Gastrointestinal Stromal Tumors Research Articles

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

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

Development of a simultaneous quantification method of imatinib and sunitinib and their main metabolites and its application in patients with gastrointestinal stromal tumor.

Correlations between plasma concentrations of imatinib and sunitinib with efficacy and toxicity have been established. It is crucial to develop a sensitive and precise method for determining the plasma concentrations of imatinib and sunitinib, along with their active metabolites, to facilitate therapeutic drug monitoring and individualized therapy. Plasma samples were separated on an Agilent ZORBAX SB-C18 chromatographic column using gradient elution. Quantification was performed using a mass spectrometer equipped with electrospray ionization in multiple reaction monitoring. The analysis time was 18 min per run, with all analytes and internal standards eluting within 8 min. The calibration range was 25-4000 ng/mL for imatinib, 5-800 ng/mL for N-desmethyl imatinib (CGP74588), and 2.5-400 ng/mL for sunitinib and N-desethyl sunitinib (SU12662). Intra- and inter-assay precision were both below 15%, and accuracy ranged between 90.0% and 101.9%. The method was successfully applied to determine blood samples from 120 patients with gastrointestinal stromal tumors who received imatinib (n = 115) and sunitinib (n = 5). It has been validated as linear, accurate, precise, and robust, making it suitable for therapeutic drug monitoring of imatinib and sunitinib in routine clinical practice.

Resection of a giant gastrointestinal stromal tumor and subsequent gastric reconstruction

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal neoplasms of the digestive tract (80%). The stomach is the most commonly affected organ. Complete resection of the tumor is the only curative treatment. The size and number of mitoses are parameters to determine the prognosis and the use of adjuvant therapies. Although sometimes the GIST is giant it should be completely resected and if possible the stomach reconstructed to preserve function and quality of life.

Recent advances in gastrointestinal stromal tumors: where are we going?

Recent advances in gastrointestinal stromal tumors: where are we going?

Endoscopic resection for the treatment of gastric gastrointestinal stromal tumors: a retrospective study from a large tertiary hospital in China.

With the continuous development of endoscopic technology, endoscopic resection (ER) has gradually become an optional method for the treatment of gastric gastrointestinal stromal tumors (GISTs). However, studies with a large sample or a long follow-up are lacking. Therefore, this research aims to evaluate the efficacy and safety of ER for gastric GISTs in the real-world setting with more than 300 enrolled patients and a follow-up period longer than 45months. From January 2013 to February 2023, 409 patients with a pathological diagnosis of GISTs after ER were retrospectively enrolled in this study. After excluding 86 patients with non-gastric GISTs, we assessed 323 patients with gastric GISTs. The main outcome measures were en bloc resection, complete resection, residual disease, recurrence, and complications. There were 194 (60.06%) females and 129 (39.94%) males, and the median age of the included patients was 58years (51, 63). The median tumor size was 15.0 (10.0, 20.0) mm. According to the modified NIH criteria, 246 (75.85%) patients were classified as very low risk, 62 (19.20%) were classified as low risk, 12 (3.72%) were classified as moderate risk, and 3 (0.93%) were classified as high risk. A total of 287 (88.85%) patients achieved en bloc resection, and 287 (88.85%) also achieved complete resection. Only one patient showed residual and no recurrent lesions were noted during the follow-up. Regarding complications, three patients had complications, with a complication rate of 0.93%, and no severe complications requiring surgical intervention occurred. ER is an appropriate alternative method for the treatment of gastric GISTs, with an en bloc resection rate of 88.85% and a complication rate of 0.93%. No recurrence was noted during follow-up, even for GISTs with piecemeal resection.

