Evaluation of serum fibronectin level and fibronectin gene polymorphism in patients receiving intravesical BCG treatment due to non-muscle invasive bladder cancer

Bladder cancers are tumors that have a spectrum ranging from non-invasive tumors, which are generally not aggressive and have a high recurrence rate, to aggressive and invasive tumors with disease-specific high mortality rates. They rank 10th among the most commonly detected cancers worldwide, and patients are subjected to long-term invasive surveillance. In our study, we aimed to predict the effects of serum fibronectin levels and fibronectin gene polymorphisms on the diagnosis of bladder cancer and the response to treatment in patients with non-invasive bladder cancer treated with intravesical BCG and individuals without any malignancies. The study included 73 patients who underwent intravesical BCG treatment for non-invasive bladder cancer and 56 individuals without any malignancies. Demographic data of all individuals were examined. Serum fibronectin levels were measured using the ELISA method. PCR testing was used for fibronectin gene polymorphisms RS10202709 and RS35343655. Differences between continuous measurements and sociodemographic factors were examined. There was no statistically significant difference between groups in terms of age, gender, smoking, and body mass index (Tables 6 and 9). The mean fibronectin level of the patient group was 76.794 ± 66.998 ng/ml, and the mean fibronectin level of the control group was 50.486 ± 25.156 ng/ml. The differences in serum fibronectin levels were statistically significant (p=0.003). However, there was no statistically significant difference in mean serum fibronectin levels and response to intravesical BCG treatment with RS35343655 and RS10202709 gene polymorphisms (Tables 12, 13, and 14). In conclusion, the statistically significant difference in serum fibronectin levels between patients with non-invasive bladder cancer and the control group suggests that the measurement of serum fibronectin levels could be considered as a tumor biomarker in the diagnosis of bladder cancer. However, our findings indicate that fibronectin gene polymorphisms do not have a prognostic significance in the diagnosis of bladder cancer or in the evaluation of response to treatment. Keywords: Bladder cancer, serum fibronectin, gene polymorphisms, intravesical BCG therapy