Objective: To analyze the clinicopathological features and gene mutations of primary gastrointestinal stromal tumors (GISTs) of the stomach and intestine and the prognosis of intermediate- and high-risk GISTs. Methods: This was a retrospective cohort study. Data of patients with GISTs admitted to Tianjin Medical University Cancer Institute and Hospital from January 2011 to December 2019 were collected retrospectively. Patients with primary gastric or intestinal disease who had undergone endoscopic or surgical resection of the primary lesion and were confirmed pathologically as GIST were included. Patients treated with targeted therapy preoperatively were excluded. The above criteria were met by 1061 patients with primary GISTs, 794 of whom had gastric GISTs and 267 intestinal GISTs. Genetic testing had been performed in 360 of these patients since implementation of Sanger sequencing in our hospital in October 2014. Gene mutations in KIT exons 9, 11, 13, and 17 and PDGFRA exons 12 and 18 were detected by Sanger sequencing. The factors investigated in this study included: (1) clinicopathological data, such as sex, age, primary tumor location, maximum tumor diameter, histological type, mitotic index (/5 mm²), and risk classification; (2) gene mutation; (3) follow-up, survival, and postoperative treatment; and (4) prognostic factors of progression-free survival (PFS) and overall survival (OS) for intermediate- and high-risk GIST. Results: (1) Clinicopathological features: The median ages of patients with primary gastric and intestinal GIST were 61 (8-85) years and 60 (26-80) years, respectively; The median maximum tumor diameters were 4.0 (0.3-32.0) cm and 6.0 (0.3-35.0) cm, respectively; The median mitotic indexes were 3 (0-113)/5 mm² and 3 (0-50)/5 mm², respectively; The median Ki-67 proliferation indexes were 5% (1%-80%) and 5% (1%-50%), respectively. The rates of positivity for CD117, DOG-1, and CD34 were 99.7% (792/794), 99.9% (731/732), 95.6% (753/788), and 100.0% (267/267), 100.0% (238/238), 61.5% (163/265), respectively. There were higher proportions of male patients (χ²=6.390, P=0.011), tumors of maximum diameter > 5.0 cm (χ²=33.593, P<0.001), high-risk (χ²=94.957, P<0.001), and CD34-negativity (χ²=203.138, P<0.001) among patients with intestinal GISTs than among those with gastric GISTs. (2) Gene mutations: Gene mutations were investigated in 286/360 patients (79.4%) with primary gastric GISTs and 74/360 (20.6%) with primary intestinal GISTs. Among the 286 patients with gastric primary GISTs, 79.4% (227/286), 8.4% (24/286), and 12.2% (35/286), had KIT mutations, PDGFRA mutations, and wild-type, respectively. Among the 74 patients with primary intestinal GISTs, 85.1% (63/74) had KIT mutations and 14.9% (11/74) were wild-type. The PDGFRA mutation rate was lower in patients with intestinal GISTs than in those with gastric GISTs[ 0% vs. 8.4%(24/286), χ²=6.770, P=0.034], whereas KIT exon 9 mutations occurred more often in those with intestinal GISTs [22.2% (14/63) vs. 1.8% (4/227), P<0.001]. There were no significant differences between gastric and intestinal GISTs in the rates of KIT exon 11 mutation type and KIT exon 11 deletion mutation type (both P>0.05). (3) Follow-up, survival, and postoperative treatment: After excluding 228 patients with synchronous and metachronous other malignant tumors, the remaining 833 patients were followed up for 6-124 (median 53) months with a follow-up rate of 88.6% (738/833). None of the patients with very low or low-risk gastric (n=239) or intestinal GISTs (n=56) had received targeted therapy postoperatively. Among 179 patients with moderate-risk GISTs, postoperative targeted therapy had been administered to 88/155 with gastric and 11/24 with intestinal GISTs. Among 264 patients with high-risk GISTs, postoperative targeted therapy had been administered to 106/153 with gastric and 62/111 with intestinal GISTs. The 3-, 5-, and 10-year PFS of patients with gastric or intestinal GISTs were 96.5%, 93.8%, and 87.6% and 85.7%, 80.1% and 63.3%, respectively (P<0.001). The 3-, 5-, and 10-year OS were 99.2%, 98.8%, 97.5% and 94.8%, 92.1%, 85.0%, respectively (P<0.001). (4) Analysis of predictors of intermediate- and high-risk GISTs: The 5-year PFS of patients with gastric and intestinal GISTs were 89.5% and 73.2%, respectively (P<0.001); The 5-year OS were 97.9% and 89.3%, respectively (P<0.001). Multivariate analysis showed that high risk (HR=2.918, 95%CI: 1.076-7.911, P=0.035) and Ki-67 proliferation index > 5% (HR=2.778, 95%CI: 1.389-5.558, P=0.004) were independent risk factors for PFS in patients with intermediate- and high-risk GISTs (both P<0.05). Intestinal GISTs (HR=3.485, 95%CI: 1.407-8.634, P=0.007) and high risk (HR=3.753,95%CI:1.079-13.056, P=0.038) were independent risk factors for OS in patients with intermediate- and high-risk GISTs (both P<0.05). Postoperative targeted therapy was independent protective factor for PFS and OS (HR=0.103, 95%CI: 0.049-0.213, P<0.001; HR=0.210, 95%CI:0.078-0.564,P=0.002). Conclusions: Primary intestinal GIST behaves more aggressively than gastric GISTs and more frequently progress after surgery. Moreover, CD34 negativity and KIT exon 9 mutations occur more frequently in patients with intestinal GISTs than in those with gastric GISTs.
Male ; Humans ; Gastrointestinal Stromal Tumors/surgery* ; Retrospective Studies ; Ki-67 Antigen ; Stomach Neoplasms/pathology* ; Prognosis ; Mutation ; Intestines/pathology* ; Proto-Oncogene Proteins c-kit/genetics* ; Receptor, Platelet-Derived Growth Factor alpha/genetics*

