Research Article: Development and external validation of a nomogram to predict survival and guide surgical strategy for colorectal cancer with synchronous liver and lung metastases: a SEER-based analysis
Abstract:
Surgical management of colorectal cancer with synchronous liver and lung metastases (CRC-SLLM) remains challenging because of marked clinical heterogeneity, and reliable tools for individualized risk assessment are lacking. We aimed to develop and externally validate a nomogram for overall survival (OS) prediction and to explore its potential value in guiding selection for primary tumor resection (PTR). Patients diagnosed with CRC-SLLM between 2010 and 2015 were identified from the Surveillance, Epidemiology, and End Results (SEER) database and randomly assigned to a training cohort (n = 808) and an internal validation cohort (n = 345) in a 7:3 ratio, whereas external validation was performed using 65 patients from the Fourth Hospital of Hebei Medical University, China. After feature selection with least absolute shrinkage and selection operator (LASSO) regression, a multivariable Cox-based nomogram was constructed, and its performance was assessed using time-dependent receiver operating characteristic curves, calibration plots, decision curve analysis (DCA), and risk stratification. The final nomogram incorporated nine predictors: age, primary tumor site, histological grade, tumor size, N stage, bone metastasis, carcinoembryonic antigen status, metastasectomy, and chemotherapy. It showed stable discrimination across the training, internal validation, and external validation cohorts, with 12-month areas under the curve (AUCs) of 0.791, 0.714, and 0.778 and 24-month AUCs of 0.742, 0.740, and 0.730, respectively; calibration was good in all cohorts, and DCA supported potential clinical utility. Nomogram-based risk stratification separated patients into prognostically distinct low- and high-risk groups, and an exploratory analysis indicated that the survival benefit of PTR was largely confined to low-risk patients. This externally validated nomogram provides individualized survival prediction and risk stratification for patients with CRC-SLLM and may help identify those more likely to benefit from PTR, although this finding remains exploratory and warrants confirmation in prospective multicenter studies.
Introduction:
Colorectal cancer (CRC) ranks among the most prevalent malignancies globally and constitutes a major contributor to cancer mortality ( 1 ). At initial diagnosis, distant metastases are identified in 20%–25% of patients with colorectal cancer, which constitutes the primary cause of treatment failure and death. While the liver and lungs are the most common sites of hematogenous spread, synchronous liver and lung metastases (SLLM) represent a unique and highly aggressive clinical phenotype, accounting for roughly 3%…
Read more