Published online May 15, 2025. doi: 10.4251/wjgo.v17.i5.104341
Revised: February 2, 2025
Accepted: February 28, 2025
Published online: May 15, 2025
Processing time: 148 Days and 13.3 Hours
Metastatic colorectal cancer (mCRC) is a global health challenge with a poor prognosis. Prognostic markers are critical for survival prediction.
To evaluate a novel tumor marker index (TMI) combining carcinoembryonic antigen and carbohydrate antigen 19-9.
This multicenter, retrospective study measured baseline carcinoembryonic antigen and carbohydrate antigen 19-9 levels to calculate a TMI as the geometric mean of values normalized to their upper limits of normal. Receiver operating characteristic curve analysis assessed TMI’s prognostic accuracy, and patients were stratified into high-TMI (≥ 1.39) and low-TMI (< 1.39) groups. The primary endpoint was overall survival (OS), with progression-free survival and treatment response as secondary endpoints.
The study included 305 mCRC patients with a median follow-up of 22.9 months. The median OS for high-TMI patients was 29.5 months, significantly lower than the 45.6 months observed in the low-TMI group (P = 0.02). The 2-year OS rates for the high- and low-TMI groups were 59.4% and 72.9%, respectively. Median progression-free survival was also shorter for the high-TMI group (14.0 vs 16.0 months, P = 0.84). High TMI is an independent prognostic factor for worse OS.
TMI is a simple, cost-effective prognostic tool for mCRC, with high TMI associated with poorer survival outcomes.
Core Tip: The tumor marker index (TMI), derived from the combination of carcinoembryonic antigen and carbohydrate antigen 19-9, offers a novel and cost-effective approach to prognostication in metastatic colorectal cancer. This study demonstrates that a high TMI is independently associated with significantly shorter overall survival, with potential implications for risk stratification and individualized patient management. These findings highlight the clinical value of integrating TMI into routine practice for better outcome prediction.