Eosinophilia/genetics* ; Gene Rearrangement ; Humans ; Myeloproliferative Disorders/genetics* ; Neoplasms ; Oncogene Proteins, Fusion/genetics* ; Receptor, Platelet-Derived Growth Factor alpha/genetics*

Objective: To investigate the clinicopathological features of gastrointestinal stromal tumor (GIST) with KIT/PDGFRA "homozygous mutation", the efficacy of targeted therapy and the prognosis. Methods: A retrospective cohort study and propensity score matching were used. "Homozygous mutation" was defined as the detection of KIT/PDGFRA gene status of GIST by Sanger sequencing, which showed that there was only mutant gene sequence in the sequencing map, lack of wild-type sequence or the peak height of mutant gene sequence was much higher than that of wild-type gene sequence (> 3 times). "Heterozygous mutation" was defined as the mutant gene sequences coexisted with wild type gene sequences, and the peak height was similar (3 times or less). The clinicopathological data and follow-up information of 92 GIST patients with KIT/PDGFRA "homozygous mutation" were collected from 4 hospitals in Shanghai from January 2008 to May 2021 (Renji Hospital, Shanghai Jiaotong University School of Medicine: 70 cases; Zhongshan Hospital, Fudan University: 14 cases; Changhai Hospital, Naval Military Medical University: 6 cases and Ruijin Hospital, Shanghai Jiaotong University School of Medicine: 2 cases). Patients with perioperative death, other malignancies, and incomplete clinicopathological information were excluded. The clinicopathological features of the patients and the efficacy of targeted drug therapy were observed and analyzed. The efficacy was evaluated using Choi criteria, which were divided into complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD). In addition, a total of 230 patients with high-risk GIST with "heterozygous mutation" in exon 11 of KIT gene and 117 patients with recurrent or metastatic GIST with "heterozygous mutation" in exon 11 of KIT gene were included. The propensity score matching method was used to match GIST patients with "heterozygous" and "homozygous" mutations in exon 11 of KIT gene (1∶1) for survival analysis. The disease-free survival (DFS) between two groups of high-risk GIST patients who underwent complete surgical resection were compared. And progression-free survival (PFS) in patients with recurrent or metastatic GIST were compared. Results: Of the 92 GIST cases with KIT/PDGFRA "homozygous mutation", 58 were males and 34 were females, with a median onset age of 62 (31-91) years. Primary GIST 83 cases. Primary high-risk GIST (53 cases), metastatic GIST (21 cases) and recurrent GIST (9 cases) accounted for 90.2% (83/92). There were 90 cases of KIT gene"homozygous mutation" (exon 11 for 88 cases, exon 13 for 1 case, exon 17 for 1 case), and 2 cases of PDGFRA gene "homozygous mutation" (exon 12 for 1 case, exon 18 for 1 case). The median follow-up time was 49 (8-181) months. Among the 61 cases of primary localized GIST undergoing complete surgical resection, 2 cases were intermediate-risk GIST, 5 cases were low-risk GIST, and 1 case was very low-risk GIST, of whom 1 case of