The Landmark Series: Systemic Therapy for Resectable Gastrointestinal Stromal Tumors

A population-based analysis of gender differences in survival outcomes for gastric gastrointestinal stromal tumors

BACKGROUND

Although gender-based differences have been demonstrated to affect the prognosis of multiple tumors, their specific influence on the survival of gastric gastrointestinal stromal tumors (gGISTs) at the population level is still uncertain. Consequently, we aimed to investigate gender disparities in the prognosis of gGISTs using the Surveillance, Epidemiology, and End Results (SEER) database.

METHODS

Patients with gGISTs from the years 2000 to 2019 were retrieved from the SEER database. To minimize selection bias, propensity score matching (PSM) was used. Kaplan-Meier analyses and Cox proportional hazard models were used to assess the influence of clinical characteristics on overall survival (OS) and cancer-specific survival (CSS).

RESULTS

A total of 3006 patients with gGISTs were analyzed, including 1459 males and 1547 females. Compared with female patients, male patients exhibited a higher proportion of Whites, more advanced T stage, larger tumor sizes, and elevated mitotic index. Before PSM, male patients experienced significantly worse OS (hazard ratio [HR], 1.55; 95% CI, 1.33-1.81; P <.001) and CSS outcomes (HR, 1.61; 95% CI, 1.28-2.02; P <.001) than female patients. Furthermore, they had lower mean OS and CSS rates at the 1-, 3-, and 5-year follow-up intervals (P <.05). Even after PSM, male patients continued to show poorer OS (HR, 1.30; 95% CI, 1.10-1.54; P =.002) and CSS outcomes (HR, 1.34; 95% CI, 1.05-1.70; P =.016) than female patients, with persistently lower mean OS and CSS rates across the 1-, 3-, and 5-year follow-up intervals (P <.05). For males without distant metastasis, 5-year OS was 78.8% and CSS was 90.0%, both lower than females' 85.5% and 93.7% (P <.05). For males with distant metastasis, 5-year OS was 48.7% and CSS was 58.8%, similar to females' 55.4% and 65.3% (P >.05). Multivariate Cox regression analysis identified age, race, gender, M stage, surgical intervention, tumor size, and mitotic index as independent risk factors for both OS and CSS.

CONCLUSION

Patients with gGISTs exhibit distinct clinical characteristics between males and females, with female patients showing a tendency toward improved OS and CSS. Surgical treatment has the potential to enhance the prognosis of patients with gGISTs.

Is there value in the routine inclusion of chest computed tomography for patients with gastrointestinal stromal tumor?

PURPOSE

National Comprehensive Cancer Network guidelines suggest chest CT when gastrointestinal stromal tumors are larger than 2 cm. We evaluate the value of screening the chest region during initial and follow-up CT.

METHOD

Single institution retrospective analysis of GIST cancer registry for patients diagnosed between May 2010 and November 2019 with tumor > 2 cm. We collected the patient demographics and clinical data; reviewed all CT scans of the chest region and recorded the lung nodules. Patients were grouped into lung nodule group and non-nodule group. Categorical variables were compared with the Chi square test and continuous variables with the Mann-Whitney U test. The survival probability was determined from Kaplan-Meier survival analysis and log-rank test for comparing differences.

RESULTS

The final cohort included 382 patients (median age 61 years-old [interquartile range: 52-71]) and grouped into non-nodule group (n = 284) and lung nodule group (n = 98). The frequency of the CT scan was more in lung nodule group (8 [5-12]) than in non-nodule group (4 [2-9], p < 0.001). The lung nodule group had more CT including the chest region (6 [3-10] vs 3 [1-7], p < 0.001). In progressive lung nodules (8/98 [8 %]), only one patient had confirmed lung metastasis from GIST (1/382 [3 %]). There was no difference in overall survival between nodule groups (p = 0.12).

