Relationship between R1 resection, tumour rupture and recurrence in resected gastrointestinal stromal tumour

Safety and efficacy of endoscopic resection for gastric gastrointestinal stromal tumors: a retrospective cohort study

BACKGROUND

The aim of this study was to verify the safety and efficacy of endoscopic resection (ER) for gastric gastrointestinal stromal tumors (GISTs).

METHODS

Among a consecutive series of resections for gastric GISTs performed in a single center, the outcomes of patients who had ER were compared to standard surgical resection (SR).

RESULTS

In the cohort, 329 consecutive primary localized gastric GISTs patients (n, ER/SR = 251/78) were enrolled. Patients receiving ER were revealed to have preferable post-treatment outcomes, prolonged overall survival (OS) and disease-free survival (DFS). Tumor diameter, the only independent risk factor for a complicated post-operative course, was utilized for propensity score matching (PSM). In the PSM cohort, patients receiving ER and SR with similar tumor size (4.0 [2.7-4.5] cm) shared similar aggressiveness in terms of stomach layers of tumor origination and invasion, and modified National Institutes of Health (mNIH) risk criteria. Shorter operative time, fewer economic costs, and shorter post-operative stay were still observed in the ER group (ER vs. SR: 80 [49-120] vs. 120 [98-160] minutes, p < 0.001; 44 [38-51] vs. 60 [49-84] thousand Renminbi [kRMB], p < 0.001; 7.0 [6.0-8.0] vs. 8.5 [6.0-12] days, p = 0.018, respectively). No significant difference in OS and DFS was demonstrated in the PSM cohort.

CONCLUSIONS

ER is safe and effective, thus a feasible treatment option for indicated gastric GISTs patients with the advantage of faster recovery and lower economic costs.

Clinical importance of tumor rupture in gastrointestinal stromal tumor

Risk factors of gastrointestinal stromal tumors (GISTs) include tumor size, location, mitosis, and tumor rupture. Although the first three are commonly recognized as independent prognostic factors, tumor rupture is not a consistent finding. Indeed, tumor rupture may be subjectively diagnosed and is rarely observed. Moreover, the criteria used for diagnosis differ among oncologists, which may result in inconsistent outcomes. Based on these conditions, a universal definition of tumor rupture was proposed in 2019 and consists of six scenarios: tumor fracture, blood-stained ascites, gastrointestinal perforation at the tumor site, histologically proven invasion, piecemeal resection, and open incisional biopsy. Although the definition is considered appropriate for selection of GISTs with worse prognostic outcomes, each scenario lacks a high level of evidence and there is yet no consensus for some, including histological invasion and incisional biopsy. It may be, however, important to have common criteria for clinical decision-making, which may facilitate reliability, external validity, and comparability of clinical studies in rare GISTs. After the definition, several retrospective reports indicated that even with adjuvant therapy, tumor rupture was associated with high recurrence rates and poor prognostic outcomes. The prognosis of patients with ruptured GISTs is improved by 5-year adjuvant therapy compared with 3-year therapy. Nevertheless, the universal definition requires further evidence, and prospective clinical studies based on the definition are warranted.

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.

Pan-Canadian consensus recommendations for GIST management in high- and low-throughput centres across Canada

Gastrointestinal stromal tumours (GISTs) are mesenchymal tumours that originate from the interstitial cells of Cajal. GISTs are mainly driven by gain-of-function mutations in receptor tyrosine kinase or platelet-derived growth factor receptor alpha. Surgical resection is the only curative treatment for localized tumours and all currently approved medical GIST treatments are based on orally available tyrosine kinase inhibitors. Recent discoveries in the molecular and clinical features of GISTs have greatly impacted GIST management. Due to the provincially rather than nationally administered Canadian healthcare system, there have been inconsistencies in the treatment of GISTs across the country. Therefore, guidance on the latest knowledge, clinical management and treatment of GIST is needed to standardize the approach to GIST management nationwide. To establish pan-Canadian guidance, provide up-to-date data and harmonize the clinical practice of GIST management in high- and low-throughput centres across Canada; a panel of 20 physicians with extensive clinical experience in GIST management reviewed relevant literature. This included radiologists, pathologists, interventional radiologists, surgeons and medical oncologists across Canada. The structured literature focused on seven key domains: molecular profiling, radiological techniques/reporting, targeted localized therapy, intricacies of systemic treatments, emerging tests, multidisciplinary care and patient advocacy. This literature review, along with clinical expertise and opinion, was used to develop this concise and clinically relevant consensus paper to harmonize the knowledge and clinical practice on GIST management across Canada. The content presented here will help guide healthcare providers, especially in Canada, in terms of approaching and managing GIST.