The impact of contour maps on estimating the risk of gastrointestinal stromal tumor recurrence: indications for adjuvant therapy: an analysis of the Kinki GIST registry

IntroductionContour maps enable risk classification of GIST recurrence in individual patients within 10 postoperative years. Although contour maps have been referred to in Japanese guidelines, their usefulness and role in determining indications for adjuvant therapy is still unclear in Japanese patients. The aims of this study are to investigate the validity of contour maps in Japanese patients with GIST and explore the new strategy for adjuvant therapy.Materials and methodsA total of 1426 Japanese GIST patients who were registered to the registry by the Kinki GIST Study Group between 2003 and 2012 were analyzed. Patients who had R0 surgery without perioperative therapy were included in this study. The accuracy of contour maps was validated.ResultsOverall, 994 patients have concluded this study. Using contour maps, we validated the patients. The 5-year recurrence-free survival rates of patients within the GIST classification groups of 0–10%, 10–20%, 20–40%, 40–60%, 60–80%, 80–90%, and 90–100% were 98.1%, 96.6%, 92.3%, 48.0%, 37.3%, 41.0% and 42.4%, respectively. We confirmed that this classification by contour maps was well reflected recurrence prediction. Further, in the high-risk group stratified by the modified National Institutes of Health consensus criteria (m-NIHC), the 10-year RFS rate was remarkably changed at a cutoff of 40% (0–40% group vs. 40–100% group: 88.7% vs. 50.3%, p < 0.001).ConclusionContour maps are effective in predicting individual recurrence rates. And it may be useful for the decision of individual strategy for high-risk patients combined with m-NIHC.

FBXW7 regulates the sensitivity of imatinib in gastrointestinal stromal tumors by targeting MCL1.

Imatinib contributes to improving prognosis of high-risk or unresectable gastrointestinal stromal tumors (GISTs). As therapeutic efficacy is limited by imatinib resistance and toxicity, the exploration of predictive markers of imatinib therapeutic efficacy that enables patients to utilize more effective therapeutic strategies remains urgent. The correlation between FBXW7 and imatinib resistance via FBXW7-MCL1 axis was evaluated in vitro and in vivo experiments. The significance of FBXW7 as a predictor of imatinib treatment efficacy was examined in 140 high-risk patients with GISTs. The ability of FBXW7 to predict therapeutic efficacy of adjuvant imatinib in high-risk GIST patients was determined through 5-year recurrence-free survival (RFS) rates analysis and multivariate analysis. FBXW7 affects imatinib sensitivity by regulating apoptosis in GIST-T1 cells. FBXW7 targets MCL1 to regulate apoptosis. MCL1 involves in the regulation of imatinib sensitivity through inhibiting apoptosis in GIST-T1 cells. FBXW7 regulates imatinib sensitivity by down-regulating MCL1 to enhance imatinib-induced apoptosis in vitro. FBXW7 regulates imatinib sensitivity of GIST cells by targeting MCL1 to predict efficacy of imatinib treatment in vivo. FBXW7 regulates imatinib sensitivity by inhibiting MCL1 to enhance imatinib-induced apoptosis in GIST, and predicts efficacy of imatinib treatment in high-risk GIST patients treated with imatinib.

Antral plexiform fibromyxoma: case report of a rare mesenchymal neoplasm

Plexiform fibromyxoma (PF) is a rare mesenchymal neoplasm of the stomach usually arising in the gastric antrum, and its main differential diagnosis is gastrointestinal stromal tumor. Most common symptoms are hematemesis, anemia. Immunohistochemically, positivity for smooth muscle actin (SMA) and vimentin suggests the diagnosis of PF. We report the case of a 56-year-old female patient with a 30- day history of nausea at presentation 4 years ago. Gastroscopy at that time revealed a subepithelial lesion (SEL) in the gastric antrum, measuring approximately 20 mm in diameter, with leakage of serous fluid after biopsy. Histopathology showed only an inflammatory process. Follow-up gastroscopies were performed 24, 36, and 48 months later, with surveillance biopsy at each follow-up. The last gastroscopies showed changes in lesion appearance, reduction in size, and absence of fluid leakage. Histopathology showed bland spindle cell proliferation, with a vaguely plexiform/multinodular pattern, in a fibromyxoid stroma with an arborizing capillary network without mitoses. The tumor cells were positive for SMA and negative for DOG1, CD117, CD34, S100, desmin, EMA, CD10, calponin, and beta-catenin. The choice of treatment and follow-up depends on the SEL features, but because no cases of malignancy or metastatic disease have previously been reported, the patient chose a conservative approach.