CONCLUSIONS

GIST patients with tumors larger than 2 cm have extremely low risk for lung metastasis. Routine inclusion of chest CT scan in staging and follow up is unnecessary.

circ_SMA4 promotes gastrointestinal stromal tumors malignant progression by sponging miR-494-3p/KIT axis and activating JAK/STAT pathway

Recent evidence has demonstrated that abnormal expression and regulation of circular RNA (circRNAs) are implicated in the development and progression of various tumors. The aim of this study was to investigate the effects of circ_SMA4 in Gastrointestinal Stromal Tumors (GISTs) malignant progression. Human circRNAs microarray analysis was conducted to identify differentially expressed (DE) circRNAs in GISTs. The effect of circ_SMA4 on cell proliferation, invasion, migration, and apoptosis was assessed in both in vitro and in vivo settings. Dual-luciferase reporter assay, RT-qPCR, Western-blot, and rescue assay were employed to confirm the interaction between circ_SMA4/miR-494-3p/ KIT axis. The results revealed that circ_SMA4 was significantly upregulated in GISTs, and exhibited high diagnostic efficiency with an AUC of 0.9824 (P < 0.01). circ_SMA4 promoted cell proliferation, invasion, migration, while inhibiting apoptosis in GISTs cells, both in vitro and in vivo. Silencing circ_SMA4 partially inhibited GISTs malignant progression. Additionally, circ_SMA4 acted as a competing endogenous RNA (ceRNA) by targeting miR-494-3p, and KIT was identified as a functional gene for miR-494-3p in GISTs. Furthermore, the results confirmed that circ_SMA4/miR-494-3p/ KIT axis plays a role in activating the JAK/STAT signaling pathway in GISTs. Therefore, for the first time, we have identified and emphasized that circ_SMA4 is significantly upregulated and plays an oncogenic role in GISTs by sponging miR-494-3p to activate the KIT/JAK/STAT pathway. These findings underscore circ_SMA4 may serve as a novel diagnostic biomarker and therapeutic target for GISTs.

Safety, effectiveness and the optimal duration of preoperative imatinib in locally advanced gastric gastrointestinal stromal tumors: A retrospective cohort study

BACKGROUND

The optimal duration of preoperative imatinib (IM) remains controversial. This study aimed to evaluate the safety, therapeutic effectiveness, and optimal duration of preoperative IM in patients with locally advanced gastric gastrointestinal stromal tumors (GIST).

METHODS

The clinicopathologic data of 41 patients with locally advanced gastric GIST who received preoperative IM and underwent surgical resection from January 2014 and December 2021 were retrospectively analyzed.

RESULTS

After a median of 7.0 (IQR: 4.5-10) months of preoperative IM treatment, 30 patients experienced adverse events (AEs), 80% of which were grade 1/2 AEs. The mean tumor size decreased from 12.71 ± 5.34 cm to 8.26 ± 4.00 cm, with a reduction rate of 35%. Setting 8 months as the cut-off value according to the results of ROC analysis. The proportion of laparoscopic surgery was higher in patients with short-term (≤8 months) versus long-term (>8 months) preoperative IM. Compared with the subtotal/total gastrectomy group, patients in the local gastrectomy group exhibited less intraoperative blood loss, shorter length of postoperative hospital stay, and fewer postoperative complications. The 3-year recurrence-free survival (RFS) and overall survival (OS) rates were 82.9% and 97.6%, and the expected 5-year RFS and OS rates were 75.6% and 90.2% respectively. RFS was better in the short-term than in the long-term preoperative IM treatment group, and it was also better in pre- plus postoperative IM treatment group than that in the preoperative IM alone group. Both univariate and multivariate COX analysis showed that a higher mitotic index and long-term preoperative IM treatment were associated with worse RFS, while postoperative IM treatment could significantly improve RFS.

CONCLUSIONS

The study suggests that in patients with locally advanced gastric GIST, preoperative short-term (≤8 months) use of IM is associated with higher RFS than long-term use.