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.

Duodenal gastrointestinal stromal tumor presenting with life-threatening upper GI bleeding in a young patient: A case report and literature review

Key Clinical Message

Duodenal GISTs are rare and challenging tumors. Acute life-threatening upper GI bleeding is a possible presentation of duodenal GISTs. Surgery is the standard treatment for localized duodenal GISTs. Imatinib is an effective adjuvant therapy for duodenal GISTs.

Abstract

GIST is the most common mesenchymal neoplasm of the gastrointestinal tract, accounting for 1%-2% of gastrointestinal tumors. They originate from the interstitial cells of Cajal and are rare in patients younger than 30 years. The stomach is the most common site, followed by the small intestine and colon. GISTs are caused by a gain-of-function mutation in the proto-oncogene receptor tyrosine kinase, with activating mutations in KIT being the most common. Most GISTs are asymptomatic. Even if gastrointestinal bleeding is the most common complication life-threatening hemorrhage is extremely uncommon. We present a case of a 31-year-old male patient presented with massive active hematemesis and melena with hemorrhagic shock. The patient presented with massive hematemesis and melena of 1 h duration. Endoscopy showed pulsating active bleeding from the third part of the duodenum which was difficult to manage via endoscopy. Histopathologic evaluation showed spindle cell type GIST. Intraoperatively, there was a nodular mass with active bleeding on the third part of the duodenum. Duodenectomy with end-to-end anastomosis was done. Discharged with no postoperative complication and was put on imatinib. There are considerable challenges that arise in the diagnosis and treatment of duodenal gastrointestinal stromal tumors (GISTs) when they present with life-threatening upper gastrointestinal hemorrhage. In order to achieve the best possible outcomes for patients, it is crucial to have a comprehensive understanding of the clinical presentation, diagnostic methods, and treatment approaches.

Referral patterns of GIST patients: data from a nationwide study

BACKGROUND

This study compares the characteristics, referral and treatment patterns and overall survival (OS) of gastrointestinal stromal tumor (GIST) patients treated in reference and non-reference centers in the Netherlands.

PATIENTS AND METHODS

This retrospective cohort study on patients diagnosed between 2016 and 2019, utilises data from the Netherlands Cancer Registry and the Dutch Nationwide Pathology Database. Patients were categorized into two groups: patients diagnosed in or referred to reference centers and patients diagnosed in non-reference centers without referral.

RESULTS

This study included 1,550 GIST patients with a median age of 67.0 in reference and 68.0 years in non-reference centers. Eighty-seven per cent of patients were diagnosed in non-reference centers, of which 36.5% (493/1,352) were referred to a reference center. Referral rates were higher for high-risk (62.2% [74/119]) and metastatic patients (67.2% [90/134]). Mutation analysis was performed in 96.9% and 87.6% of these cases in reference and in non-reference centers (p < 0.01), respectively. Systemic therapy was given in reference centers versus non-reference in 89.5% versus 82.0% (p < 0.01) of high-risk and in 94.1% versus 65.9% (p < 0.01) of metastatic patients, respectively. The proportion of positive resection margins and tumor rupture did not differ between reference and non-reference centers. Median OS was not reached.

CONCLUSION

A substantial amount of metastatic GIST patients in non-reference centers did not receive systemic treatment. This might be due to valid reasons. However, optimisation of the referral strategy of GIST patients in the Netherlands could benefit patients. Further research is needed to explore reasons for not starting systemic treatment in metastatic GIST patients.

