CEACAM5 and cancer: LDH has also been utilized in the oncology practice as a biomarker of tumor progression. Both biomarkers are not specific for CRC only, as elevated levels of CEA and LDH can also be concurrent with other cancers and in several inflammatory and metabolic disorders [10,11]. Nevertheless, CEA remains a non-invasive tumor biomarker to monitor CRC progression and the efficacy of anticancer treatment.