Microscopically positive margins for primary gastrointestinal stromal tumors: analysis of risk factors and tumor recurrence

Endoscopic full-thickness resection for gastric submucosal tumors: Japanese multicenter prospective study

OBJECTIVES

Early gastric cancer endoscopic resection (ER) is prominent in Japan. However, evidence regarding ER of gastric submucosal tumors (SMT) is limited. This prospective multicenter phase II study investigated the efficacy and safety of endoscopic full-thickness resection (EFTR) for gastric SMT.

METHODS

Endoscopic full-thickness resection indication for gastric SMT was 11-30 mm, histologically proven or clinically suspicious (irregular margin, increasing size, or internal heterogeneity) gastrointestinal stromal tumors (GIST), with no ulceration and intraluminal growth type. The primary end-point was the complete ER (ER0) rate, with a sample size of 42.

RESULTS

We enrolled 46 patients with 46 lesions between September 2020 and May 2023 at seven Japanese institutions. The mean ± SD (range) endoscopic tumor size was 18.8 ± 4.5 (11-28) mm. The tumor resection and defect closure times were 54 ± 26 (22-125) min and 33 ± 28 (12-186) min, respectively. A 100% ER0 was achieved in all 46 patients. The EFTR procedure was accomplished in all patients without surgical intervention. One patient had delayed perforation and was managed endoscopically. GIST accounted for 76% (n = 35) of the cases. R0, R1, and RX rates were 33 (77%), 3 (6.5%), and 7 (15%), respectively.

CONCLUSION

Endoscopic full-thickness resection for gastric SMT of 11-30 mm is efficacious. It warrants further validation in a large-scale cohort study to determine the long-term outcome of this treatment for patients with gastric GIST.

Improvement of perioperative outcomes of gastric gastrointestinal stromal tumour (GIST) resections and the influence of minimal invasive surgery

BACKGROUND

Safety of minimally invasive surgery (MIS) for gastrointestinal stromal tumours (GISTs) is still under debate since it might increase the risk of tumour rupture, especially in larger tumours. The aim of this study was to investigate trends in treatment and perioperative outcomes of patients undergoing resections of gastric GISTs over time.

METHODS

This was a multicentre retrospective study of consecutive patients who underwent wedge resection or partial gastrectomy for localized gastric GIST at five GIST reference centres between January 2009 and January 2022. To evaluate changes in treatment and perioperative outcomes over time, patients were divided into four equal periods. Perioperative outcomes were analysed separately and as a novel composite measure textbook outcome (TO).

RESULTS

In total 385 patients were included. Patient and tumour characteristics did not change over time, except for median age (62-65-68-68 years, p = 0.002). The proportion of MIS increased (4.0%-9.8%-37.4%-53.0 %, p < 0.001). Postoperative complications (Clavien Dindo ≥2; 22%-15%-11%-10 %, p = 0.146), duration of admission (6-6-5-4 days, p < 0.001) and operating time (92-94-77-73 min, p = 0.007) decreased over time while TO increased (54.0%- 52.7%-65.9%-76.0 %, p < 0.001). No change was seen in perioperative ruptures (6.0%- 3.6%-1.6%-3.0 %, p = 0.499). MIS was correlated with less CD ≥ 2 complications (p = 0.006), shorter duration of admission (p < 0.001) and more TO (p < 0.001). Similar results were observed in tumours ≤5 cm and >5 cm.

CONCLUSION

A larger percentage of gastric GIST were treated with MIS over time. MIS was correlated with less complications, shorter duration of admission and more TO. Tumour rupture rates remained low over time.

English version of Japanese Clinical Practice Guidelines 2022 for gastrointestinal stromal tumor (GIST) issued by the Japan Society of Clinical Oncology

The Japan Society of Clinical Oncology Clinical Practice Guidelines 2022 for gastrointestinal stromal tumor (GIST) have been published in accordance with the Minds Manual for Guideline Development 2014 and 2017. A specialized team independent of the working group for the revision performed a systematic review. Since GIST is a rare type of tumor, clinical evidence is not sufficient to answer several clinical and background questions. Thus, in these guidelines, we considered that consensus among the experts who manage GIST, the balance between benefits and harms, patients' wishes, medical economic perspective, etc. are important considerations in addition to the evidence. Although guidelines for the treatment of GIST have also been published by the National Comprehensive Cancer Network (NCCN) and the European Society for Medical Oncology (ESMO), there are some differences between the treatments proposed in those guidelines and the treatments in the present guidelines because of the differences in health insurance systems among countries.

Transvaginal removal of rectal stromal tumor with Martius flap interposition: a feasible option for a large tumor at the anterior wall of the rectum

Neoadjuvant imatinib treatment, followed by complete transvaginal removal, presents a feasible option for large rectal gastrointestinal tumors located on the anterior wall of the rectum and protruding into the vagina. The use of Martius flap interposition is convenient and can be employed to prevent rectovaginal fistula.

Clinical outcomes of endoscopic resection for the treatment of intermediate- or high-risk gastric small gastrointestinal stromal tumors: a multicenter retrospective study

BACKGROUND AND AIMS

Many studies of gastric gastrointestinal stromal tumors (g-GISTs) following endoscopic resection (ER) have typically focused on tumor size, with most tumors at low risk of aggressiveness after risk stratification. There have been few systematic studies on the oncologic outcomes of intermediate- or high-risk g-GISTs after ER.

METHODS

From January 2014 to January 2020, we retrospectively collected patients considered at intermediate- or high-risk of g-GISTs according to the modified NIH consensus classification system. The primary outcome was overall survival (OS).

RESULTS

Six hundred and seventy nine (679) consecutive patients were diagnosed with g-GISTs and treated by ER between January 2014 and January 2020 in three hospitals in Shanghai, China. 43 patients (20 males and 23 females) were confirmed at intermediate-or high-risk. The mean size of tumors was 2.23 ± 1.01 cm. The median follow-up period was 62.02 ± 15.34 months, with a range of 28 to 105 months. There were no recurrences or metastases, even among patients having R1 resections. The 5-year OS rate was 97.4% (42/43).

CONCLUSION

ER for intermediate- or high-risk gastric small GISTs is a feasible and safe method, which allows for a wait-and-see approach before determining the necessity for imatinib adjuvant or surgical treatment. This approach to g-GISTs does require that patients undergo close follow-up.

Prognostic impact of positive microscopic margins (R1 resection) in patients with GIST (gastrointestinal stromal tumours): Results of a multicenter European study

BACKGROUND

Although several prognostic factors in GIST have been well studied such as tumour size, mitotic rate, or localization, the influence of microscopic margins or R1 resection remains controversial. The aim of this study was to evaluate the influence of R1 resection on the prognosis of GIST in a large multicentre retrospective series of patients.

METHODS

From 2001 to 2013, 1413 patients who underwent surgery for any site of GIST were identified from 61 European centers. 1098 patients were included, excluding synchronous metastases, concurrent malignancies, R2 resection or GIST recurrence. Tumour rupture (TR) was reclassified according to the Oslo sarcoma classification. Cox proportional hazards ratio and Kaplan-Meier survival estimates were used to analyse 5-year recurrence-free survival (RFS).

RESULTS

Of 1098 patients, 38 (3%) underwent R1 resection with a risk of TR of 11%. The 5-year RFS was 89.6% with a median follow-up of 81 months [range: 31.2-152 months]. On univariate analysis, lower RFS was significantly associated with R1 resection [HR = 2.13; p = 0.04], high risk score according to the modified NIH classification, administration of adjuvant therapy [HR = 2.24; p < 0.001] and intraoperative complications [HR = 2.82; p < 0.001]. Only intraoperative complications [HR = 1.79; p = 0.02] and high risk according to the modified NIH classification including the updated definition of TR [HR = 3.43; p = 0.04] remained significant on multivariate analysis.

CONCLUSION

This study shows that positive microscopic margins are not an independent predictive factor for RFS in GIST when taking into account the up-dated classification of TR. R1 resection may be considered a reasonable alternative to avoid major functional sequelae and should not lead to reoperation.

