIST-T1-CAD cells). GIST-T1-CAD cells had reduced ability to proliferate, migrate and invade compared with the original GIST-T1 cells, but showed significantly higher ability to adhere to human umbilical vein endothelial cells and migrate through endothelial cell monolayers. Thus, CADM1 may contribute to higher metastasis rates in small intestinal GISTs facilitating tumor cell adhesion to vascular endothelial cell and transendothelial migration of tumor cells. CADM1 might serve as a potential target for inhibition of metastasis in small intestinal GISTs.

Prognostic Value of Bleeding in Gastrointestinal Stromal Tumors: A Meta-Analysis

Background:

Gastrointestinal bleeding is the most common clinical manifestation of gastrointestinal stromal tumor. It is of great significance to the prognosis of patients. But the results are controversial. The purpose of this study was to evaluate the relationship between gastrointestinal bleeding and clinical prognosis in patients with GIST.

Methods:

A systematic literature search was performed in Pumbed, Cochrane Library, EMBASE, ClinicalTrials.gov, CNKI, VIP and wanfang databases with the pattern of unlimited languages. 12 studies with 2781 individuals were included in the final analysis. The overall survival (OS), recurrence-free survival/disease-free survival (RFS/DFS) and related factors affecting bleeding in patients with gastrointestinal stromal tumor (GIST) were extracted. Hazard ratio (HR) and 95% confidence interval (CI) were used for in the meta-analysis.

Results:

A total of 12 articles were included in the study, including 2781 patients with GIST, including 845 patients with gastrointestinal bleeding. The OS of GIST patients with gastrointestinal bleeding was significantly worse (HR = 2.54, 95% CI = 1.13-5.73, P = 0.025). But there was no significant difference in RFS between gastrointestinal bleeding patients and non-bleeding patients (HR = 1.35, 95% CI = 0.70-2.61, P = 0.371). Further analysis of the related factors of GI bleeding in GIST patients was observed, besides the aging factor (HR = 1.02, 95% CI = 0.69-1.50, P = 0.929), Small intestinal stromal tumor (HR = 0.56, 95% CI = 0.41-0.76, P < 0.001), tumor diameter ≥ 5 cm (HR = 2.09, 95% CI = 1.20-3.63, P = 0.009), Mitotic index ≥ 5/50 HPF (HR = 1.66, 95% CI = 1.11-2.49, P = 0.014) and tumor rupture (HR = 2.04, 95% CI = 1.0-3.82, P = 0.026) all increased the risk of GI bleeding in patients with GIST.

Conclusions:

The OS of GIST patients with GI bleeding was worse than non-GI bleeding, but had no significant effect on RFS. Nevertheless the aging factor, the location of GIST in the small intestine, tumor diameter ≥ 5 cm, Mitotic index ≥ 5/50 HPF and tumor rupture all increased the risk of GI bleeding in patients with GIST.

Gastrointestinal Stromal Tumors-A Mini Review

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. They are potentially malignant, and have an unpredictable evolution. The origin of these tumors is in the interstitial cells of Cajal, which are cells that are interposed between the intramural neurons and the smooth muscle cells of the digestive tract. GISTs are characterized by mutations in the gene c-Kit, but also other mutations, such as those of the platelet-derived growth factor receptor alpha. The most common locations of these tumors are the stomach and small intestine, although they can occur at any level of the digestive tract and occasionally in the omentum, mesentery and peritoneum. Most cases of GISTs are sporadic, and about 5% of cases are part of family genetic syndromes. The correct diagnosis of GIST is determined by histopathological examination and immunohistochemistry. According to histopathology, there are three main types of GISTs: spindle cell type, epithelioid type and mixed type. The therapeutic management of GIST includes surgery, endoscopic treatment and chemotherapy. The prognosis of patients with GIST varies depending on a number of factors, such as risk category, GIST stage, treatment applied and recurrence after treatment.