intermediate-risk GIST received 1-year adjuvant imatinib mesylate (IM) therapy after operation, and no tumor recurrence developed during the follow-up period. The remaining 53 cases were high-risk GIST, and follow-up data were obtained from 50 cases, of whom 22 developed tumor recurrence during follow-up. Of 9 patients directly receiving neoadjuvant targeted therapy (IM or avapritinib), 5 had complete imaging follow-up data, and the evaluation of efficacy achieved PR. Of all the 92 GIST cases with KIT/PDGFRA "homozygous mutation", 50 (54.4%) had tumor metastasis or tumor recurrence or progression during follow-up, and 12 (13.0%) died of the tumor. Survival analysis combined with propensity score showed that in 100 cases of high-risk GISTs with complete resection, GISTs with "homozygous mutation" in exon 11 of KIT gene had shorter disease-free survival (DFS) than GISTs with "heterozygous mutation" in exon 11 of KIT gene (median DFS: 72 months vs. 148 months, P=0.015). In 60 cases of recurrent or metastatic GISTs with KIT gene exon 11 mutation, IM was used as the first-line treatment, and the progression-free survival (PFS) of GISTs with "homozygous mutation" was shorter compared to GISTs with "heterozygous mutation" (median PFS: 38 months vs. 69 months, P=0.044). The differences were statistically significant. Conclusions: "Homozygous mutation" in KIT/PDGFRA gene is associated with the progression of GIST. The corresponding targeted therapeutic drugs are still effective for GIST with KIT/PDGFRA gene "homozygous mutation". Compared with GIST patients with "heterozygous mutation" in KIT exon 11, GIST patients with "homozygous mutation" in KIT exon 11 are more likely to relapse after surgery and to develop resistance to IM. Therefore, it is still necessary to seek more effective treatment methods for this subset of cases.
Aged ; Aged, 80 and over ; Antineoplastic Agents/therapeutic use* ; China ; Female ; Gastrointestinal Stromal Tumors/genetics* ; Humans ; Male ; Middle Aged ; Mutation ; Neoplasm Recurrence, Local ; Prognosis ; Proto-Oncogene Proteins c-kit/genetics* ; Pyrazoles ; Pyrroles ; Receptor, Platelet-Derived Growth Factor alpha/genetics* ; Retrospective Studies ; Triazines

Gastrointestinal stromal tumors(GISTs)are the most common mesenchymal tumors of the gastrointestinal tract and respond poorly to conventional radiochemotherapy.Complete excision is the only possible way to cure GISTs.Although targeted therapy is effective for GISTs,multiple and/or secondary mutations of KIT or PDGFRA gene have lead to increased drug resistance and disease relapse.A variety of tumor infiltrating immune cells and complex immune microenvironments have been found in GISTs.Many immune cells participate in the occurrence and development of GISTs and play key roles in targeted therapy.The feasibility and effectiveness of immunotherapy for GISTs have been well demonstrated in preclinical and clinical studies.
Gastrointestinal Stromal Tumors ; immunology ; therapy ; Humans ; Immunotherapy ; Mutation ; Proto-Oncogene Proteins c-kit ; genetics ; Receptor, Platelet-Derived Growth Factor alpha ; genetics ; Tumor Microenvironment

