Search

Tenascin C has been recently suggested as a tumor marker, however, its levels in serum has been evaluated only in patients with head and neck cancer and melanoma. In this study, we investigated Tenascin C expression in blood samples from colorectal and bladder cancer patients, compared to that of epidermal growth factor receptor (EGFR), a known circulating tumor marker in these cancer types. RT-PCR specific for Tenascin C and EGFR was performed on RNAs extracted from blood samples of 60 patients affected by colon or bladder cancer. We then investigated the statistical association between Tenascin C, EGFR expression and disease-free survival using the Kaplan-Meier method. Furthermore, in order to select which variable between EGFR and Tenascin C was the most predictive for recurrence, a Cox model for proportional risk was applied. Among all patients analysed, a significantly higher disease-free time was found in the group negative for both EGFR and Tenascin C expression; EGFR expression was significantly correlated to disease progression in stages III and IV, whereas in all patients with stage I and II disease Tenascin C correlated better with prognosis. Negative expression of both EGFR and Tenascin C identifies a group of patients with poor tendency to disease recurrence and longer relapse-free time. While Tenascin C expression seems to influence prognosis in patients with low-stage disease, EGFR appears a marker of worse prognosis in patients with high-staged tumors.

Despite the large number of studies performed in solid tumors, few attempts at molecular detection of urothelial cells in blood have been made. Specifically, only uroplakin II (UP-II) and cytokeratin 20 (CK-20) have been suggested as tumor markers in the blood of bladder cancer patients. Epidermal growth factor receptor (EGFR) mRNA expression was found in the blood of patients with some types of carcinoma; nevertheless, its expression has been never investigated in the blood of patients with urothelial tumors. We used a EGFR-based reverse transcription-PCR assay for the detection of tumoral cells in the blood of 27 patients with bladder cancer, in 30 healthy donors, and in 9 patients with cystitis. EGFR expression was compared with that of known markers of circulating epithelial cells, CK-19 and CK-20, and to a urothelial-specific marker, UP-II. Analysis by reverse transcription-PCR and Southern blot hybridization showed no evidence of EGFR and UP-II mRNA expression in any of the samples used as controls. Analysis of healthy donors showed mRNA expression for CK-19 and CK-20 in 6 of 30 and in 4 of 30 samples, respectively. All patients with cystitis resulted negative for EGFR expression, whereas 3 of 9, 2 of 9, and 3 of 9 were found expressing CK-19, CK-20, and UP-II, respectively. Among blood samples from tumoral patients, 74% had EGFR mRNA and 41% had positive signals for CK-19, whereas positivity for CK-20 and UP-II was found in 15% and 37% of patients, respectively. These results seem to indicate that EGFR mRNA in the blood may be a useful tumor marker in bladder cancer patients, as well as in other patients with epithelial tumors.