Radiofrequency ablation vs. hepatectomy for liver metastases from gastrointestinal stromal tumors

For patients with gastrointestinal stromal tumors (GISTs) and liver metastases, there is still debate about whether radiofrequency ablation (RFA) or hepatectomy is preferable. The present study aimed to compare the clinical outcomes of RFA with hepatectomy in patients with GISTs and liver metastases. The present retrospective study consisted of a cohort of 43 patients who had been diagnosed with liver metastases from GISTs between January 2010 and December 2022. The study included 18 patients who received RFA combined with tyrosine kinase inhibitor (TKI) therapy (RFA group) and 25 patients who underwent hepatectomy combined with TKI therapy (hepatectomy group). For the patients with liver metastases, the progression-free survival (PFS) rates at 1, 3 and 5 years were 66.5, 38.2 and 33.9%, respectively. Notably, patients in the hepatectomy group exhibited significantly improved PFS times compared with those in the RFA group (median PFS, 42.7 months vs. 14.3 months; P=0.034). Furthermore, the time to imatinib treatment failure (TTF) was notably improved in the hepatectomy group compared with that in the RFA group, and this difference was statistically significant (median TTF, 71.1 vs. 38.0 months; P=0.041). However, the overall survival (OS) times of patients who received RFA and those who had hepatectomy did not differ significantly (median OS, not reached vs. not reached, P=0.120). There was no statistically significant distinction in PFS and TTF between patients who underwent hepatectomy combined with postoperative TKI and those who underwent hepatectomy combined with perioperative TKI (median PFS, 29.5 vs. not reached; P=0.520; median TTF, 66.4 months vs. 71.1 months; P=0.430). The univariate and multivariate analyses consistently identified the sole prognostic factor affecting PFS as hepatectomy combined with TKI therapy (hazard ratio, 0.379; 95% CI, 0.159-0.899; P=0.028). In conclusion, hepatectomy combined with TKI therapy improved prognosis for patients with liver metastases to a greater extent than RFA combined with TKI therapy. For this type of patient, hepatectomy may be a preferable option.

TATA-box-binding protein-associated factor 15 is a novel biomarker that promotes cell proliferation and migration in gastrointestinal stromal tumor

BACKGROUND

Gastrointestinal stromal tumor (GIST) is a common neoplasm with high rates of recurrence and metastasis, and its therapeutic efficacy is still not ideal. There is an unmet need to find new molecular therapeutic targets for GIST. TATA-box-binding protein-associated factor 15 (TAF15) contributes to the progress of various tumors, while the role and molecular mechanism of TAF15 in GIST progression are still unknown.

AIM

To explore new molecular therapeutic targets for GIST and understand the biological role and underlying mechanisms of TAF15 in GIST progression.

METHODS

Proteomic analysis was performed to explore the differentially expressed proteins in GIST. Western blotting and immunohistochemical analysis were used to verify the expression level of TAF15 in GIST tissues and cell lines. Cell counting kit-8, colony formation, wound-healing and transwell assay were executed to detect the ability of TAF15 on cell proliferation, migration and invasion. A xenograft mouse model was applied to explore the role of TAF15 in the progression of GIST. Western blotting was used to detect the phosphorylation level and total level of RAF1, MEK and ERK1/2.

RESULTS

A total of 1669 proteins were identified as differentially expressed proteins with 762 upregulated and 907 downregulated in GIST. TAF15 was selected for the further study because of its important role in cell proliferation and migration. TAF15 was significantly over expressed in GIST tissues and cell lines. Overexpression of TAF15 was associated with larger tumor size and higher risk stage of GIST. TAF15 knockdown significantly inhibited the cell proliferation and migration of GIST in vitro and suppressed tumor growth in vivo. Moreover, the inhibition of TAF15 expression significantly decreased the phosphorylation level of RAF1, MEK and ERK1/2 in GIST cells and xenograft tissues, while the total RAF1, MEK and ERK1/2 had no significant change.

