A correlation research of Ki67 index, CT features, and risk stratification in gastrointestinal stromal tumor

Abstract

Background and ObjectivesRecurrence and metastasis are the most important factors affecting the quality of life and survival rate of patients with gastrointestinal stromal tumors (GISTs). Accurate preoperative determination of the malignant degree of GISTs and the development of a reasonable treatment plan can effectively reduce the recurrence rate. CT is currently considered the preferred imaging modality for initial assessment. Until now, there have only been a few studies investigating the relationship between CT features and recurrence of GISTs. However, the value of CT features in prognostic assessment is still unclear. In this study, we attempted to investigate the prognostic significance of CT features and the Ki67 index in GISTs.MethodsWe retrospectively analyzed the clinicopathological and imaging data for 151 patients with a histopathological diagnosis of GIST who had received contrast‐enhanced CT examination and surgical resection at XinHua Hospital from October 2008 to December 2015 or Sir Run Run Shaw Hospital in 2017. Then, we explored the correlation among CT features, the Ki67 index, and risk stratification of GISTs. The correlation among CT features, the Ki67 index, and risk stratification was mainly analyzed using the Spearman rank correlation.ResultsThe incidence of high‐risk disease or metastasis was clearly higher in the group with Ki67 > 5% than that in the group with Ki67 ≤ 5% (P < 0.001). The Ki67 index was positively correlated with risk stratification (r = 0.558) or mitotic index (r = 0.619). CT imaging features including size, contour, and margin of the tumor were associated with the Ki67 index (r = 0.332, 0.333, and 0.302, respectively). The multivariate logistic regression analysis revealed that the tumor size [P = 0.043 Exp (B) = 1.150] and the presence of ulceration [P = 0.011, Exp (B) = 3.669] were effective variables in distinguishing between the groups with Ki67 ≤ 5% and >5%. The presence of necrosis or cystic degeneration, tumor contour, tumor margin, and pattern of enhancement were associated with risk stratification (r = 0.530, 0.501, 0.419, and 0.447, respectively).ConclusionsOur findings suggest that the Ki67 index is an effective complementation in predicting the prognosis of GISTs, and CT features including size, contour, and margin of the tumor, presence of necrosis or cystic degeneration, and pattern of enhancement provide evidence to support the importance of preoperative assessment.

Risk stratification in GIST: shape quantification with CT is a predictive factor

“…Ki-67 is a proliferation marker for tumors and has been used for tumor staging, poorly differentiated malignancies [22]. Li et al [23] reported that the Ki-67 index was positively correlated with mitotic counts. Meanwhile, Kemmerling et al [24] reported that Ki-67 could accurately predict mitotic When we set the cutoff value for BiA as 90.5°, BiA/SmA ratio as 1.35, and long diameter (LD) as 6.15 cm, the sensitivity values for high-risk GISTs were 82.4%, 85.3%, and 83.8%, respectively; the specificity values were 87.1%, 71%, and 77.4%, respectively; and the AUC values were 0.852, 0.818, and 0.844, respectively.…”

<p>Nomogram to Predict Preoperative Occult Peritoneal Metastasis of Gastrointestinal Stromal Tumors (GIST) Based on Imaging and Inflammatory Indexes</p>

“…25 Preoperative imaging showed that extensive tumor capsule and necrosis were also associated with the risk of tumor recurrence and metastasis. 29 In our study, tumor size, tumor location and tumor capsule status were strongly predictive of occult PM in the multivariable analysis. Therefore, we incorporated the tumor size, primary site and tumor capsule status into the nomogram and demonstrated excellent predictive ability.…”

Intestinal tumors in neurofibromatosis 1 with special reference to fatal gastrointestinal stromal tumors (GIST)

“…Only four GISTs were analyzed for mutations at the time of the diagnosis, and all were negative for KIT and PDGFRA mutations. At the time of diagnosis, six of the eight GISTs were estimated to have a high risk for malignant behavior (size over >5 cm, and >5 mitoses per 50 high‐power microscopic fields, or Ki67 >5%), whereas the risk was low in two patients suggesting benign prognosis (Li et al, ; von Mehren & Joensuu, ; Segales‐Rojas, Lino‐Silva, Aguilar‐Cruz, & Salcedo‐Hernández, ; Zhou et al, ). However, the two NF1 patients with the low‐risk primary tumors in the duodenal localization died of GIST within one year of diagnosis.…”