Endoscopic resection of gastric gastrointestinal stromal tumor using clip-and-cut endoscopic full-thickness resection: a single-center, retrospective cohort in Korea

BACKGROUND/AIMS

To overcome the technical limitations of classic endoscopic resection for gastric gastrointestinal stromal tumors (GISTs), various methods have been developed. In this study, we examined the role and feasibility of clip-and-cut procedures (clip-and-cut endoscopic full-thickness resection [cc-EFTR]) for gastric GISTs.

METHODS

Medical records of 83 patients diagnosed with GISTs after endoscopic resection between 2005 and 2021 were retrospectively reviewed. Moreover, clinical characteristics and outcomes were analyzed.

RESULTS

Endoscopic submucosal dissection (ESD) and cc-EFTR were performed in 51 and 32 patients, respectively. The GISTs were detected in the upper third of the stomach for ESD (52.9%) and cc-EFTR (90.6%). Within the cc-EFTR group, a majority of GISTs were located in the deep muscularis propria or serosal layer, accounting for 96.9%, as opposed to those in the ESD group (45.1%). The R0 resection rates were 51.0% and 84.4% in the ESD and cc-EFTR groups, respectively. Seven (8.4%) patients required surgical treatment (six patients underwent ESD and one underwent cc-EFTR,) due to residual tumor (n=5) and post-procedure adverse events (n=2). Patients undergoing R0 or R1 resection did not experience recurrence during a median 14-month follow-up period, except for one patient in the ESD group.

CONCLUSIONS

cc-EFTR displayed a high R0 resection rate; therefore, it is a safe and effective therapeutic option for small gastric GISTs.

Comparable long‑term survival outcomes of endoscopic treatment versus surgical treatment for gastrointestinal stromal tumors with a diameter of 5-10 cm

Currently, endoscopic treatment for small gastrointestinal stromal tumors (GIST) has been widely accepted. However, for tumors larger than 5 cm, endoscopic treatment has not been recognized by national guidelines as the standard therapy due to concerns about safety and adverse tumor outcomes. Therefore, this study compares the long-term survival outcomes of endoscopic treatment and surgical treatment for GIST in the range of 5-10 cm. We selected patients with GIST from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2015. Kaplan-Meier analysis and the log-rank test were employed to compare the long-term survival outcomes between endoscopic treatment and surgical treatment. A multivariate Cox proportional hazards model was used for analysis to identify risk factors influencing patient prognosis. To balance baseline data, we performed 1:1 propensity score matching (PSM). A total of 1223 GIST patients were included, with 144 patients (11.8%) received endoscopic treatment and 1079 patients (88.2%) received surgical treatment. Before PSM, there was no significant difference in the long-term survival rates between the two groups [5-year OS (86.5% vs. 83.5%, P = 0.42), 10-year OS (70.4% vs. 66.7%, P = 0.42)]. After adjusting for covariates, we found that the overall survival (HR = 1.26, 95% CI 0.89-1.77, P = 0.19) and cancer-specific survival (HR = 1.69, 95% CI 0.99-2.89, P = 0.053) risks were comparable between the endoscopic treatment group and the surgical treatment group. In the analysis after PSM, there was no significant difference between the endoscopic treatment group and the surgical treatment group. Our study found that for GIST patients with tumor sizes between 5 and 10 cm, the long-term OS and CSS outcomes were similar between the endoscopic treatment group and the surgical treatment group.

Assessing prognostic factors of long-term survival after surgery for colorectal gastrointestinal stromal tumours

AIM

Due to their rarity, the management of colorectal gastrointestinal stromal tumours (CR GISTs) is still under debate. The aim of this study was to assess prognostic factors.

METHOD

We performed a retrospective review of patients who underwent surgery with curative intent for CR GIST at our centre from 2002 to 2019. Factors associated with overall (OS) and recurrence-free survival (RFS) were analysed.

RESULTS

Fifty-six patients were included [median age 63 years, 29 (52%) female, 30 (54%) Miettinen high-risk, 40 (71%) with rectal GIST]. Nineteen (34%) patients received perioperative (neoadjuvant and/or adjuvant) imatinib. All cases of colonic GIST had an R0 resection, compared with 28 (70%) of rectal GISTs. After a median follow-up of 97 months (interquartile range 48-155 months), 14 (25%) deaths and 14 (25%) recurrences occurred. In the high-risk cohort, factors associated with improved RFS were R0 resection (OR 0.19, 95% CI 0.1-0.5, p = 0.002) and perioperative imatinib (OR 0.33, 95% CI 0.42-0.97, p = 0.04). Patients who had received perioperative imatinib had longer RFS (60% vs. 11% at 5 years, p = 0.006) but not OS. In rectal GISTs, 5-year OS was 85% for R0 and 70% for R1 resections (p = 0.164) and 5-year RFS was 85% for R0 and 12% for R1 resection (p < 0.001). When stratifying patients by perioperative imatinib, there were no differences in OS or RFS in the R0 or R1 groups.

CONCLUSION

Perioperative imatinib and R0 resection were associated with improved RFS in high-risk patients with CR GIST. In patients with rectal GIST, R1 resection was associated with worse RFS irrespective of perioperative imatinib treatment.

Survival outcome of local versus radical resection for jejunoileal gastrointestinal stromal tumors: a propensity score-matched population-based analysis

PURPOSE

Survival after local resection (LR) versus radical resection (RR) has been revealed comparable for patients with rectal and duodenal gastrointestinal stromal tumors (GISTs), but is unknown for jejunoileal (JI) GISTs. This study aimed to compare the long-term survival between patients with JI GISTs who underwent LR and RR, and to find out the prognostic factors for JI GISTs.

METHODS

Patients diagnosed with JI GISTs in 1975-2019 were identified from Surveillance, Epidemiology, and End Results (SEER) database and grouped according to surgical modality. Propensity score matching (PSM) was performed to balance the LR and RR groups. Overall survival (OS) and disease-specific survival (DSS) were compared in the full and matched cohorts using Kaplan-Meier (KM) analysis. Subgroup sensitivity analyses were also performed. Risk factors associated with DSS were analyzed in multivariate Cox analysis following model selection.

RESULTS

1107 patients diagnosed with JI GISTs were included in the study cohort. After PSM, OS and DSS were comparable in LR and RR groups. Consistently, the two groups had similar DSS in all subgroup analyses. Moreover, multivariate Cox analysis identified lymphadenectomy, older age, larger tumor size, distant metastasis, high and unknown mitotic rate, but not LR, as independent prognostic risk factors for JI GISTs.

CONCLUSIONS

We conducted the first population-based comparison between the effect of different surgical modes on survival for patients with JI GISTs. LR can be carried out safely without compromising oncological outcome, and should be considered as a treatment option in selected patients with JI GISTs.

SEOM-GEIS clinical guideline for gastrointestinal stromal tumors (2022)

Gastrointestinal stromal tumor (GIST) is the most common malignant neoplasm of mesenchymal origin, and a paradigmatic model for a successful rational development of targeted therapies in cancer. The introduction of tyrosine kinase inhibitors with activity against KIT/PDGFRA in both localized and advanced stages has remarkably improved the survival in a disease formerly deemed resistant to all systemic therapies. These guidelines are elaborated by the conjoint effort of the Spanish Society of Medical Oncology (SEOM) and the Spanish Sarcoma Research Group (GEIS) and provide a multidisciplinary and updated consensus for the diagnosis and treatment of GIST patients. We strongly encourage that the managing of these patients should be performed within multidisciplinary teams in reference centers.

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.

Goldilocks principle of minimally invasive surgery for gastric subepithelial tumors

BACKGROUND

Minimally invasive surgery had been tailored to individual cases of gastric subepithelial tumors (SETs) after comparing the clinical outcomes of endoscopic resection (ER), laparoscopic resection (LR), and hybrid methods.

AIM

To study the use of Goldilocks principle to determine the best form of minimally invasive surgery for gastric SETs.

