Prognostic Role of Endocan and Platelet-Derived Growth Factor Isoforms in Metastatic Colorectal Cancer

To investigate whether pretreatment serum endocan, platelet-derived growth factor (PDGF)-CC, and -DD levels are elevated in metastatic colorectal cancer (mCRC) patients compared to healthy controls, and to assess their independent associations with chemotherapy response and survival, along with their comparative predictive performance. Adult patients with mCRC receiving systemic chemotherapy combined with an anti-angiogenic agent (bevacizumab or aflibercept) were prospectively enrolled, along with healthy controls. Pretreatment serum samples were collected prior to therapy initiation. Endocan, PDGF-CC, and PDGF-DD levels were measured in duplicate using enzyme-linked immunosorbent assay. Treatment response was evaluated according to Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 and categorized as responders (complete or partial response) and non-responders (stable or progressive disease). Progression-free survival (PFS) and overall survival (OS) were recorded. Median serum levels of endocan (405.5 vs. 269.0 pg/mL), PDGF-DD (499.9 vs. 315.1 pg/mL), and PDGF-CC (2330 vs. 1118 pg/mL) were significantly higher in the mCRC group compared to controls (p < 0.001). In multivariable logistic regression, all three biomarkers were independently associated with non-response to chemotherapy [Odds ratio (ORs): 1.10 for endocan, 1.05 for PDGF-DD, 1.05 for PDGF-CC; all p < 0.05]. For disease progression, Cox regression showed that higher levels of endocan [Hazard ratio (HR) = 1.04], PDGF-DD (HR = 1.03), and PDGF-CC (HR = 1.04) were significant predictors (all p < 0.01). Similar associations were observed for overall mortality (HR = 1.04, 1.02, and 1.02, respectively; all p < 0.05). Endocan, PDGF-DD, and PDGF-CC are elevated in mCRC and independently predict poor treatment response and adverse survival outcomes, highlighting their potential as prognostic biomarkers.