Serum tumour necrosis factor-alpha levels in cancer patients are discontinuous and correlate with weight loss

Background Tumour necrosis factor-alpha (TNF) has been regarded as a potent ial mediator of cancer cachexia. Assessment of TNF circulating levels in ca ncer patients and their correlation with weight loss has led to controversi al results. Materials and methods We measured TNF circulating levels in 28 patients wit h gastrointestinal cancer and 29 controls with benign gastrointestinal dise ases at different times (08.00 h, 14.00 h, 20.00 h) before operation. Results TNF activity was not detected in any of controls at any times. In c ancer patients, TNF circulating levels were detectable in 18 cases (64.3%) and appeared to be discontinuous. TNF levels above the limit of detection w ere present in 15 patients (53.6%) at 08.00 h, in 14 (50%) at 014.00 h and in nine (32.1%) at 20.00 h. Mean TNF levels were 14.3 +/- 4 pg mL(-1) at 08 .00 h, 16.7 +/- 4.6 pg mL(-1) at 14.00 h (P = 0.05) and 18.5 +/- 10.2 pg mL (-1) at 20.00 h (P < 0.05 vs. 08.00 h and 14.00 h). According to Spearman's analysis, the sum of TNF concentrations at the three times significantly c orrelated with the severity of weight loss (Spearman's correlation coeffici ent = - 0.420; P = 0.026). TNF concentrations were consistently and signifi cantly higher in patients with severe weight loss than in those with modera te or light weight loss at 08.00 h (26.3 +/- 8.3, 8.9 +/- 4.2, 3.8 +/- 2.1, respectively; P = 0.04 at one-way anova). TNF levels were higher in anorec tic than in nonanorectic patients at any hour, but the differences were not statistically significant. Conclusions The present study demonstrates that TNF is intermittently or di scontinuously detectable in patients with gastrointestinal cancer and that its levels correlate with the severity of weight loss.