Nomograms that predict the survival of patients with adenocarcinoma in villous adenoma of the colorectum: a SEER-based study

BACKGROUND: Considering that the knowledge of adenocarcinoma in villous adenoma of the colorectum is limited to several case reports, we designed a study to investigate independent prognostic factors and developed nomograms for predicting the survival of patients. METHODS: Univariate and multivariate Cox regression analyses were used to evaluate prognostic factors. A nomogram predicting cancer-specific survival (CSS) was performed; internally and externally validated; evaluated by receiver operating characteristic (ROC) curve, C-index, and decision curve analyses; and compared to the 7th TNM stage. RESULTS: Patients with adenocarcinoma in villous adenoma of the colorectum had a 1-year overall survival (OS) rate of 88.3% (95% CI: 87.1–89.5%), a 3-year OS rate of 75.1% (95% CI: 73.3–77%) and a 5-year OS rate of 64.5% (95% CI: 62–67.1%). Nomograms for 1-, 3- and 5-year CSS predictions were constructed and performed better with a higher C-index than the 7th TNM staging (internal: 0.716 vs 0.663; P < 0.001; external: 0.713 vs 0.647; P < 0.001). Additionally, the nomogram showed good agreement between internal and external validation. According to DCA analysis, compared to the 7th TNM stage, the nomogram showed a greater benefit across the period of follow-up regardless of the internal cohort or external cohort. CONCLUSION: Age, race, T stage, pathologic grade, N stage, tumor size and M stage were prognostic factors for both OS and CSS. The constructed nomograms were more effective and accurate for predicting the 1-, 3- and 5-year CSS of patients with adenocarcinoma in villous adenoma than 7th TNM staging.