Survival of advanced/recurrent gastrointestinal stromal tumors treated with tyrosine kinase inhibitors in Taiwan: a nationwide registry study.

BACKGROUND: Most gastrointestinal stromal tumors (GISTs) harbor c-KIT or PDGFRA mutations. Administration of tyrosine kinase inhibitors (TKIs) has significantly improved the survival of patients with GISTs. We aimed to evaluate the clinical outcome of advanced or recurrent GIST patients in Taiwan. METHODS: Patients diagnosed between 2010 and 2020 were enrolled. The collected data included baseline characteristics, treatment pattern, treatment outcome, genetic aberrations and survival status. Progression-free survival (PFS) and overall survival (OS) were analyzed and plotted with the Kaplan-Meier method. Cox regression analysis was used to analyze the prognostic factors of survival. RESULTS: A total of 224 patients with advanced or recurrent GISTs treated with TKIs were enrolled. All patients received imatinib treatment. Ninety-three and 42 patients received sunitinib and regorafenib treatment, respectively. The 48-month PFS and OS rates for patients treated with imatinib were 50.5% and 79.5%, respectively. c-KIT exon 9 and PDGFRA mutations were prognostic factors for a poor PFS and PDGFRA mutation was a prognostic factor for a poor OS in patients treated with imatinib in multivariate Cox regression analysis. The median PFS of patients who received sunitinib treatment was 12.76 months (95% confidence interval (CI), 11.01-14.52). Patients with c-KIT exon 9 mutations had a longer PFS than those with other genetic aberrations. The median PFS of patients treated with regorafenib was 7.14 months (95% CI, 3.39-10.89). CONCLUSIONS: We present real-world clinical outcomes for advanced GIST patients treated with TKIs and identify mutational status as an independent prognostic factor for patient survival.

[A Case of Recurrent Gastric GIST with Long-Term Survival after Multidisciplinary Treatment].

An 80-year-old male patient presented with a 2.5 cm-sized submucosal tumor on the greater curvature side of the upper gastric body during an endoscopic examination in 200X. We diagnosed gastric GIST by biopsy and performed laparoscopic- assisted partial gastrectomy. Imatinib was started as postoperative adjuvant therapy, but was discontinued after 1 month due to eyelid edema. The patient was followed up with a contrast-enhanced CT scan and a PET-CT scan. A 7 cm-sized mass in the gastrosplenic region was discovered on a 200X+7 years CT scan; this mass was thought to be possible recurrence of peritoneal dissemination. The patient did not want to undergo surgery or drug treatment, and was followed up. Five months later he complained of abdominal pain. The CT scan showed that the mass had shrunk slightly, but a small amount of ascites was observed, and tumor rupture was suspected. Therefore, we performed resection of the tumor in the office. Numerous disseminated nodules were found in the intra-abdominal cavity. Pathological examination revealed recurrence of GIST, and the patient was started on imatinib 200 mg/day. The dose was temporarily increased to 300 mg/day, but was reduced again to 200 mg/day 1 month later due to eyelid edema. Thereafter, the dose was temporarily discontinued due to stomatitis, and from 200X+8 years, 200 mg/day was administered for 2 weeks and then discontinued for 2 weeks. At present, 14 years after the first surgery and 6 years after recurrence, he remains alive thanks to imatinib continuation.

Successful post-incomplete resection management of gastrointestinal stromal tumor using imatinib based on adenosine triphosphate-based tumor sensitivity assay in a dog.

Gastrointestinal stromal tumors arising from gastric cardia are uncommon in dogs. A few studies have shown the effectiveness of tyrosine kinase inhibitors in the treatment of canine gastrointestinal stromal tumors, but no standardized protocols are currently available. An 11-year-old spayed female Maltese dog was diagnosed with a gastrointestinal stromal tumor using histopathological and immunohistochemical analyses. An adenosine triphosphate-based tumor chemosensitivity assay revealed that imatinib at lower concentrations had a stronger inhibitory effect than toceranib. Based on the results of the assay, the dog was treated with imatinib after surgery. After 28 mo of therapy, there was no recurrence of the tumor. Key clinical message: Adenosine triphosphate-based tumor chemosensitivity assays may help clinicians to select appropriate postoperative chemotherapeutic drugs for incompletely resected gastrointestinal stromal tumors in dogs.