OBJECTIVE: To investigate the biological behavior characteristics of gastrointestinal stromal tumors (GIST) with PDGFRA mutation and the patients' survival, and elucidate the efficacy of imatinib therapy. METHODS: Patients with PDGFRA D842V and non-D842V mutations were screened from a database of 1163 patients with GIST who were treated at Peking University Cancer Hospital from 2003 to 2018. Clinicopathological data of these patients were collected, including gender, age, tumor size, mitotic phase, primary position, metastatic site, and expressions of CD117, CD34, DOG-1. The association of gene mutations with biological behavior of GIST, prognosis of patients, and efficacy of imatinib therapy was examined. Fisher's exact test was used to compare the clinical characteristics of the two groups. Kaplan-Meier method was used to analyze overall survival and recurrence-free survival. RESULTS: A total of 27 patients with PDGFRA mutations were screened, among whom the D842V mutation was 1.6%(19/1 163), and the rate of non-D842V mutation was 0.7%(8/1 163). There were 11 male patients and 8 female patients of D842V mutation with male to female ratio of 1.38:1 and median age of 56 (35-72) years. There were 4 male patients and 4 female patients of non-D842V mutations with male to female ratio of 1:1 and median age of 51.5 (34-82) years. The primary lesions of D824V mutation were located in stomach for 18 cases and in parenteral area for 1 case. The primary lesions of non-D842V mutation were located in stomach for 6 cases, in jejunoileum for 1 case and in colorectum for 1 case. The proportion of nuclear fission <5/50 HPF in PDGFRA mutation GIST was 17/27. Among D842V mutation patients, mitotic phase <5/50 HPF accounted for 11/19, mitotic phase >10/50 HPF accounted for 3/19, and 5-10/50 HPF accounted for 5/19. Among non-D842V mutation patients, mitotic phase <5/50 HPF accounted for 6/8, 5-10/50 HPF accounted for 2/8. Of D842V mutation patients, positive CD117 was found in 15 cases(15/19); positive DOG-1 was found in 15 cases(15/19); positive CD34 was found in 16/17 cases. Among patients with non-D842V mutation, 7 patients were positive for CD117(7/8); only 5 patients were tested for CD34, and all 5 patients were positive(5/5); only 3 patients were tested for DOG-1, and all 3 cases were positive (3/3). The 3-year recurrence-free survival rate after radical resection in D842V mutation patients was 51.9%, and that in non-D842V mutation patients was 62.5% without significant difference(P=0.380). Recurrence-free rate did not decreased in patients with D842V mutation after adjuvant imatinib treatment and the benefit rate of first-line treatment with imatinib in patients with advanced disease was zero. CONCLUSIONS The PDGFRA gene mutation rate is low, mostly derived from gastric GIST. D842V and non-D842V mutations present inert biological behavior. D842V mutation GIST is resistant to imatinib, and non-D842V mutation GIST can obtain benefit from imatinib treatment.
Adult ; Aged ; Aged, 80 and over ; Drug Resistance, Neoplasm ; genetics ; Female ; Gastrointestinal Stromal Tumors ; drug therapy ; genetics ; Humans ; Imatinib Mesylate ; therapeutic use ; Male ; Middle Aged ; Mutation ; genetics ; Neoplasm Recurrence, Local ; genetics ; Prognosis ; Proto-Oncogene Proteins c-kit ; genetics ; Receptor, Platelet-Derived Growth Factor alpha ; genetics

OBJECTIVETodelineate the clinical and genetic features of a patient with myeloproliferative neoplasm (MPN) in association with PDGFRA and EVI1 genes rearrangements.

