Colorectal cancer is one of the most common cancers of the gastrointestinal tract and the fourth cause of cancer death in the world. It has been shown that local chronic inflammation may lead to colorectal carcinogenesis via adenomatous polyps. Interleukin-6 and C-reactive protein are biomarkers of inflammation and indicators of the immune response to tumors. Serum levels of interleukin-6, carcinoembryonic antigen and carbohydrate antigen 19-9 were determined using immunoenzymatic assays, and C-reactive protein concentrations by immunoturbidimetric kits in 76 colorectal cancer patients before surgery, in 38 colorectal adenoma patients and in 35 healthy controls. Serum levels of interleukin-6, C-reactive protein and carcinoembryonic antigen were significantly higher in cancer patients when compared to adenoma patients and healthy subjects, and increased in more advanced stages of disease and in patients with non-resectable tumors. Based on Cox's analysis, the elevated preoperative serum level of C-reactive protein was an independent significant prognostic factor for patients' survival. Our findings suggest the usefulness of interleukin-6 in the diagnosis of colorectal cancer patients and C-reactive protein in the survival prognosis.

Gastric cancer (GC) is a second most common cause of cancer-related death and represents an inflammation-driven malignancy. It has been suggested that interleukin 6 (IL-6) and C-reactive protein (CRP) play a potential role in the growth and progression of GC. The aim of the present study was to compare clinical significance of IL-6 and CRP with classic tumor markers—carcinoembryonic antigen (CEA) and carbohydrate antigen (CA 19-9) in GC patients. The study included 92 patients with GC and 70 healthy subjects. The serum concentrations of IL-6, CEA and CA 19-9 were determined using immunoenzyme assays, whereas CRP using immunoturbidimetric method. We defined the diagnostic criteria and prognostic value for proteins tested. In GC patients, the serum concentrations of all the proteins tested were significantly higher than in healthy subjects. The IL-6, CEA and CA 19-9 levels correlated with nodal metastases, while CRP with tumor stage, gastric wall invasion, presence of nodal and distant metastases. Diagnostic sensitivity of IL-6 was higher (85%) than those of other markers (CRP 66%, CA 19-9 34%, CEA 22%) and increased in combined use with CRP or CEA (88%). The area under ROC curve for IL-6 was larger than those of CRP and classic tumor markers (CEA and CA 19-9). None of the proteins tested was independent prognostic factor for the survival of GC patients. Our findings indicate better usefulness of serum proinflammatory proteins—IL-6 and CRP than classic tumor markers—CEA and CA 19-9 in the diagnosis of GC.

Pancreatic cancer (PC) is a malignant tumor with high mortality. Aggressive growth and metastases of PC are the result of basement membrane degradation that may be attributed to the action of matrix metalloproteinase-9 (MMP-9). The aim of the study was to determine the diagnostic and prognostic significance of the measurements of serum MMP-9 and tissue inhibitor of metalloproteinase-1 (TIMP-1) in patients with PC. The study involved 78 patients with PC, 45 with chronic pancreatitis, and 70 healthy subjects. We assayed the serum concentrations of MMP-9, TIMP-1, and classic tumor markers (carbohydrate antigen 19-9 and carcinoembryonic antigen) and defined the prognostic value and the diagnostic criteria for all the proteins tested. In the patients with PC, the serum levels of MMP-9, TIMP-1, and the tumor markers were higher as compared with those in the patients with chronic pancreatitis and the healthy subjects. The diagnostic sensitivity and the area under the receiver operating characteristic curve for TIMP-1 were higher than for MMP-9 and the tumor markers. The elevated preoperative concentration of MMP-9 was a significant independent prognostic factor for the patients' survival. These findings indicate a potential clinical significance of serum TIMP-1 and MMP-9 measurements in the diagnosis and prognosis of patients with PC, respectively.