In 40 out of 99 patients (40.4%) with solid tumours of different tissu
e, but the same stage (IV), elevated serum levels of interleukin-10 we
re observed. The mean levels of the cytokine in patients with malignan
t melanoma (24.3 ng/ml), pancreatic (6.8 ng/ml) or gastric (6.3 ng/ml)
adenocarcinoma were significantly higher than in healthy subjects (3.
4 ng/ml) or in patients with uterine fibroma (1.7 ng/ml). Patients wit
h colon (6.8 ng/ml) and renal (5.7 ng/ml) carcinoma had similar values
of interleukin-10 but did not significantly differ from controls. Int
erleukin-10 is known to suppress the functions of both T lymphocytes a
nd macrophages, working as a general dampener of the immune and inflam
matory responses. The observation of increased circulating levels of i
nterleukin-10 in cancer patients may have important implications for f
uture investigations, immunological monitoring and therapeutic interve
ntion on neoplastic patients, and suggests a mechanism for tumour cell
s escaping from immune surveillance.