Gastrointestinal stromal tumors: diagnosis, therapy and follow-up care in Austria

Gastrointestinal Stromal Tumours (GIST): A Review of Cases from Nigeria

PURPOSE

Gastrointestinal stromal tumours (GIST) are rare and studies on GIST in Nigeria are extremely uncommon. This study aims to achieve a comprehensive systematic review of the cases of this tumour in Nigerians.

METHODS

A systematic search of all available literature on GIST published from Nigeria between January 2000 and December 2018 was done and reviewed. Simple descriptive data on all the cases are presented.

RESULTS

The search yielded 15 publications but 13 publications with a total of 67 patients were analysed. The other two studies centred on imatinib therapy and overall survival, and molecular characteristics respectively and were therefore reviewed independently. Age at diagnosis ranged from 9 to 75 years, with mean age being in the 50s and 60s across most studies. There is no gender disparity. Anatomical location of primary tumours showed gastric location as the most frequent (61%) followed by large intestine accounting for 15%, the small intestine (9%) and other locations (15%). Tumour size ranged from 5-39.5 cm. Over 85% of patients had tumour size greater than 10 cm at presentation, hence fell into intermediate or high-risk group irrespective of location of tumour. The overall survival of a cohort of 27 patients that had imatinib therapy was 69.5% after 4 years of follow-up. KIT exon 11 mutations were the only mutations detected from a small cohort of 12 patients.

CONCLUSIONS

Characteristics of GIST in Nigerians are fairly similar to other parts of the world. However, most of our patients present with large masses which are of poor prognostic characteristics.

Laparoscopic resection of large gastric gastrointestinal stromal tumours

Introduction

Gastrointestinal stromal tumours (GISTs) are a rare class of neoplasms that are seen most commonly in the stomach. Due to their malignant potential, surgical resection is the recommended method for management of these tumours. Many reports have described the ability to excise small and medium sized GISTs laparoscopically, but laparoscopic resection of GISTs greater than 5 cm is still a matter of debate.

Aim

To investigate the feasibility and effectiveness of laparoscopic surgical techniques for management of large gastric GISTs greater than 4 cm and to detail characteristics of this type of tumour.

Material and methods

The study cohort consisted of 11 patients with suspected gastric GISTs who were treated from 2011 to April 2014 in a single institution. All patients underwent laparoscopic resection of a gastric GIST.

Results

Eleven patients underwent laparoscopic resection of a suspected gastric GIST between April 2011 and April 2014. The cohort consisted of 6 males and 5 females. Mean age was 67 years (range: 43–92 years). Sixty-four percent of these patients presented with symptomatic tumours. Four (36.4%) patients underwent laparoscopic transgastric resection (LTR), 3 (27.3%) laparoscopic sleeve gastrectomy (LSG), 3 (27.3%) laparoscopic wedge resection (LWR) and 1 (9%) laparoscopic distal gastrectomy (LDG). The mean operative time was 215 min. The mean tumour size was 6 cm (range: 4–9 cm). The mean tumour size for LTR was 5.5 cm (range: 4–6.3 cm), for LWR 5.3 cm (range: 4.5–7 cm), for LSG 6.5 cm (range: 4–9 cm) and for LDG 9 cm. We experienced only minor postoperative complications.

Conclusions

Laparoscopic procedures can be successfully performed during management of large gastric GISTs, bigger than 4 cm, and should be considered for all non-metastatic cases. The appropriate approach can be determined by assessing the anatomical location of each tumour.

[Gastrointestinal stromal tumors: diagnostics and therapy]

Gastrointestinal stromal tumors (GIST) are the most frequent mesenchymal tumors of the gastrointestinal tract. The standard therapy is complete surgical resection with safety margins of 1-2 cm. Intraoperative rupture of the tumor capsule must be avoided because this carries a very high risk of tumor spread. A lymph node dissection is not routinely indicated as lymph node metastases very rarely occur with GIST. Smaller GISTs can normally be removed laparoscopically according to the rules of tumor surgery. Depending on the size of the tumor, the mitosis index and the localization of the primary tumor, the risk of recurrence after potentially curative resection is considerable in many cases. Patients with intermediate and high risks according to Miettinen's classification should receive adjuvant treatment with the tyrosine kinase inhibitor imatinib. Exceptions are those patients whose tumors exhibit the mutation D842V in exon18 of the PDGFRA gene. According to current European Society for Medical Oncology (ESMO) guidelines this therapy should be continued for 3 years. This leads to a significant improvement in progression-free survival compared to a 1-year therapy, and more important to an improvement in overall survival.

