Development and validation of a preoperative risk nomogram prediction model for gastric gastrointestinal stromal tumors

BACKGROUND AND STUDY AIMS

Gastrointestinal stromal tumors (GIST) carry a potential risk of malignancy, and the treatment of GIST varies for different risk levels. However, there is no systematic preoperative assessment protocol to predict the malignant potential of GIST. The aim of this study was to develop a reliable and clinically applicable preoperative nomogram prediction model to predict the malignant potential of gastric GIST.

PATIENTS AND METHODS

Patients with a pathological diagnosis of gastric GIST from January 2015 to December 2021 were screened retrospectively. Univariate and multivariate logistic analyses were used to identify independent risk factors for gastric GIST with high malignancy potential. Based on these independent risk factors, a nomogram model predicting the malignant potential of gastric GIST was developed and the model was validated in the validation group.

RESULTS

A total of 494 gastric GIST patients were included in this study and allocated to a development group (n = 345) and a validation group (n = 149). In the development group, multivariate logistic regression analysis revealed that tumor size, tumor ulceration, CT growth pattern and monocyte-to- lymphocyte ratio (MLR) were independent risk factors for gastric GIST with high malignancy potential. The AUC of the model were 0.932 (95% CI 0.890-0.974) and 0.922 (95% CI 0.868-0.977) in the development and validation groups, respectively. The best cutoff value for the development group was 0.184, and the sensitivity and specificity at this value were 0.895 and 0.875, respectively. The calibration curves indicated good agreement between predicted and actual observed outcomes, while the DCA indicated that the nomogram model had clinical application.

CONCLUSIONS

Tumor size, tumor ulceration, CT growth pattern and MLR are independent risk factors for high malignancy potential gastric GIST, and a nomogram model developed based on these factors has a high ability to predict the malignant potential of gastric GIST.

Gastric gastrointestinal stromal tumors: therapeutic strategies and long-term prognosis

OBJECTIVES

This study aimed to evaluate the clinical and prognostic characteristics of primary gastric gastrointestinal stromal tumors (GIST).

METHODS

Patients who underwent resection for primary gastric GIST between January 2002 and December 2017 were included. Recurrence-free survival (RFS) was calculated by Kaplan-Meier analysis, and Cox proportional hazards model was used to identify independent prognostic factors.

RESULTS

Altogether, 653 patients were enrolled. The median patient age was 59 years (range 15-86 years). Open, laparoscopic, and endoscopic resections were performed in 394 (60.3%), 105 (16.1%), and 154 (23.6%) patients, respectively. According to the modified NIH consensus classification, 132 (20.2%), 245 (37.5%), 166 (25.4%), and 88 (13.5%) patients were categorized into very low-, low-, intermediate-, and high-risk, respectively. A total of 136 (20.8%) patients received adjuvant imatinib treatment. The median follow-up time was 78 months (range 4-219 months), and the estimated 5-year RFS rate was 93.0%. In all patients, tumor size and rupture, mitotic counts, and adjuvant imatinib treatment were independent prognostic factors. The prognosis of gastric GIST treated with endoscopic resection was not significantly different from that of laparoscopic or open resection after adjusting for covariates using propensity score matching (log-rank p = .558). Adjuvant imatinib treatment (HR = 0.151, 95%CI 0.055-0.417, p < .001) was a favorable prognostic factor for high-risk patients, but was not associated with prognosis in intermediate-risk patients.

CONCLUSION

Patients with small gastric GISTs who successfully underwent endoscopic resection may have a favorable prognosis. Adjuvant imatinib treatment improve the prognosis of high-risk gastric GISTs, however, its use in intermediate-risk patients remains controversial.

Is minimally invasive surgery for large gastric GIST actually safe? A comparative analysis of short- and long-term outcomes

INTRODUCTION

While minimally invasive surgery (MIS) is frequently utilized to remove small gastric gastrointestinal stromal tumors (GIST), MIS surgery for tumors ≥ 5 cm is currently not endorsed by national guidelines as standard of care due to concerns of safety and inferior oncologic outcomes. Hence this study investigates the perioperative and long-term outcomes of MIS for T3 gastric GIST measuring 5-10 cm.