Factors associated with gastrointestinal stromal tumor rupture and pathological risk: A single-center retrospective study

BACKGROUND

Gastrointestinal stromal tumor (GIST) is a rare gastrointestinal mesenchymal tumor with potential malignancy. Once the tumor ruptures, regardless of tumor size and mitotic number, it can be identified into a high-risk group. It is of great significance for the diagnosis, treatment, and prognosis of GIST if non-invasive examination can be performed before surgery to accurately assess the risk of tumor.

AIM

To identify the factors associated with GIST rupture and pathological risk.

METHODS

A cohort of 50 patients with GISTs, as confirmed by postoperative pathology, was selected from our hospital. Clinicopathological and computed tomography data of the patients were collected. Logistic regression analysis was used to evaluate factors associated with GIST rupture and pathological risk grade.

RESULTS

Pathological risk grade, tumor diameter, tumor morphology, internal necrosis, gas-liquid interface, and Ki-67 index exhibited significant associations with GIST rupture (P < 0.05). Gender, tumor diameter, tumor rupture, and Ki-67 index were found to be correlated with pathological risk grade of GIST (P < 0.05). Multifactorial logistic regression analysis revealed that male gender and tumor diameter ≥ 10 cm were independent predictors of a high pathological risk grade of GIST [odds ratio (OR) = 11.12, 95% confidence interval (95%CI): 1.81-68.52, P = 0.01; OR = 22.96, 95%CI: 2.19-240.93, P = 0.01]. Tumor diameter ≥ 10 cm, irregular shape, internal necrosis, gas-liquid interface, and Ki-67 index ≥ 10 were identified as independent predictors of a high risk of GIST rupture (OR = 9.67, 95%CI: 2.15-43.56, P = 0.01; OR = 35.44, 95%CI: 4.01-313.38, P < 0.01; OR = 18.75, 95%CI: 3.40-103.34, P < 0.01; OR = 27.00, 95%CI: 3.10-235.02, P < 0.01; OR = 4.43, 95%CI: 1.10-17.92, P = 0.04).

CONCLUSION

Tumor diameter, tumor morphology, internal necrosis, gas-liquid, and Ki-67 index are associated with GIST rupture, while gender and tumor diameter are linked to the pathological risk of GIST. These findings contribute to our understanding of GIST and may inform non-invasive examination strategies and risk assessment for this condition.

Clinical observation of laparoscopic seromuscular dissection in the treatment of gastric stromal tumors

OBJECTIVE

To investigate the safety and oncological prognosis of laparoscopic seromuscular dissection (LSD) in the treatment of gastric stromal tumors.

MATERIAL AND METHODS

From June 2016 to July 2022, 67 patients with gastric stromal tumors underwent laparoscopic seromuscular dissection (LSD), and 58 patients underwent non-LSD surgery during the same period (52 patients underwent laparoscopic gastric wedge resection (LWR), two patients underwent proximal gastrectomy, three patients underwent total gastrectomy, one patient underwent distal gastrectomy and partial hepatectomy). Gastric stromal tumor patients were compared to compare the surgical results, tumor relapse rate, and survival rate of the two groups.

RESULTS

The results of the two groups were compared. For gastric stromal tumors, especially gastric stromal tumors located at 'difficult sites', LSD can reduce the amount of bleeding and the number of cutting staplers used during the operation, reduce the incidence of postoperative complications, shorten the postoperative hospitalization time, reduce the hospitalization cost and improve the quality of life of patients without increasing the operation time.

CONCLUSION

Laparoscopic seromuscular dissection for gastric stromal tumors is safe and technically feasible in the hands of experienced laparoscopic surgeons.

Long-term outcome after surgical resection of non-high-risk gastrointestinal stromal tumours without adjuvant therapy

BACKGROUND

Gastrointestinal stromal tumour (GIST) is the most common intra-abdominal sarcoma. Risk classification systems, commonly the modified National Institutes of Health consensus criteria, identify tumour properties relating to patient outcomes. However, owing to limited long-term evidence, most guidelines recommend up to 10-year follow-up for all risk groups except very low-risk GIST.