METHODS

In this retrospective study, 194 patients of gastric SETs with high probability of surgical intervention were included. All patients underwent tumor resection in the operating theater between January 2013 and December 2021. The patients were divided into two groups, ER or LR, according to the tumor characteristics and the initial intent of intervention. Few patients in the ER group required further backup laparoscopic surgery after an incomplete ER. The patients who had converted open surgery were excluded. A logistic regression model was used to assess the associations between patient characteristics and the likelihood of a treatment strategy. The area under the curve was used to assess the discriminative ability of tumor size and Youden's index to determine the optimal cut-off tumor size.

RESULTS

One-hundred ninety-four patients (100 in the ER group and 94 in the LR group) underwent tumor resection in the operating theater. In the ER group, 27 patients required backup laparoscopic surgery after an incomplete ER. The patients in the ER group had small tumor sizes and shorter procedure durations while the patients in the LR group had large tumor sizes, exophytic growth, malignancy, and tumors that were more often located in the middle or lower third of the stomach. Both groups had similar durations of hospital stays and a similar rate of major postoperative complications. The patients in the ER group who underwent backup surgery required longer procedures (56.4 min) and prolonged stays (2 d) compared to the patients in the LR group without the increased rate of major postoperative complications. The optimal cut-off point for the tumor size for laparoscopic surgery was 2.15 cm.

CONCLUSION

Multidisciplinary teamwork leads to the adoption of different strategies to yield efficient clinical outcomes according to the tumor characteristics.

2023 GEIS Guidelines for gastrointestinal stromal tumors

Gastrointestinal stromal tumor (GIST) is the most common malignant neoplasm of mesenchymal origin. GIST spans a wide clinical spectrum that ranges from tumors with essentially no metastatic potential to malignant and life-threatening spread diseases. Gain-of-function mutations in KIT or PDGFRA receptor tyrosine kinases are the crucial drivers of most GISTs, responsible for tumor initiation and evolution throughout the entire course of the disease. The introduction of tyrosine kinase inhibitors targeting these receptors has substantially improved the outcomes in this formerly chemoresistant cancer. As of today, five agents hold regulatory approval for the treatment of GIST: imatinib, sunitinib, regorafenib, ripretinib, and avapritinib. This, in turn, represents a success for a rare neoplasm. During the past two decades, GIST has become a paradigmatic model in cancer for multidisciplinary work, given the disease-specific particularities regarding tumor biology and tumor evolution. Herein, we review currently available evidence for the management of GIST. This clinical practice guideline has been developed by a multidisciplinary expert panel (oncologist, pathologist, surgeon, molecular biologist, radiologist, and representative of patients' advocacy groups) from the Spanish Group for Sarcoma Research, and it is conceived to provide, from a critical perspective, the standard approach for diagnosis, treatment, and follow-up.

Clinical outcomes of endoscopic resection for the treatment of esophageal gastrointestinal stromal tumors: a ten-year experience from a large tertiary center in China

BACKGROUNDS

Esophageal gastrointestinal stromal tumors (E-GISTs) are extremely rare and surgical resection is the recommended approach. However, surgical resection usually causes severe trauma that may result in significant postoperative morbidity. Endoscopic resection (ER) has developed rapidly in recent years and has been widely used in gastrointestinal lesions. Nevertheless, the feasibility and efficacy of ER in the management of E-GISTs are unknown.

METHODS

Retrospective data were collected from January 2011 to December 2020 in a large tertiary center of China. Twenty-eight patients with E-GISTs treated by ER were included in the study.

RESULTS

Of the 28 patients, there were 21 males and 7 females, with a median age of 55 years (40-70 years). The median tumor size was 15 mm (5-80 mm). The technical success rate was 100% (28/28), while the en bloc resection rate was 96.4% (27/28). The median operation time was 35 min (10-410 min). Sixteen (57.2%) tumors were categorized into very low risk group, six (21.4%) into low risk group, and six (21.4%) into high risk group. Pathologists carefully examined margins of each lesion. There were 11 lesions (39.3%) determined as R0 resection and 17 lesions (60.7%) as R1 resection with positive margins. The median hospital stay was 2 days (range, 1-8 days). One patient suffered from hydrothorax and required drainage, leading to a major adverse event rate of 3.6% (1/28). There was no conversion to surgery, and no death occurred within 30 days after the procedure. Imatinib was given to two patients after ER under multidisciplinary team surveillance. During follow-up (median of 54 months, 9-122 months), no recurrences or metastasis were observed.

CONCLUSION

ER is safe and effective for E-GISTs and might become an optional choice in the future. Multicenter, prospective, large samples with long-term follow-up studies are still needed.

Anal canal gastrointestinal stromal tumour (GIST)

SummaryGastrointestinal stromal tumours (GISTs) are malignant mesenchymal tumours that originate from the interstitial pacemaker cells of Cajal. They are particularly rare, comprising only 5% of all GISTs, and often present at an advanced stage. Treatment for these tumours is still a topic of debate due to their low incidence and insidious location. A woman in her mid-70s presented with rectal bleeding and anal discomfort. A 4.5×4 cm anal GIST was diagnosed. A local excision was performed and the patient was further treated with tyrosine kinase inhibitors. At a 6-month follow-up, the MRI showed that she was disease free. Anorectal GISTs are unusual and tend to be aggressive. Surgical resection is the first-line treatment for primary, localised GISTs. However, the appropriate surgical technique for these tumours is still a topic of debate. Further studies are needed to fully understand the oncologic behaviour of these rare neoplasms.

Local recurrence in primary localized resected gastro-intestinal stromal tumors A registry observational national cohort study including 912 patients

BACKGROUND AND OBJECTIVES

Previous literature showed a high risk of recurrence following surgical treatment in patients with gastrointestinal stromal tumours (GISTs). However, little is known about the patient- and treatment characteristics of local recurrences (LRs) in GIST patients. Therefore, this study aimed to better understand patterns of LR in surgically treated localised GIST and to describe treatment options based on our Dutch GIST Registry (DGR).

METHODS

Data of primary surgically treated localised GIST between January 2009 until July 2021 were retrospectively retrieved from the DGR.

RESULTS

Of 1452 patients registered in the DGR, 912 patients were included in this study. Only 3.8% (35/912) of patients developed LR, including 20 patients with LR only and 15 patients with simultaneous LR and distant metastases (DM). Median time to LR was 30 (interquartile range 8-53) months from date of surgery. Eleven percent (100/912) of patients developed only DM. A total of 2.3% (6/259) of patients treated with adjuvant treatment developed an LR during adjuvant therapy. Seventy percent of patients with LR only (14/20) were treated with surgery (85.7% R0), which was mostly combined with systemic treatment.

CONCLUSIONS

Patients with primary surgically treated localised GIST have a limited risk of developing recurrence. Fifteen percent developed recurrence, of which one quarter developed an LR. Therefore, less intensified follow-up schedules could be considered, especially during treatment with adjuvant imatinib. In patients with LR only, potentially curative treatment strategies, including surgical (re-)resection, are often possible as treatment for LR.

Endoscopic resection for gastric submucosal tumors: Japanese multicenter retrospective study

OBJECTIVES

Limited information is available on the efficacy and safety of endoscopic resection (ER) of gastric submucosal tumors (SMTs) in Japanese endoscopic practice where ER for gastric tumors is extremely popular.

METHODS

We conducted this study to elucidate the current scenario of ER for gastric SMTs in Japanese endoscopic practice. Patients (from 12 institutions) with gastric SMTs who underwent ER were enrolled from the first case until August 2020.

RESULTS

We enrolled 117 patients with 118 lesions. The number of patients who underwent ER increased over the years. The mean endoscopic tumor size was 20 ± 7.2 (8-40) mm. The growth type was primarily intraluminal (90%). The mean resection and wound closure times were 58 ± 38 (range, 12-254) min and 31 ± 41 (range, 3-330) min, respectively. Complete ER was achieved for 117 (99%) lesions. Full-thickness resection rate was 44%; however, only 12 (10%) patients required abdominal paracentesis for decompression. Endoscopic treatments were completed in 115 (97%) lesions, while three lesions required conversions to laparoscopic surgery due to luminal collapse, uncontrolled bleeding, and difficulty in defect closure. Gastrointestinal stromal tumors were the most common pathology (74%). No recurrence was observed during the mean follow-up period of 4.3 ± 2.9 years. The 5-year overall survival rate was 98.9% (95% confidence interval 97.8-100%).

