Noninvasive imaging evaluation of tumor immune microenvironment to predict outcomes in gastric cancer
Menée à partir de données portant sur 1 778 patients atteints d'un cancer de l'estomac et ayant subi une tomographie numérique avec rehaussement de contraste, cette étude évalue la performance d'une signature, basée sur 13 caractéristiques radiomiques des régions intratumorale et péritumorale, pour prédire la réponse à une chimiothérapie adjuvante et établir un pronostic
Background : The tumor immune microenvironment can provide prognostic and predictive information. A previously validated ImmunoScore of gastric cancer (ISGC) evaluates both lymphoid and myeloid cells in the tumor core and invasive margin with immunohistochemistry staining of surgical specimens. We aimed to develop a noninvasive radiomics-based predictor of ISGC.
Patients and methods : In this retrospective study including four independent cohorts of 1778 patients, we extracted 584 quantitative features from the intratumoral and peritumoral regions on contrast-enhanced CT images. A radiomic signature (RIS) was constructed to predict ISGC by using regularized logistic regression. We further evaluated its association with prognosis and chemotherapy response.
Results : A 13-feature radiomic signature for ISGC was developed and validated in 3 independent cohorts (area under the curve=0.786, 0.745, and 0.766). The RIS signature was significantly associated with both disease-free and overall survival in the training and all validation cohorts (HR range: 0.296-0.487, all P<0.001). In multivariable analysis, the RIS remained an independent prognostic factor adjusting for clinicopathologic variables (adjusted HR range: 0.339-0.605, all P<0.003). For stage II and III disease, patients with a high RIS derived survival benefit from adjuvant chemotherapy, HR=0.436 (95% CI: 0.253-0.753), P=0.002; HR=0.591 (95% CI: 0.428-0.818), P<0.001, respectively; while those with a low RIS did not.
Conclusion : The radiomic signature is a reliable tool for evaluation of immunoscore and retains the prognostic significance in gastric cancer. Future prospective studies are required to confirm its potential to predict treatment response and select patients who will benefit from chemotherapy.
Annals of Oncology , résumé, 2020