Comments on "No-touch endoscopic full-thickness resection technique for gastric gastrointestinal stromal tumors".

Comments on "No-touch endoscopic full-thickness resection technique for gastric gastrointestinal stromal tumors".

Individualized Dosing Patterns in the Treatment of Older Patients with Gastrointestinal Stromal Tumors: Results of a Registry-Based Observational National Cohort Study Including 871 Patients.

While the effectiveness of tyrosine kinase inhibitors (TKIs) seems similar in older patients with gastrointestinal stromal tumors (GIST) compared with younger patients, toxicities in older patients treated with TKIs more often lead to discontinuation of treatment. To better understand the age-related pharmacology and pharmacodynamic differences in patients with GIST treated with TKIs, the primary aim of this study was to evaluate TKI dosing patterns in older patients with GIST, while the secondary aims were to evaluate differences in imatinib trough plasma concentrations between age groups and to compare the overall survival (OS) in patients with and without dose reductions in all treatment lines in a palliative setting. Patients (18 years of age or older) with histologically proven GIST diagnosed between January 2009 and June 2021 and treated with one or more lines of TKIs were selected from the Dutch GIST Registry (DGR) database. Age groups were divided into younger patients (age <70 years) and older patients (age ≥70 years). All imatinib trough plasma concentrations of blood withdrawals taken from initiation of imatinib until a maximum of 1 year of treatment with imatinib were collected. Reasons for first adjustment of treatment were classified as adverse event, dose modification, progressive disease and other reasons. The next treatment steps after first adjustment of treatment were defined as dose escalation, dose reduction, dose interruption, or end of treatment. The association of dose reduction and OS was analyzed using the landmark approach. Overall, 871 patients were included in this study, including 577 younger patients and 294 older patients. Older patients more often had an adverse event as the reason for first adjustment of treatment with both imatinib (45.6%; p<0.001) and sunitinib (58.6%; p=0.224) compared with younger patients (19.5% and 42.7%, respectively). Adjustment of imatinib and sunitinib after starting on a standard dose because of an adverse event most often resulted in dose reduction in both age groups. Median trough plasma concentrations of all samples taken within the first year after initiation of imatinib were higher in older patients (1228ng/mL, interquartile range [IQR] 959-1687) compared with younger patients (1035ng/mL [IQR 773-1377]; p<0.001). No significant differences were seen between OS in patients with or without dose reduction in all treatment lines (imatinib: p=0.270; sunitinib: p=0.547; and regorafenib: p=0.784). Older patients showed higher imatinib trough plasma concentrations compared with younger patients and also had earlier and more often adverse events as the reason for first adjustment of treatment with imatinib followed by dose reduction. However, in a landmark analysis, patients with imatinib dose reductions had no poorer outcomes compared with patients not requiring a dose reduction.

Characteristics of gastrointestinal stromal tumors associated to other tumors: Características de los tumores del estroma gastrointestinal asociados a otras neoplasias.

IntroductionOur aim is to analyze the differences between sporadic gastrointestinal stromal tumors and those associated with other tumors. MethodsRetrospective cohort study including patients with diagnosis of gastrointestinal stromal tumors operated at our center. Patients were divided into two groups, according to whether or not they had associated other tumors, both synchronously and metachronously. Disease free survival and overall survival were calculated for both groups. Results96 patients were included, 60 (62.5%) were male, with a median age of 66.8 (35–84). An association with other tumors was found in 33 cases (34.3%); 12 were synchronous (36.3%) and 21 metachronous (63.7%). The presence of mutations in associated tumors was 70% and in non-associated tumors 75%. Associated tumors were classified as low risk tumors based on Fletcher’s stratification scale (p = 0.001) as they usually were smaller in size and had less than ≤5 mitosis per 50 HPF compared to non-associated tumors. When analyzing overall survival, there were statistically significant differences (p = 0,035) between both groups. ConclusionThe relatively high proportion of gastrointestinal stromal tumors cases with associated tumors suggests the need to carry out a study to rule out presence of a second neoplasm and a long-term follow-up should be carried out in order to diagnose a possible second neoplasm. Gastrointestinal stromal tumors associated with other tumors have usually low risk of recurrence with a good long-term prognosis.