Gestion réussie à la suite d'une résection incomplète d'une tumeur stromale gastro-intestinale à l'aide de l'imatinib basée sur un test de sensibilité tumorale à base d'adénosine triphosphate chez un chien. Les tumeurs stromales gastro-intestinales résultant du cardia gastrique sont rares chez le chien. Quelques études ont montré l'efficacité des inhibiteurs de la tyrosine kinase dans le traitement des tumeurs stromales gastrointestinales canines, mais aucun protocole standardisé n'est actuellement disponible. Une chienne maltaise stérilisée de 11 ans a reçu un diagnostic de tumeur stromale gastro-intestinale à l'aide d'analyses histopathologiques et immunohistochimiques. Un test de chimiosensibilité tumorale à base d'adénosine triphosphate a révélé que l'imatinib à des concentrations plus faibles avait un effet inhibiteur plus fort que le tocéranib. Sur la base des résultats du test, le chien a été traité avec de l'imatinib après l'opération. Après 28 mois de traitement, il n'y a eu aucune récidive de la tumeur.Message clinique clé :Les tests de chimiosensibilité tumorale à base d'adénosine triphosphate peuvent aider les cliniciens à sélectionner les médicaments chimiothérapeutiques postopératoires appropriés pour les tumeurs stromales gastro-intestinales incomplètement réséquées chez le chien.(Traduit par Dr Serge Messier).

Exudative pleural effusion during sunitinib treatment.

Drug-induced pleural effusion is one of the rare causes of exudative pleural effusion and a high index of suspicion is necessary to lead to early diagnosis. We hereby present the case of a young male in his late 30s, known case of metastatic gastrointestinal stromal tumour on sunitinib therapy, who presented with right-sided mild pleural effusion. Diagnostic thoracentesis showed the effusion to be a monomorphic exudate with low adenosine deaminase, which was negative for malignant cells on cytopathology. A contrast-enhanced CT chest revealed an enlarged lymph node (LN) at the 4R station, cytological analysis of which was suggestive of reactive lymphoid hyperplasia. Infective workup of the LN aspirate and bronchoalveolar lavage taken from the right middle lobe was negative. After systematically excluding the usual causes of exudative pleural effusion, sunitinib was considered to be a possible cause and was, therefore, withheld. A repeat chest X-ray after 3 weeks of stopping the drug showed resolution of the pleural effusion.

Survival of patients with ruptured gastrointestinal stromal tumour treated with adjuvant imatinib in a randomised trial.

BACKGROUND: Patients with ruptured gastrointestinal stromal tumour (GIST) have poor prognosis. Little information is available about how adjuvant imatinib influences survival. METHODS: We explored recurrence-free survival (RFS) and overall survival (OS) of patients with ruptured GIST who participated in a randomised trial (SSG XVIII/AIO), where 400 patients with high-risk GIST were allocated to adjuvant imatinib for either 1 year or 3 years after surgery. Of the 358 patients with confirmed localised GIST, 73 (20%) had rupture reported. The ruptures were classified retrospectively using the Oslo criteria. RESULTS: Most ruptures were major, four reported ruptures were reclassified unruptured. The 69 patients with rupture had inferior RFS and OS compared with 289 patients with unruptured GIST (10-year RFS 21% vs. 55%, OS 59% vs. 78%, respectively). Three-year adjuvant imatinib did not significantly improve RFS or OS of the patients with rupture compared with 1-year treatment, but in the largest mutational subset with KIT exon 11 deletion/indel mutation OS was higher in the 3-year group than in the 1-year group (10-year OS 94% vs. 54%). CONCLUSIONS: About one-fifth of ruptured GISTs treated with adjuvant imatinib did not recur during the first decade of follow-up. Relatively high OS rates were achieved despite rupture. CLINICAL TRIAL REGISTRATION: NCT00116935.

Adjuvant imatinib in high-risk resected gastrointestinal stromal tumors: Merely delaying the inevitable?