METHODS

The National Cancer Database (NCDB) 2017 was queried for gastric GIST measuring 5-10 cm or T3 category. Inclusion criteria were known: stage, size, comorbidities, grade, lymphovascular invasion, type of surgery, approach, conversion info, margin status, mitotic rate, neoadjuvant and adjuvant treatment, hospital stay, readmission, 30- and 90-day mortality, complete follow-up, type of institution, and hospital gastric surgery case volume. Binary logistic regression, linear regression models, and Kaplan-Meier survival analysis were used.

RESULTS

In 3765 patients, mean tumor size was 67.3 mm; 26.3% MIS; and 73.8% open. Median hospital stay was shorter for MIS (4.77 vs 7.04 days, p < 0.001). There was no significant difference in incidence of R1 margins [2.9% MIS vs. 3.1% open (p = 0.143)], unplanned readmission [2.9% MIS and 4.1% open (OR 0.474 p = 0.025)], 30-day mortality [0.5% MIS vs 1.2% open (OR 0.325, p = 0.031)], and 90-day mortality [0.9% MIS vs 2.1% open (OR 0.478 p = 0.036)]. Cox regression models for OS showed no difference in survival (p = 0.137, HR 0.808).

CONCLUSION

This analysis provides substantial evidence that MIS for gastric GIST ≥ 5-10 cm may not only offer improved postoperative morbidity but also oncologic safety. Moreover, as both approaches lead to similar long-term survival, national guidelines may need to incorporate this new information.

Hand-assisted laparoscopic resection versus total laparoscopic gastric surgery for primary gastric gastrointestinal stromal tumors (GISTs): an analysis from a high-volume institution

Background

Laparoscopic resection of gastric gastrointestinal stromal tumors (GISTs) is technically feasible and associated with favorable outcomes. We compared the clinical efficacy of hand-assisted laparoscopic surgery (HLS) and total laparoscopic surgery (TLS) for gastric GISTs.

Methods

We retrospectively analyzed the clinical data of 69 consecutive patients diagnosed with a gastric GIST in a tertiary referral teaching hospital from December 2016 to December 2020. Surgical outcomes were compared between two groups.

Results

Fifty-three patients (TLS group: n = 36; HLS group: n = 17) were included. The mean age was 56.9 and 58.1 years in the TLS and HLS groups, respectively. The maximum tumor margin was significantly shorter in the HLS group than in the TLS group (2.3 ± 0.9. vs. 3.0 ± 0.8 cm; P = 0.004). The operative time of the HLS group was significantly shorter than that of the TLS group (70.6 ± 19.1 min vs. 134.4 ± 53.7 min; P < 0.001). The HLS group had less intraoperative blood loss, a shorter time to first flatus, and a shorter time to fluid diet than the TLS group (P < 0.05). No significant difference was found between the groups in the incidence or severity of complications within 30 days after surgery. Recurrence or metastasis occurred in four cases (HLS group; n = 1; TLS group; n = 3).

Conclusions

This study demonstrated that compared with TLS, HLS for gastric GISTs has the advantages of simpler operation, shorter operative time, and faster postoperative recovery.

A bleeding GIST in pandemic times, a cooperative approach to a delayed complication, a case report

INTRODUCTION

Upper gastrointestinal bleeding is one of the major manifestations of the stomach's gastrointestinal stromal tumors; when gastric GISTs bleed, they are associated with a poor prognosis and must be treated promptly to avoid dangerous complications. A worrisome side effect of the Covid-19 pandemic is the delay in surgical treatment for seriously ill patients, a rise in surgical complications due to delayed care, lack of access to the healthcare system, and patients' hesitancy to seek care due to fear of the virus. In Ecuador, where limitations were present even in the absence of a pandemic, we are yet to fully know the full extent of the damage this pandemic has caused to ourselves and our patients.

PRESENTATION OF CASE

We present the case of a 51-year-old female; she presented with upper gastrointestinal bleeding, and a gastric GIST was diagnosed. Due to the size and the symptoms, surgery was planned. Nonetheless, as Ecuador was hit hard by the Covid-19 pandemic to cope with the respiratory patients, surgeries were delayed or canceled. Our patient surgery was delayed for five months until she presented with severe gastrointestinal bleeding that required urgent action and care. Thankfully, she completely recovered.

