Prognostic value of desmoplastic stromal reaction, tumor budding and tumor-stroma ratio in stage II colorectal cancer.

Background: Existing high-risk factors are insufficient to accurately predict the postoperative recurrence risk of stage II colorectal cancer (CRC). The discovery of additional prognostic markers may be the key to improving the current status of stage II CRC treatment. The present study aimed to evaluate the relationship among desmoplastic reaction (DR), tumor budding (TBd), the tumor-stroma ratio (TSR) and their prognostic value for relapse-free survival (RFS). Methods: In this study, 207 patients with histologically confirmed stage II CRC from January 2012 to August 2018 were retrospectively reviewed from a single center; the cohort was divided into subgroups based on low or high TSR, and low, intermediate or high DR and TBd. Kaplan-Meier curve analysis and log-rank test were applied to examine RFS among subgroups. Univariate and multivariate Cox proportional hazards analyses were used to identify independent factors associated with RFS, and a nomogram was subsequently developed. Results: Abnormal CA242, CEA, T4 stage, presence of hypertension, internal obstruction or perforation (IOP), lymphovascular or/and perineural invasion (PNI), number of nodes examined less than 12, low-frequency microsatellite instability (MSI-L), higher Ki-67 and immature DR were associated with a lower RFS. In multivariable analysis, DR (HR =2.111; 95% CI: 1.184-3.766; P=0.011), LVI (HR =1.919; 95% CI: 1.004-3.669; P=0.049) and PNI (HR =2.724; 95% CI: 1.362-5.448; P=0.005) were prognostic factors for RFS. On this basis, a nomogram that integrated DR and clinicopathologic predictors for predicting RFS passed the calibration and had an area under the curve of 0.826. Conclusions: The prognostic significance of DR outperformed TBd and TSR, therefore, we recommend adding DR as a biomarker in routine pathological reports. The novel nomogram combining these factors may be used as a reliable and effective tool for the prediction of RFS in stage II CRC, thus helping optimize therapeutic regimens under cooperation of oncologists and surgeons. Further multicentric studies are required for validation of this novel, simple and cost-effective prognostic model.