Researchers suggested that computed tomography (CT) may not be a reliable tool to estimate tumor size for preoperative risk stratification of gastrointestinal stromal tumors (GISTs) in a Chinese population, as published in the European Journal of Surgical Oncology.
The study showed an underestimation of the sizes of gastric GISTs by 0.30 cm when compared with pathological sizes (95% CI, 0.42-0.19, P <.001).
Further subgroup analyses showed a mean difference in tumors’ largest diameter of -0.10 cm (95% limit of agreement [LOA], 1.37-1.17) in GISTs ≤ 5 cm and -0.75 cm (95% LOA, 3.69-2.19) in GISTs > 5 cm.
CT-based estimations of tumor size were able to classify most (86.3%) of the cases into the appropriate risk category. The remaining cases were either underestimated (9.2%) or overestimated (4.5%).
The underestimated group had a greater proportion of smaller tumors (≤ 5 cm, 93.1% vs 70.8%, P =.010) and lower mitotic index (≤ 5/50 high-power fields, 96.6% vs 76.0%, P =.011) than the group correctly classified.
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ROC curve analysis suggested a cutoff value for CT-measured tumor size of 3.65 cm to distinguish high-risk gastric GISTs from low-risk gastric GISTs.
“Gastric GISTs with the largest diameter over 3.65 cm by CT could be categorized into intermediate/high-risk, watchful surveillance needs to be interpreted with caution and surgery prioritization should be considered even in the continuing COVID-19 pandemic,” the authors said.
The study enrolled 314 individuals (median age, 60 years, age range, 24-88 years, 53.5% female) diagnosed with gastric GISTs. Most (44.59%) had tumors localized in the middle third of the stomach, followed by the upper third (42.04%), and the lower third (13.37%).
Li Y, Chen X, Ma X, Lu X. Computed tomography in the size measurement of gastric gastrointestinal stromal tumors: implication to risk stratification and “wait-and-see” tactics. Eur J Surg Oncol. Published online January 4, 2022. doi:10.1016/j.ejso.2022.01.007