METHODS

This retrospective multicentre study included patients who had complete resection of primary, non-metastatic GIST from three Scandinavian sarcoma centres: Gothenburg (2004-2020), Stockholm (2000-2019), and Oslo (2000-2017). Medical records were reviewed for clinical details regarding diagnosis, treatment, and follow-up, and recurrence-free and disease-specific survival evaluated.

RESULTS

The total cohort consisted of 1213 patients with GIST. High-risk patients and those treated with tyrosine kinase inhibitors were excluded. The remaining 649 patients were included in the present analysis: 118 with very low-, 381 with low-, and 150 with intermediate-risk GISTs. Five-year recurrence-free survival rates were 100, 98.5, and 100 per cent for the intermediate-, low-, and very low-risk groups respectively (P = 0.246). Disease-specific survival rates 10 years after surgery were 100, 98.4, and 100 per cent for the intermediate-, low-, and very low-risk groups respectively (P = 0.262).

CONCLUSION

Patients with completely resected non-high-risk GISTs have an excellent long-term outcome, irrespective of risk group. Follow-up programmes to detect disease recurrences in these patients are probably not indicated.

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.

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.

Minimally invasive technique for gastric GIST at challenging locations: single incision surgical gastroscopy

Organ sparing resection of gastrointestinal stromal tumors (GISTs) located in the proximal stomach or esophagogastric junction can be challenging, resulting in proximal or total gastrectomy to facilitate a radical resection without tumor spill. We developed and evaluated a single incision surgical gastroscopy (SISG) procedure to provide a technically feasible alternative for the removal of gastric GISTs at these challenging locations. We developed an endoluminal resection of gastric GISTs through a small single abdominal incision and longitudinal ventral gastrotomy. Patients with a proximal tumor location, in whom a wedge resection was deemed challenging on pre-operative investigation were included in the current series. Safety, short-term oncological and surgical outcome were evaluated. We performed SISG in six consecutive patients with histopathological proven or suspected gastric GIST. In all patients, the procedure was performed successfully with no tumor rupture. The mean operative time was 61 min and there were no significant complications. Pathological examination showed a microscopically radical resection in all patients. Single incision surgical gastroscopy is a feasible technique with excellent short-term oncological and surgical outcomes. This technique serves as a good alternative for complicated resections for gastric GISTs at challenging locations.

Clinical outcomes and prognostic factors for patients with high-risk gastrointestinal stromal tumors treated with 3-year adjuvant imatinib

Three years of adjuvant imatinib is the current standard for patients with high-risk gastrointestinal stromal tumors (GIST). We aimed to investigate the safety and efficacy profiles of 3-year imatinib, focusing on the prognostic value of various factors. In this registry-based study, 222 patients with high-risk GIST who underwent surgical resection followed by 3 years of adjuvant imatinib between 2010 and 2018 were included. The imatinib dose was reduced in 39 (17.6%), and 13 (5.9%) discontinued imatinib due to toxicity. With a median follow-up duration of 65.7 months, 5-year recurrence-free survival (RFS) and overall survival (OS) were 73.2% and 93.9%, respectively. Tumor rupture, tumor size of > 10 cm, mitotic index of > 10/50 high power fields (HPF) were independent factors for short RFS. Patient subgroups stratified by the risk factors showed distinct RFS (P < 0.001): patients without the above risk factors or those with only a tumor size of >10 cm showed favorable RFS (5-year RFS 83.8% and 92.3%, respectively), whereas those with tumor rupture or those with tumor size of > 10 cm and mitotic index of >10/50 HPF showed prominently poor RFS (5-year RFS of 54.8% and 47.9%, respectively). Three years of adjuvant imatinib treatment was generally tolerable and effective, which were consistent with the clinical outcomes of previous reports. The presence of tumor rupture, large tumor, and high mitotic count was independently associated with poor RFS. Based on these risk factors, different management strategies, such as different durations of adjuvant imatinib, deserve further investigation. This article is protected by copyright. All rights reserved.

