Prognostic impact of plasma ORM2 levels in patients with stage II colorectal cancer

Purpose: Orosomucoid 2 (ORM2) or alpha-1-acid glycoprotein 2 is associated with intestinal system disease and cancers, including stage II colorectal cancer (CRC). The highly heterogeneous characteristics of CRC have made the application of adjuvant therapies in patients with stage II CRC controversial. This study aimed to validate the prognostic significance of plasma ORM2 in patients with stage II CRC.

Methods: Plasma ORM2 levels were determined with enzyme-linked immunosorbent assay (ELISA). Curves were constructed with the Kaplan-Meier method and compared by using log-rank test with data both on overall and cancer-specific survival. The Cox proportional hazards regression model was used to estimate the independent prognostic factors.

Results: The median plasma ORM2 level in stage II CRC patients was significantly higher than that of healthy controls (P<0.001), and 56.4% of the patients with stage II CRC had plasma ORM2 levels above the 95(th) percentile of healthy controls. Thus, the association between plasma ORM2 level with local invasion of stage II CRC (P=0.048) and lymph node numbers (P=0.011) was significant. Patients with elevated plasma ORM2 had significantly shorter overall and cancer-specific survival rates (P=0.008 and P=0.015, respectively). Multivariate analyses indicated that plasma ORM2 was an independent prognostic factor both for overall and for cancer-specific survival in patients with stage II CRC (all P<0.05).

Conclusions: These findings demonstrate that plasma ORM2 is an independent prognostic factor in patients with stage II CRC. This could help healthcare providers to identify the patients most eligible for adjuvant therapies.