CONCLUSION

TAF15 is over expressed in GIST tissues and cell lines. Overexpression of TAF15 was associated with a poor prognosis of GIST patients. TAF15 promotes cell proliferation and migration in GIST via the activation of the RAF1/MEK/ERK signaling pathway. Thus, TAF15 is expected to be a novel latent molecular biomarker or therapeutic target of GIST.

Role of Surgery in the Management of Liver Metastases From Gastrointestinal Stromal Tumors

Background

The clinical benefit of hepatectomy in patients with liver metastases from gastrointestinal stromal tumors (GIST) has not been well defined in this era of tyrosine kinase inhibitor (TKI). Our study aims to demonstrate the survival advantage of adding hepatectomy in patients with GIST liver metastases.

Methods

Information on patients with metastatic GIST treated or consulted between January 2006 and December 2018 was retrieved. Patients without extrahepatic metastases were included and classified into the surgical (S group) and non-surgical (NS group). Clinicopathological features were compared and their association with survival was assessed.

Results

A total of 119 patients were included in this retrospective analysis, 62 in the S group and 59 in the NS group. Comparison of clinicopathological features showed that a markedly higher proportion of patients in the S group had ≤3 hepatic lesions (79.0% vs. 29.8%, p<0.001). After a median follow-up duration of 56 months, patients in the S group had significantly better progression-free survival (PFS) and marginally improved overall survival (OS) than those in the NS group (3y PFS:86.2% vs. 64.6%, p=0.002; 5y OS: 91.5% vs. 78.3%, p=0.083). After propensity score matching, multivariate analysis identified hepatectomy as the only significant prognostic factor for PFS while age, hepatectomy and max tumor diameter were significant predictor for OS.

Conclusions

Addition of hepatectomy provided longer disease control in patients with metastatic GIST confined to the liver. Upfront hepatectomy followed by imatinib therapy is worthwhile trying in patients with single and easily removable lesions.

Neoadjuvant tyrosine kinase inhibitor therapy for patients with gastrointestinal stromal tumor: A propensity-matched analysis

BACKGROUND

Tyrosine kinase inhibitor (TKI) neoadjuvant therapy (NAT) is often given in gastrointestinal stromal tumors (GISTs) with the goal to facilitate less morbid resections and improve oncologic outcomes; however, the use of NAT for GIST is poorly studied.

METHODS

We reviewed patients with resected nonmetastatic GIST from 2003 to 2019. Overall (OS) and recurrence-free survival (RFS) were assessed with Kaplan-Meier modeling. We performed 1:1 propensity-matching for relevant clinicopathologic variables for receipt of NAT.

RESULTS

We identified 254 patients. Propensity 1:1 matching resulted in 33 patients per group. The median follow-up was 77 months with no difference in 10-year OS (68% vs. 73%), 5-year RFS (13% vs. 10%), or median RFS (24 vs. 27 months) for patients treated with NAT versus upfront resection (all P > 0.9). Hospital length-of-stay (both median 7 days) and Clavien-Dindo ≥ III complications (12% vs. 3%) were not different between groups (both P ≥ 0.35).

DISCUSSION

TKI NAT can be used to facilitate resection in select patients with surgically higher-risk GIST, however it does not result in an independent oncologic benefit.

Open and minimally invasive surgery for gastrointestinal stromal tumours: a systematic review and network meta-analysis protocol

INTRODUCTION

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the digestive system, and complete resection is the only way to provide a radical cure for resectable GISTs. Open surgery and minimally invasive approaches, including laparoscopy, robotic surgery and endoscopy, consist of the mainstream GIST resection. However, there is still a lack of evidence regarding which surgical outcomes and long-term prognosis would be better. Thus, we are planning to conduct a network meta-analysis and systematic review aiming to determine the comparative effectiveness among laparotomy, laparoscopy, endoscopy, robotic surgery, and laparoscopic and endoscopic cooperative surgery in GISTs.

