Comparative study between the free DNA in peripheral blood and TNM staging in patients with colorectal cancer for prognostic evaluation in the university hospital of the State of Alagoas

colorectal neoplasm is one of the most common cancers in developed countries and its incidence has grown progressively. the currently used attempts to prognostic assessment are limited, since they are restricted to the observation of tumor morphology, such as the tnm staging. the quantification of free dna in peripheral blood aims to find a way to relate it to the clinical status of patients with cancer. objective: to evaluate the prognosis of patients with colorectal cancer with the quantification of alu247 fragments in peripheral blood and tnm staging. methods: we evaluated 79 patients in the following groups: operated, and non-operated and control as to the alu247 fragment dosage and its correlation with tumor staging. results: the amount of alu247 fragments revealed very different results when comparing the different groups. the mean quantity in the non-operated group was 14.62 pg, while the mean was 0.48 pg for the control group and 0.93 pg for the operated group. serum levels of alu247 were higher in more advanced morphofunctional classes of the tnm staging. conclusions: we suggest there is a relation between the advanced tnm stage and high doses of free dna in peripheral blood with worse prognosis.