CONCLUSION

Performance of ER for gastric SMTs is increasing in Japan. The technique seems feasible in Japanese endoscopic practice, warranting further validation in a prospective study.

Outcomes of Local Excision Compared to Radical Excision of Rectal Gastrointestinal Stromal Tumors: A Propensity-Score Matched Analysis of the NCDB

BACKGROUND

Gastrointestinal stromal tumors (GISTs) account for <1% of gastrointestinal cancers. The present study aimed to assess the outcomes of local and radical excision of non-metastatic rectal GISTs.

METHODS

This study was a retrospective cohort analysis of patients with non-metastatic rectal GISTs in the NCDB. Patients were divided according to the surgical approach into local and radical excision and were compared in regard to the baseline characteristics and outcomes. A propensity-score matched analysis was performed to match the two groups for baseline confounders. The main outcomes were 5-year overall survival (OS), surgical margins, hospital stay, short-term mortality, and readmission.

RESULTS

228 patients (54.8% male) with rectal GISTs were included. Before matching, 127 (55.7%) patients underwent local excision and 101 (44.3%) had radical excision. Patients who underwent local excision had more cT1-T2 and low-grade GISTs whereas patients who had radical excision received more neoadjuvant systemic treatment. After matching for clinical T stage, tumor grade, and neoadjuvant systemic therapy, 52 patients were included in each group. Local excision had a significantly higher rate of positive resection margins (42.2% vs. 19.1%, p = 0.02) and a shorter hospital stay (0 vs. 3 days, p < 0.001) than radical excision. The two groups had similar mean OS (139.8 vs. 133.1 months, p = 0.52).

CONCLUSIONS

Local excision was associated with a significantly higher incidence of positive resection margins and shorter hospital stay, yet similar overall survival to radical excision.

Advances of endoscopic and surgical management in gastrointestinal stromal tumors

As one of the most common mesenchymal malignancies in the digestive system, gastrointestinal stromal tumors (GISTs) occur throughout the alimentary tract with diversified oncological characteristics. With the advent of the tyrosine kinase inhibitor era, the treatment regimens of patients with GISTs have been revolutionized and GISTs have become the paradigm of multidisciplinary therapy. However, surgery resection remains recognized as the potentially curative management for the radical resection and provided with favorable oncological outcomes. The existing available surgery algorithms in clinical practice primarily incorporate open procedure, and endoscopic and laparoscopic surgery together with combined operation techniques. The performance of various surgery methods often refers to the consideration of risk evaluation of recurrence and metastases; the degree of disease progression; size, location, and growth pattern of tumor; general conditions of selected patients; and indications and safety profile of various techniques. In the present review, we summarize the fundamental principle of surgery of GISTs based on risk assessment as well as tumor size, location, and degree of progress with an emphasis on the indications, strengths, and limitations of current surgery techniques.

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.

Prognostic Nomogram for Gastrointestinal Stromal Tumors after Surgery Based on the SEER Database

We aimed to determine prognostic factors and develop an effective and practical nomogram for predicting cancer-specific survival in gastrointestinal stromal tumor (GIST) patients. Postoperative data were obtained from the SEER database (2000-2018). Patients were divided into training and validation cohorts at random (7 : 3). Prognostic factors were screened, and a prognostic nomogram was established using log-rank testing and Cox regression. We used DCA, ROC curves, C-index, and calibration curves to evaluate our model's predictive performance. The clinical value of the nomogram and the modified National Institute of Health (M-NIH) classification were compared using the NRI and IDI. The Kaplan-Meier method was applied to examine survival by risk group, and log-rank tests were applied to compare variations in survival curves. Independent prognostic risk factors associated with cancer-specific survival on multivariate Cox proportional hazards regression analysis were age, race, and tumor location, size, grade, and stage. Clinically relevant variables need to be considered in addition to statistically significant variables when developing prognostic models to aid clinical decision-making. We included two additional variables (mitotic rate and chemotherapy) when constructing the prognostic model. The C-index was 0.766 (95% confidence interval (CI): 0.737-0.794) in the training cohort and 0.795 (95% CI: 0.754-0.836) in the internal validation group suggesting robustness. The areas under the ROC curve for three-year and five-year survival were >0.700, indicating satisfactory discrimination. The calibration curves showed good agreement between the predictions of the nomogram and the actual results. The NRI (0.346 for 3-year and 0.265 for 5-year cancer-specific survival for patients with GIST (GSS) prediction; validation cohort: 0.356 for 3-year and 0.246 for 5-year GSS prediction) and IDI values (0.047 for 3-year and 0.060 for 5-year GSS prediction; validation cohort: 0.071 for 3-year and 0.084 for 5-year GSS prediction) suggested that the established nomogram performed significantly better than the M-NIH classification. The DCA indicated that the nomogram was clinically useful and had a high discriminative ability in identifying patients who were at high risk of poor outcomes. According to nomogram findings, patients were divided into three groups (high, moderate, and low risk), with significantly different prognoses in both cohorts. Our nomogram satisfactorily predicted survival in postsurgical GIST patients, which may assist clinicians to evaluate the postoperative status and guide subsequent treatments.

Laparoscopic resection is not superior to endoscopic resection for relative small gastric gastrointestinal stromal tumors: A propensity score-matched study

Background and Aim

Endoscopic resection (ER) and laparoscopic resection (LAP) have been recommended for the treatment of gastric gastrointestinal stromal tumors (GISTs) less than 2 cm. However, the therapeutic approach for gastric GISTs between 2 and 5 cm in diameter is still under debate. In this retrospective study, we aimed to evaluate the feasibility, efficacy, and safety of ER for gastric GISTs (2–5 cm) compared with LAP.

Methods

From January, 2011 to January, 2018, 197 patients with GISTs at our institution with tumor diameter between 2 and 5 cm were included in our study. Clinical baseline characteristics, histopathological results, and perioperative outcomes were collected and compared in all the patients. Propensity score matching (PSM) methods were used to balance baseline characteristics.

Results

There was no significant difference in age (p = 0.246), gender (p = 0.572), tumor location (p = 0.333), pathological risk classification (p = 0.543), Ki-67 index (p = 0.212), and follow-up time (p = 0.831) in the ER and LAP groups. However, significance difference was found in times to liquid diet intake (4.45 ± 1.2 vs. 5.40 ± 1.5 days, p = 0.013) and hospital stays (7.72 ± 1.1 vs. 10.01 ± 1.3 days, p &lt; 0.001). During the follow-up period, there was one recurrence in the ER group vs. two recurrences in the LAP group. After PSM, the tumor size was balanced between the two groups with 49 patients in each group. The times to liquid diet intake (4.18 ± 1.3 vs. 5.16 ± 1.6 days, p = 0.042) and hospital stay days (7.12 ± 1.1 vs. 9.94 ± 1.3, p &lt; 0.0001) were still short in the ER group.

Conclusions

ER is more associated with a quick postoperative recovery than LAP. ER could be an alternative approach for gastric GISTs (2–5 cm). However, the long-term follow-up outcomes are still unclear and random control trials are needed.