The role of neoadjuvant imatinib in gastrointestinal stromal tumor (GIST) patients - 20 years of experience from a tertial referral center

Surgery is the cornerstone of gastrointestinal stromal tumor (GIST) treatment, and adjuvant therapy with imatinib has improved survival for high‐risk tumors. The use of imatinib preoperatively has been increasing, but efficacy and impact on patient outcomes have not been formally investigated. This is a retrospective study from a single‐center cohort of patients diagnosed with GIST and treated with neoadjuvant imatinib at Karolinska University Hospital in Stockholm, Sweden over a 20‐year period. Eighty‐four patients diagnosed with GIST and treated with neoadjuvant imatinib were identified and included. Tumors were located throughout the whole gastrointestinal tract but most frequently in the stomach (n = 29; 35%) and the small intestine (n = 30; 36%), followed by the rectum (n = 12; 14%) and the gastroesophageal junction (n = 10; 12%). The tumors were large (mean 10.5 cm) and decreased after treatment (mean 7.6 cm). Main indications for neoadjuvant imatinib were tumor size or anatomical location. None of the patients with stomach tumors and four patients with tumors near the gastroesophageal junction underwent gastrectomy. Three patients with tumors in the small intestine underwent pancreaticoduodenectomy, whereas seven patients with rectal tumors underwent rectal amputation. After surgery, 94% (n = 79) of the tumors had R0‐resection. About one‐fourth experienced local relapse or distant metastasis. In conclusion, neoadjuvant imatinib can reduce tumor size and prevent high morbidity due to more extensive surgery, or at least reduce the extent of the surgery, especially for tumors in the stomach or small intestine.

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.

Clinical Features of Extragastrointestinal Stromal Tumor Compared with Gastrointestinal Stromal Tumor: A Retrospective, Multicenter, Real-World Study

Objective

This study aimed to compare the tumor characteristics and long-term outcomes between EGIST and GIST. The confounding function was applied to improve the result credibility in the case of small sample size. Design, Setting, and Participants. This cohort study enrolled 55 patients with EGIST who underwent surgery and were selected from four high-volume hospitals in China and 221 GIST patients who were collected from one of the four hospitals between January 2006 and September 2017. We used propensity score matching (PSM) and subgroup analysis to compare EGIST with GIST in terms of prognosis. The confounding function was used for sensitivity analysis to reduce unmeasured confounding.

Results

We matched 43 patients in each of the GIST and EGIST groups by PSM. We compared EGIST data with GIST data to explore the prognostic factors between them. In the multivariate Cox regression model, tumor location of EGIST was negatively correlated with overall survival (after PSM: HR, 4.32; 95% CI, 1.22–15.26) or disease-free survival (after PSM: HR, 9.79; 95% CI, 2.22–43.31), which was also intuitively shown in the Kaplan–Meier survival curves (all P values < 0.05). In the subgroup analysis, EGIST with high risk factors had a worse prognosis than GIST. In unmeasured confounding analysis, the overall curve tends to show all combinations of c(0) of c(1) up to 2.0, none of which would bring the corrected relative risk to 1 for OS and DFS. Conclusions and Relevance. EGIST was associated with worse prognosis compared with GIST patients, particularly in EGIST patients with high risk factors, while there was a similar prognosis without those high risk factors.

Comparison Among Endoscopic, Laparoscopic, and Open Resection for Relatively Small Gastric Gastrointestinal Stromal Tumors (<5 cm): A Bayesian Network Meta-Analysis

Background

Endoscopic resection (ESR) is a novel minimally invasive procedure for superficial tumors. Its safety, efficiency, and outcome for gastric gastrointestinal stromal tumors (gGISTs) less than 5 cm remains unclear compared to laparoscopic resection (LAR) and open resection (ONR). The current network meta-analysis aimed to review and analyze the available evidence of this question.

Methods

PubMed, Embase, Cochrane Library, and Web of Science databases were searched to identify eligible studies published up to July 6, 2020. The perioperative and long-term oncological outcomes among ESR, LAR, and ONR for gGIST (<5 cm) were estimated through the Bayesian network meta-analysis with a random-effect model.

