Background and Objective: Interleukin 10 (IL-10) has been shown to be
elevated in the plasma of cancer-bearing patients. The source of syste
mic IL-IO may be the tumor microenvironment. We therefore tried to eva
luate if ablative surgery for gastrointestinal cancer could affect the
levels of circulating IL-10. Methods: Plasma IL-10 concentration was
measured in 45 patients with adenocarcinoma of the gastrointestinal tr
act. Forty healthy subjects, 15 women undergoing hysterectomy for uter
ine fibroma, and 15 patients undergoing palliative operation for pancr
eatic cancer were used as control groups. Plasma IL-10 was assessed 1
day before surgery (baseline) and 1, 4, and 8 days after operation. Re
sults: The baseline concentration of IL-IO was significantly higher in
cancer patients than in healthy subjects and in women with fibroma (8
.6 ng/mL, 2.1 and 1.8 respectively; P = 0.015). After radical surgery,
the IL-10 levels significantly dropped in cancer patients (from 8.6 n
g/mL to 3.8: P = 0.024), whereas in subjects undergoing palliative ope
ration, the concentration remained elevated (8.5 ng/mL baseline versus
7.9 on day +1). Conclusions: The origin of circulating IL-10 may be t
he tumor microenvironment. (C) 1997 Wiley-Liss, Inc.