EUS diagnosis and rescue of gastrointestinal stromal tumor rupture and massive hemorrhage (with video).

EUS diagnosis and rescue of gastrointestinal stromal tumor rupture and massive hemorrhage (with video).

Imatinib induces ferroptosis in gastrointestinal stromal tumors by promoting STUB1-mediated GPX4 ubiquitination

Imatinib (IM) has significantly improved the prognosis of gastrointestinal stromal tumor (GIST) patients, but some patients still have primary resistance to IM, and approximately half of patients develop acquired drug resistance within 2 years of treatment, necessitating exploration of new treatment strategies. Targeting ferroptosis as a novel approach to tumor treatment has gained attention. Yet, there is limited research on ferroptosis in GIST, and the underlying mechanism remains unclear. In this study, we revealed that IM increased lipid reactive oxygen species and intracellular Fe2+ levels, and decreased glutathione levels in GIST. This effect could be partially inhibited by Ferrostatin-1. Additionally, knocking down STUB1 and overexpressing GPX4 reversed the IM-induced ferroptosis effect. Moreover, STUB1 was identified as a novel E3 ubiquitin ligase of GPX4, promoting the ubiquitination at site K191 of GPX4. The combination of the GPX4 inhibitor RSL3 and IM synergistically induces ferroptosis, inhibiting GIST proliferation both in vivo and in vitro. Furthermore, STUB1 and GPX4 expression serve as independent prognostic factors for GIST. In conclusion, This study is the first to demonstrate that IM induces ferroptosis by promoting STUB1-mediated GPX4 ubiquitination in GIST, and the combination of RSL3 and IM emerges as a promising therapeutic strategy for GIST.

Single-port intragastric wedge resection using the tunnel method: a novel surgical approach for treating endophytic gastric subepithelial tumors.

Intragastric wedge resection is an effective method for treating endophytic gastric subepithelial tumors (SETs). However, retracting the stomach wall to the umbilicus is difficult in certain patients. In response, we developed a novel surgical technique for single-port intragastric wedge resection, which we termed the "tunnel method." A transumbilical incision is made, and a wound retractor is applied. After diagnostic laparoscopy, a gastrostomy is made on the greater curvature, lower body. Another small wound retractor is inserted into the gastrostomy, and extracted through the transumbilical incision, creating a tunnel from the gastrostomy site to the umbilicus. Articulating laparoscopic instruments are inserted via the tunnel, and intragastric wedge resection is performed. We collected and analyzed the clinicopathologic and operative data of patients who underwent intragastric wedge resection via the tunnel method. Twenty-seven patients who underwent single-port intragastric wedge resection via the tunnel method in a single tertiary referral hospital were included in this study. The mean age of the patients was 54.6 ± 11.4years, body mass index was 26.5 ± 3.4kg/m2. Twenty-four (88.9%) patients had tumors located in the upper third of the stomach. The average operative time was 65.0 ± 24.2min. None of the patients experienced Clavien-Dindo grade IIIa or higher postoperative complications. The average postoperative hospital stay length was 2.5 ± 0.8days. Thirteen gastrointestinal stromal tumors, nine leiomyomas, and one neuroendocrine carcinoma, schwannoma, lipoma, spindle cell proliferative lesion, and fibrotic lesion were pathologically diagnosed. The average tumor size was 2.6 ± 1.3cm. All cases had negative resection margins. Single-port intragastric wedge resection by the tunnel method is a feasible and safe approach for treating endophytic gastric SETs.

MicroRNA-128 acts as a suppressor in the progression of gastrointestinal stromal tumor by targeting B-lymphoma Mo-MLV insertion region 1.