INTRODUCTION: Patients with high-risk resected gastrointestinal stromal tumors (GIST) receiving adjuvant imatinib have improved recurrence-free survival (RFS), however whether a complete cytocidal effect exists is unknown. We investigated this using a normalized recurrence timeline measured from end of oncologic treatment (EOOT), defined as the later of resection or end of adjuvant therapy. METHODS: We reviewed patients with resected high-risk GIST at our cancer center from 2003 to 2018. RFS (measured from resection and EOOT), overall survival (OS), and time to imatinib resistance (TTIR) were analyzed using Kaplan-Meier analysis and multivariable Cox proportional hazards modeling. The performance of the Memorial Sloan Kettering (MSK) GIST nomogram was assessed. RESULTS: We identified 86 patients with high-risk GIST with a median 106 months of postsurgical follow-up. One-third (n = 29; 34%) did not receive adjuvant imatinib, while 57 (66%) did for a median of 3 years. The MSK nomogram-predicted 5-year RFS for patients receiving adjuvant imatinib was similar to those who did not (29% vs. 31%, p = 0.64). When RFS was measured from EOOT, the MSK-predicted RFS was independently associated with EOOT RFS (hazard ratio 0.22, p = 0.02), while adjuvant imatinib receipt and duration were not. Neither receipt nor duration of adjuvant imatinib were associated with TTIR or OS (all p > 0.05). CONCLUSIONS: Treatment with adjuvant imatinib delays, but does not clearly impact ultimate recurrence, TTIR, or OS, suggesting many patients with high-risk GIST may receive adjuvant imatinib unnecessarily. Additional studies are needed to establish the benefit of adjuvant therapy versus initiating therapy at first radiographic recurrence.

Sunitinib for the treatment of metastatic gastrointestinal stromal tumors: the effect of TDM-guided dose optimization on clinical outcomes.

BACKGROUND: Sunitinib is an oral anticancer drug approved for the treatment of among others gastrointestinal stromal tumor (GIST). Previous analyses demonstrated an exposure-response relationship at the standard dose, and minimum target levels of drug exposure have been defined above which better treatment outcomes are observed. Therapeutic drug monitoring (TDM) could be used as a tool to optimize the individual dose, aiming at sunitinib trough concentrations ≥37.5 ng/ml for continuous dosing. Nonetheless, data on the added value of TDM-guided dosing on clinical endpoints are currently lacking. Therefore, we evaluate the effect of TDM in patients with advanced and metastatic GIST treated with sunitinib in terms of efficacy and toxicity. PATIENTS AND METHODS: A TDM-guided cohort was compared to a non-TDM-guided cohort in terms of median progression-free survival (mPFS) and overall survival (mOS). Also, mPFS between patients with and without dose-limiting toxicities (DLTs) was compared. Patients in the prospective cohort were included in two studies on TDM-guided dosing (the DPOG-TDM study and TUNE study). The retrospective cohort consisted of patients from the Dutch GIST Registry who did not receive TDM-guided dosing. RESULTS: In total, 51 and 106 patients were included in the TDM-guided cohort and non-TDM-guided cohort, respectively. No statistical difference in mPFS was observed between these two cohorts (39.4 versus 46.9 weeks, respectively; P = 0.52). Patients who experienced sunitinib-induced DLTs had longer mPFS compared to those who did not (51.9 versus 28.9 weeks, respectively; P = 0.002). CONCLUSIONS: Our results do not support the routine use of TDM-guided dose optimization of sunitinib in patients with advanced/metastatic GIST to improve survival.

Discontinuation of imatinib in patients with oligometastatic gastrointestinal stromal tumour who are in complete radiological remission: a prospective multicentre phase II study.

INTRODUCTION: Metastatic gastrointestinal stromal tumour (GIST) is considered incurable, and life-long treatment with tyrosine kinase inhibitors is recommended. We investigated whether selected patients with metastatic GIST may remain in durable remission despite imatinib discontinuation. PATIENTS: In this 1-group, prospective, multicentre phase II trial selected patients with oligometastatic (≤3 metastases) GIST discontinued imatinib treatment. Eligible patients had been treated with imatinib >5 years without progression and had no radiologically detectable metastases after metastasectomy, radiofrequency ablation (RFA) or complete response to imatinib. The primary endpoint was progression-free survival (PFS) 3-years after stopping imatinib. Overall survival (OS) and quality of life (QoL) were secondary endpoints. RESULTS: The trial closed prematurely due to slow accrual. Between January 5, 2017, and June 5, 2019, 13 patients were enrolled, of whom 12 discontinued imatinib. The median follow-up time was 55 months (range, 36 to 69) after study entry. Five (42%) of the 12 eligible patients remained progression free, and seven (58%) progressed with a median time to progression 10 months. Median PFS was 23 months and the estimated 3-year PFS 41%. Six of the seven patients who progressed restarted imatinib, and all six responded. Three-year OS was 100%, and all patients were alive at the time of the study analysis. QoL measured 5 and 11 months after discontinuation of imatinib demonstrated improvement compared to the baseline. INTERPRETATION: A substantial proportion of selected patients with oligometastatic GIST treated with imatinib and metastasis surgery/RFA may remain disease-free for ≥3 years with improved QoL after stopping of imatinib.