DISCUSSION AND CONCLUSIONS

This case is an example of the many complications we expect due to the pandemic; delay in treatment leads to troublesome complications. In these emergencies, time is of the essence, and surgical services must rise to the challenge; in a particular way, this case also proves that if there are the necessary tools to enhance the patient's recovery, we should hesitate to use them. Complete resection of the gastric GIST in a prompt matter must be done to avoid these potentially deadly complications.

Gastrointestinal stromal tumors (GIST): a proposal of a "CT-based predictive model of Miettinen index" in predicting the risk of malignancy

PURPOSE

To identify the predictors of malignancy on CT for the evaluation of gastrointestinal stromal tumors (GIST) by correlating CT findings with the mitotic index in order to propose a "CT-based predictive model of Miettinen index."

METHODS

One radiologist and one resident in radiology with 14- and 4-year experience in oncological field reviewed the CT findings of 42 patients by consensus, with respect to lesion site, size, contour, tumor growth pattern, enhancing pattern, degree of enhancement of tumor, percentage of tumor necrosis, mesenteric fat infiltration, ulceration, calcification, regional lymphadenopathy, direct invasion to adjacent organs, and distant metastasis. All parameters were correlated with the mitotic index evaluated at histopathological analysis following surgery. Normality of variables was evaluated using Shapiro-Wilk test. Pearson's correlation test was used to assess the interaction between variables. The diagnostic accuracy percentage of tumor necrosis was measured by receiver operating characteristic (ROC) analysis for detecting whether the number of mitosis per 50 high-power fields was > 5.

RESULTS

A significant statistical correlation was found between percentage of tumor necrosis and the mitotic index (p < 0.005), dimension, and location of the tumor.

CONCLUSION

CT could be an accurate technique in the prediction of malignancy of GIST in a CT risk assessment system, based on the location of the tumor, its size, and the percentage of tumor necrosis.

Intragastric single-port surgery (IGS) for gastric endophytic gastrointestinal stromal tumor (GIST): A novel surgical treatment

BACKGROUND

Intragastric surgery with a single incision has been performed for several diseases, such as gastric tumors[1] and pancreatic pseudocyst[2], safety, feasibility and potential benefits of which have been reported in previous relevant studies[3].

METHODS

The video shows a 65-year-old man with upper gastrointestinal hemorrhage, preoperative abdominal CT scan and endoscopy suggested an endophytic tumor located in gastric corpus, suggesting gastrointestinal stromal tumor (GIST). Intragastric single-port surgery (IGS) was indicated.

RESULTS

Under general anesthesia, patient was placed in supine position. Surgeons stood on the right side of the patient. After a 2.5cm transverse incision was made on left upper abdominal wall, gastric anterior wall was exteriorized and fixed to the skin incision. Single-port device was inserted inside the stomach after anterior gastric wall was opened. Next, laparoscope was introduced into gastric cavity and identified the location of tumor. Full thickness resection of the tumor was performed by using linear stapler, then stapler line was embedded with continuous sutures. Finally, after specimen and single-port device removal, the stomach incision was closed extracorporeally. The operation time was 112 minutes. Final pathology confirmed GIST (4.5cm) with negative margins and patient discharged after 4 days, without postoperative complications. In 1-year follow-up time, without recurrence or death.

CONCLUSION

IGS is safe and effective for gastric endophytic GIST resection, which not only preserves all advantages of conventional laparoscopic operation, but also includes other benefits like obviating the need of abdominal cavity exploration, potential reduction of risk of neoplasm seeding, and offering good postoperative cosmetic result.

