Associations of circulating C-reactive protein and interleukin-6 with cancer risk: findings from two prospective cohorts and a meta-analysis.
OBJECTIVE
We investigated the associations of circulating C-reactive protein (CRP) and interleukin-6 (IL-6) with cancer risk.


METHODS
We examined the associations of CRP and IL-6 with incident cancer in two prospective cohorts, the British Women's Heart and Health Study (4,286 women aged 60-80) and the Caerphilly Cohort (2,398 men aged 45-59) using Cox regression and pooled our findings with previous prospective studies' in fixed and random effects meta-analyses.


RESULTS
CRP and IL-6 were associated with some incident cancers in our cohorts, but the numbers of cancer cases were small. In our meta-analyses elevated CRP was associated with an increased overall risk of cancer (random effects estimate (RE): 1.10, 95% CI: 1.02, 1.18) and lung cancer (RE: 1.32, 95% CI: 1.08, 1.61). Its associations with colorectal (RE: 1.09, 95% CI: 0.98, 1.21) and breast cancer risks (RE: 1.10, 95% CI: 0.97, 1.26) were weaker. CRP appeared unrelated to prostate cancer risk (RE: 1.00 0.88, 1.13). IL-6 was associated with increased lung and breast cancer risks and decreased prostate cancer risk, and was unrelated to colorectal cancer risk.


CONCLUSIONS
Our findings suggest an etiological role for CRP and IL-6 in some cancers. Further large prospective and genetic studies would help to better understand this role.
Heikkilä
Katriina
K
Department of Social Medicine, University of Bristol, Canynge Hall, Whiteladies Road, Bristol, BS8 2PR, UK.
Harris
Ross
R
Lowe
Gordon
G
Rumley
Ann
A
Yarnell
John
J
Gallacher
John
J
Ben-Shlomo
Yoav
Y
Ebrahim
Shah
S
Lawlor
Debbie A
DA
D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000453:epidemiology; D002097:C-Reactive Protein / Q000378:metabolism*; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000453:epidemiology; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008175:Lung Neoplasms / Q000453:epidemiology; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology*; D011446:Prospective Studies; D012307:Risk Factors
D015850:Interleukin-6; D002097:C-Reactive Protein