A case-matched study of imatinib mesylate between different formulations on plasma trough concentration, adverse events, quality of life and outcomes in gastrointestinal stromal tumor patients.

Genike, the imatinib (IM)-alpha form is widely used in the treatment of gastrointestinal stromal tumor (GIST) patients in China. We wanted to investigate whether there are differences in IM plasma concentrations, adverse events, health-related quality of life (QOL) and outcomes between patients treated with Genike and Glivec. Thirty included GIST patients receiving IM treatment were matched to either Genike or Glivec according to gastrectomy, body weight, body surface area and sex. There was no statistically significant difference in IM trough plasma levels between the two groups. There were no significant differences in very common adverse events of IM between the Genike and Glivec groups. IM was well tolerated, although it was associated with a significant change in cognitive function (P < 0.001), fatigue (P = 0.015), pain (P = 0.015), nausea/vomiting (P = 0.029), insomnia (P = 0.019), diarrhea (P = 0.003) and financial difficulties (P < 0.001). Physical functioning, financial burden and insomnia were significantly different between the two groups (P = 0.026). Until Aug. 2022, there was no significant difference in time to imatinib treatment failure (TTF) between the two groups. In conclusion, there was no difference in IM plasma concentration and adverse events between Genike and Glivec. Both Genike and Glivec could partially decrease the QOL of GIST patients. Physical functioning was worse in Genike group than in Glivec group, while the economic burden and symptoms of insomnia in Glivec patients were worse. There was no significant difference in TTF between the two groups.

Monitoring advanced gastrointestinal stromal tumor with circulating tumor DNA.

PURPOSE OF REVIEW: This review explores the role of circulating tumor (ct)DNA as a biomarker for clinical decision-making and monitoring purposes in metastatic gastrointestinal stromal tumor (GIST) patients. We discuss key insights from recent clinical trials and anticipate the future perspectives of ctDNA profiling within the clinical landscape of GIST. RECENT FINDINGS: The identification and molecular characterization of KIT/platelet-derived growth factor receptor alpha (PDGFRA) mutations from ctDNA in metastatic GIST is feasible and reliable. Such identification through ctDNA serves as a predictor of clinical outcomes to tyrosine-kinase inhibitors (TKIs) in metastatic patients. Additionally, conjoined ctDNA analysis from clinical trials reveal the evolving mutational landscapes and increase in intratumoral heterogeneity across treatment lines. Together, this data positions ctDNA determination as a valuable tool for monitoring disease progression and guiding therapy in metastatic patients. These collective efforts culminated in the initiation of a ctDNA-based randomized clinical trial in GIST, marking a significant milestone in integrating ctDNA testing into the clinical care of GIST patients. SUMMARY: The dynamic field of ctDNA technologies is rapidly evolving and holds significant promise for research. Several trials have successfully validated the clinical utility of ctDNA in metastatic GIST, laying the foundations for its prospective integration into the routine clinical management of GIST patients.

A systematic review and meta-analysis of neoadjuvant imatinib use in locally advanced and metastatic gastrointestinal stromal tumors.

