Increased TGF‐Beta1 protein expression in patients with advanced colorectal cancer

Abstract Introduction There is evidence that TGF‐β1 plays a role as a tumor suppressor in early disease and has pro‐oncogenic effects in advanced tumor stage. The aim of the study was to correlate TGF‐β1 in plasma and tissue to clinical and pathological parameters in patients with various stages of disease progression. Methods One hundred sixty‐nine patients who underwent surgery for a colorectal carcinoma were prospectively included. Blood samples, tumor free mucosa and tumor biopsies were assayed. Results TGF‐β1 protein expression in tumors increased with increasing T‐stage regardless of whether patients with metastatic disease were included or not ( P = 0.0006). Patients with metastatic disease showed elevated TGF‐β1 protein expression in both tumor tissue ( P = 0.004) and plasma ( P = 0.001) compared to those without metastatic disease. TGF‐β1 protein expression was higher in the colon compared with the rectum in both tumor tissue and tumor‐free bowel ( P = 0.03), regardless of whether patients with metastatic disease were included or not. This difference was mainly attributable to a higher TGF‐β1 protein expression in non‐metastatic patients with lymph node positivity ( P = 0.005). Conclusions Higher TGF‐β1 protein expression is associated with increasing T‐stage and metastatic disease, indicating that TGF‐β1 is of importance in tumor progression. The localization of the tumor seems to influence the TGF‐β1 protein expression in patients with tumor cell‐positive lymph nodes. J. Surg. Oncol. 2008;97:409–415. © 2008 Wiley‐Liss, Inc.