Gastric and Small Intestine Gist: Results of 156 Cases in 20 Years

PURPOSE

Gastric and small intestine are the most common gastrointestinal stromal tumors (GISTs). There are few studies of patients who underwent surgical treatment with disparate findings. We aimed to evaluate the differences between groups and the risk factors for recurrence and mortality.

METHODS

A retrospective study of 96 gastric and 60 small intestine GIST was performed between 1995 and 2015. Both groups were compared in terms of clinicopathologic features, morbidity, recurrence, and mortality. Statistical analysis was performed with SPSS®.

RESULTS

Eighty-one gastric GISTs and 56 small intestine GISTs underwent surgical treatment. Gastrointestinal bleeding was the most common cause of emergency surgery being more frequent in gastric GIST (P = 0.009); however, emergency surgery was indicated more frequently in the small intestinal GIST (P = 0.004) and was mostly due to perforation (P = 0.009). With a median follow-up of 66.9 (39.7-94.8) months, 28 (20.4%) patients had recurrence. A mitotic index > 5 (P ≤ 0.001) and the intestinal location (P = 0.012) were significantly associated to recurrence. Tumor size > 15 cm (P = 0.001) and an age of ≥ 75 years (P = 0.014) were associated to mortality. On univariate analysis, higher mean values of Ki-67 were associated to higher mortality (P = 0.0032). Small intestine GIST presented lower disease-free survival (DFS) than that of gastric GIST (65.7% vs 90.8%) with P = 0.003. The overall survival (OS) of gastric and small intestine GIST was 74.7% and 71.6%, respectively (P = 0.68).

CONCLUSION

Small intestine GIST received emergency surgery more frequently showing lower DFS and same OS than that of gastric GIST. We found that Ki-67 could be a prognostic factor. Further studies are necessary to assess whether Ki-67 is a prognostic risk factor for GISTs.

Differential Expression of CADM1 in Gastrointestinal Stromal Tumors of Different Sites and with Different Gene Abnormalities

Gastrointestinal stromal tumor (GIST), the most common mesenchymal tumor of the human gastrointestinal tract, differentiating toward the interstitial cell of Cajal (ICC), arises predominantly in the stomach and small intestine. Small intestinal GISTs appear to have worse prognosis than gastric GISTs. In a pilot study of a cDNA expression chip using several GISTs, we found that Cell Adhesion Molecule 1 (CADM1), which could contribute to tumor growth and infiltration, is expressed more strongly in small intestinal GISTs than gastric GISTs. In the present study, we examined CADM1 expression in GISTs of different sites and with different gene abnormalities using a large number of gastric and small intestinal GISTs. First, immunoblotting confirmed significantly higher CADM1 expression in small intestinal GISTs with exon 11 c-kit mutation than gastric GISTs with exon 11 c-kit mutation. Real-time PCR also revealed that small intestinal GISTs with exon 11 c-kit mutation showed significantly higher CADM1 mRNA than gastric GISTs with exon 11 c-kit mutation. Although most small intestinal GISTs showed high CADM1 mRNA expression regardless of gene abnormality types, different CADM1 expression was detected between gastric GISTs with c-kit mutation and those with PDGFRA mutation. Immunohistochemistry showed that many small intestinal GISTs were CADM1-positive but most gastric GISTs CADM1-negative or -indefinite. In the normal gastric and small intestinal walls, immunoreactivity of CADM1 was detected only in nerves, but neither in gastric ICCs nor small intestinal ICCs, indicating that the high CADM1expression in small intestinal GISTs might be acquired during tumorigenesis. Different CADM1 expression between gastric and small intestinal GISTs might be related to different prognoses between them. Further functional experiments are needed to elucidate the role of CADM1 on GIST biology, and there is a possibility that targeting therapy against CADM1 has a preventive effect for tumor spreading in small intestinal GISTs.