BACKGROUND: Several doubts remain regarding the optimal use of neoadjuvant imatinib in gastrointestinal stromal tumors (GISTs), such as ideal treatment duration, patient selection, and long-term survival outcomes. This manuscript provides a comprehensive review on neoadjuvant imatinib treatment outcomes and facilitate evidence-based decision-making for the use of imatinib therapy in GISTs. METHODS: Four databases (PubMed, EMBASE, Scopus, and Cochrane Library) were searched from inception to September 9, 2023. Meta-analyses of proportions were performed for the outcomes of R0 resection, disease responses, and 1-year, 3-year, and 5-year overall survival (OS) as well as 1-year, 3-year, and 5-year disease free survival (DFS). Sensitivity analyses in the form of leave-one-out analyses, meta-regression, and subgroup analyses were performed for outcomes with substantial statistical heterogeneity. RESULTS: The search yielded 1254 articles, and 36 studies were included in our analysis. Meta-analysis of proportions revealed that 1-year, 3-year, and 5-year OS was 100%, 94%, and 88%, while 1-year, 3-year and 5-year DFS was 99%, 89%, and 79%, respectively. An R0 resection rate of 89% and a disease response rate of 67% was achieved after a mean duration of treatment of 8.41 ± 0.367 months. KIT exon 9 mutation was significantly associated with poorer 5-year DFS. CONCLUSION: This study quantified key outcomes for neoadjuvant imatinib in locally advanced and metastatic or recurrent GIST. Patients with gastric and rectal tumous stand to benefit from neoadjuvant imatinib with an optimal treatment duration of 8 months. Furthermore, the potential utility of mutational analysis in guiding treatment with neoadjuvant imatinib was demonstrated.

RAF1 facilitates KIT signaling and serves as a potential treatment target for gastrointestinal stromal tumor.

The aberrant activation of RAS/RAF/MEK/ERK signaling is important for KIT mutation-mediated tumorigenesis of gastrointestinal stromal tumor (GIST). In this study, we found that inhibition of RAF1 suppresses the activation of both wild-type KIT and primary KIT mutations in GIST, with primary KIT mutations showing greater sensitivity. This suggests a positive feedback loop between KIT and RAF1, wherein RAF1 facilitates KIT signaling. We further demonstrated that RAF1 associates with KIT and the kinase activity of RAF1 is necessary for its contribution to KIT activation. Accordingly, inhibition of RAF1 suppressed cell survival, proliferation, and cell cycle progression in vitro mediated by both wild-type KIT and primary KIT mutations. Inhibition of RAF1 in vivo suppressed GIST growth in a transgenic mouse model carrying germline KIT/V558A mutation, showing a similar treatment efficiency as imatinib, the first-line targeted therapeutic drug of GIST, while the combination use of imatinib and RAF1 inhibitor further suppressed tumor growth. Acquisition of drug-resistant secondary mutation of KIT is a major cause of treatment failure of GIST following targeted therapy. Like wild-type KIT and primary KIT mutations, inhibition of RAF1 suppressed the activation of secondary KIT mutation, and the cell survival, proliferation, cell cycle progression in vitro, and tumor growth in vivo mediated by secondary KIT mutation. However, the activation of secondary KIT mutation is less dependent on RAF1 compared with that of primary KIT mutations. Taken together, our results revealed that RAF1 facilitates KIT signaling and KIT mutation-mediated tumorigenesis of GIST, providing a rationale for further investigation into the use of RAF1 inhibitors alone or in combination with KIT inhibitor in the treatment of GIST, particularly in cases resistant to KIT inhibitors.

[A Case of a Gastrointestinal Stromal Tumor of the Stomach with Lymph Node Metastasis].

A 87-year-old female was pointed out wall thickness in the upper part of gastric body for examination of anemia. The mass had a contrast effect, some of it protruded outside the wall, and the surrounding lymph nodes were enlarged. Upper endoscopy showed irregular ulcerative lesion with submucosal volume from posterior wall to the greater curvature in the upper part of gastric body. Biopsy was performed, and GIST of stomach was diagnosed. Surgery was performed for the GIST of the stomach. During open surgery, invasion of pancreatic tail was observed, therefore proximal gastrectomy with D1 lymph node dissection and distal pancreatectomy were performed. Pathologically, the tumor measured 95×78×65 mm with mitotic figures(38/50 high-power fields). Immunohistochemical analysis revealed that tumor cells expressed positive results for c-kit, α-SMA and CD34, and negative results for S-100 and desmin on the basis of the histology and immunostaining profile, the tumor was diagnosed as a GIST. The patient was classed as high risk according to Fletcher's risk classification. Tumor invades pancreatic tail, and lymph node metastasis was observed. She was discharged on the postoperative day 27 and alive without tumor recurrence at 6 months after surgery, not undergoing adjuvant chemotherapy.