Effect of endoscopic resection of gastrointestinal stromal tumors in the stomach under double-channel gastroscopy: A retrospective observational study

We aimed to investigate the safety and efficacy of endoscopic resection for the treatment of gastric gastrointestinal stromal tumors (GISTs) under single-channel gastroscopy and double-channel gastroscopy. We identified 154 patients with GISTs of the stomach who underwent endoscopic resection and were retrospectively analyzed at our hospital between May 2016 and March 2020, including 49 patients by single-channel gastroscopy and 105 patients by double-channel gastroscopy. We observed the clinical efficacy, complications, and safety of endoscopic resection of gastric GISTs, and the data were evaluated retrospectively. All patients underwent endoscopic resection successfully, without conversion to open surgery. In the single-channel gastroscopy group, 7 patients had lesions in the gastric cardia, 17 in the gastric fundus, 20 in the gastric corpus, and 5 in the gastric antrum. In the double-channel gastroscopy group, 13 patients had lesions in the gastric cardia, 34 in the gastric fundus, 46 in the gastric body, 10 in the gastric antrum, 1 in the pylorus, and 1 in the gastric angular incisure. The double-channel gastroscopy group had a shorter operation time than the single-channel gastroscopy group (59.9 ± 34.9 minutes vs 74.8 ± 26.7 minutes; P = .009 and P < .01, respectively), while they also had a lower perforation rate than the single-channel gastroscopy group (34.3% vs 51.0%; P = .048 and P < .05, respectively). No residual or recurrent lesions were discovered in any patients by gastroscopy reexamination. Both single-channel gastroscopy and double-channel gastroscopy can provide safe, effective, feasible endoscopic resection. However, double-channel gastroscopy has some distinct advantages in endoscopic resection.

Comparison of safety and short-term outcomes between endoscopic and laparoscopic resections of gastric gastrointestinal stromal tumors with a diameter of 2-5 cm

BACKGROUND AND AIM

Developments of endoscopic techniques brought the possibility of endoscopic resection for gastrointestinal stromal tumors (GISTs) of larger sizes. We aim to compare safety and short-term outcomes between endoscopic and laparoscopic resections of gastric GISTs with a diameter of 2-5 cm.

METHODS

This is a single-center, retrospective cohort study. The clinical data, perioperative conditions, and the adverse events of patients who underwent endoscopic or laparoscopic resection for gastric GIST of 2-5 cm in Zhongshan Hospital, Fudan University, from January 2016 to December 2020 were retrospectively reviewed.

RESULTS

A total of 346 patients were reviewed; 12 patients who failed to accomplish the planned procedure were excluded; 182 underwent laparoscopic resection; and 152 underwent endoscopic resection. Significant differences exist in the tumor size between the laparoscopic group (3.43 ± 0.86 cm) and the endoscopic group (2.78 ± 0.73 cm) (P < 0.01). Compared with laparoscopic resection, endoscopic resection was associated with faster recovery (P < 0.01), shorter hospital stays (P < 0.01), and lower cost (P < 0.01). The incidence of Clavien-Dindo grade II-V adverse events in the endoscopic group (3/152) was significantly lower than that in the laparoscopic group (12/182) (P = 0.04). After a propensity score matching analysis, the endoscopic group showed similar incidences of complications with the laparoscopic group, while the advantages over laparoscopic resection in postoperative hospital stay, time to first oral intake, and hospitalization expenses remained significant (P < 0.01).

CONCLUSIONS

Endoscopic resection is a safe and cost-effective method for 2-5 cm of gastric GISTs compared with laparoscopic resection.

Long-term prognosis of small gastric gastrointestinal stromal tumors with high histological grade: a longitudinal nested cohort study

BACKGROUND AND AIMS

Gastrointestinal stromal tumors (GIST) are mostly seen in the stomach. Clinical data on GISTs ≤ 2 cm with > 5 mitosis/50 HPFs are limited. This study aimed to analyze small GISTs with high histological grades to gain a more comprehensive understanding of their clinical characteristics with long-term follow-up.

METHODS

This was a nested cohort study of patients with gastric GISTs ≤ 2 cm and > 5 mitosis/50 HPFs. Individuals with endoscopically resected gastric specimens diagnosed as GISTs between January 2008 and July 2019 were enrolled. We analyzed baseline clinicopathological characteristics, perioperative characteristics, risk of recurrence, and metastasis during follow-up.

RESULTS

A total of 55 patients diagnosed with gastric GISTs ≤ 2 cm and > 5 mitosis/50 HPFs were enrolled. The mean tumor size was 1.6 ± 0.4 cm (median 1.7 cm, range 0.8-2.0 cm). ESD was performed in 33 patients (60.0%) and EFTR in 22 patients (40.0%). Mean mitotic figures were 8.9/50 HPFs. Postoperative bleeding in one patient (1.8%) was the only severe adverse event. The mean follow-up period was 61.2 ± 33.9 months (median 53 months, range 13-133 months). Five patients (5/55, 9.1%) received additional therapies, including partial gastrectomy and adjuvant Imatinib. Only two patients (2/55, 3.6%) showed signs of recurrence. We observed no significant difference regarding baseline clinical characteristics and recurrence among GISTs with mitosis < 10/50 HPF and ≥ 10/50 HPF. No patient had signs of metastasis during follow-up.

CONCLUSION

Endoscopic resection of gastric GISTs ≤ 2 cm with > 5 mitosis/50 HPFs has a low risk of recurrence and metastasis in the long term. Endoscopic resection of GISTs is safe and feasible.

Ki67 for evaluating the prognosis of gastrointestinal stromal tumors: A systematic review and meta‑analysis

Overexpression of Ki67 is observed in tumor cells, and it has been suggested to be a marker for cancer prognosis. However, the relationship between Ki67 expression and the risk of recurrence of gastrointestinal stromal tumors (GISTs) remains poorly defined. In the present study, a meta-analysis was used to examine the associations between Ki67 levels and GIST recurrence. Studies reporting GIST and Ki67 were found by searching Cochrane Library, PubMed and Embase until October 14, 2021. The Newcastle-Ottawa Scale (NOS) was used to verify the quality of the evidence. Totally, 1682 patient cases were included. The odds ratio (OR) estimates and 95% confidence interval (CI) for each publication were determined by a fixed-effects (Mantel-Haenszel) model. A total of 20 studies that fulfilled the inclusion criteria were finally included in the analysis. The average score of quality evaluation was 6.4 points according to NOS. It was found that Ki67 levels were significantly higher in the NIH L group compared with the NIH VL group (OR: 0.51; 95% CI: 0.26-0.99; P=0.04; P heterogeneity=0.44). There was also greater Ki67 overexpression in the NIH I group compared with the NIH L group (OR: 0.45, 95% CI: 0.31-0.65; P<0.0001; P heterogeneity=0.32), while Ki67 levels were greater in the NIH H group than in the NIH I group (OR: 0.20; 95% CI: 0.15-0.28; P<0.00001; P heterogeneity=0.56). In conclusion, Ki67 overexpression may be a useful marker of the risk of recurrent GIST transformation.

Comparison of Prognosis Between Microscopically Positive and Negative Surgical Margins for Primary Gastrointestinal Stromal Tumors: A Systematic Review and Meta-Analysis

Background

This meta-analysis aimed to determine the prognostic impact of microscopically positive margins (R1) on primary gastrointestinal stromal tumors.

Methods

A literature search was performed using PubMed, Embase, Web of Science, and Cochrane Library for studies up to 23 November 2020. The pooled disease-free survival (DFS) and overall survival (OS) between R1 and negative margins (R0) were estimated using a random-effects model.

Results

Twenty studies with 6,465 patients were included. Compared with R0 resection, R1 was associated with poor DFS in patients who did not receive adjuvant Imatinib (HR: 1.62, 95% CI: 1.26-2.09; P = 0.48, I² = 0%; reference: R0). This negative impact of R1 disappeared with the use of adjuvant Imatinib (HR: 1.23, 95% CI: 0.95-1.60; P = 0.38, I2 = 6%; reference: R0). R1 was related to poor DFS in gastric GISTs (HR: 2.15, 95% CI: 1.15-5.02, I² = 0%; reference: R0), which was attenuated in the subgroup of adjuvant Imatinib (HR: 2.24, 95% CI: 0.32-15.60; P = 0.84, I² = 0%; reference: R0). Rectal GIST with R1 margin who even received adjuvant Imatinib still had poor DFS (HR: 3.79, 95% CI: 1.27-11.31; P = 0.54, I² = 0%; reference: R0). Patients who underwent R1 resection had similar OS compared with those underwent R0 resection regardless of the use of adjuvant Imatinib.