METHODSClinical data of the patient was collected. Conventional cytogenetics, fluorescence in situ hybridization (FISH) and nested PCR were carried out for the patient.

RESULTSThe patient has featured recurrent rash, joint pain, and intermittent fever. Laboratory tests showed hyperleukocytosis and marked eosinophilia. Physical examination revealed splenomegaly. His karyotype was 46,XY,t(3;5)(q26;q15)[6]/46,XY[10]. FISH assay showed that both PDGFRA and EVI1 genes were rearranged. Molecular studies of the mRNA suggested that there was a in-frame fusion between exon 12 of the PDGFRA gene and exon 9 of the FIP1L1 gene. Imatinib was initiated at a dosage of 200 mg, and after 10 months, the signal of the FIP1L1-PDGFRA fusion gene was undetectable in bone marrow sample. However, the expression of EVI1 mRNA was stable, with no significant difference found between the patient and 10 healthy controls.

CONCLUSIONMPN in association with PDGFRA and EVI1 genes rearrangements have unique clinical and genetic features. Genetic testing is helpful for early diagnosis. Imatinib may be effective for the treatment.

Antineoplastic Agents ; therapeutic use ; Base Sequence ; Chromosome Banding ; Chromosomes, Human, Pair 3 ; genetics ; Chromosomes, Human, Pair 5 ; genetics ; DNA-Binding Proteins ; genetics ; Gene Rearrangement ; Humans ; Imatinib Mesylate ; therapeutic use ; In Situ Hybridization, Fluorescence ; Karyotyping ; MDS1 and EVI1 Complex Locus Protein ; Male ; Myeloproliferative Disorders ; drug therapy ; genetics ; Proto-Oncogenes ; genetics ; Receptor, Platelet-Derived Growth Factor alpha ; genetics ; Transcription Factors ; genetics ; Translocation, Genetic ; Treatment Outcome ; Young Adult

BACKGROUNDSystemic lupus erythematosus (SLE) is a prototypic autoimmune disease with complex genetic inheritance. This study was conducted to examine whether the association of a proliferation-inducing ligand (APRIL), spermatogenesis associated 8 (SPATA8), platelet-derived growth factor receptor-alpha (PDGFRA), and DNA polymerase beta (POLB) with SLE can be replicated in a Chinese Han population.

METHODSChinese SLE patients (n = 1247) and ethnically and geographically matched healthy controls (n = 1440) were genotyped for the APRIL, SPATA8, PDGFRA, and POLB single-nucleotide polymorphisms (SNPs), rs3803800, rs8023715, rs1364989, and rs12678588 using the Sequenom MassARRAY System.

RESULTSThe Chinese Han SLE patients and controls had statistically similar frequencies of alleles and genotypes of four gene polymorphisms. Moreover, no association signal was detected on different genetic models (additive, dominant, and recessive, all, P> 0.05) or in SLE subgroups stratified by various clinical manifestations (all, P> 0.05).

CONCLUSIONSDifferent genetic backgrounds from different ancestries and various populations may result in different genetic risk factors for SLE. We did not detect any significant association with SNPs of APRIL, SPATA8, PDGFRA, and POLB.

Adult ; Alleles ; Asian Continental Ancestry Group ; DNA Polymerase II ; genetics ; Female ; Genetic Predisposition to Disease ; genetics ; Genotype ; Humans ; Intracellular Signaling Peptides and Proteins ; genetics ; Lupus Erythematosus, Systemic ; genetics ; Male ; Middle Aged ; Polymorphism, Single Nucleotide ; genetics ; Receptor, Platelet-Derived Growth Factor alpha ; genetics ; Tumor Necrosis Factor Ligand Superfamily Member 13 ; genetics ; Young Adult

