Urinary 5-Aminolevulinic Acid Concentrations as a Potential Tumor Marker for Colorectal Cancer Screening and Recurrence

Abstract

Background/aim: Tumor biomarkers, such as carcinoembryonic antigen (CEA) and cancer antigen 19-9 (CA19-9), are used to screen and monitor tumor recurrence in patients with colorectal cancer (CRC). 5-Aminolevulinic acid (5-ALA) is used in photodynamic diagnosis and therapy. Porphyrins produced by tumor cells are excreted in the urine after 5-ALA administration. In this study, we evaluated the use of porphyrins as novel tumor markers in urine samples from patients with CRC.

Patients and methods: Porphyrin metabolite concentrations were measured in urine samples of 33 patients with CRC, 16 patients with benign disease and 8 healthy adults, after 5-ALA administration.

Results: The porphyrin metabolite concentrations were significantly increased in the CRC group compared to the control group, while in CRC patients, the porphyrin metabolite concentrations in urine were significantly decreased after surgery.

Conclusion: These results suggest that the measurement of porphyrin metabolites in urine may potentially serve as a new screening and recurrence marker for CRC.

Keywords: 5-aminolevulinic acid; colorectal cancer; photodynamic; screening; tumor markers.