Clinical and Biomarker Analysis of a Phase I/II Study of PDR001 Plus Imatinib for Advanced Treatment-Refractory Gastrointestinal Stromal Tumors.

PURPOSE: In this phase Ib/II study, we aimed to evaluate the safety and efficacy of PDR001, an anti-PD1 antibody, in combination with imatinib in patients with treatment-refractory gastrointestinal stromal tumor (GIST). PATIENTS AND METHODS: Patients with advanced GIST whose disease had progressed on imatinib, sunitinib, and regorafenib were enrolled. In phase Ib, the standard 3 + 3 dose escalation scheme was applied. Intravenous administration of PDR001 at 400 mg for every 4 weeks plus imatinib (300 and 400 mg daily for dose levels I and II, respectively) was given. The primary outcome for phase II was the disease control rate at 12 weeks. Exploratory biomarker analysis was performed based on PDL1 IHC, next-generation sequencing, and multiplexed IHC. RESULTS: No dose-limiting toxicity was observed in the phase Ib part (n = 10), and dose level II was selected as the recommended phase II dose. In the phase II part (n = 29), there was no objective response, and the disease control rate at 12 weeks was 37.9%, not meeting the primary efficacy endpoint. For patients in phase Ib-dose level II and phase II (n = 36), the median progression-free survival (PFS) and overall survival were 2.3 and 9.5 months, respectively. The most common grade 3 to 4 adverse event was anemia. Exploratory biomarker analysis indicated that a higher CD8+ T-cell density was associated with a favorable PFS but to a limited degree. Tumor mutational burden and PDL1 were not associated with better PFS. CONCLUSIONS: In patients with treatment-refractory GIST, PDR001 in combination with imatinib was generally tolerable, but it was not effective.

The correlation of sarcopenia and adverse events of imatinib therapy postoperatively in gastrointestinal stromal tumor through computed tomography quantitative body composition.

PURPOSE: This study aimed to investigate the correlation between sarcopenia and adverse events (AEs) of postoperative imatinib therapy through computed tomography (CT) quantitative body composition for intermediate- and high-risk gastrointestinal stromal tumors (GISTs). METHODS: The study retrospectively analyzed the clinical data of 208 patients with intermediate- and high-risk GIST treated surgically and treated with imatinib afterward at the First Affiliated Hospital of Wenzhou Medical University between October 2011 and October 2021. Images of preoperative CT scans within 1 month were used to determine the body composition of the patients. On the basis of the L3 skeletal muscle index, patients were classified into sarcopenia and nonsarcopenia groups. In 2 groups, AEs related to imatinib were analyzed. RESULTS: The proportion of AEs related to imatinib in the sarcopenia group was higher, and this disparity had a significant statistical significance (P = .013). Sarcopenia was significantly associated with hemoglobin reduction compared with nonsarcopenia (P = .015). There was a significant difference between the sarcopenia group and the nonsarcopenia group in the ratio of severe AEs (grades 3-4). Hemoglobin content (odds ratio [OR], 0.981; 95% CI, 0.963-1.000; P = .045), sex (OR, 0.416; 95% CI, 0.192-0.904; P = .027), and sarcopenia (OR, 5.631; 95% CI, 2.262-14.014; P < .001) were the influential factors of imatinib severe AEs in patients with intermediate- and high-risk GIST within 1 year after imatinib treatment. CONCLUSION: Patients with preoperative sarcopenia have a higher incidence and severity of AEs during adjuvant imatinib therapy.

Low Dose Sorafenib in Gastric Gastrointestinal Stromal Tumour with PDGFRA p.1843-D846 Deletion in an 88-Year-Old Male.

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Treatment Access for Gastrointestinal Stromal Tumor in Predominantly Low- and Middle-Income Countries.

