Fig 2: PRTN3 expression in peripheral blood cells of patients with mCRC. a Representative data of CD66b/PRTN3 staining of living cells. b Percentage of CD66b expression according to PRTN3 expression (n=12). c Percentage of PRTN3 expression according to CD66b expression (n=12). (d) Correlation between the serum PRTN3 level and the PRTN3-positive neutrophil count (n=12). R=0.3163. P=0.3166. *P<0.05 (e) The relationship between serum PRTN3 levels (the cut-off value is 21.6 ng/ml) and Progression-free survival in the subgroup of 8 patients who received chemotherapy. P=0.043. Abbreviations: mCRC, metastatic colorectal cancer; PRTN3, proteinase-3

Fig 3: Consort diagram of this study. In total, 79 patients with mCRC are enrolled in the study. Patient sera are used to measure PRTN3 levels with ELISA. Overall, 48 primary tumor and 5 liver tumor samples obtained surgically from the 79 patients are subjected to IHC staining. The prognostic impact and association with the efficacy of first-line chemotherapy of PRTN3 levels are examined. Flow cytometric analysis is performed using peripheral whole blood samples from 12 patients with mCRC. Abbreviations: IHC, immunohistochemistry; mCRC, metastatic colorectal cancer; PRTN3, proteinase-3

Fig 4: Survival analysis according to serum PRTN3 levels in patients with mCRC. The patients are divided into two groups according to serum PRTN3 levels based on a cutoff value of 21.6 ng/ml identified using time-dependent receiver operating characteristic curve analysis: high expression group (≥21.6 ng/ml) and low expression group (<21.6 ng/ml). a Progression-free survival. b Overall survival and overall survival rates. Abbreviations: mCRC, metastatic colorectal cancer; PRTN3, proteinase-3

Fig 5: PRTN3 expression in resected specimens. Immunohistochemical (IHC) analysis is performed using primary and metastatic specimens. Scale bar: 100 µm. a Representative images of PRTN3 expression in primary tumors. CES=4 × (intensity score − 1) + frequency score. The intensity scores are 0 (negative), 1 (weakly positive), 2 (moderately positive), and 3 (strongly positive). The frequency scores are 1 (5–24%), 2 (25–49%), 3 (50–74%), and 4 (75–100%). b Correlation between serum PRTN3 and CES levels. c and e Representative cases of PRTN3 expression in stromal cells of primary colorectal and metastatic liver specimens. The upper row shows the case with a few positive cells in the stroma. The lower row shows the case with many positive cells in the stroma. d and f Correlation between serum PRTN3 levels and number of PRTN3-positive cells in the stroma of primary and metastatic tumors, respectively. *P<0.05. Abbreviations: CES, composite expression score; HPF, high-power field; PRTN3, proteinase-3