Gastrointestinal stromal tumor of unusual phenotype after imatinib treatment: A case report and diagnostic utility of ETV1 mRNA in situ hybridization

Advances in the diagnosis and treatment of MET-variant digestive tract tumors

The receptor tyrosine kinase encoded by the MET gene plays an important role in various cellular processes such as growth, survival, migration and angiogenesis, and its abnormal activation is closely related to the occurrence and development of various tumors. This article reviews the recent advances in diagnosis and treatment of MET-variant digestive tract tumors. In terms of diagnosis, the application of next-generation sequencing technology and liquid biopsy technology makes the detection of MET variants more accurate and efficient, providing a reliable basis for individualized treatment. In terms of treatment, MET inhibitors such as crizotinib and cabotinib have shown good efficacy in clinical trials. In addition, the combination of immunotherapy and MET inhibitors also demonstrated potential synergies, further improving the therapeutic effect. However, the complexity and heterogeneity of drug resistance mechanisms are still one of the difficulties in current research. In the future, it is necessary to further deepen the understanding of the mechanism of MET variation and explore new combination treatment strategies to improve the overall survival rate and quality of life of patients. The diagnosis and treatment of MET-variant digestive tract tumors are moving towards precision and individualization, and have broad application prospects.

Prognostic value of PEA3 subfamily gene expression in cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma (CCA) is a lethal malignancy with limited treatment options and poor prognosis. The PEA3 subfamily of E26 transformation specific genes: ETV1, ETV4, and ETV5 are known to play significant roles in various cancers by influencing cell proliferation, invasion, and metastasis.

AIM

To analyze PEA3 subfamily gene expression levels in CCA and their correlation with clinical parameters to determine their prognostic value for CCA.

METHODS

The expression levels of PEA3 subfamily genes in pan-cancer and CCA data in the cancer genome atlas and genotype-tissue expression project databases were analyzed with R language software. Survival curve and receiver operating characteristic analyses were performed using the SurvMiner, Survival, and Procr language packages. The gene expression profiling interactive analysis 2.0 database was used to analyze the expression levels of PEA3 subfamily genes in different subtypes and stages of CCA. Web Gestalt was used to perform the gene ontology/ Kyoto encyclopedia of genes and genomes (GO/KEGG) analysis, and STRING database analysis was used to determine the genes and proteins related to PEA3 subfamily genes.

RESULTS

ETV1, ETV4, and ETV5 expression levels were significantly increased in CCA. There were significant differences in ETV1, ETV4, and ETV5 expression levels among the different subtypes of CCA, and predictive analysis revealed that only high ETV1 and ETV4 expression levels were significantly associated with shorter overall survival in patients with CCA. GO/KEGG analysis revealed that PEA3 subfamily genes were closely related to transcriptional misregulation in cancer. In vitro and in vivo experiments revealed that PEA3 silencing inhibited the invasion and metastasis of CCA cells.

CONCLUSION

The expression level of ETV4 may be a predictive biomarker of survival in patients with CCA.

Development and characterization of an ETV1 rabbit monoclonal antibody for the immunohistochemical detection of ETV1 expression in cancer tissue specimens

BACKGROUND

Aberrant ETV1 overexpression arising from gene rearrangements or mutations occur frequently in prostate cancer, round cell sarcomas, gastrointestinal stromal tumors, gliomas, and other malignancies. The absence of specific monoclonal antibodies (mAb) has limited its detection and our understanding of its oncogenic function.

METHODS

An ETV1 specific rabbit mAb (29E4) was raised using an immunogenic peptide. Key residues essential for its binding were probed by ELISA and its binding kinetics were measured by surface plasmon resonance imaging (SPRi). Its selective binding to ETV1 was assessed by immunoblots and immunofluorescence assays (IFA), and by both single and double-immuno-histochemistry (IHC) assays on prostate cancer tissue specimens.

RESULTS

Immunoblot results showed that the mAb is highly specific and lacked cross-reactivity with other ETS factors. A minimal epitope with two phenylalanine residues at its core was found to be required for effective mAb binding. SPRi measurements revealed an equilibrium dissociation constant in the picomolar range, confirming its high affinity. ETV1 (+) tumors were detected in prostate cancer tissue microarray cases evaluated. IHC staining of whole-mounted sections revealed glands with a mosaic staining pattern of cells that are partly ETV1 (+) and interspersed with ETV1 (-) cells. Duplex IHC, using ETV1 and ERG mAbs, detected collision tumors containing glands with distinct ETV1 (+) and ERG (+) cells.

CONCLUSIONS

The selective detection of ETV1 by the 29E4 mAb in immunoblots, IFA, and IHC assays using human prostate tissue specimens reveals a potential utility for the diagnosis, the prognosis of prostate adenocarcinoma and other cancers, and the stratification of patients for treatment by ETV1 inhibitors.

