In 302 BCSs, examined approximately four years after treatment for breast cancer stage II/III, data on high sensitivity (hs)CRP, leukocytes and mRNA interleukin (IL)1¦Â and IL6R expression, depression and chronic fatigue were available. Three years thereafter, 236 BCSs were re-examined. The associations between fatigue and SNPs in inflammation-related genes; IL1¦Â (rs16944), IL6 (rs1800795), IL6receptor (rs4129267, rs4845617, rs2228145), CRP (rs2794521, rs3091244) were investigated, together with the relations between SNPs in IL6R, IL1¦Â and CRP genes and mRNA blood expression levels of IL6R and IL1¦Â and serum hsCRP-levels, respectively. All analyses were repeated after exclusion of depressed individuals and separating BCSs with persistent fatigue from never-fatigued individuals.
Even after exclusion of depressed individuals neither the SNPs nor the mRNA IL1¦Â and IL6R expression levels were associated with chronic or persistent fatigue. In the subset of persistent fatigued and never-fatigued individuals the CRP SNP (rs3091244) was associated with hsCRP level (p = 0.02). IL1¦Â and IL6R mRNA expression levels were not related to the IL1¦Â and IL6R genotypes.
In a large cohort of BCSs the investigated SNPs in inflammation-related genes were not associated with fatigue, though subset analyses indicated an association between the CRP SNP (rs3091244) and serum hsCRP.