Latest advances in adult gastrointestinal stromal tumors

Gastrointestinal stromal tumors of the stomach: A 10-year experience of a single-center

Background

Gastrointestinal tract stromal tumors (GIST) are the most common mesenchymal tumors in the gastrointestinal tract (GIS). GISTs may cause significant morbidity and mortality rates.

Aim

In this study, it was aimed to evaluate 10 years of gastric GIST cases followed in our hospital, and to analyze the prognostic factors.

Subjects and Methods

In this single-center retrospective study, a total of 64 patients who were operated between May 2010 and May 2020 due to gastric GIST tumor were reviewed. Clinical and pathological features, risk classifications, overall survival (OS) and disease-free survival (DFS) were evaluated.

Results

According to the risk classification, 18.8% of the patients were in the high-risk group. The overall 5-year OS and DFS rates were 85.7%. The mean OS of the patients was 47.9 SD36.2 months, and the duration of DFS was 45.5 months. Patients with a 5-year OS rate above 5 cm in diameter (P = 0.024), with a mitotic index above 5/50 high power field (HPF) (P = 0.038), and those with a high-risk group (P = 0.011) were significantly lower than the other group. In the correlation analysis, it was found that tumor diameter correlated significantly with OS (P = 0.034; r = -0.317). Tumor diameter and mitotic index were found to be inversely correlated with DFS duration (P = 0.004; r = -0.425 and P = 0.035; r = -0.316, respectively).

Conclusion

Our findings showed that in gastric GIST cases, as the primary tumor diameter and mitotic index increase, correlate with survival rates and the mean overall and disease-free survival times decrease.

Translating Knowledge About the Immune Microenvironment of Gastrointestinal Stromal Tumors into Effective Clinical Strategies

OPINION STATEMENT

The role of targeted therapy is firmly established for gastrointestinal stromal tumors (GISTs); other modalities for targeting this disease are necessary for recurrent and refractory disease. There are several lines of evidence pointing to an active role of the immune system in GIST. Preclinical and clinical studies revealed that the most common type of immune cell infiltration in GISTs is tumor-associated macrophages (TAMs). The mechanism of how TAMs sculpt the tumor microenvironment in GIST is not clear, but it seems that the presence of immunosuppressive regulatory T cells (Tregs) is correlated with the number of TAMs, thus linking macrophages to immunosuppression. CD3+ T cells and NK infiltrates are found in the GIST microenvironment and carry some prognostic value. In early clinical trials, there is evidence for an active role for immunotherapy in treating GIST patients. Moreover, preclinical evidence has indicated that combining TKIs with checkpoint blockers may be synergistic in murine GIST models. Overall, there is substantial preclinical and clinical evidence to support a role for immunoregulation in GIST and further studies will be important for the development of immunotherapies for GIST.

Gastrointestinal stromal tumor - A review of clinical studies

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract. With the advent of Imatinib, the treatment of gastrointestinal stromal tumor has been revolutionized as both the progression-free and overall survival rates have increased dramatically. Unfortunately, gastrointestinal stromal tumor patients on Imatinib do eventually fail due to resistance. Even though sunitinib and regorafenib have been shown to be highly effective as second- and third-line treatments, both have limited effects. New treatments are highly warranted for this reason. In this present review, 25 registered pharmacological clinical trials at ClinicalTrials.gov have been reviewed and show promising and encouraging results.