For 52 of the 94 patients a paired comparison between pre-treatment and post-treatment samples was performed. miR-17, miR-18b, miR-20a, miR-31, and miR-193a_3p, were significantly downregulated in pre-treatment plasma samples of patients with rectal cancer (<i>p</i> < 0.05). miR-29c, miR-30c, and miR-195 showed a trend of differential regulation.