# Characteristics and Prognosis of Early‐Onset vs. Late‐Onset Colon Cancer: A Propensity Score Matching Analysis Based on Histology

## TL;DR

This study compares the prognosis of early-onset and late-onset colon cancer, showing that age and histology together influence survival outcomes.

## Contribution

The study introduces a novel approach combining age at diagnosis and histology to assess colon cancer prognosis.

## Key findings

- Early-onset adenocarcinoma had the best cancer-specific and surgery-specific survival.
- Late-onset mucinous adenocarcinoma showed the worst survival outcomes.
- Nonmetastatic early-onset adenocarcinoma had poorer surgery-specific survival than late-onset adenocarcinoma.

## Abstract

The prognostic value of age at diagnosis in colon cancer is poorly understood. This study evaluated the influence of age at diagnosis and histologic subtype on colon cancer prognosis using data from 180,804 patients in the SEER database.

Patients were stratified into early‐onset and late‐onset groups and by histology—adenocarcinoma or mucinous adenocarcinoma. Early‐onset colon cancer was associated with more advanced tumor stages. Propensity score matching balanced cohorts for Kaplan–Meier and Cox regression analyses of cancer‐specific survival (CSS) and surgery‐specific survival (SSS).

Survival analyses revealed that patients with early‐onset adenocarcinoma had the most favorable CSS and SSS, whereas those with late‐onset mucinous adenocarcinoma experienced the worst outcomes; no significant age‐related differences emerged histology‐stratified. Importantly, among nonmetastatic patients, early‐onset adenocarcinoma showed significantly poorer SSS compared to late‐onset adenocarcinoma.

These findings emphasize the necessity of integrating age and histologic type for accurate prognostic assessment and personalized treatment strategies in colon cancer.