Importance: Gastrointestinal stromal tumor (GIST) is a rare cancer treated with the tyrosine kinase inhibitors imatinib mesylate or sunitinib malate. In general, in low- and middle-income countries (LMICs), access to these treatments is limited. Objective: To describe the demographic characteristics, treatment duration, and survival of patients with GIST in LMICs treated with imatinib and sunitinib through The Max Foundation programs. Design, Setting, and Participants: This retrospective database cohort analysis included patients in 2 access programs administered by The Max Foundation: the Glivec International Patient Assistance Program (GIPAP), from January 1, 2001, to December 31, 2016, and the Max Access Solutions (MAS) program, January 1, 2017, to October 12, 2020. Sixty-six countries in which The Max Foundation facilitates access to imatinib and sunitinib were included. Participants consisted of patients with approved indications for imatinib, including adjuvant therapy in high-risk GIST by pathologic evaluation of resected tumor or biopsy-proven unresectable or metastatic GIST. All patients were reported to have tumors positive for CD117(c-kit) by treating physicians. A total of 9866 patients received treatment for metastatic and/or unresectable disease; 2100 received adjuvant imatinib; 49 received imatinib from another source and were only included in the sunitinib analysis; and 53 received both imatinib and sunitinib through The Max Foundation programs. Data were analyzed from October 13, 2020, to January 30, 2024. Main Outcomes and Measures: Demographic and clinical information was reported by treating physicians. Kaplan-Meier analysis was used to estimate time to treatment discontinuation (TTD) and overall survival (OS). An imputation-based informed censoring model estimated events for patients lost to follow-up after treatment with adjuvant imatinib. Patients who were lost to follow-up with metastatic or unresectable disease were presumed deceased. Results: A total of 12 015 unique patients were included in the analysis (6890 male [57.6%]; median age, 54 [range, 0-100] years). Of these, 2100 patients were treated with imatinib in the adjuvant setting (median age, 54 [range 8-88] years) and 9866 were treated with imatinib for metastatic or unresectable disease (median age, 55 [range, 0-100] years). Male patients comprised 5867 of 9866 patients (59.5%) with metastatic or unresectable disease and 1023 of 2100 patients (48.7%) receiving adjuvant therapy. The median OS with imatinib for unresectable or metastatic disease was 5.8 (95% CI, 5.6-6.1) years, and the median TTD was 4.2 (95% CI, 4.1-4.4) years. The median OS with sunitinib for patients with metastatic or unresectable GIST was 2.0 (95% CI, 1.5-2.5) years; the median TTD was 1.5 (95% CI, 1.0-2.1) years. The 10-year OS rate in the adjuvant setting was 73.8% (95% CI, 67.2%-81.1%). Conclusions and Relevance: In this cohort study of patients with GIST who were predominantly from LMICs and received orally administered therapy through the GIPAP or MAS programs, outcomes were similar to those observed in high-resource countries. These findings underscore the feasibility and relevance of administering oral anticancer therapy to a molecularly defined population in LMICs, addressing a critical gap in cancer care.

ETV6::NTRK3 Fusion-Positive Wild-Type Gastrointestinal Stromal Tumor (GIST) with Abundant Lymphoid Infiltration (TILs and Tertiary Lymphoid Structures): A Report on a New Case with Therapeutic Implications and a Literature Review.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract, with proto-oncogene, receptor tyrosine kinase (c-kit), or PDGFRα mutations detected in around 85% of cases. GISTs without c-kit or platelet-derived growth factor receptor alpha (PDGFRα) mutations are considered wild-type (WT), and their diverse molecular alterations and biological behaviors remain uncertain. They are usually not sensitive to tyrosine kinase inhibitors (TKIs). Recently, some molecular alterations, including neurotrophic tyrosine receptor kinase (NTRK) fusions, have been reported in very few cases of WT GISTs. This novel finding opens the window for the use of tropomyosin receptor kinase (TRK) inhibitor therapy in these subtypes of GIST. Herein, we report a new case of NTRK-fused WT high-risk GIST in a female patient with a large pelvic mass (large dimension of 20 cm). The tumor was removed, and the histopathology displayed spindle-predominant morphology with focal epithelioid areas, myxoid stromal tissue, and notable lymphoid infiltration with tertiary lymphoid structures. Ten mitoses were quantified in 50 high-power fields without nuclear pleomorphism. DOG1 showed strong and diffuse positivity, and CD117 showed moderate positivity. Succinate dehydrogenase subunit B (SDHB) was retained, Pan-TRK was focal positive (nuclear pattern), and the proliferation index Ki-67 was 7%. Next-generation sequencing (NGS) detected an ETV6::NTRK3 fusion, and this finding was confirmed by fluorescence in situ hybridization (FISH), which showed NTRK3 rearrangement. In addition, an RB1 mutation was found by NGS. The follow-up CT scan revealed peritoneal nodules suggestive of peritoneal dissemination, and Entrectinib (a TRK inhibitor) was administered. After 3 months of follow-up, a new CT scan showed a complete response. Based on our results and the cases from the literature, GISTs with NTRK fusions are very uncommon so far; hence, further screening studies, including more WT GIST cases, may increase the possibility of finding additional cases. The present case may offer new insights into the potential introduction of TRK inhibitors as treatments for GISTs with NTRK fusions. Additionally, the presence of abundant lymphoid infiltration in the present case may prompt further research into immunotherapy as a possible additional therapeutic option.