The critical role of microRNA-128 (miR-128) in gastrointestinal-related diseases has been documented. In the current study, we tried to clarify the specific role miR-128 in gastrointestinal stromal tumor (GIST) and the underlying mechanism. Differentially expressed genes in GIST were identified following bioinformatics analysis. Then, expression patterns of miR-128 and B-lymphoma Mo-MLV insertion region 1 (BMI-1) in clinical tissue samples and cell lines were characterized, followed by validation of their correlation. GIST-T1 cells were selected and transfected with different mimic, inhibitor, or siRNA plasmids, after which the biological functions were assayed. We identified low miR-128 and high BMI-1 expression in GIST tissues of 78 patients and 4 GIST cell lines. Ectopic expression of miR-128 or silencing of BMI-1 suppressed the malignant potentials of GIST-T1 cells. As a target of miR-128, BMI-1 re-expression could partly counteract the suppressive effect of miR-128 on the malignancy of GIST-T1 cells. Our study provided evidence that miR-128-mediated silencing of BMI-1 could prevent malignant progression of GIST, highlighting a promising anti-tumor target for combating GIST.

Molecular features of gastrointestinal stromal tumors “wild-type” (&lt;i&gt;KIT/PDGFRA&lt;/i&gt; WT)

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract. Their main features are the expression of CD117 (KIT) and mutations of KIT or PDGFRA in 85 % of patients. however, 10–15 % of adult GIST and 85 % of pediatric GIST do not have KIT/PDGFRA mutations (KIT/PDGFRA WT GIST or “wild-type” GIST). The prognosis and clinical course of these tumors and GIST with KIT/PDGFRA mutations differ. “Wild-type” GIST are quite heterogeneous group of tumors in terms of clinical phenotype, genetic etiology, and molecular pathways. Gastrointestinal stromal tumors are divided into SDH-deficient and SDH-competent based on the succinate dehydrogenase (SDH) complex. SDH-deficient GIST occur predominantly in children and young patients with Carney–Stratakis syndrome and Carney triad; there are also sporadic tumors. More than half of SDH-deficient GIST contain mutations in SDHA, SDHB, SDHD or SDHC, while the rest are caused by hypermethylation of the SDHC promoter. SDH-competent “wild-type” GIST include tumors with BRAF, RAS, or NF1 mutations that activate the RAS-RAF-MAPK pathway and KIT/PDGFRA/SDH/RAS-P WT GIST subtype or “quadruple wild type” GIST. The genomic profiles of these tumors and GIST with KIT/PDGFRA mutation or SDH deficiency differ significantly. One of the features of “quadruple wild type” GIST is activation of the FGFR (fibroblast growth factor receptors) signaling pathway due to chimeric FGFR, FGFR mutations, or overexpression of FGF (fibroblast growth factor). Another feature is chimeric genes containing fragments of NTRK, BRAF, FGFR and other genes that behave as oncogene drivers. In “quadruple wild-type” GIST the somatic mutations in TP53, MAX, MEN1, CTNND2, CHD4, ARIDIA and other genes were revealed as well as in the cell cycle genes RB1, CDK4, CDKN1B. There is no specific treatment for patients with “wild-type” GIST; the choice of drug is determined by the genetic disorder. There is a need to improve our understanding of the molecular mechanisms underlying the different GIST subtypes to develop more effective therapeutic approaches.

Multifocal gastrointestinal stromal tumor with osseous metaplasia: a case report

BackgroundGastrointestinal stromal tumor is considered the most common mesenchymal neoplasm of the gastrointestinal tract. The majority of gastrointestinal stromal tumor cases are located in the stomach and usually affects older adults. Most of gastrointestinal stromal tumor cases are sporadic; however, few have a syndromic association, including Carney triad, Carney–Stratakis syndrome, familial gastrointestinal stromal tumor syndrome, and neurofibromatosis type 1.Case presentationHerein, we report a rare case of a 54-year-old Middle-Eastern female with multifocal gastrointestinal stromal tumor mixed type (epithelioid and spindle cell type) with osseous metaplasia. Fluoresce in situ hybridization analysis of platelet-derived growth factor receptor alpha revealed deletion in 42% of the tumor cells studied. Interestingly, next generation sequencing revealed platelet-derived growth factor receptor alpha exon 12 mutation (p.Y555C) and exon 14 mutation (p.N659Y).ConclusionsIn conclusion, osseous metaplasia in GIST is a very rare event and only few cases are reported in the literature. The number of reported cases is inadequate to confirm the pathogenesis and the prognosis.

