# Colorectal Cancer in Young Adults in Panama: Clinical, Molecular, and Epidemiological Characterization in a National Cohort

## TL;DR

This study examines colorectal cancer in young adults in Panama, finding that it often presents at advanced stages and is linked to poor survival rates.

## Contribution

The study provides the first national characterization of early-onset colorectal cancer in Panama, identifying key prognostic factors and molecular features.

## Key findings

- Most patients presented with stage III-IV disease, and median overall survival was 34 months.
- Stage IV diagnosis, poor ECOG score, and tumor recurrence were independent predictors of worse survival.
- RAS mutations were common in advanced-stage cases, and geographic disparities were observed.

## Abstract

Background: Early-onset colorectal cancer (≤49 years) is rising worldwide, yet data from Central America are scarce. We characterized clinical, molecular, and therapeutic features, estimated overall survival, and identified independent prognostic factors in young adults with colorectal cancer in Panama.

Methods: We used a retrospective cohort (2020-2023) from two national oncology referral hospitals. Demographic, clinical, molecular (RAS, microsatellite instability-high), behavioral (tobacco, alcohol, body mass index), and treatment data were collected. Overall survival was estimated using the Kaplan-Meier method; multivariable Cox regression assessed prognostic factors. The statistical software Stata version 18 (StataCorp, College Station, TX, USA) was used for data analysis.

Results: We included 242 patients (median age 44 years), 126 (52%) of whom were female. Stage III-IV comprised 172 patients (71%), and stage IV comprised 103 patients (47%). Rectal tumors accounted for 83 patients (35%). RAS mutation was detected in 63 patients (36% overall and 61.3% of evaluable stage IV cases) and microsatellite instability-high in 19 patients (7.8%). Risk factors included tobacco use in 31 patients (12.8%), alcohol intake in 73 patients (32%), and overweight/obesity in 108 patients (44%). The geographical areas with the highest population density in the country have the highest case percentages, such as the province of Panama, with 105 patients (43.7%). Median overall survival was 34 months; overall survival at one, three, and five years was 78%, 49%, and 32% (95% CI 19.4-47.0). In multivariable analysis, independent predictors of worse overall survival were stage IV at diagnosis (p=0.001), baseline Eastern Cooperative Oncology Group (ECOG) score ≥2 (p=0.008), poor differentiation (p=0.020), and recurrence (p=0.030).

Conclusions: Early-onset colorectal cancer in Panama presents predominantly at advanced stages and is associated with limited survival. Stage, functional status, histologic differentiation, and recurrence independently predict mortality. Findings underscore the need for earlier detection, access to molecular testing, and equitable delivery of modern therapies.