Conclusion

R1 was associated with poor DFS for primary GISTs, which was attenuated by adjuvant therapy with Imatinib. Similar result was observed in the gastric GISTs subgroup. Rectal GIST patients with R1 resection had poor DFS even when they received adjuvant Imatinib. The R1 margin did not influence the OS of GISTs.

Efficiency of an endoscopic resection strategy for management of submucosal tumors < 20 mm in the upper gastrointestinal tract

Background and study aims  The histologic diagnosis of submucosal tumors (SMTs) < 20 mm is challenging. Monitoring is the main option offered, but compliance is debatable. Endoscopic resection (ER) of malignant SMTs or those with an uncertain diagnosis is an alternative that has already been reported about and proposed in our center. The aims of this study were to confirm the safety of this resection strategy and to perform long-term follow-up of malignant SMTs after resection. Patients and methods  All patients who underwent ER for SMTs < 2 cm in a single center between 2007 and 2019 were included retrospectively. Patients were classified into two groups according to the need for postresection follow-up: benign SMTs (B-SMTs) and follow-up SMTs (FU-SMTs). Results  One hundred and one patients were included. The mean tumor size was 16.7 mm. In total, 92 of 101 SMTs had an uncertain diagnosis. Macroscopic resection was completed for 95 SMTs (93.1 %), with en bloc resection in 94 (92.1%). The morbidity rate was 3 %, with no mortality. A total of 84 of 101 SMTs (84 %) were B-SMTs and did not need monitoring, and 17 SMTs (19.7 %) were FU-SMTs (8 gastrointestinal stromal tumors, 6 neuroendocrine tumors, and 3 others). No relapse was reported in the FU-SMT group, with a median follow-up duration of 33 months [4-127] (61 months [17-127] for the gastrointestinal stroma tumor group). Conclusions  The study results suggest ER is a potentially reliable and effective strategy for upper gastrointestinal tract SMTs < 20 mm. Although the strategy needs further validation in advanced care units, it could eliminate the need for long-term monitoring, therefore targeting such follow-up efforts to patients with FU-SMTs.

Predictors of the difficulty for endoscopic resection of gastric gastrointestinal stromal tumor and follow-up data

BACKGROUND AND AIM

Gastrointestinal stromal tumors (GISTs) are among the most common submucosal tumors in the stomach that require therapeutic intervention. We aim to identify the predictors of technical difficulty during endoscopic resection of gastric GIST and to investigate follow-up outcomes.

METHODS

Patients with gastric GISTs were reviewed from June 2009 to June 2020 at Zhongshan Hospital. Clinical and pathological features, endoscopic procedure information, and follow-up data were collected and analyzed. A nomogram was developed and validated internally and externally.

RESULTS

A total of 628 GISTs were finally analyzed. The difficulty was experienced in 66 cases. GISTs size (2-3 cm: OR 2.431 P = 0.018 and > 3 cm: OR 9.765 P < 0.001), invasion depth beyond submucosal (MP: OR 2.280, P = 0.038 and MP-ex: OR 4.295, P = 0.002), and lack of experience (OR 2.075, P = 0.016) were independent risk factors of difficulty. The nomogram prediction model showed a bias-corrected C-index value of 0.778 and acquired an area under curve (AUC) of 0.756 on the external validation cohort. At the cut-off of 0.15, the nomogram's negative predictive value (NPV) and accuracy (ACC) were 94.9% and 79.8% in identifying non-difficult GISTs. Follow-up results showed that only five GIST patients had local recurrence after endoscopic resection.

CONCLUSIONS

Tumor size, invasion depth, and endoscopists' experience were risk factors for the difficulty of endoscopic GIST resection. Our nomogram provided a valuable tool for screening non-difficult GIST resection.

Laparoscopic Transgastric Resection of a Large Gastric GIST: A Case Report and Review of Literature

Introduction  Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal (GI) tract. Their primary treatment is surgical.

Case Report  Here we report a case of a 36-year-old male patient who was being evaluated for weakness, anemia, and melena. Upper GI endoscopy showed a mass projecting into the lumen and an abdominal computed tomography (CT) confirmed a well-defined mass close to the lesser curvature on the posterior wall. An endoscopic ultrasound-guided fine needle aspiration suggested a diagnosis of GIST. After optimization, the patient was taken up for a laparoscopic transgastric resection of the GIST. The resected specimen measured 9.5 × 8.5 × 7.5 cm. Postoperatively, the patient recovered well and was discharged by the fifth postoperative day.

Discussion  While traditionally, open surgery has been advocated for GISTs, for fear of spillage and peritoneal seeding, the role of minimal access surgery has been growing in recent years. The use of a transgastric approach avoids the potential complication of luminal stenosis following a wedge resection of a tumor close to the cardia. Because lymphadenectomies are rarely required and local invasion is uncommon, a wide local resection is usually curative. Thus, a laparoscopic approach can be considered as the first line in uncomplicated GISTs, irrespective of tumor size.

GIST case turned out to be a perforated peptic ulcer: a case report

Gastrointestinal stromal tumors (GISTs) are tumors arising from the fourth layer of the stomach. They are the most common form of mesenchymal neoplasms in the gastrointestinal tract. The diagnosis for the aforementioned tumors is made through endoscopic ultrasonography (EUS) with no further inspection through biopsies and aspirations. Regarding the fact that biopsies are not made in these cases, pathological misdiagnoses, however rare and effectless in the final outcome of the surgery, do occur. Here, we present a case of a 35-year-old male diagnosed with GIST through the means of EUS however, the post-op pathology report showed something very interesting. This patient was reported to be a case of perforated peptic ulcer and we found vegetable fiber component in the tissue of this patient. Bearing in mind the finding, misdiagnoses of GIST patients are probable, and careful planning prior to the surgery is recommended.

Recent Progress and Challenges in the Diagnosis and Treatment of Gastrointestinal Stromal Tumors

Simple Summary

Gastrointestinal stromal tumors (GIST) are potentially malignant tumors and require evidence-based surgical and/or medical treatment. Laparoscopy has similar safety and prognostic outcomes to those of laparotomy and is currently a standard procedure for localized GISTs. However, surgery for gastric GISTs less than 2 cm may be re-evaluated due to the indolent nature of the GIST and other competing risks among GIST patients. A work-up with endoscopy and endoscopic ultrasonography as well as endoscopic or percutaneous biopsy is important for the preoperative diagnosis of GISTs. Medical treatment with tyrosine kinase inhibitors is the mainstay for recurrent/metastatic GISTs. The activity of an individual drug is well correlated with gene alterations, and, in the era of precision medicine, cancer genome profiling should be considered before medical treatment.

Abstract

Gastrointestinal stromal tumors (GISTs) are the most frequent malignant mesenchymal tumors in the gastrointestinal tract. The clinical incidence of GISTs is estimated 10/million/year; however, the true incidence is complicated by frequent findings of tiny GISTs, of which the natural history is unknown. The initial work-up with endoscopy and endoscopic ultrasonography plays important roles in the differential diagnosis of GISTs. Surgery is the only modality for the permanent cure of localized GISTs. In terms of safety and prognostic outcomes, laparoscopy is similar to laparotomy for GIST treatment, including tumors larger than 5 cm. GIST progression is driven by mutations in KIT or PDGFRA or by other rare gene alterations, all of which are mutually exclusive. Tyrosine kinase inhibitors (TKIs) are the standard therapy for metastatic/recurrent GISTs. Molecular alterations are the most reliable biomarkers for TKIs and for other drugs, such as NTRK inhibitors. The pathological and genetic diagnosis prior to treatment has been challenging; however, a newly developed endoscopic device may be useful for diagnosis. In the era of precision medicine, cancer genome profiling by targeted gene panel analysis may enable potential targeted therapy even for GISTs without KIT or PDGFRA mutations.

