Abstract:

Objective To develop a multimodal nomogram for predicting the risk of postoperative metastasis and recurrence in patients with stage Ⅱ colorectal cancer （CRC） who do not receive adjuvant therapy. Methods A total of 424 patients with stage Ⅱ CRC who underwent radical resection without adjuvant therapy at our institution between January 2016 and December 2021 were retrospectively enrolled. Clinicopathological characteristics ［including T stage， carcinoembryonic antigen （CEA） levels， and tumor differentiation］， inflammatory markers （preoperative neutrophil-to-lymphocyte ratio and lymphocyte-to-monocyte ratio）， radiomic features （MRI texture entropy）， and molecular biomarkers （KRAS mutation status） were collected. Radiologically confirmed metastasis or recurrence was defined as the primary endpoint. Univariate and multivariate logistic regression analyses were performed to identify independent prognostic factors and construct a predictive nomogram. The model’s discriminatory performance was assessed using receiver operating characteristic （ROC） curve analysis. Internal validation was conducted via bootstrapping， and model calibration was evaluated using the Hosmer?Lemeshow goodness-of-fit test. Decision curve analysis was applied to assess the clinical utility of the nomogram， and risk stratification was subsequently performed. Results Among the patients， 104 （24.53%） developed metastasis or recurrence within three years after surgery. Multivariate analysis revealed the following independent risk factors （all P < 0.05）： CEA > 5 μg/L， moderate to poor differentiation， presence of lymphovascular invasion， perineural invasion， elevated neutrophil-to-lymphocyte ratio （NLR）， increased radiomic entropy， and KRAS mutation. The nomogram demonstrated strong predictive accuracy （AUC = 0.870， 95%CI： 0.850 ~ 0.930）， and the calibration curve indicated excellent agreement between predicted and observed outcomes. Following risk stratification， the recurrence rate was only 6.1% in the low-risk group， compared to 74.2% in the high-risk group （P < 0.05）. Conclusions This study develops a clinical-inflammatory-radiomic integrated prediction model specifically for stage Ⅱ colorectal cancer patients who do not receive adjuvant therapy. The model effectively identifies the risk of postoperative metastasis and recurrence， enabling the establishment of a risk stratification system to guide subsequent treatment decisions.

Key words: colorectal cancer, without adjuvant therapy, multimodal, metastasis recurrence, nomogram