The long-term efficacy of imatinib with hepatic resection or other local treatment for gastrointestinal stromal tumours liver metastases: a retrospective cohort study.

BACKGROUND: The liver is the most common site of metastasis from gastrointestinal stromal tumors (GISTs). The authors aimed to evaluate imatinib (IM) combined with hepatic resection (HR) or other local treatments such as radiofrequency ablation (RFA) and transarterial chemoembolization (TACE), compared to IM monotherapy in long-term survival benefits in patients suffering from GIST liver metastases. METHODS: Our research encompassed 238 patients diagnosed with liver metastases of GISTs from January 2002 to April 2022 at the First Affiliated Hospital of Sun Yat-Sen University. The oncological outcomes of concern included overall survival (OS), progression-free survival (PFS), and liver-specific PFS. RESULTS: Of all 238 patients, 126 were treated with IM alone (IM group), 81 with IM combined with HR (IM+HR group), and 31 with IM combined with RFA/TACE (IM+RFA/TACE group). The median follow-up time was 44.83 months. The median OS in the IM group was 132.60 months and was not reached in either the IM+HR group or the IM+RFA/TACE group. The 10-year OS rate in the IM+HR group was significantly superior to the IM group and the IM+RFA/TACE group (91.9% vs. 61.1% vs. 55.2%, respectively, P =0.015), and the liver-specific PFS ( P =0.642) and PFS ( P =0.369) in the three groups showed a beneficial trend in the combined treatment group. Multivariate analyses showed that age less than or equal to 60 years (HR 0.280, P< 0.001) and IM+HR (HR 0.361, P =0.047) were independently associated with better OS. Achieving no evidence of disease through surgical intervention was independently correlated with enhanced OS (HR 0.099, P =0.034), liver-specific PFS (HR 0.388, P =0.014), and PFS (HR 0.402, P =0.004). CONCLUSIONS: In patients with GIST liver metastases, IM combined with HR might improve OS in selected patients compared with IM alone and IM combined with RFA/TACE. Achieving no evidence of disease status with surgical treatment of patients results in significant prolonging of OS, liver-specific PFS, and PFS.

Financial difficulties experienced by patients with gastrointestinal stromal tumours (GIST) in the Netherlands: data from a cross-sectional multicentre study.

PURPOSE: This study aims to (1) explore the prevalence of patient-reported financial difficulties among GIST patients, differentiating between those currently undergoing tyrosine kinase inhibitor (TKI) treatment and those who are not; (2) investigate associations between financial difficulties and sociodemographic and clinical characteristics, work, cancer-related concerns, anxiety and depression and (3) study the impact of financial difficulties on health-related quality of life. METHODS: A cross-sectional study was conducted among Dutch GIST patients diagnosed between 2008 and 2018, who were invited to complete a one-time survey between September 2020 and June 2021. Patients completed nine items of the EORTC item bank regarding financial difficulties, seven work-related questions, the Hospital Anxiety and Depression Scale, Cancer Worry Scale and EORTC QLQ-C30. RESULTS: In total, 328 GIST patients participated (response rate 63.0%), of which 110 (33.8%) were on TKI treatment. Patients currently treated with TKIs reported significantly more financial difficulties compared to patients not on TKIs (17.3% vs 8.7%, p = 0.03). The odds of experiencing financial difficulties was 18.9 (95% CI 1.7-214.7, p = 0.02) times higher in patients who were less able to work due to their GIST diagnosis. Patients who experienced financial difficulties had significantly lower global quality of life and functioning, and more frequently reported psychological symptoms as compared to patients who did not report financial difficulties. CONCLUSION: Even in a country where the costs of TKIs and follow-up care are covered by health insurance, financial difficulties can be present in GIST patients, especially in patients on TKI treatment, and may negatively influence the quality of life.