Results

Fifteen studies with 1,631 patients were included. ESR was associated with a shorter operative time [mean difference, MD: -36; 95% confidence interval, CI (-55, -16)], a higher rate of positive margin [odds ratio, OR: 5.1 × 10¹⁰, 95% CI (33, 2.5 × 10³²)], and less costs [MD: -1 × 10⁴, 95% CI (-1.6 × 10⁴, -4.4 × 10³)] but similar time to resume flatus [MD: 0.52, 95% CI (-0.16, 1.1)] and diet [MD: -3.5, 95% CI (-5.6, -1.6)] compared to LAR. A higher rate of total complications [OR: 11, 95% CI (1.2, 140)] was observed in patients who received ESR compared to patients who received LAR. After excluding perforation from the total complication category, the difference of complication between ESR and LAR disappeared [OR: 0.87, 95% CI (0.22, 2.3)]. The recurrence rate [OR: 1.3, 95% CI (0.40, 4.5)] and disease-free survival [hazard ratio: 1.26, 95% CI (0.60, 2.63)] showed no significant difference between ESR and LAR. ESR was associated with better or equivalent perioperative and long-term outcomes compared to ONR, except for positive margin. A subgroup analysis (<2 and 2–5 cm) showed no significantly different results among these three procedures either.

Conclusion

ESR was shown to be a safe and efficient alternative procedure to both LAR and ONR for gGISTs less than 2 cm and within 2–5 cm, respectively, without worsening the oncologic outcomes. However, preoperative assessment of tumor site is of importance for the determination of procedures regarding the increased incidence of a positive margin related to ESR.

Dynamic survival analysis of gastrointestinal stromal tumors (GISTs): a 10-year follow-up based on conditional survival

Background

The prognosis of patients with gastrointestinal stromal tumors (GISTs) is generally evaluated at the time of diagnosis but does not reflect the survival dynamics of patients in the future. Therefore, the purpose of this article was to evaluate the conditional survival (CS) of Chinese patients with GISTs after radical resection.

Methods

This retrospective study included 451 patients who underwent radical surgery for GISTs. A Cox proportional hazard model was used to evaluate the prognostic factors of disease-free survival (DFS). The 3-year conditional DFS (CDFS₃) of patients who survived for x years was expressed as CDFS₃₌DFS_(x + 3)/DFS_(x).

Results

The traditional 3-year DFS rate decreased gradually from 94.0% at 3 years to 77.3% at 7 years, while the CDFS₃ rate increased from 94.0 to 95.2% over the survival time of the patients. In addition, classic clinicopathological prognostic factors had different effects on CDFS_3, with changes observed in survival time, but these effects were only slight or moderate (|d|<0.5). Although multivariate analysis showed that age, sex, mitotic index and tumor rupture were independent risk factors for DFS at baseline, all adverse prognostic factors, except for the mitotic index, lost their predictive significance at 5 years after operation. When the Modified NIH criteria were included, the risk staging was found to be an independent risk factor for recurrence or death. Time-dependent Cox regression analysis showed that the modified NIH criteria independently affected the recurrence or death of GIST patients within 2 years after operation.

Conclusion

CS provides detailed dynamic survival information about Chinese patients with primary resected GISTs. The mitotic index is of great clinical significance for the monitoring and follow-up of patient populations with a high risk of tumor recurrence or death until 5 years after surgery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08828-y.

[Surgical and interdisciplinary treatment of gastrointestinal stromal tumors]

Gastrointestinal stromal tumors (GISTs) are the most frequent potentially malignant mesenchymal tumors of the gastrointestinal tract. The treatment of GISTs has been revolutionized since imatinib and other tyrosine kinase inhibitors were introduced for the treatment of GISTs, which inhibit the tyrosine kinases c‑KIT and platelet-derived growth factor receptor (PDGFR) alpha. Even after the introduction of this targeted treatment GISTs can only be cured by surgical resection. With interdisciplinary multimodal treatment the prognosis of metastasized GIST can now be further improved by surgical resection of the primary tumor and the metastases, potentially leading to a cure. Neoadjuvant therapy can reduce the extent of surgical resection and hereby enable organ preservation and reduce surgical morbidity. To evaluate molecular and clinical predictors and to offer an optimal therapeutic plan, patients with GISTs and certainly patients with advanced GISTs should be evaluated by interdisciplinary sarcoma boards.

