Optimal thresholds of risk parameters for gastrointestinal stromal tumors

Genomic Complexity as a Biomarker to De-Escalate Adjuvant Imatinib Treatment in High-Risk Gastrointestinal Stromal Tumor

PURPOSE

Adjuvant imatinib treatment is recommended for patients with localized gastrointestinal stromal tumor (GIST) at high risk of recurrence. Almost half of high-risk patients are cured by surgery alone, indicating a need for improved selection of patients for adjuvant therapy. The aim of this study was to investigate if genomic tumor complexity could be used as a prognostic biomarker.

METHODS

The discovery cohort consisted of patients who underwent resection of primary GIST at Oslo University Hospital between 1998 and 2020. Karyotypes were categorized as simple if they had ≤ 5 chromosomal changes and complex if there were > 5 chromosomal aberrations. Validation was performed in an independent patient cohort where chromosomal imbalances were mapped using comparative genomic hybridization.

RESULTS

Chromosomal aberrations were detected in 206 tumors, of which 76 had a complex karyotype. The most frequently observed changes were losses at 14q, 22q, 1p, and 15q. The 5-year recurrence-free survival (RFS) in patients classified as very low, low, or intermediate risk was 99%. High-risk patients with a simple tumor karyotype had an estimated 5-year RFS of 94%, and patients with a complex karyotype had an estimated 5-year RFS of 51%. A complex karyotype was associated with poor RFS in patients with and without adjuvant imatinib treatment and in multivariable analysis adjusted for tumor site, size, mitotic count, and rupture. The prognostic impact of genomic complexity was confirmed in the validation cohort. In both cohorts, the 5-year disease-specific survival was > 90% for high-risk patients with genomically simple tumors.

CONCLUSION

Genomic tumor complexity is an independent prognostic biomarker in localized, high-risk GIST. Recurrences were infrequent for tumors with simple karyotypes. De-escalation of adjuvant imatinib treatment should be explored in patients with cytogenetically simple GISTs.

Prognostic Value of Bleeding in Gastrointestinal Stromal Tumors: A Meta-Analysis

Background:

Gastrointestinal bleeding is the most common clinical manifestation of gastrointestinal stromal tumor. It is of great significance to the prognosis of patients. But the results are controversial. The purpose of this study was to evaluate the relationship between gastrointestinal bleeding and clinical prognosis in patients with GIST.

Methods:

A systematic literature search was performed in Pumbed, Cochrane Library, EMBASE, ClinicalTrials.gov, CNKI, VIP and wanfang databases with the pattern of unlimited languages. 12 studies with 2781 individuals were included in the final analysis. The overall survival (OS), recurrence-free survival/disease-free survival (RFS/DFS) and related factors affecting bleeding in patients with gastrointestinal stromal tumor (GIST) were extracted. Hazard ratio (HR) and 95% confidence interval (CI) were used for in the meta-analysis.

Results:

A total of 12 articles were included in the study, including 2781 patients with GIST, including 845 patients with gastrointestinal bleeding. The OS of GIST patients with gastrointestinal bleeding was significantly worse (HR = 2.54, 95% CI = 1.13-5.73, P = 0.025). But there was no significant difference in RFS between gastrointestinal bleeding patients and non-bleeding patients (HR = 1.35, 95% CI = 0.70-2.61, P = 0.371). Further analysis of the related factors of GI bleeding in GIST patients was observed, besides the aging factor (HR = 1.02, 95% CI = 0.69-1.50, P = 0.929), Small intestinal stromal tumor (HR = 0.56, 95% CI = 0.41-0.76, P < 0.001), tumor diameter ≥ 5 cm (HR = 2.09, 95% CI = 1.20-3.63, P = 0.009), Mitotic index ≥ 5/50 HPF (HR = 1.66, 95% CI = 1.11-2.49, P = 0.014) and tumor rupture (HR = 2.04, 95% CI = 1.0-3.82, P = 0.026) all increased the risk of GI bleeding in patients with GIST.

Conclusions:

The OS of GIST patients with GI bleeding was worse than non-GI bleeding, but had no significant effect on RFS. Nevertheless the aging factor, the location of GIST in the small intestine, tumor diameter ≥ 5 cm, Mitotic index ≥ 5/50 HPF and tumor rupture all increased the risk of GI bleeding in patients with GIST.