Serum miRNA expression on pathological diagnosis variables was statistically significant with an increase in the expression of miR-34 as a predictive biomarker for the type of metastasis M1b (P=0.020), adenocarcinoma cancer cell types (P=0.009) and adenocarcinoma negative EGFR mutation (P=0.031). This evidence concerns the gene EGFR and adenocarcinoma.