Differential Expression of CADM1 in Gastrointestinal Stromal Tumors of Different Sites and with Different Gene Abnormalities

Acute Jejunal Diverticulitis Induced by a Malignant Gastrointestinal Neuroectodermal Tumor: A Case Report

Small intestinal diverticula induced by malignant mesenchymal tumors are extremely rare clinical entities. We present the case of a 46-year-old female who reported a one-week history of worsening generalized abdominal pain accompanied by constipation. A computed tomography (CT) scan of her abdomen revealed an ulcerative mass at the proximal/midjejunal junction, suggestive of jejunal diverticulitis. She initially underwent diagnostic laparoscopy, which was converted to an open procedure for resection of the jejunal mass and side-to-side anastomosis. The final histopathological examination revealed features consistent with a gastrointestinal neuroectodermal tumor.

Anti-tumor effect of antibody-drug conjugate targeting cell adhesion molecule 1 on GIST cells representing small intestinal GIST

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the alimentary tract. The prognosis depends on the primary site, and small intestinal GISTs have a worse prognosis than gastric GISTs. Molecularly targeted drugs to inhibit tyrosine kinase activity of KIT were used for unresectable or recurrent GISTs. However, secondary resistance to the drugs is often acquired, and treatments based on other mechanisms are needed. Previously, we reported that cell adhesion molecule 1 (CADM1) was highly expressed in most of small intestinal GISTs but not in most of gastric GISTs. In the present study, we examined whether the antibody-drug conjugate (ADC) with anti-CADM1 antibody and monomethyl auristatin E (anti-CAD-ADC) shows anti-tumor effect on CADM1-expressing human GIST cells. The ADC adhibited in this study was previously used for CADM1-expressing human mesothelioma cells and showed anti-tumor effect for them in vitro. GIST-T1 cell line of gastric origin which scarcely expresses CADM1 and GIST-T1 cells transfected with CADM1 cDNA (GIST-T1-CAD cells) which highly expresses CADM1 and represents small intestinal GIST were used. In vitro, anti-CAD-ADC showed remarkable cytotoxic activity on GIST-T1-CAD cells, but control ADC did not. Both anti-CAD-ADC and control ADC did not show anti-tumor effect on original GIST-T1 cells. When GIST-T1-CAD cells were subcutaneously injected to the nude mice, intravenous administration of anti-CAD-ADC showed inhibitory effect for tumor enlargement. Tumor of GIST-T1 cells grew even after anti-CAD-ADC injection. When GIST-T1-CAD cells were injected into peritoneal cavity of the SCID mice, intraperitoneal administration of anti-CAD-ADC showed reduction of the peritoneal tumor. On the other hand, peritoneal tumor grew after control ADC administration. Tissue and organ damage due to administration of anti-CAD-ADC was not apparent by macroscopic and histological examinations in mice. These results indicate that anti-CAD-ADC could have apparent anti-tumor effect on CADM1-expressing human GIST cells both in in vitro and in vivo mouse models.

Lymph node metastases in young patients with gastrointestinal stromal tumor: A nationwide analysis

BACKGROUND

Children, adolescents, and young adults (CAYA) (age ≤39 years) with GIST have high rates of LNM, but their clinical relevance is undefined. This study analyzed the impact of LNM on overall survival (OS) for CAYA with GIST.

METHODS

The National Cancer Database was queried for patients with resected GIST and pathologic nodal staging data from 2004-2019. Factors associated with LNM were identified. Survival was assessed stratified by presence of LNM.

RESULTS

Of 4420 patients with GIST, 238 were CAYA (5.4%). When compared to older adults, CAYA more often had small intestine primaries (51.8% vs. 36.6%, p < 0.0001), T4 tumors (30.7% vs. 24.5%, p = 0.0275) and pN1 disease (11.3% vs. 4.7%, p < 0.0001). Within a multivariable Cox proportional hazards regression model adjusting for age, comorbid disease, mitotic rate, tumor size, and primary site, LNM were associated with increased hazard of death for older adults (hazard ratio [HR]: 1.83; confidence interval [CI]: 1.35-2.42; p < 0.0001), but not CAYA (HR: 3.38; CI: 0.50-14.08; p = 0.13). For CAYA, only high mitotic rate predicted mortality (HR: 4.68; CI: 1.41-18.37: p = 0.02).

CONCLUSIONS

LNM are more commonly identified among CAYA with resected GIST who undergo lymph node evaluations, but do not appear to impact OS as observed in older adults. High mitotic rate remains a predictor of poor outcomes for CAYA with GIST.

Jejunojejunal intussusception with chronic bleeding caused by gastrointestinal stromal tumor: a case report and literature review

Background

Intussusception is a rare clinical condition in adults. The majority of patients present with symptoms of bowel obstruction. Intussusception is often misdiagnosed and the majority of cases are diagnosed intraoperatively. In this paper, we present a rare case of adult jejunojejunal intussusception with chronic bleeding caused by a gastrointestinal stromal tumor (GIST). We emphasize the role of contrast-enhanced computed tomography (CT) and enteroscopy in the presurgical diagnosis and the good prognosis in the high-risk GIST patient after surgery and targeted therapy.

Case Description

Herein, we present the case of a 63-year-old female patient with small bowel intussusception with chronic bleeding caused by a GIST. Her main symptoms were intermittent melena and progressive anemia. She had a 20-year history of hypertension and had never undergone previous abdominal surgery. After failure of an esophagogastroduodenoscopy and colonoscopy to locate the hemorrhagic foci in the gastrointestinal tract, contrast-enhanced CT and enteroscopy were used and a small bowel intussusception and an intraluminal mass with a bleeding ulcer was identified. The patient underwent laparoscopic partial small bowel resection, and postoperative pathological examinations showed a small intestinal GIST with a high risk of recurrence. It was suggested that the patient take imatinib regularly for at least 3 years. At the time of writing, she has remained in good health without relapse for 24 months after discharge. We also review 20 published cases of intussusception caused by small bowel GIST in the PubMed database.

Conclusions

Obscure gastrointestinal hemorrhage needs meticulous examinations to promptly determine the cause and location of bleeding. This case and literature review revealed that comprehensive surgical resection-centered treatment was the standard treatment for primary localized GISTs in patients at significant risk of relapse.

CADM1 promotes adhesion to vascular endothelial cells and transendothelial migration in cultured GIST cells

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the human gastrointestinal tract. Small intestinal GISTs appear to be associated with poorer prognosis and higher metastasis rate than gastric GISTs of the same size and mitotic index. Recently, we reported that cell adhesion molecule 1 (CADM1) is expressed specifically in most small intestinal GISTs, but not in most gastric GISTs, suggesting that this difference in CADM1 expression between gastric GISTs and small intestinal GISTs might influence the difference in clinical behavior between them. The aim of the present study was to examine whether high CADM1 expression affected proliferation, migration, invasion, adhesion to endothelial cells and transendothelial migration of cultured GIST cells by comparing original GIST-T1 cells with very low CADM1 expression with GIST-T1 cells with high CADM1 expression induced by CADM1 cDNA transfection (GIST-T1-CAD cells). GIST-T1-CAD cells had reduced ability to proliferate, migrate and invade compared with the original GIST-T1 cells, but showed significantly higher ability to adhere to human umbilical vein endothelial cells and migrate through endothelial cell monolayers. Thus, CADM1 may contribute to higher metastasis rates in small intestinal GISTs facilitating tumor cell adhesion to vascular endothelial cell and transendothelial migration of tumor cells. CADM1 might serve as a potential target for inhibition of metastasis in small intestinal GISTs.