Interleukin-6 blood level is associated with circulating carcinoembryonic antigen and prognosis in patients with colorectal cancer.
BACKGROUND
Interleukin-6 (IL-6) is an important proinflammatory cytokine that has multiple effects on stimulating inflammation and cell growth. Experimental data suggest that carcinoembryonic antigen (CEA) induces the systemic production of IL-6 and that IL-6 may stimulate tumor cell growth at metastatic sites. We tested the hypothesis that blood concentrations of IL-6 are associated with the amount of circulating CEA and with prognosis in patients with colorectal cancer.


METHODS
CEA and IL-6 concentrations were measured by using enzyme immunoassay in preoperative serum samples from 208 patients with stages I through IV colorectal cancer.


RESULTS
Linear regression analysis showed a significant association between serum values of CEA and IL-6 (r = .544; R2 = .296; P < .001). Patients with stage III and stage IV disease had a significantly higher IL-6 serum concentration than those with stage I and stage II disease. In patients with stages I through III, 5-year survival was 83% in cases with concentrations of IL-6 at 10 pg/ml or less (n = 94) and 56% in cases with IL-6 concentrations of more than 10 pg/ml (n = 54; P = .001; median follow-up time, 46 months). By using multivariate analysis, an IL-6 concentration of more than 10 pg/ml was an independent prognostic factor of survival (relative risk = 1.820; P = .020).


CONCLUSIONS
In patients with colorectal cancer, blood concentration of IL-6 is associated with high circulating CEA and advanced stage. Furthermore, an IL-6 concentration of more than 10 pg/ml is an independent negative prognostic marker of survival.
Belluco
C
C
Department of Oncological and Surgical Sciences, University of Padova, Italy.
Nitti
D
D
Frantz
M
M
Toppan
P
P
Basso
D
D
Plebani
M
M
Lise
M
M
Jessup
J M
JM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002272:Carcinoembryonic Antigen / Q000097:blood*; D003110:Colonic Neoplasms / Q000097:blood* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D011379:Prognosis; D012004:Rectal Neoplasms / Q000097:blood* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D016896:Treatment Outcome
D002272:Carcinoembryonic Antigen; D015850:Interleukin-6