METHOD AND ANALYSIS

PubMed, EMBASE, the Cochrane Library and Web of Science will be searched for published studies to identify the proper literature comparing open resection, laparoscopy, endoscopy, robotic surgery, and laparoscopic and endoscopic cooperative surgery for resecting GISTs from inception to February 2021. Randomised controlled trials (RCTs) and non-randomised studies comparing at least two different interventions for GIST resection will be included. RCTs and non-randomised studies will be synthesised and analysed separately. Bayesian network meta-analysis will be performed to compare the surgical outcomes and long-term prognosis among the resection methods above. The included studies will be divided into several subgroups according to tumour location and size for further analysis. Sensitivity analysis will be performed to identify and explain heterogeneity to make our results robust. Meta-regression will serve as a supplementary method if data are available. The quality of evidence will be evaluated by the Grading of Recommendations, Assessment, Development and Evaluation.

ETHICS AND DISSEMINATION

No ethical approval is required for this network meta-analysis, as it is based on already published data. The findings of the review will be published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42021237892.

Targeting CD82/KAI1 for Precision Therapeutics in Surmounting Metastatic Potential in Breast Cancer

Metastasis is the main cause of mortality in breast cancer patients. There is an unmet need to develop therapies that can impede metastatic spread. Precision oncology has shown great promise for the treatment of cancers, as the therapeutic approach is tailored to a specific group of patients who are likely to benefit from the treatment, rather than the traditional approach of "one size fits all". CD82, also known as KAI1, a glycoprotein belonging to the tetraspanin family and an established metastasis suppressor, could potentially be exploited to hinder metastases in breast cancer. This review explores the prospect of targeting CD82 as an innovative therapeutic approach in precision medicine for breast cancer patients, with the goal of preventing cancer progression and metastasis. Such an approach would entail the selection of a subset of breast cancer patients with low levels of CD82, and instituting an appropriate treatment scheme tailored towards restoring the levels of CD82 in this group of patients. Proposed precision treatment regimens include current modalities of treating breast cancer, in combination with either clinically approved drugs that could restore the levels of CD82, CD82 peptide mimics or non-coding RNA-based therapeutics.

A CT-based nomogram for predicting the malignant potential of primary gastric gastrointestinal stromal tumors preoperatively

PURPOSE

To develop and validate a computerized tomography (CT)-based nomogram for predicting the malignant potential of primary gastric gastrointestinal stromal tumors (GISTs).

METHODS

The primary and validation cohorts consisted of 167 and 39 patients (single center, different time periods) with histologically confirmed primary gastric GISTs. Clinical data and preoperative CT images were reviewed. The association of CT characteristics with malignant potential was analyzed using univariate and stepwise logistic regression analyses. A nomogram based on significant CT findings was developed for predicting malignant potential. The predictive accuracy of the nomogram was determined by the concordance index (C-index) and calibration curves. External validation was performed with the validation cohort.

RESULTS

CT imaging features including tumor size, tumor location, tumor necrosis, growth pattern, ulceration, enlarged vessels feeding or draining the mass (EVFDM), tumor contour, mesenteric fat infiltration, and direct organ invasion showed significant differences between the low- and high-grade malignant potential groups in univariate analysis (P < 0.05). Only tumor size (> 5 cm vs ≤ 5 cm), location (cardiac/pericardial region vs other), EVFDM, and mesenteric fat infiltration (present vs absent) were significantly associated with high malignant potential in multivariate logistic regression analysis. Incorporating these four independent factors into the nomogram model achieved good C-indexes of 0.946 (95% confidence interval [CI] 0.899-0.975) and 0.952 (95% CI 0.913-0.977) in the primary and validation cohorts, respectively. The cutoff point was 0.33, with sensitivity, specificity, and diagnostic accuracy of 0.865, 0.915, and 0.780, respectively.

DISCUSSION

Primary gastric GISTs originating in the cardiac/pericardial region appear to be associated with higher malignant potential. The nomogram consisting of CT features, including size, location, EVFDM, and mesenteric fat infiltration, could be used to accurately predict the high malignant potential of primary gastric GISTs.

