Assessment of metastatic risk of gastric GIST based on treatment-naïve CT features

• Published in: European journal of surgical oncology Vol. 42; no. 8; pp. 1222 - 1228
• Main Authors: O'Neill, A.C, Shinagare, A.B, Kurra, V, Tirumani, S.H, Jagannathan, J.P, Baheti, A.D, Hornick, J.L, George, S, Ramaiya, N.H
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.08.2016
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Chemotherapy, Adjuvant; Cytoreduction Surgical Procedures; Female; Gastrectomy; Gastrointestinal stromal tumor; Gastrointestinal Stromal Tumors - diagnostic imaging; Gastrointestinal Stromal Tumors - pathology; Gastrointestinal Stromal Tumors - secondary; Gastrointestinal Stromal Tumors - therapy; Hematology, Oncology and Palliative Medicine; Humans; Male; Metastasis; Middle Aged; Multivariate Analysis; Neoadjuvant Therapy; Neoplasm Metastasis; Protein Kinase Inhibitors - therapeutic use; Retrospective Studies; Risk Assessment; Risk stratification; Stomach; Stomach Neoplasms - diagnostic imaging; Stomach Neoplasms - pathology; Stomach Neoplasms - therapy; Surgery; Tomography, X-Ray Computed; Tumor Burden; Young Adult; Stomach; CT; Metastasis; Risk stratification; Gastrointestinal stromal tumor
• ISSN: 0748-7983; 1532-2157
• DOI: 10.1016/j.ejso.2016.03.032

Abstract Objective To study whether the CT features of treatment-naïve gastric GIST may be used to assess metastatic risk. Methods In this IRB approved retrospective study, with informed consent waived, contrast enhanced CT images of 143 patients with pathologically confirmed treatment-naïve gastric GIST (74 men, 69 women; mean age 61 years, SD ± 14) were reviewed in consensus by two oncoradiologists blinded to clinicopathologic features and clinical outcome and morphologic features were recorded. The metastatic spread was recorded using available imaging studies and electronic medical records (median follow up 40 months, interquartile range, IQR, 21–61). The association of maximum size in any plane (≤10 cm or >10 cm), outline (smooth or irregular/lobulated), cystic areas (≤50% or >50%), exophytic component (≤50% or >50%), and enhancing solid component (present or absent) with metastatic disease were analyzed using univariate (Fisher's exact test) and multivariate (logistic regression) analysis. Results Metastatic disease developed in 42 (29%) patients (28 at presentation, 14 during follow-up); 23 (16%) patients died. On multivariate analysis, tumor size >10 cm (p = 0.0001, OR 9.9), irregular/lobulated outline (p = 0.001, OR 5.6) and presence of a enhancing solid component (p < 0.0001, OR 9.1) were independent predictors of metastatic disease. On subgroup analysis, an irregular/lobulated outline and an enhancing solid component were more frequently associated with metastases in tumors ≤5 cm and >5–≤10 cm (p < 0.05). Conclusion CT morphologic features can be used to assess the metastatic risk of treatment-naïve gastric GIST. Risk assessment based on pretreatment CT is especially useful for patients receiving neoadjuvant tyrosine kinase inhibitors and those with tumors <5 cm in size.