A case report of gastrointestinal stromal tumor of the duodenum

INTRODUCTION

Gastrointestinal stromal tumors (GISTs) rarely occur in the duodenum, and only a few cases have been reported. Its clinical manifestations are not specific, and the imaging examination results are not typical, so a preoperative diagnosis is difficult. Pathologic examinations and genetic testing after surgical resection are the main diagnostic methods. Here, a case of duodenal stromal tumor complicated by gastrointestinal perforation is reported. A 57-year-old man presented with paroxysmal abdominal pain and bloating for 7 days. Contrast-enhanced computed tomography of the abdomen revealed a large mass (10 cm in diameter) in the right upper abdomen, which was considered neoplastic. The mass was anterior and inferior to the head of the pancreas, and medial to the mesenteric vessels. The tumor surrounded the descending and horizontal parts of the duodenum, and it ruptured into the lumen of the descending duodenum. After the patient underwent tumor resection, we found a rupture of the descending duodenal opening. After that, duodenal fistula drainage, gastrostomy, jejunostomy, small intestinal adhesion release and abdominal irrigation drainage were performed. Immunohistochemical staining results were as follows: CD34 (-), desmin (-), S-100 (-), CD117 (9.7) (+), DoG-1 (+), SDHB (+), Ki-67 (+5%). Based on these results, the lesion was finally diagnosed as duodenal GIST. The patient underwent surgical resection without targeted therapy and recovered well.

DISCUSSION

Duodenal stromal tumors often present with gastrointestinal bleeding and other clinical symptoms, requiring urgent surgery. Complete resection of the tumor is an effective surgical method. Extended resection does not prolong survival. However, surgical treatment should be determined according to the size and location of the tumor and its relationship to the pancreas. This highly malignant duodenal stromal tumor was >10 cm, accompanied by gastrointestinal perforation and necrosis. Surgical resection was required while protecting the organ function.

Gastrointestinal Stromal Tumor With Chondrosarcomatous Dedifferentiation Following Imatinib Therapy

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the digestive tract, followed by schwannomas, lipomas, leiomyomas, and vascular tumors. They arise more often in the stomach, followed by the small bowel, esophagus, and rectum. Imatinib mesylate, a tyrosine kinase inhibitor with activity against ABL, BCR-ABL, platelet-derived growth factor receptor-alpha (PDGFRA), and c-KIT (CD117), constitutes the cornerstone of treatment for inoperable or metastatic GIST. Cases showing disease progression or resistance to imatinib mesylate may retain their morphology or present unusual morphologic and immunohistochemical characteristics.

We herein describe a case of a 67-year-old patient with a previous history of GIST of the stomach, with local recurrence, who was admitted with a workup of lung nodule on chest computed tomography as part of the routine follow-up. The nodule was resected which showed a malignant tumor composedof epithelioid cells, with an abrupt transition to chondrosarcoma. Epithelioid cells were immunostained for CD117, DOG1, and Vimentin, whereas chondrosarcomatous cells expressed only Vimentin. These findings were consistent with metachronous pulmonary metastasis of the previously diagnosed GIST with chondrosarcomatous dedifferentiation. No KIT or PDGFRA mutation was detected. A review of all accessible pertinent papers disclosed 26 similar cases with unusual morphological and immunohistochemical findings, either post-imatinib treatment or, less commonly, de novo, with heterogeneous differentiation.

Awareness of the histological and immunohistochemical changes in GISTs post imatinib therapy is essential to avoid a severe diagnostic pitfall.

Neoadjuvant chemotherapy combined with laparoscopic surgery for treatment of advanced gastric cancer: Efficacy and impact on quality of life

AIM

To investigate the clinical effect of neoadjuvant chemotherapy combined with laparoscopic-assisted radical gastrectomy in treating advanced gastric cancer and the effect on the quality of life of patients.

METHODS

A retrospective analysis was performed of 104 cases of advanced gastric cancer admitted from February 2014 to November 2016 at Taizhou Hospital. According to whether the patients would like to undergo neoadjuvant chemotherapy or not, they were divided into an observation group (neoadjuvant chemotherapy plus laparoscopic surgery; n = 56) or a control group (direct laparoscopic-assisted radical gastrectomy; n = 48). Both groups were given six courses of XELOX chemotherapy after operation. Clinical efficacy, operation indexes, postoperative recovery, quality of life, adverse reactions, and recurrence or metastasis were compared between the two groups.

RESULTS

After neoadjuvant chemotherapy, the effective rate and disease control rate in the observation group were 48.21% and 92.45%, respectively. There was no significant difference in operative time, intraoperative blood loss, number of cases of conversion to open laparotomy, surgical excision range, number of cases of palliative surgery, or number of lymph nodes dissected between the two groups (P > 0.05). The R₀ resection rate in the observation group was significantly higher than that of the control group (85.71% vs 52.08%, P < 0.05). There was no significant difference in time to ambulation, time to anal exhaust, postoperative complications, or hospital stay between the two groups (P > 0.05). The KPS scores of the observation group at 3 and 6 months after chemotherapy were significantly higher than those of the control group (82.8 ± 6.9 vs 76.2 ± 5.1, 91.6 ± 8.1 vs 85.2 ± 7.3, P < 0.05). As of December 2017, the follow-up period ranged from 9 to 46 mo, and the median follow-up time was 24 mo. During the follow-up period, four patients died and ten patients developed recurrence or metastasis in the observation group. In the control group, 11 patients died and 19 developed recurrence or metastasis. There was a significant difference in the rates of death and recurrence/metastasis between the two groups (χ² = 5.210, 6.067, P < 0.05). Log-rank test analysis showed that the risk of death in the observation group was significantly lower than that of the control group (P < 0.05).

CONCLUSION

Neoadjuvant chemotherapy combined with laparoscopic radical gastrectomy for advanced gastric cancer has significant curative effects and can significantly improve the resection rate and quality of life, reduce recurrence and metastasis, and improve the survival of patients.