Clinical outcomes and functional analysis of third space robotic and endoscopic cooperative surgery versus laparoscopic wedge resection for gastric submucosal tumours: a propensity score-matched study

Third space robotic and endoscopic cooperative surgery (TS-RECS) is a novel minimally invasive surgery for resecting gastric submucosal tumours (GSMTs), which could accomplish the completely oncological curability and maximal functional preservation. This study investigated the clinical outcomes and gastrointestinal function after TS-RECS versus laparoscopic wedge resection (LWR) for GSMTs. This was a single-centre retrospective study that included 130 patients with GSMTs who underwent LWR or TS-RECS from 2013 to 2019. To overcome selection biases, we performed propensity score matching (1:1) using seven covariates that could impact the group assignment and outcomes. Then, the clinical outcomes and gastrointestinal function in the LWR and TS-RECS groups were compared in a matched cohort. Among the 130 enrolled patients, 96 patients underwent LWR, and 34 underwent TS-RECS and were matched into 30 patients for each group. There was no significant difference in the operation time between the two groups (P = 0.543). However, the TS-RECS group had significantly less blood loss (20,5–100 vs 95,10–310 ml, P < 0.0001) and better postoperative recovery in terms of time to oral intake (2,2–4 vs 3,2–6 days, P < 0.0001) and postoperative hospital stay (5,4–10 vs 8.5,5–16 days, P < 0.0001) than the LWR group. The severity and frequency scores of postoperative gastrointestinal symptoms in the TS-RECS group were significantly lower than those in the LWR group. The median follow-up period was 24 months (10–60 months) in the LWR group and 18 months (10–27 months) in the TS-RECS group, and there was in total a single recurrence in the LWR group. TS-RECS appears to be a technically safe and effective surgery with preservation of gastrointestinal function for resection of GSMT resection.

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

Purpose

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

Patients and Methods

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

Results

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

Conclusion

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

Outcome of 1000 Patients With Gastrointestinal Stromal Tumor (GIST) Treated by Surgery in the Pre- and Post-imatinib Eras

OBJECTIVE

To characterize the results of surgery for gastrointestinal stromal tumor (GIST) in the pre and post-imatinib eras at a single institution and to identify current prognostic clinicopathologic factors.

BACKGROUND

Imatinib has radically changed the management of GIST, yet the magnitude of impact on outcome across the spectrum of GIST presentation and relevance of historical prognostic factors are not well defined.

METHODS

We retrospectively analyzed 1000 patients who underwent surgery for GIST at our institution from 1982 to 2016. Patients were stratified by presentation status as primary tumor only (PRIM), primary with synchronous metastasis (PRIM + MET), or metachronous recurrence/metastases (MET), and also imatinib era (before and after it became available). Cox proportional-hazard models and Kaplan-Meier methods were used to model and estimate overall survival (OS) and recurrence-free survival (RFS).

RESULTS

OS was longer in the imatinib era compared with the pre-imatinib era in each presentation group, including in Miettinen high-risk primary tumors. Among PRIM patients from the pre-imatinib era, tumor site, size, and mitotic rate were independently associated with OS and RFS on multivariate analysis. PRIM patients in the imatinib era who received imatinib (neoadjuvant and/or adjuvant) had higher risk tumors, but after adjusting for treatment, only size >10 cm remained independently prognostic of RFS [hazard ratio (HR) 3.85, 95% confidence interval (CI) 2.00-7.40, P < 0.0001) and OS (HR 3.37, 95% CI 1.60-7.13, P = 0.001)].

CONCLUSIONS

Patients treated in the imatinib era had prolonged OS across all presentations. In the imatinib era, among site, size, and mitotic rate, high-risk features were associated with treatment with the drug, but only size >10 cm correlated with outcome. Imatinib should still be prescribed for patients with high-risk features.

Association between R1 resection and oncological outcome in resectable gastrointestinal stromal tumors without tumor rupture: A systematic review and meta-analysis

BACKGROUND

The influence of positive microscopic margin (R1) resection on the prognosis of gastrointestinal stromal tumors (GISTs) is controversial. Tumor rupture is significantly associated with the occurrence of R1 resection and may be a confounder of R1 resection in GISTs. The present meta-analysis evaluated the real influence of R1 resection on the prognosis of GISTs by excluding the confounding effect of tumor rupture.

METHODS

The PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov databases were searched. Studies that compared R1 with negative microscopic margin (R0) resection in GIST patients and reported the time-to-event data of recurrence-free survival (RFS) or disease-free survival (DFS) were eligible for inclusion. The quality of the observational studies was assessed using the Newcastle-Ottawa scale.

RESULTS

Of the 4896 records screened, 23 retrospective studies with 6248 participants were selected. In the overall analysis, R1 resection resulted in a significantly shorter RFS/DFS than R0 resection for GISTs (HR = 1.80, 95% CI = 1.54-2.10, P < 0.001, I² = 14%). However, the inferior RFS/DFS vanished when tumor rupture cases were excluded (HR = 1.34, 95% CI = 0.98-1.83, P = 0.07, I² = 33%). Sensitivity analysis by high-quality studies brought about a more robust HR of 1.15 (95% CI = 0.88-1.50, P = 0.29), with low heterogeneity (I² = 0%). The qualities of evidence for the outcomes were high.

CONCLUSIONS

This meta-analysis shows that R1 resection did not influence the survival outcome of GISTs. Reresection may not be necessary when positive microscopic margins exist. This analysis could provide high-quality evidence for the development of guidelines.

Laparoscopic vs. open surgery for gastrointestinal stromal tumors of esophagogastric junction: A multicenter, retrospective cohort analysis with propensity score weighting

Objective

Laparoscopic resection is increasingly performed for gastrointestinal stromal tumors (GISTs). However, the laparoscopic approach for GISTs located in the esophagogastric junction (EGJ-GIST) is surgically challenging. This study compares the efficacy of laparoscopic surgery and the open procedure for EGJ-GIST through the propensity score weighting (PSW) method.

Methods

Between April 2006 and April 2018, 1,824 surgical patients were diagnosed with primary gastric GIST at four medical centers in South China. Of these patients, 228 were identified as EGJ-GISTs and retrospectively reviewed clinicopathological characteristics, operative information, and long-term outcomes. PSW was used to create the balanced cohorts.

Results

PSW was carried out in laparoscopic and open-surgery cohorts according to year of surgery, sex, age, body mass index (BMI), tumor size, mitotic rates and recurrence risk. After PSW, 438 patients consisting of 213 laparoscopic (L group) and 225 open surgery (O group) patients were enrolled. After PSW, the following measures in the L group were superior to those in the O group: median operative time [interquartile range (IQR)]: 100.0 (64.5−141.5)vs. 149.0 (104.0−197.5) min, P<0.001; median blood loss (IQR): 30.0 (10.0−50.0)vs. 50.0 (20.0−100.0) mL, P=0.002; median time to liquid intake (IQR): 3.0 (2.0−4.0)vs. 4.0 (3.0−5.0) d, P<0.001; median hospital stay (IQR): 6.0 (4.0−8.0)vs. 7.0 (5.0−12.0) d, P<0.001; and postoperative complications (10.3%vs. 22.7%, P=0.001). The median follow-up was 55 (range, 2−153) months in the entire cohort. No significant differences were detected in either relapse-free survival (RFS) [hazard ratio (HR): 0.372, 95% confidence interval (95% CI): 0.072−1.910, P=0.236) or overall survival (OS) (HR: 0.400, 95% CI: 0.119−1.343, P=0.138) between the two groups.

Conclusions

Laparoscopic surgery for EGJ-GIST is associated with the advantages of shorter operative time, reduced blood loss, shorter time to liquid intake, and shorter length of stay, all without compromising postoperative outcomes and long-term survival.

Positive microscopic surgical margins: Is there an association with survival in resected small gastrointestinal stromal tumors?

BACKGROUND

Few studies evaluate the relationships between surgical approach, histologic margin, and overall survival in gastrointestinal stromal tumor. We test the hypothesis that margin positive resection is associated with compromised overall survival.

METHODS

We queried the National Cancer Data Base to identify patients undergoing resections for gastrointestinal stromal tumors ≤3 cm in size between 2010 and 2015. Multivariable logistic regression was used to identify factors associated with positive microscopic margins on final pathology. Cox proportional hazard methods were used to evaluate factors associated with overall survival.