The efficacy of full-thickness endoscopic resection of subepithelial tumors in the gastric cardia.

Gastric subepithelial tumors (SETs) may harbor potential malignancy. Although it is well recognized that large SETs should be resected, the precise treatment strategy remains controversial. Compared to surgical resection, endoscopic resection (ER) has many advantages; however, ER of SETs in the cardia is challenging. To evaluate the safety and efficacy of endoscopic full-thickness resection (EFTR) for the treatment of gastric cardia SETs. We retrospectively reviewed data from all patients with SETs originating from the muscularis propria layer in the gastric cardia that were treated by EFTR or submucosal tunneling ER (STER) at Zhongshan Hospital Fudan University between November 2014 and May 2022. Baseline characteristics and clinical outcomes, including procedure times and complications rates, were compared between groups of patients receiving EFTR and STER. A total of 171 tumors were successfully removed [71 (41.5%) tumors in the EFTR and 100 (58.5%) tumors in the STER group]. Gastrointestinal stromal tumors (GISTs) were the most common SET. The en bloc resection rate was 100% in the EFTR group vs 97.0% in STER group (P > 0.05). Overall, the EFTR group had a higher complete resection rate than the STER group (98.6% vs 91.0%, P < 0.05). The procedure time was also shorter in the EFTR group (44.63 ± 28.66 min vs 53.36 ± 27.34, P < 0.05). The most common major complication in both groups was electrocoagulation syndrome. There was no significant difference in total complications between the two groups (21.1% vs 22.0%, P = 0.89). EFTR of gastric cardia SETs is a very promising method to facilitate complete resection with similar complications and reduced operative times compared to STER. In cases of suspected GISTs or an unclear diagnosis, EFTR should be recommended to ensure complete resection.

Capsule endoscopy in the diagnosis of exophytic gastrointestinal stromal tumor of the small intestine

The frequency of gastrointestinal stromal tumors (GISTs) is 0.1–0.3% of all neoplasms in the gastrointestinal tract. The most common clinical feature of GISTs is gastrointestinal bleeding caused by ulceration of the tumor. Based on a clinical case, the eff ectiveness of capsule endoscopy in diagnosing GISTs is demonstrated.

Bioequivalence/bioavailability study of a new formulation of imatinib mesylate 100 mg coated tablets versus Glivec® in Brazilian healthy male volunteers in fed state

Introduction: Imatinib mesylate is currently the first-line oral treatment for all stages of chronic myeloid leukemia (CML) and is also used in some cases of gastrointestinal stromal tumor (GIST) and acute lymphoblastic leukemia (ALL). Objective: Investigate the bioavailability of two products containing imatinib mesylate, 100 mg coated tablet, to determine if they are bioequivalent. Method:The study was conducted using an open-label, randomized, balanced design and the formulations were administered orally in a single dose to 48 healthy adult males, in fed state, followed by sequential blood withdraws for the next 72 hours. Forty-eight male healthy volunteers were selected to participate in the study. Test formulation from Eurofarma Laboratórios S.A. Brazil was compared to that from Novartis Biociências S.A. The comparative bioavailability of the formulations was assessed based on statistical comparisons of relevant pharmacokinetic parameters obtained from drug concentration data from collected blood samples measured using an analytical method based on high-performance liquid chromatography coupled to mass spectrometry. Results: The ratio of the geometric means between the test and the reference, with a 90% confidence interval, of pharmacokinetic parameters for Cmax was 102.26% (94.17-111.04%) and for AUC0-t was 101.24% (95.19-107.68%). Conclusion: Imatinib mesylate 100 mg (test product) from Eurofarma Laboratórios S.A. was considered bioequivalent to the reference Glivec® 100 mg manufactured by Novartis Biociências S.A, and the test product can be interchangeable with the reference, based on their pharmacokinetic performance.