Post-cancer fatigue is not associated with immune activation or altered cytokine production.
BACKGROUND
Prolonged fatigue after cancer treatment is common. The pathophysiology of such post-cancer fatigue (PCF) is unknown, although cross-sectional studies suggest increased pro-inflammatory cytokine production. This study investigated the association between cytokine levels and fatigue from the time of treatment to 12 months later.


METHODS
A representative nested case-control series was derived from a prospective cohort of women treated for early-stage breast cancer, including 13 PCF cases and 15 matched control subjects who recovered uneventfully. Serum levels and in vitro production of the cytokines interleukin (IL)-1α, IL-2, interferon (IFN)-γ, IL-4, IL-6, IL-10, IL-12, and tumour necrosis factor (TNF)-β were measured by multiplex immunoassay in longitudinally collected samples. In addition, serum levels of neopterin and the anti-inflammatory regulators, IL-1 receptor antagonist, sIL-6R, and sTNF-rII, were assayed by enzyme-linked immunosorbent assay. Flow cytometric analysis of activated leukocyte subsets was performed.


RESULTS
No significant differences in any of these parameters were found between cases and control subjects. Cytokine levels and symptoms showed no clear correlation pattern.


CONCLUSIONS
The findings in this well-characterised subject group argue against the notion that PCF is mediated by peripheral inflammation.
Infection and Inflammation Research Centre, School of Medical Sciences, University of New South Wales, Sydney. Electronic address: b.cameron@unsw.edu.au.
B A
BA
Cameron
Infection and Inflammation Research Centre, School of Medical Sciences, University of New South Wales, Sydney; Prince of Wales Clinical School, University of NSW, Sydney.
B
B
Bennett
Infection and Inflammation Research Centre, School of Medical Sciences, University of New South Wales, Sydney.
H
H
Li
Patricia Ritchie Centre, The Mater Hospital, Sydney.
F
F
Boyle
Cancer Care Centre, St George Hospital, Sydney.
P
P
deSouza
Westmead and Nepean Hospitals, Sydney, Australia.
N
N
Wilcken
Prince of Wales Clinical School, University of NSW, Sydney.
M
M
Friedlander
Prince of Wales Clinical School, University of NSW, Sydney.
D
D
Goldstein
Infection and Inflammation Research Centre, School of Medical Sciences, University of New South Wales, Sydney.
A R
AR
Lloyd
D001943:Breast Neoplasms / Q000097:blood / Q000276:immunology / Q000628:therapy*; D016022:Case-Control Studies; D016207:Cytokines / Q000097:blood*; D005221:Fatigue / Q000209:etiology* / Q000276:immunology; D005260:Female; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008875:Middle Aged; D019798:Neopterin / Q000097:blood; D011446:Prospective Studies; D019947:Receptors, Interleukin-6 / Q000097:blood; D047889:Receptors, Tumor Necrosis Factor, Type II / Q000097:blood
D016207:Cytokines; D019947:Receptors, Interleukin-6; D047889:Receptors, Tumor Necrosis Factor, Type II; D019798:Neopterin