Significance of transforming growth factor β1 as a new tumor marker for colorectal cancer

Transforming growth factor β1 (TGF‐β1) is thought to be involved in cancer growth and progression. TGF‐β1 changes to its active form after being secreted in its latent form. Our aim was to clarify the significance of plasma concentrations of active and total TGF‐β1 of patients with colorectal cancer. Plasma concentrations of active and total TGF‐β1 in 45 patients with colorectal cancer and 23 healthy volunteers were measured using ELISA and the activation rate (ratio of active to total TGF‐β1) was determined. Plasma concentrations of active TGF‐β1 (21.9 ± 12.8 pg/ml) were significantly higher in patients with colorectal cancer than in healthy volunteers (9.9 ± 5.9 pg/ml; p < 0.001, Welch's t‐test). Concentration of total TGF‐β1 was also significantly higher for patients with colorectal cancer (18.0 ± 13.0 ng/ml vs. 11.1 ± 6.4 ng/ml; p < 0.01, Welch's t‐test). However, there was no significant difference in the TGF‐β1 activation rate between the 2 groups. There was a correlation between Dukes' stage and plasma concentration of active or total TGF‐β1 (p < 0.01, Spearman's rank correlation test) and on day 7 the active TGF‐β1 levels for patients recovering from curative resection were similar to those of the control group of healthy volunteers. These results suggest that active TGF‐β1 might be used as a tumor marker for colorectal cancer. © 2001 Wiley‐Liss, Inc.