RESULTS

2064 patients met inclusion criteria; 135 (6.5%) had a microscopically positive surgical margin. On multivariable regression, minimally invasive approach was not associated with risk of a positive margin (OR 1.06 95% CI [0.71, 1.59]). On Cox analysis, positive margin status was not associated with OS (R1: 1.03, CI [0.46-2.31], reference R0).

CONCLUSIONS

Positive microscopic surgical margins are not associated with compromised overall survival in patients undergoing resection of small gastrointestinal stromal tumors. Minimally invasive surgical approaches do not compromise oncologic outcomes in these cases.

The Outcome of Neoadjuvant Imatinib Therapy Combined With Surgery for Rectal Gastrointestinal Stromal Tumors: A Report of Three Cases and a Review of the Literature

Gastrointestinal stromal tumors (GISTs) represent the most frequent mesenchymal tumors of the gastrointestinal tract. They occur most frequently in the stomach. Rectal localization remains rare and represents only 5% of all GIST cases and 0.1% of all rectal tumors. Immunohistochemical staining (CD117, DOG1) and molecular analysis remain the gold standard for diagnosis; DOG1 represents a very sensitive marker regardless of CD117 expression. Complete en-bloc resection constitutes the only curative treatment; however, surgical management of rectal GIST remains challenging and can involve extensive surgery such as abdominoperineal resection with significant morbidity. The role of neoadjuvant Imatinib therapy in rectal GISTs is controversial and mainly indicated in a locally advanced tumor or sphincter invasion to increase the chance of complete resection and sphincter preservation. Herein, we report three cases of a rectal GIST treated with neoadjuvant Imatinib therapy and who underwent extensive surgery with complete resection (R0), as well as a recent review of the literature, to study clinicopathological features, surgical challenges, and perioperative Imatinib therapy outcome of rectal GISTs.

Gastrointestinal Stromal Tumor – An Overview

Gastrointestinal stromal tumors (GISTs) are rare tumors but are most common mesenchymal tumors of the digestive tract. They are commonly seen in the stomach (60%) and small intestine (30%). GISTs are likely derived from the interstitial cells of Cajal or their stem cell precursors. They are best characterized by computerized tomography and have a specific staining pattern on immunohistochemistry, i.e., C-Kit and DOG-1. The treatment of GIST is based on the risk assessment for relapse, and patients with localized GIST require resection with or without adjuvant imatinib mesylate (IM). Advanced unresectable tumors are usually treated with IM, with a number of further options available for patients post progression on IM. There is an increasing emphasis on identifying C-Kit and platelet-derived growth factor receptor alpha mutations in all patients with GIST, as these are driver mutations with current and future therapeutic implications.

Surgical Management of Sarcoma Metastatic to Liver

Sarcomas are rare mesenchymal tumors with a propensity for hematogenous metastasis. Gastrointestinal stromal tumor (GIST) is the most common histologic subtype and the most common source of hepatic metastases. In the case of metastatic GIST, neoadjuvant imatinib can be used as a selection tool for the judicious application of surgery, where treatment-responsive patients who undergo resection to prevent the development of treatment-resistant clones have associated 10-year actuarial survival of 40%. Further advances for many of the non-GIST sarcoma subtypes will depend on the development of improved systemic therapies and evaluation of their activity in subtype or molecularly defined trials.

Retrospective analysis of prognostic factors affecting the recurrence and disease-free survival following surgical management of gastrointestinal stromal tumors

Objectives

The aim of this study was to evaluate the prognostic factors effecting recurrence risk and disease-free survival of the patients who were diagnosed as gastrointestinal stromal tumor after complete resection of the tumor with or without adjuvant therapy.

Material and Methods

Between the years 2005 and 2013, data of 71 patients including clinical and demographic features, tumor localizations, pathologic examinations, survival and recurrence rates were enrolled into this retrospective study.

Results

Male/female ratio was 1.71, and mean age was 60.27 ± 14.65 years. Forty-two (59.2%) patients had tumor in stomach, 16 (22.5%) in small bowel, whereas 12 (16.9%) had extra-gastrointestinal system and one patient (%1.4) had rectal localization. Modified NIH risk stratification scheme categorized 9 (12.68%) patients in very low-, 12 (16.90%) in low-, 21 (29.58%) patients in moderate-and 29 (40.85%) patients in high-risk group. Twenty-four (33.8%) patients had a metastatic disease at follow-up while 13 (18.3%) patients were metastatic at admission. R0 resection was successfully performed in 51 (71.8%) patients, while R1 resection in 9 (12.7%) and R2 resection in 11 (15.5%) were achieved. Mean follow-up time was 47.12 ± 33.52 months (range, 1-171 months). Nineteen (26.8%) patients demonstrated recurrence with a mean time of 22.16 ± 15.89 months (range, 3-57 months). During follow-up 17 (23.9%) patients were deceased. In univariate analysis, high-risk group, small bowel and extra-gastrointestinal system localization, R1-2 resection, necrosis, positive resection margin and invasion of surrounding tissues, metastatic disease and adjuvant therapy were statistically significant in terms of recurrence. Multivariate analysis presented small bowel and extra-gastrointestinal system localization, R2 resection, mitoses count, invasion and adjuvant therapy as independent prognostic risk factors affecting disease-free survival rates. The 1, 3 and 5 years of disease-free survival rates of the patients were 89.6%, 75.4%, 64.3%, respectively.

Conclusion

As mentioned in the literature, the mainstay of curative therapy of gastrointestinal stromal tumor is surgery. In our study, not only small bowel, extra-gastrointestinal system localization and invasion of surrounding tissues by tumor, but also R2 resection that complicate the local control of the disease were represented as independent adverse prognostic factors for disease-free survival. Unfavourable clinical outcomes of adjuvant therapy over the disease-free survival was linked to higher tumor stage with metastatic disease and emphasized that prospective trials with more cases should be practiced.

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.

Do microscopic surgical margins matter for primary gastric gastrointestinal stromal tumor?

BACKGROUND

Although tumor size and mitotic rate are established prognostic factors for worse survival in patients undergoing surgical resection for gastric gastrointestinal stromal tumors, the impact of microscopic margins, or R1 resection, is not completely established.

METHODS

Patients who received no neoadjuvant therapy and underwent surgical resection for stage I to III gastric gastrointestinal stromal tumors were identified from the 2010 to 2013 National Cancer Database and divided into 2 cohorts, R0 and R1 resections. Cox proportional hazards ratio and Kaplan Meier survival estimates were utilized to analyze 5-y overall survival.

RESULTS

Of 2,084 patients, those with R1 resection (57, 2.7%) were more likely to have tumors >10 cm (28.1% vs 11.9%, odds ratio 3.51, P = .017) and stage III disease (26.3% vs 11.2%, odds ratio 2.26, P = .047). Although margin status was associated with higher risk tumors, it was not associated with receipt of adjuvant therapy. After multivariate Cox regression, R1 and R0 patients did not have a difference in 5-y overall survival (82.5% vs 88.6%, hazards ratio 1.26, P = .49). When stratified by stage of disease, there remained no difference in survival across all stages when comparing R1 and R0 patients.

CONCLUSION

Positive microscopic margins are uncommon but do not appear to impact survival outcomes in patients with resected localized gastric gastrointestinal stromal tumors.

Endoscopic Full-Thickness Resection for Gastric Subepithelial Lesions Arising from the Muscularis Propria

Most cases of gastric subepithelial lesions follow a good clinical course; however, some lesions progress to malignant tumors, and treatment of tumors with a high risk of malignancy is essential. Surgical excision has been the primary treatment for tumors originating from the propria muscle layer, but it has the disadvantages of being invasive and causing postoperative functional abnormalities. With the development of endoscopic techniques and instruments, the role of endoscopic resection, which is a less invasive method for the removal of gastric subepithelial lesions, has been attracting attention. We performed an endoscopic full-thickness resection for 8 patients with gastric subepithelial lesions originating from the muscularis propria. No fatal complications occurred. Our findings suggest the need to develop various devices for resection and closure and to accumulate further experience through additional studies to prevent complications and specimen loss.