The Combination of Neoadjuvant Therapy and Surgical Resection: A Safe and Effective Treatment for Rectal Gastrointestinal Stromal Tumors

Background

Rectal gastrointestinal stromal tumors (GISTs) are rare digestive tumors. The treatment methods of rectal GISTs are diverse, while no standardized treatment was recommended. The aim of this study was to report the treatment mode of rectal GISTs in our center.

Methods

Patients with pathologically confirmed rectal GISTs who received neoadjuvant therapy and surgical resection were retrospectively collected. Perioperative complications and long-term prognosis were evaluated.

Results

From January 2010 to December 2019, 36 patients were pathologically diagnosed with primary rectal GISTs. After excluding patients who were treated with surgery or imatinib alone, 21 patients received neoadjuvant therapy and surgery was enrolled. During neoadjuvant treatment, tumors shrank significantly (6.53cm to 4.68cm, p<0.001) without toxicities over grade 2. The total postoperative complication rate was 42.9% (all grade). R0 resection was achieved in 76.2% patients. Transanal resection had advantages on anus preservation and postoperative recovery. No patients died during the follow-up period, 4 patients relapsed and the relapse-free survival was 81.0%.

Conclusion

The combination of neoadjuvant therapy and surgical resection was a safe and effective treatment for rectal gastrointestinal stromal tumors.

Meta-Analysis on the Efficacy and Safety of Laparoscopic Surgery for Large Gastric Gastrointestinal Stromal Tumors

BACKGROUND

The aim of this study was to conduct a meta-analysis comparing the safety and feasibility of laparoscopic versus open resection for gastric gastrointestinal stromal tumors (GISTs) larger than 5 cm.

METHOD

We searched the Cochrane Library, PubMed, and Embase for relevant articles. Randomized and nonrandomized clinical trials were identified and included in this study. Searching for related articles on large GIST (>5 cm) for laparoscopic resection (laparoscopic group [LAPG]) and open resection (open group [OG]), RevMan 5.3 was used for data analysis, comparing 2 groups of operation time, intraoperative blood loss, complications, length of hospital stay, recurrence rate, disease-free survival, and overall survival.

RESULTS

Seven studies including 440 patients were identified for the meta-analysis. Meta-analysis revealed that LAPG had less bleeding, shorter postoperative hospital stay, and a better 5-year disease-free survival. There was no significant difference between LAPG and OG in operation time, postoperative complications, recurrence rate, and overall survival.

CONCLUSION

Laparoscopic resection of large (>5 cm) GIST is safe and feasible and has the advantages of less intraoperative blood loss and fast postoperative recovery, with a good outcome in the recent oncology.

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.

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.

Quality of Surgery and Outcome in Localized Gastrointestinal Stromal Tumors Treated Within an International Intergroup Randomized Clinical Trial of Adjuvant Imatinib

Importance

The association between quality of surgery and overall survival in patients affected by localized gastrointestinal stromal tumors (GIST) is not completely understood.

Objective

To assess the risk of death with and without imatinib according to microscopic margins status (R0/R1) using data from a randomized study on adjuvant imatinib.

Design, Setting, and Participants

This is a post hoc observational study on patients included in the randomized, open-label, phase III trial, performed between December 2004 and October 2008. Median follow-up was 9.1 years (IQR, 8-10 years). The study was performed at 112 hospitals in 12 countries. Inclusion criteria were diagnosis of primary GIST, with intermediate or high risk of relapse; no evidence of residual disease after surgery; older than 18 years; and no prior malignancies or concurrent severe/uncontrolled medical conditions. Data were analyzed between July 17, 2017, and March 1, 2020.