Expression profile of microRNAs in gastrointestinal stromal tumors revealed by high throughput quantitative RT-PCR microarray

AIM: To investigate the microRNA (miRNA) expression profile in gastrointestinal stromal tumor (GIST) tissues that could serve as a novel diagnostic biomarker for GIST detection.

METHODS: We performed a quantitative real-time quantitative reverse transcriptase polymerase chain reaction assay to analyze the expression of 1888 miRNAs in a sample set that included 54 GIST tissue samples.

RESULTS: We found that dysregulation of several miRNAs may be related to the malignant potential of GISTs. Six of these miRNAs, hsa-let-7c, miR-218, miR-488#, miR-4683, miR-34c-5p and miR-4773, were selected as the final list of biomarkers to separate the malignant GISTs (M group) from the benign GISTs (B group). In addition, MiR-29b-2#, hsa-let-7c, miR-891b, miR-218, miR-204, miR-204-3p, miR-628-5p, miR-744, miR-29c#, miR-625 and miR-196a were used to distinguish between the borderline (BO group) and M groups. There were 11 common miRNAs selected to separate the benign and borderline (BB) group from the M group, including hsa-let-7c, miR-218, miR-628-5p, miR-204-3p, miR-204, miR-891b, miR-488#, miR-145, miR-891a, miR-34c-5p and miR-196a.

CONCLUSION: The identified miRNAs appear to be novel biomarkers to distinguish malignant from benign GISTs, which may be helpful to understand the mechanisms of GIST oncogenesis and progression, and to further elucidate the characteristics of GIST subtypes.

Expression of L1 protein correlates with cluster of differentiation 24 and integrin β1 expression in gastrointestinal stromal tumors

The present study examined 66 cases of gastrointestinal stromal tumors (GISTs), 20 cases of smooth muscle tumors, 20 cases of schwannomas and 20 cases of normal gastric tissues in order to analyze the expression of L1, cluster of differentiation (CD)24 and integrin β1 by immunohistochemical staining. Patients were subjected to follow-up, and survival data were evaluated. L1 expression was detected in 57.6% of GIST cases; this was a significantly higher percentage compared with that found in the smooth muscle tumor cases or the normal control group. CD24 and integrin β1 were also expressed at significantly higher levels in the GIST cases than in the normal control group, although no significant difference was found in the expression levels of these proteins in smooth muscle tumor or schwannoma cases. These higher levels of L1 and integrin β1 expression were associated with an increased risk of invasive GIST, and were significantly positively correlated with Ki-67 expression. CD24 expression was not associated with the risk of GIST invasion or Ki-67 expression. There were positive correlations between L1, CD24 and integrin β1 expression; however, these had no significant association with patient survival. Therefore, L1 alone or in conjunction with CD24 (L1 + CD24), or integrin β1 (L1 + integrin β1) can be considered a valuable indicator for the differential diagnosis of GIST. Furthermore, L1 and integrin β1 can be used alone or in combination to evaluate the biological behavior of GISTs. Future studies are required to evaluate the prognostic value of these markers.

Large cystic-based gastrointestinal stromal tumor: A case report

A 60-year-old male with increasing abdominal distension was admitted to The Fifth Affiliated Hospital of Guangzhou Medical University (Guangzhou, China). The abdominal sonogram exhibited a huge abdominal cystic-based mass with solid components in the left upper quadrant. A contrast-enhanced computed tomography scan of the abdomen revealed a large heterogeneous cystic solid tumor, but the source of the tumor could not be determined. The laparotomy demonstrated a huge cystic-based tumor with an integrated cystic wall, arising from the posterior wall of the gastric body. Multiple septa and ~3,500 ml of yellowish fluid were found in the cystic cavity. Pathological analysis showed that the tumor contained a mixture of polygonal and spindle cells. Immunohistochemical study indicated that the tumor cells were positive for CD117 and CD34. The final diagnosis was gastric gastrointestinal stromal tumor. The patient recovered well and no recurrence or metastasis was identified following a 12-month follow-up.

IgE-based Immunotherapy of Cancer -A Comparative Oncology Approach

Antibody-based immunotherapies are important therapy options in human oncology. Although human humoral specific immunity is constituted of five different immunoglobulin classes, currently only IgG-based immunotherapies have proceeded to clinical application.

This review, however, discusses the benefits and difficulties of IgE-based immunotherapy of cancer, with special emphasis on how to translate promising preclinical results into clinical studies. Pursuing the “Comparative Oncology” approach, novel drug candidates are investigated in clinical trials with veterinary cancer patients, most often dogs. By this strategy drug development could be speeded up, animal experiments could be reduced and novel therapy options could be introduced benefitting humans as well as man’s best friend.