Prognostic biomarker potential of quantifying endotrophin in serum from pancreas cancer patients.
e16804 Background: Pancreas cancer (PC) is the most stroma rich tumor type defined by increased collagen deposition and remodeling (desmoplasia/tumor fibrosis), which result in poor prognosis and lack of treatment response. The cleavage product of the type VI collagen alpha 3 (COL6a3) chain, also knowns as endothrophin, has been shown to signaling properties and affect several pro-tumorigenic events by augmenting desmoplasia, angiogenesis, inflammation and tumor growth. Here we evaluate the clinical utility of a biomarker (PRO-C6) quantifying endothrophin in serum from patients with PC. Methods: Serum PRO-C6 was measured by ELISA (Nordic Bioscience) in 814 PC patients (n = 15, 201, 164 and 434 for stage 1-4, respectively) and 87 patients with benign conditions from the clinical study BIOPAC (NCT03311776, Denmark). PC was histologically confirmed, and patients received standard of treatment (surgical resection or palliative chemotherapy). PRO-C6 was compared between PC and benign conditions and correlated to stage. Association between OS and PRO-C6 in PC patients was analyzed by Kaplan-Meyer curves and Cox regression analysis alone, and after adjusting for age, gender, BMI, diabetes, smoking, performance status, cachexia, CA19-9, stage and metastatic sites. Results: PRO-C6 was elevated in PC compared to benign disease (p = 0.009) and increased with tumor stage (p = 0.0006). When dividing PRO-C6 into quartiles (Q1-Q4) a stepwise decrease was detected in median OS time (Q1:380 days, Q2:264 days, Q3:236 days, Q4:176 days, p < 0.0001). Patients in Q4 had 85% increased risk of dying compared to Q1 (HR:1.85, p < 0.0001). High PRO-C6 (Q4) remained associated with poor OS after adjusting for co-variates (HR: 1.66, p = 0.0018). Conclusions: Pretreatment serum PRO-C6 (a measure of the COL6a3 chain/endothrophin) is associated with PC and has independent prognostic value. This suggests that endothrophin, and the desmoplastic reaction, plays a key role in PC and indicate that PRO-C6 may provide means for a theragnostic approach for stratifying and treating PC patients in the future. Clinical trial information: NCT03311776 .