Improved understanding of gastrointestinal stromal tumors biology as a step for developing new diagnostic and therapeutic schemes

A gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the human gastrointestinal tract, with an estimated incidence of 10-15 per 1 million per year. While preparing holistic care for patients with GIST diagnosis, scientists might face several difficulties - insufficient risk stratification, acquired or secondary resistance to imatinib, or the need for an exceptional therapy method associated with wild-type tumors. This review summarizes recent advances associated with GIST biology that might enhance diagnostic and therapeutic strategies. New molecules might be incorporated into risk stratification schemes due to their proven association with outcomes; however, further research is required. Therapies based on the significant role of angiogenesis, immunology, and neural origin in the GIST biology could become a valuable enhancement of currently implemented treatment schemes. Generating miRNA networks that would predict miRNA regulatory functions is a promising approach that might help in better selection of potential biomarkers and therapeutical targets in cancer, including GISTs.

Characteristics and prognosis of jejunoileal gastrointestinal stromal tumours (GISTs) in the era of imatinib: a comparative study with gastric GISTs

BACKGROUND

Gastrointestinal stromal tumours (GISTs) located in the jejunum or ileum (JI-GIST) are considered worse prognosis compared to those of gastric (G-GIST) location. It has been suggested that this dogma should be revised. The aim of this study was to describe the characteristics of jejunoileal GISTs and its prognosis and to compare them with G-GISTs in the era of imatinib.

METHODS

We retrospectively reviewed the clinical histories of all the patients diagnosed with GISTs between January 2000 and November 2016: Clinical and pathological data, as recurrence, metastatic state, disease-free survival (DFS) as well as overall survival (OS) rates of patients were reviewed.

RESULTS

JI-GIST patients comprise 29 cases (37.7%). Compared to G-GIST, JI-GIST patients had undergone emergency surgery more frequently (37.9% vs. 10.4%, p = 0.007). According to the NIH-Fletcher classification, the low or very-low risk group represents 17.2% of JI-GISTs as opposed to 37.6% of G-GISTs (p < 0.005). When the AFIP-Miettinen system was used the low or very-low group represented 17.2% of JI-GISTs vs. 58.4% in the G-GISTs group (p < 0.001). Both local recurrence (24.1% vs. 12.5%, p < 0.05) and metastatic rate (34.5% vs. 22.9%, p < 0.05) were higher in the JI-GIST group than in G-GIST. 5- and 10-year DFS and 10-year OS rate were lower for JI-GIST (54.5% and 39.6% vs. 77.2% and 60.8%, and 57.9% vs. 65%, respectively, p < 0.05).

CONCLUSIONS

The observed differences between both groups in DFS and OS rates at long term could be attributed to the effect of imatinib.

Small bowel gastrointestinal stromal tumor presenting with gastrointestinal bleeding in patient with type 1 Neurofibromatosis: Management and laparoscopic treatment. Case report and review of the literature

INTRODUCTION AND IMPORTANCE

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm of the gastrointestinal tract. It may be asymptomatic; nevertheless, gastrointestinal bleeding is the most frequent symptom, due to mucosal erosion. Its poor lymph node metastatic spread makes GIST often suitable of minimally invasive surgical approach. The importance of this study is to increase the awareness among physicians about this condition in particular scenarios as in our case and to stress the role of laparoscopic surgery.

CASE PRESENTATION

A 74-year-old female patient presented to the emergency department with hematemesis, followed by haematochezia and melena. The patient had a medical history of type 1 Neurofibromatosis (NF1). She underwent, after CT scan, esophagogastroduodenoscopy, and endoscopic haemostasis. Finally, we performed a laparoscopic resection of a mass of the first jejunal loop. The postoperative period was predominantly uneventful. Pathological examination confirmed a low-risk GIST.

CLINICAL DISCUSSION

Proximal jejunal GIST may cause an upper and lower gastrointestinal bleeding. A multidisciplinary team approach is mandatory for the correct management of this disease and its complications (bleeding). GISTs are indicated as the most commonly gastrointestinal NF1 associated tumours. In case of localised and resectable GIST surgical treatment is the mainstay and laparoscopic surgery is a valid alternative.

