Prognostic analysis of 2-5 cm diameter gastric stromal tumors with exogenous or endogenous growth

Association between calcification and risk stratification in gastric gastrointestinal stromal tumors

BACKGROUND

Risk assessment of gastric gastrointestinal stromal tumors (GISTs), particularly those with a diameter ≤ 5 cm, remains a clinical challenge. Previous research has primarily focused on tumor size, ulceration, necrosis, and enhancement patterns, with less emphasis on the role of tumor calcification, which remains controversial regarding its correlation with malignancy risk.

OBJECTIVE

This study aims to explore the characteristics of calcification in gastric GISTs and its correlation with risk stratification as defined by the National Institutes of Health (NIH), to improve preoperative risk assessment for gastric GISTs ≤ 5 cm.

METHODS

A retrospective analysis of 385 pathologically confirmed gastric GIST patients, including 178 with small gastric GISTs (< 2 cm), was conducted. Tumors were categorized into low-risk (very low / low) and high-risk (intermediate / high) groups based on NIH criteria. Variables such as age, gender, tumor long-axis diameter, calcification rates, calcification size, the number and distribution of calcification, calcification to tumor long-axis diameter ratio were analyzed. Logistic regression was used to identify independent predictors of malignancy for gastric GISTs, with predictive values assessed via receiver operating characteristic (ROC) curves.

RESULTS

Significant differences were found between high-risk and low-risk groups in treatment methods, tumor long-axis diameter, the ratio of calcification to tumor long-axis, and calcification distribution (P < 0.05). Calcification rates varied across risk categories, with 23.6% in very low-risk, 31.6% in low-risk, 9.8% in intermediate-risk, and 31.7% in high-risk categories (P < 0.05). In GISTs ≤ 5 cm, both tumor long-axis diameter (OR = 3.07, 95% CI: 2.29-4.10) and calcification (OR = 0.36, 95% CI: 0.13-0.97) were independent predictors of malignancy risk (both P < 0.05). ROC curve analysis yielded areas of 0.849 for tumor long-axis diameter, 0.578 for calcification, and 0.862 for their combination.

CONCLUSION

The study indicates lower calcification rates in intermediate-risk gastric GISTs and higher rates in other risk categories. Additionally, tumors of different sizes exhibit two distinct calcification patterns, suggesting possible differing mechanisms of calcification in tumors. Calcification in gastric GISTs ≤ 5 cm acts as a protective factor against higher malignancy risk, and when combined with tumor long-axis diameter, significantly enhances predictive accuracy over long-axis diameter alone.

Clinical characteristics and prognostic analysis of postoperative recurrence or metastasis of low-risk gastrointestinal stromal tumors

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the digestive tract. This study aimed to investigate the clinical characteristics and prognosis of postoperative recurrence or metastasis in patients with low-risk stromal tumors, in order to take individualized postoperative management and treatment for patients with low-risk GISTs with relatively high recurrence.

METHODS

We retrospectively analyzed the clinicopathological and follow-up data of patients with GISTs who underwent surgical resection in Nanjing Drum Tower Hospital from March 2010 to December 2021. A total of 282 patients with low-risk GISTs were included, none of whom were treated with imatinib. Univariate and multivariate Cox analysis and survival curves were used to explore the relationship between clinical features and recurrence or metastasis in patients with low-risk GISTs.

RESULTS

Of the 282 patients with low-risk GISTs who met inclusion criteria, 14 (4.96%) had recurrence or metastasis. There was a correlation between tumor size, primary site, resection type, Ki67 index, neutrophil lymphocyte ratio (NLR) and CD34 expression and postoperative recurrence or metastasis of GISTs (P < 0.05). Subsequently, multifactorial analysis showed that tumor primary site, tumor size, and Ki67 index were independent risk factors affecting postoperative recurrent or metastasis in patients with low-risk GISTs (P < 0.05). Ultimately, According to Kaplan-Meier analysis, non-gastric primary tumors, larger tumors, and high Ki67 index were significantly associated with poor progression-free survival ( PFS ).

CONCLUSIONS

Tumor location, tumor size and Ki-67 were independent risk factors for postoperative recurrence and metastasis in patients with low-risk GISTs. Based on the 2008 modified NIH recurrence risk grading system, combined with the above three factors, it can be used to evaluate the prognosis of patients with low-risk GISTs and provide personalized postoperative review and follow-up management recommendations.