Disease-free Interval Is Associated with Oncologic Outcomes in Patients with Recurrent Gastrointestinal Stromal Tumor

BACKGROUND

Gastrointestinal stromal tumors (GIST) commonly recur following curative-intent resection. Patients with recurrent GIST display heterogeneous outcomes with limited prognostic tools. We investigated factors associated with post-recurrence survival (PRS) and progression-free survival (PFS).

METHODS

We performed a review of our institutional cancer registry from 2003 to 2018 for patients with GIST. Clinicopathologic and outcome data were collected. The disease-free interval (DFI) was calculated from the end of curative-intent oncologic therapy until recurrence. Outcomes were evaluated using Kaplan-Meier and Cox proportional hazards modeling.

RESULTS

Overall, 254 patients underwent resection of primary, non-metastatic GIST, with 81 (32%) recurrences. The median age was 58 years and more than half of the patients with recurrence (n = 44; 54%) received adjuvant imatinib. Recurrence was most common in the liver (n = 34, 42%), peritoneum (n = 31, 38%), or liver plus peritoneum (n = 10, 12%). The median DFI was 14 months (interquartile range 2-26 months); 51 (63%) patients had a DFI ≤24 months and 30 (37%) had a DFI > 24 months. The median post-recurrence follow-up was 46 months. Compared with a DFI ≤24 months, patients with a DFI >24 months had increased 10-year PRS (77% vs. 41%, p < 0.05) and 10-year PFS (73% vs. 19%, p < 0.001). On multivariable analysis controlling for mutational and clinicopathologic features, a DFI >24 months was independently associated with increased PRS (hazard ratio [HR] 0.24, p < 0.01) and PFS (HR 0.18, p < 0.001).

CONCLUSIONS

The DFI is independently associated with oncologic outcomes in recurrent GIST and may be useful in treatment planning. Recurrence after 24 months may signify indolent disease biology that may benefit from additional treatment, including metastasectomy.

Surgical Management of Metastatic Gastrointestinal Stromal Tumors

Treatment with the tyrosine kinase inhibitor (TKI), imatinib is the standard first-line treatment for metastatic gastrointestinal stromal tumors (GISTs). Unfortunately, acquired c-kit mutations cause secondary resistance to imatinib in a median of 18-24 months. Sunitinib and regorafenib are multi-kinase inhibitors that can be used as second-line or third-line therapy in imatinib-resistant or -intolerant GISTs, respectively. Ripretinib (a switch-control tyrosine kinase inhibitor) has recently been approved for fourth-line treatment in metastatic GIST. The TKI avapritinib has been approved for metastatic GIST harboring the imatinib-resistant PDGFRA exon 18 mutation. Although TKI therapies have revolutionized the treatment of metastatic GISTs, they cannot cure metastatic GISTs. Therefore, cytoreductive surgery is of considerable interest and has been accordingly investigated. Retrospective non-randomized studies demonstrated the feasibility and safety of continuous TKI therapy and surgical resection. Most studies demonstrate response to TKI therapy, completeness of resection, extent of disease, and surgical complexity as predictors of outcomes. Most TKIs can be stopped shortly before surgery and restarted shortly after. There is no known survival benefit from debulking operations or R2 resections and this should not be considered. However, debulking/palliative surgery may be necessary for patients with complications of hemorrhage, pain, or intestinal obstruction. SDH-deficient GISTs have an indolent natural history despite metastatic disease and may be another uncommon subgroup that would benefit from surgical debulking (R2 resection). At the time of operation, care should be taken to avoid tumor rupture. After surgical resection, patients should resume tyrosine kinase inhibitor (TKI) therapy as soon as possible and be monitored for disease progression. In all patients with metastatic GIST, the decision to pursue metastasectomy for GIST should be made in a multidisciplinary setting and be individualized according to patient age, comorbidities, functional status, symptoms, mutation status, extent of disease, completeness of resection, TKI response, and goals of the patient.