CONCLUSION

In case of abdominal bleeding mass in a NF1 patient, it is important to keep in mind the well-known association between NF1 and GIST to facilitate the diagnosis and to quickly perform the appropriate treatment. Laparoscopic approach is safe and effective if the oncological radicality is respected.

Cross-testing of major molecular markers indicates distinct pathways of tumorigenesis in gastric adenocarcinomas and synchronous gastrointestinal stromal tumors

Small subtype of the gastrointestinal stromal tumor (micro-GIST, MG) is usually asymptomatic and is frequently found incidentally in association with gastric adenocarcinoma (GAC). The background of this coincidence is still an open question. This study comprehensively characterized nine MGs and GACs present in the same surgical specimen by cross-testing the markers of the major pathogenetic pathways of both tumor types. All of the MGs were immunohistochemically positive for CD117/KIT, CD34, and DOG1. DOG1 was also detected in four GACs. Four MGs carried mutations in c-KIT (exons 9, 11, and 13) and two cases in PDGFRα (exon 18). None of the GACs carried activating mutations in c-KIT or PDGFRα. MMR immunopanel identified one GAC as microsatellite unstable tumor. No EBV-positive tumor was found. According to the TCGA molecular classification, one GAC was categorized in the MSI subgroup, three GACs in the genomically stable subgroup, and the rest into the chromosomal instability subgroup. Although a common carcinogenic effect cannot be ruled out, our data suggest a distinct molecular background in the evolvement of the synchronous MGs and GACs. The presence of a MG in gastric resection specimens may be indicative of the development of synchronous malignant tumors in or outside the stomach.

NARFIB: A Novel Prognostic Score Based on the Neutrophil-to-Albumin Ratio and Fibrinogen Can Predict the Prognosis of Gastrointestinal Stromal Tumors

Objective

The neutrophil-to-albumin ratio (NAR) and fibrinogen are significantly related to tumor progression. The present study evaluated the prognostic impact of the NAR plus fibrinogen concentration in gastrointestinal stromal tumor (GIST) cases.

Methods

The baseline characteristics, postoperative NAR, and fibrinogen concentrations were retrospectively analyzed for 229 Chinese patients who underwent radical gastrectomy for GIST. Receiver operating characteristic (ROC) curves were applied to estimate the optimal critical points for NAR and fibrinogen. Cox regression analysis was applied to determine significant prognostic variables.

Results

Multivariate analyses revealed that poor recurrence-free survival was associated with elevated values for fibrinogen (hazard ratio [HR]: 5.015, 95% confidence interval [CI]: 1.993-12.619, P=0.001) and NAR (HR: 4.669, 95% CI: 1.776-12.273, P = 0.002). Combining fibrinogen and the NAR into the NARFIB score provided an area under the ROC curve of 0.833, which was greater than the areas for NAR (0.708) or fibrinogen (0.778). When the NAR and fibrinogen were replaced by the NARFIB score in the multivariate analysis, the independent prognosticators were tumor site (HR: 2.927, 95% CI: 1.417-6.045, P=0.004), mitotic index (HR: 2.661, 95% CI: 1.110-6.380, P=0.028), and the NARFIB score (HR: 14.116, 95% CI: 3.243-61.443, P<0.001). The NARFIB score retained its prognostic significance in various subgroup analyses and was significantly related to gender, surgical approach, tumor size, mitosis, tumor site, risk classification, and recurrence.

Conclusion

These results suggest that the NARFIB score may help guide prognostication and risk stratification for GIST, which might benefit from targeted therapy.

