Figure 3

Concentration of cfDNA in HNSCC patients depending on selected variables. (a) CfDNA concentration in range 35–250 bp depending on the tumor location during ongoing tumor growth: group 1 (n = 9), group 2 (n = 43), group 4 (n = 6), group 5 (n = 101), group 6 (n = 6). Kruskal–Wallis Rank Sum Test followed by post hoc Dunn's test was performed. (b) Concentration of cfDNA in different ranges of length depending on the tumor type: primary (PTu, n = 137), recurrent (RTu, n = 29). The Mann–Whitney, two-sided test was performed. (c) Concentration of cfDNA in different ranges of length depending on the course of disease: (I) donation at the time of primary tumor diagnosis from patients free of cancer longer than two years (n = 96); (II) donation at the time of primary tumor diagnosis from patients free of cancer with follow-up shorter than two years (n = 18); (III) donation at the time of primary tumor diagnosis from patients with recurrence in follow-up (n = 19); (IV) donation at the time of recurrence diagnosis (n = 29). Kruskal–Wallis Rank Sum Test followed by post hoc Dunn's test was performed. (d) Concentration of cfDNA in range 35–250 bp depending on tumor location and the course of disease: group 1 PTu (n = 7), RTu (n = 2); group 2 PTu (n = 37), RTu (n = 6); group 4 PTu (n = 4), RTu (n = 2); group 5 PTu (n = 84), RTu (n = 17); group 6 PTu (n = 4), RTu (n = 2). The Mann–Whitney, two-sided test was performed. (e) Concentration of cfDNA in range 250–500 bp in larynx cancers, PTu (n = 84), RTu (n = 17). The Mann–Whitney, two-sided test was performed.