Interventions

Patients were randomized after surgery to either receive imatinib (400 mg/d) for 2 years or no adjuvant treatment. Randomization was stratified by center, risk category (high vs intermediate), tumor site (gastric vs other), and quality of surgery (R0 vs R1). Tumor rupture was included in the R1 category but also analyzed separately.

Main Outcomes and Measures

Primary end point of this substudy was overall survival (OS), estimated using Kaplan-Meier method and compared between R0/R1 using Cox models adjusted for treatment and stratification factors.

Results

A total of 908 patients were included; 51.4% were men (465) and 48.6% were women (440), and the median age was 59 years (range, 18-89 years). One hundred sixty-two (17.8%) had an R1 resection, and 97 of 162 (59.9%) had tumor rupture. There was a significant difference in OS for patients undergoing an R1 vs R0 resection, overall (hazard ratio [HR], 2.05; 95% CI, 1.45-2.89) and by treatment arm (HR, 2.65; 95% CI, 1.37-3.75 with adjuvant imatinib and HR, 1.86; 95% CI, 1.16-2.99 without adjuvant imatinib). When tumor rupture was excluded, this difference in OS between R1 and R0 resections disappeared (HR, 1.05; 95% CI, 0.54-2.01).

Conclusions and Relevance

The difference in OS by quality of surgery with or without imatinib was associated with the presence of tumor rupture. When the latter was excluded, the presence of R1 margins was not associated with worse OS.

Trial Registration

ClinicalTrials.gov Identifier: NCT00103168.

Microscopically Positive Resection Margins in Laparoscopic Gastric GIST Resection May Not Confer a Poorer Prognosis

Laparoscopic resection of gastrointestinal stromal tumor (GIST) has increased popularity with studies showing good outcomes for patients with tumors <5 cm, with a shorter hospital stay, lower blood loss, and morbidity. Our study aims to audit the clinical profile and surgical outcomes of GISTs, with an evaluation of laparoscopic versus open surgery and the prognostic role of positive R1 margins. In our retrospective study, 62 GIST patients who underwent surgery were included and further analysis was made for the 48 gastric GISTs patients. In total, 33 patients underwent laparoscopic gastric GIST resection, whereas the rest underwent open resection. There was no difference in operative duration but the blood loss was lesser and length of stay shorter in the laparoscopic group. The laparoscopic group had a higher incidence of R1 resection but none developed recurrence or metastasis during follow-up. Laparoscopic resection in the management of gastric GISTs resulted in higher R1 resection rates but this did not affect recurrence rates or overall survival.

Is Peritoneal Tumor Penetration of Prognostic Importance in Gastrointestinal Stromal Tumors?

BACKGROUND

Peritoneal tumor penetration (PP) strongly affects prognosis in gastrointestinal carcinomas. In gastrointestinal stromal tumor (GIST), its significance in the absence of tumor rupture has not been subjected to detailed analysis.

METHODS

Patients undergoing complete resection for non-metastatic GIST from 2000 to 2017 were identified in the regional sarcoma database at Oslo University Hospital. Patients with extraperitoneal tumors (esophagus, rectum) or ruptured tumors were excluded from the study. Rupture was defined according to the Oslo criteria, and PP was assessed via routine histopathologic examination by sarcoma pathologists.

RESULTS

The study enrolled 341 patients. The median follow-up period was 51 months (range 0-175) months. In 82 (24%) of the 341 patients, PP was recorded. There were 32 recurrences, 9 in patients with PP and 23 in patients without PP. Despite statistically significant associations between PP and established risk factors (size, mitotic index, non-gastric location), the 5-year recurrence-free survival rate did not differ between the patients with PP (86%) and those without PP (90%) (hazard ratio 1.25; 95% confidence interval 0.58-2.70; P = 0.577). Adjuvant imatinib was administered to 53 of 97 patients in the high-risk category. The recurrence rates did not differ between the PP-positive and PP-negative patients in either group.

CONCLUSIONS

In GIST, PP without tumor rupture appears not to influence prognosis. This lack of prognostic significance may reflect unexplored differences between epithelial and mesenchymal malignancies.