Safety and efficiency of endoscopic resection versus laparoscopic resection in gastric gastrointestinal stromal tumours: A systematic review and meta-analysis

The application of endoscopic resection (ER) in gastric gastrointestinal stromal tumours (GIST) is controversial. We carried out a meta-analysis to compare the safety and efficiency of ER with laparoscopic resection (LR) in patients with gastric GISTs. We searched PubMed to identify studies comparing ER with LR in GIST. The outcomes focused on two areas: safety, including operation time, blood loss, length of hospital stay, time to flatus, time to liquid, time to soft diet, and postoperative complications; and efficiency, including positive margin, recurrence, and long-term survival. A total of 1292 patients from 12 studies were included in the meta-analysis. Patients undergoing ER had a shorter operation time (standardised mean difference [SMD] -1.48, 95% confidence interval [CI] -2.18 to -0.78) and shorter time to soft diet (SMD -1.02, 95% CI -1.52 to -0.52) than those undergoing LR. No significant differences were observed between the groups in terms of blood loss, length of hospital stay, time to flatus, time to liquid, and postoperative complications. ER was also associated with greater positive margins compared with LR (relative risk 6.32, 95% CI 1.41-28.26). There were no significant differences between ER and LR for recurrence and 5-year disease-free survival. The limited evidence suggests that ER is a more effective strategy for improving postoperative recovery without increasing the risk of surgery and recurrence in gastric GIST. However, close attention should be paid to margin status after ER.

Clinicopathological Outcomes and Prognosis of Elderly Patients (≥ 65 Years) with Gastric Gastrointestinal Stromal Tumors (GISTs) Undergoing Curative-Intent Resection: a Multicenter Data Review

BACKGROUND

The most common site of gastrointestinal stromal tumors (GISTs) is the stomach, and gastric GISTs (gGISTs) occur most often in elderly patients. However, the clinicopathological features, treatment patterns, and prognosis of elderly patients with gGISTs remain unclear.

METHODS

We retrospectively collected clinicopathological and prognostic data for patients with primary gGISTs who underwent curative-intent resection at 10 medical centers in China from 1998 to 2015.

RESULTS

Over the 18 years, 10 medical centers treated 1846 patients with primary gGISTs by curative-intent resection. The median age was 59 (range 18-91) years. The patients were classified into two groups according to age, namely an elderly group (≥ 65 years of age) and a nonelderly group (< 65 years of age). The elderly group had more comorbidities (40.7% vs 23.5%, p = 0.011), a higher rate of postoperative complications (14.4% vs 8.7%, p = 0.031), and a lower proportion of intermediate/high-risk patients who received adjuvant therapy (30.0% vs 66.8%, p = 0.001) than did the nonelderly group. Regarding pathological outcomes, a significant difference in tumor necrosis was observed between the two groups (p = 0.002), and more cases of tumor necrosis occurred in the elderly group than in the nonelderly group. Regarding postoperative recovery outcomes, no significant difference was observed between the two groups. Univariate analysis showed that age, postoperative complications, adjuvant therapy, tumor size, mitotic count, modified National Institutes of Health (NIH) risk category, and tumor necrosis were factors that affected disease-free survival (DFS). Multivariate analysis showed that modified NIH risk category was the only independent factor affecting DFS. The 5-year DFS rates in the nonelderly and elderly groups were 88.1% and 81.4%, respectively (p = 0.034), and the 5-year overall survival (OS) rates were 90.4% and 85.5% (p = 0.038), respectively.

CONCLUSIONS

Currently, the treatment patterns for elderly patients with gGISTs remain the same as those for young patients with gGISTs. Elderly gGIST patients had more comorbidities and postoperative complications than did nonelderly gGIST patients, and fewer elderly gGIST patients received postoperative adjuvant therapy. Elderly gGIST patients also had a higher rate of tumor necrosis and worse DFS and OS than did young gGIST patients. Further exploration into the diagnosis and treatment patterns of elderly patients is therefore essential.

A cohort study of prognostic factors associated with recurrence or metastasis of gastrointestinal stromal tumor (GIST) of stomach

Background

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm of the gastrointestinal tract. The major risk factors of recurrence and metastasis are mitotic index and tumor size. This study investigates the risk of recurrence and metastasis in solely gastric GIST. The primary outcome is to evaluate risk of recurrence and metastasis. The secondary outcome is to analyse survival rates of patients who have recurrence and metastasis after curative resection.

Method

A cohort of patients who underwent curative resection of gastric GIST between January 2006 to December 2016 was reviewed. The diagnosis was confirmed with positive CD34, DOG1 or KIT (CD117) immunohistochemistry. Risk factors of recurrence and metastasis were analyzed.

