Serum thymidine kinase 1 activity in solid tumor (breast and colorectal cancer) patients treated with adjuvant chemotherapy.

BACKGROUND: The aim of this study was to evaluate the changing of TK1 (where TK is thymidine kinase) activity before and after adjuvant chemotherapy in patients with breast and colorectal cancer. METHODS: The study included 16 breast cancer, 25 colorectal cancer, and 38 healthy volunteers as the control group. Blood samples were taken twice from each patient; first at the beginning of the chemotherapy and second after six cycles of chemotherapy. TK1 activity was measured enzyme immunoassay method. RESULTS: The mean TK1 activity in the breast and colorectal cancer was significantly higher than the controls. TK1 activity in the colorectal cancer was higher than the breast cancer but this difference was not significant. TK1 activity after six doses of chemotherapy was lower than baseline TK1 activity before the start of chemotherapy in breast and colorectal cancer. TK1 activity was positively correlated with CA15-3, before and after chemotherapy in patients with breast cancer. TK1 activity in the colorectal cancer was also positively correlated with CA19-9, before and after chemotherapy. The values for the cutoff point, sensitivity, specificity, and the area under curve were determined for TK1 as >44.36 Du/L, 68.29%, 100% and 0.819, respectively in all subjects. CONCLUSION: Our results showed that serum TK1 activity in patients with breast and colorectal cancer was significantly higher than that of the healthy controls. Moreover, after the completion of chemotherapy the values were lower than baseline. Pretreatment TK1 activity should be considered as a useful marker for assessment tumor cell proliferation in breast and colorectal cancer. Further work is needed to understand TK1 activity better in large populations of patients with solid tumor.

Serum lipid hydroperoxide levels and paraoxonase activity in patients with lung, breast, and colorectal cancer.

OBJECTIVES: The objectives of this article are to investigate the serum lipid hydroperoxide (LOOH) levels and paraoxonase-1 (PON1) and arylesterase (ARE) activity in patients with lung, breast, and colorectal cancer. DESIGN AND METHODS: Serum PON1 and ARE activities and LOOH levels were measured in 110 patients with cancer and same number of age- and sex-matched controls. RESULTS: Serum LOOH levels were found to be increased while serum PON1 and ARE activities were found to be decreased in patients compared to controls. PON1 activity was found to be lower in patients with breast cancer than in patients with lung and colorectal cancer. There were positive correlations between the serum PON1 and ARE activities in patients with colorectal cancer. CONCLUSION: We concluded that decreased PON1 and ARE activities and increased LOOH levels might have a connection to carcinogenesis. PON1 activity is decreased in all patients but it does not seem to be related to metastase status except for colorectal cancer.

Clinical significance and prognostic value of serum sHER-2/neu levels in patients with solid tumors.

The purpose of this study was to determine HER-2/neu in the serum of patients with solid tumors and to investigate its potential usefulness in predicting the clinical course of the disease. At the same time, we compared the ability of serum HER-2/neu, CA15.3, CA12-5, CA19-9, carcino embryonic antigen (CEA), and alpha-feto-protein (AFP) in breast, colorectal, and lung cancer patients. Forty, thirty-six, and twenty-three patients with lung, colon and breast cancer were included in this study, respectively. Serum levels of HER-2/neu, CA15.3, CA12-5, CA19-9, CEA, and AFP were measured. Her-2 neu levels were significantly higher in the breast cancer groups than colorectal and lung cancer and controls groups (P < 0.01). There is no significant difference when compared with others groups (P > 0.05). There was a positive correlation between the HER-2/neu and CA15-3 values in breast cancer groups. We found 0.75(0.59-0.90) for Her-2/neu from the area under the curve (AUC). P-value for breast cancer is 0.003, and we discovered that 9 ng/ml was the best inersection point. In this situation, we calculated that sensitivity was 65.2%, specificity was 100%, positive predictive value was 100%, negative predictive value 75.8%, and accuracy was 83.4%. These findings indicate that serum HER2/neu levels are clinically valuable in monitoring metastatic breast cancer and non-small cell lung cancer patients. Prognosis of breast cancer provides an additional value over the commonly used CA15-3 test. Measurements of levels of serum HER-2/neu provide prognostic and predictive information to the clinician and can especially be used for monitoring metastatic breast cancer patients. Further clinical validation is needed to confirm these findings.

Levels of plasma vitamin E, vitamin C, TBARS, and cholesterol in male patients with colorectal tumors.

Vitamin E and vitamin C are involved in the defense of the body against free radical and reactive oxygen molecule induced damage. The best characterized biological damage caused by radicals is known as lipid peroxidation. Free radical formation is known to play a major role in the development of cancer. In this study, we measured plasma levels of thiobarbituric acid reactive substances (TBARS) as a marker of lipid peroxidation, cholesterol, and vitamins E and C as antioxidants in male patients with colorectal tumors (n = 20, 54.5 +/- 8.3 years). The patients had significantly higher plasma TBARS levels than age-matched healthy subjects (p < 0.001). Plasma vitamin C levels were significantly lower in the patients compared to the healthy subjects (p < 0.001). On the other hand, plasma vitamin E levels in the patients were similar to those of healthy subjects. Plasma cholesterol levels were also found to be significantly elevated in patients with colorectal tumors (p < 0.001). Our results suggest that there is an imbalance between oxidant and antioxidant status in tumor genesis.