The acute phase protein response (APPR) and peripheral blood mononuclear cell-derived inflammatory cytokine production was assessed in patients with advanced pancreatic cancer and age-matched healthy volunteers. We examined the relationship between the APPR, cytokine production and survival in these patients. Forty-two patients with pancreatic cancer cachexia and twelve age-matched healthy controls were recruited. The nutritional status, Karnofsky performance score, C reactive protein (CRP), serum interleukin-6, and in vitro monocyte interleukin-1 and interleukin-6 production were measured. The dates of death of the pancreatic cancer patients were subsequently obtained and appropriate patient variables at baseline were entered into a Cox's proportional hazards model. The cancer patients had significantly lower: body mass index, Karnofsky performance score, serum albumin and elevated CRP and stimulated interleukin-6 production. Both univariate and multivariate analysis demonstrated a strong association between tumour stage, CRP, stimulated interleukin-6 production and survival. Monocytes in cachectic pancreatic cancer patients are primed to produce high levels of interleukin-6 when stimulated. Overproduction of interleukin-6 has a negative impact on survival. Decreased survival is associated with an elevated APPR. While the elevated APPR is probably related to locally produced interleukin-6 in the liver, it seems possible that locally and systemically produced interleukin-6 influences survival.