Results

Sixty-eight patients who received curative resection and diagnosed as gastric GIST were included in this study. Twenty (29.41%) had recurrence or metastasis. The median follow up time was 31.95 months. The mostcommon type of surgery was partial gastric resection. There were statistically-significant differences between mitotic index 6 HPF or 6 HPF in tumor size 0-5 cm, 5-10 cm and 10 cm and the risk of recurrence or metastasis (p-value 0.036). In tumors sized 6-10 cm, patients with mitotic index 6 HPF had longer survival than patients with mitotic index 6 HPF (p-value 0.0147).

Conclusion

The factor that determines the outcome of recurrence or metastasis in solely gastric GIST is high mitotic index count. Patients who have abdominal pain may be suspected as advanced disease. The type of operation and tumor size are not associated with recurrence or metastasis.

•

The factor that determines the outcome of recurrence or metastasis in gastric GIST is high mitotic index count more than 6.

•

Patients who have abdominal pain may be suspected as advanced disease.

•

The tumor size are not associated with recurrence or metastasis.

•

The overall survival did not depend on the tumor size, in contrast, the overall survival depends on the mitotic index.

[Gastrointestinal stromal tumors of the stomach and precursor lesions]

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors in the gastrointestinal tract although they are much less frequent than epithelial tumors. In more than 60% of cases they occur in the stomach. Especially small lesions measuring ≤1 cm in diameter, so-called microscopic GIST can occur multifocally, frequently in the proximal stomach wall and sometimes as an incidental finding in a gastrectomy specimen resected for gastric cancer. The multicentricity of GIST alone is not proof of a metastatic behavior or a syndromal or hereditary disease. Multiple sporadic synchronous and metachronous GIST are characterized by different primary mutations mostly in the KIT or PDGFRA genes and are often less aggressive. It is speculative whether a field effect is responsible or whether still unknown GIST-promoting factors may facilitate the development of several independent lesions. If KIT or PDGFRA mutations are lacking, a succinate dehydrogenase (SDH) deficient GIST has to be considered, either hereditary as Carney-Stratakis syndrome or syndromal as part of a Carney triad.

Serosal and muscular layers incision technique in laparoscopic surgery for gastric gastrointestinal stromal tumors

INTRODUCTION

To minimize the resection of stomach tissue, especially for lesions close to the esophagogastric junction or pyloric ring, we developed laparoscopic wedge resection with the serosal and muscular layers incision technique (SAMIT) for gastric gastrointestinal stromal tumors.

MATERIALS AND SURGICAL TECHNIQUE

SAMIT involves resection of the mucosal and submucosal layers and then an incision in serosal and muscular layers around the tumor. SAMIT is simple and does not require special devices. The data of 13 patients who underwent laparoscopic wedge resection with SAMIT for primary gastric gastrointestinal stromal tumors were reviewed. No intraoperative complications were observed, and postoperative stenosis occurred in only one case of a middle stomach lesion. Adequate oncological resection was performed in all cases.

DISCUSSION

Laparoscopic wedge resection with SAMIT is technically and oncologically safe. It is useful for treating gastric gastrointestinal stromal tumors, including those close to the esophagogastric junction or pyloric ring.

A gastrointestinal stromal tumor at the esophagogastric junction successfully treated by laparoscopic wedge resection with seromuscular layer dissection: a case report

Herein, we report a case of a gastrointestinal stromal tumor (GIST) at the esophagogastric junction (EGJ) that was successfully treated by a laparoscopic wedge resection (LWR) after dissection of the seromuscular layer around the tumor to prevent postoperative deformities and stenosis of the EGJ. Subsequently, the abdominal esophagus was wrapped by the gastric fornix according to Dor's method in order to prevent reflux esophagitis after surgery.A 71-year-old female patient was admitted with a diagnosis of a GIST (23 × 20 × 20 mm) at the EGJ. We performed the abovementioned operation.Gastroduodenal endoscopic examination revealed no deformity or stenosis of the EGJ at 6 months after the operation. The patient has not experienced any reflux symptoms. Tumor recurrence was not noted 26 months after the operation.This procedure is useful in preventing the deformity and stenosis of the EGJ as well as postoperative reflux esophagitis.