Age, Operative Intent, and Mortality After Emergency Colorectal Cancer Surgery: An Exploratory Analysis of Age-Related Patterns.

Background

Emergency surgery for complicated colorectal cancer (CRC) presenting with obstruction, perforation, or uncontrolled bleeding has high postoperative mortality, especially in older patients. However, age-related risk and the roles of radical versus palliative treatment are not fully understood. This study aimed to measure 90-day and 36-month mortality after emergency CRC surgery and to analyze whether the relationship between age and mortality is nonlinear and influenced by operative intent.

Methods

Retrospective cohort of consecutive adults undergoing emergency surgery for complicated CRC (2015-2024). The outcome was 90-day and 36-month all-cause mortality. Cox regression provided adjusted hazard ratios (HR) using two models: a primary whole-cohort model omitting pathological T/N stage, and a secondary resection-only model including pathological stage. Age was modeled with restricted cubic splines and predicted 90-day and 36-month mortality were plotted by operative intent.

Results

In 496 patients, 90-day mortality was 19.7% (98/496), while 36-month mortality was 37.3% (185/496). In the primary whole-cohort Cox model, independent predictors of 36-month mortality included age ≥75 years (HR 2.09, 95% CI 1.48-2.95, p < 0.001), Charlson Comorbidity Index (HR 1.02, 95% CI 0.98-1.06, p = 0.31), obstruction (HR 1.69, 95% CI 1.18-2.42, p = 0.004), perforation (HR 2.05, 95% CI 1.24-3.39, p = 0.005), and metastatic disease (HR 2.30, 95% CI 1.62-3.27, p < 0.001); radical operative intent was independently associated with lower 36-month mortality (HR 0.461, 95% CI 0.30-0.71, p = 0.001). In a secondary resection-only model additionally adjusting for pathological T/N stage (n = 426 with available pathology), the association for radical intent was attenuated and no longer statistically significant (HR 0.67, 95% CI 0.43-1.03, p = 0.067). The 36-month mortality spline estimate indicated an increasing risk with advancing age; a likelihood-ratio test did not show that the spline model fit significantly better than a linear age term (χ2 = 1.43, df = 1, p = 0.233), so this pattern is interpreted descriptively rather than as formal evidence of nonlinearity, and no formal interaction between age and operative intent was demonstrated.

Conclusions

Ninety-day mortality after emergency colon cancer surgery remains significant. Age-related risk shows a predominantly monotonic, descriptive pattern and should not be assumed to vary by operative intent without formal interaction testing, emphasizing individualized risk assessment and shared decision-making.