Molecular Modeling Study of c-KIT/PDGFRα Dual Inhibitors for the Treatment of Gastrointestinal Stromal Tumors

Gastrointestinal stromal tumors (GISTs) are the most common Mesenchymal Neoplasm of the gastrointestinal tract. The tumorigenesis of GISTs has been associated with the gain-of-function mutation and abnormal activation of the stem cell factor receptor (c-KIT) and platelet-derived growth factor receptor alpha (PDGFRα) kinases. Hence, inhibitors that target c-KIT and PDGFRα could be a therapeutic option for the treatment of GISTs. The available approved c-KIT/PDGFRα inhibitors possessed low efficacy with off-target effects, which necessitated the development of potent inhibitors. We performed computational studies of 48 pyrazolopyridine derivatives that showed inhibitory activity against c-KIT and PDGFRα to study the structural properties important for inhibition of both the kinases. The derivative of phenylurea, which has high activities for both c-KIT (pIC₅₀ = 8.6) and PDGFRα (pIC₅₀ = 8.1), was used as the representative compound for the dataset. Molecular docking and molecular dynamics simulation (100 ns) of compound 14 was performed. Compound 14 showed the formation of hydrogen bonding with Cys673, Glu640, and Asp810 in c-KIT, and Cys677, Glu644, and Asp836 in PDGFRα. The results also suggested that Thr670/T674 substitution in c-KIT/PDGFRα induced conformational changes at the binding site of the receptors. Three-dimensional quantitative structure-activity relationship (3D-QSAR) models were developed based on the inhibitors. Contour map analysis showed that electropositive and bulky substituents at the para-position and the meta-position of the benzyl ring of compound 14 was favorable and may increase the inhibitory activity against both c-KIT and PDGFRα. Analysis of the results suggested that having bulky and hydrophobic substituents that extend into the hydrophobic pocket of the binding site increases the activity for both c-KIT and PDGFRα. Based on the contour map analysis, 50 compounds were designed, and the activities were predicted. An evaluation of binding free energy showed that eight of the designed compounds have potential binding affinity with c-KIT/PDGFRα. Absorption, distribution, metabolism, excretion and toxicity (ADMET) and synthetic feasibility tests showed that the designed compounds have reasonable pharmaceutical properties and synthetic feasibility. Further experimental study of the designed compounds is recommended. The structural information from this study could provide useful insight into the future development of c-KIT and PDGFRα inhibitors.

Primary Tumor Resection Improves Survival in Patients With Metastatic Gastrointestinal Stromal Tumors: A Preliminary Population-Based Analysis

Background: Surgery has been the primary treatment in patients with localized gastrointestinal stromal tumors (GISTs) for many decades, whereas it remains controversial regarding the efficacy of primary tumor resection for metastatic GISTs treated with chemotherapy, and likewise it is unclear who would benefit from the surgical resection.

Methods: GISTs patients with distant metastases were identified from the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2016. Cox proportional hazards regression models were used to identify prognostic factors of overall survival (OS) and cancer-specific survival (CSS). Kaplan-Meier analyses and log-rank tests were conducted to assess the effectiveness of surgery on survival.

Results: In total, of 455 patients with metastatic GISTs, 235 patients (51.6%) underwent primary tumor resection and 220 patients (48.4%) did not. Median survival of patients in resection group was 72 (95% CI: 62.90–81.10) months vs. 40 (95% CI: 29.53–50.47) months for those in non-resection group (p < 0.001). Similarly, surgery in conjunction with chemotherapy led to a favorable impact on survival than chemotherapy alone (OS: 72 vs. 40 months, p < 0.001; CSS: 74 vs. 44 months, p < 0.001). Multivariable analysis showed that both OS (HR: 0.581, 95% CI: 0.386–0.874, p = 0.009) and CSS (HR: 0.663, 95% CI: 0.439–0.912, p = 0.042] were dramatically improved in patients with surgical removal of primary site, as well as primary tumor size between 5 and 10 cm, while increasing age was predictive of poorer survival. Stratified analysis revealed that patients with tumor locations in the stomach demonstrated a prolonged survival after surgery, with no significant differential surgical effect between the stomach and small intestine.

Conclusions: Our study preliminarily suggests that carefully selected patients with metastatic GISTs might prolong survival after treatment of surgery, especially those with a primary tumor between 5 and 10 cm and a tumor located in the stomach.