Gastrointestinal stromal tumors(GIST) are the most common mesenchymal tumors of the gastrointestinal tract. Most of these stromal tumors are characterized by mutations in the KTT or platelet-derived growth factor receptor &alpha; (PDGFRA) genes, resulting in the constitutive activation of tyrosine kinase signaling. Tyrosine kinase inhibitors(TKI), such as imatinib and sunitinib, provide the standard first-line and second-line therapy for patients with metastatic or unresectable GIST. Imatinib resistance has been a challenging problem in clinical practice and raised great concern. This review introduces the underlying mechanisms of imatinib resistance and advances of treatment strategies. Reasonable individual treatment with the guidance of molecular biology is promising to improve the efficacy and the quality of life for GIST patients.
Antineoplastic Agents ; Benzamides ; Disease Progression ; Drug Resistance, Neoplasm ; Gastrointestinal Neoplasms ; genetics ; therapy ; Gastrointestinal Stromal Tumors ; genetics ; therapy ; Humans ; Imatinib Mesylate ; Indoles ; Mutation ; Piperazines ; Proto-Oncogene Proteins c-kit ; Pyrimidines ; Pyrroles ; Quality of Life ; Receptor, Platelet-Derived Growth Factor alpha

This study was aimed to investigate the abnormal expression of PDGFRA gene in eosinophilia by FISH. Translocations of PDGFRA gene in 13 patients with eosinophilia were detected by using 4q12 three-color probe and FISH technology. Fifteen people were used as control to establish the normal cut-off value of fluorescence signal of PDGFRA. The results indicated that 1 out of 13 patients with eosinophilia was corrected and was diagnosed as CML. The fusion gene of FIP1L1-PDGFRA (F/P) was found in 2 patients and the positive rate of F/P fusion gene detected by probe 4q12 was 17% in the 12 patients with eosinophilia. Other translocation forms involving PDGFRA gene were not found. It is concluded that a variety of translocation forms of PDGFRA gene can be detected in patients with eosinophilia by using 4q12 three-color probe and FISH technology, which can provide important information for assessing diagnosis and treatment.
Chromosomes, Human, Pair 4 ; Eosinophilia ; metabolism ; Humans ; In Situ Hybridization, Fluorescence ; Oncogene Proteins, Fusion ; Receptor, Platelet-Derived Growth Factor alpha ; genetics ; Translocation, Genetic

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm of the GI tract. Aberrant activation of tyrosine kinase through mutated KIT or platelet-derived growth factor receptor (PDGFRA) is the key pathogenic factor in most cases. Tyrosine kinase inhibitors (TKI) such as imatinib and sunitinib can suppress activation of tyrosine kinase receptor and has gained wide recognition as the first-line adjuvant therapy for advanced or high-risk GIST after surgery. It has become the classic model of treatment for solid tumor with molecular targeted therapy. However, the emergence of drug-resistance limits the long-term benefit of these drugs in most patients and has been a challenging clinical concern. Many factors are related to the resistance of TKI, of which KIT/PDGFRA mutation is the most important one. Genetic amplification of KIT, loss of heterozygosity, activation of an alternative downstream signaling pathways, and drug concentration are all possible factors. Therefore, reasonable individual treatment strategy and early resistance evaluation for imatinib- and sunitinib-resistant GISTs are important to patients with drug resistance in order to improve therapeutic efficacy and quality of life.
Antineoplastic Agents ; therapeutic use ; Benzamides ; therapeutic use ; Drug Resistance, Neoplasm ; genetics ; Gastrointestinal Neoplasms ; drug therapy ; genetics ; Gastrointestinal Stromal Tumors ; drug therapy ; genetics ; Humans ; Imatinib Mesylate ; Indoles ; therapeutic use ; Mutation ; Piperazines ; therapeutic use ; Protein Kinase Inhibitors ; therapeutic use ; Proto-Oncogene Proteins c-kit ; genetics ; Pyrimidines ; therapeutic use ; Pyrroles ; therapeutic use ; Receptor, Platelet-Derived Growth Factor alpha ; genetics