452P - The relationship between BCG immunotherapy and oxidative stress parameters in patients with non-muscle invasive bladder cancer

Background

Environmental toxins have been associated to a regulation of oxidative stress markers, which have the potential for the development of bladder cancer. However, limited studies on the function of oxidative stress parameters and non-muscle invasive bladder cancer in therapy response. Thus, we studied the oxidative parameters in response to BCG immunotherapy in non-muscle invasive bladder cancer (NMIBC).

Methods

120 patients with NMIBC and treatment with BCG were enrolled and categorised into two groups on BCG response, 50 patients BCG-responsive (BCG-R) and 70 were BCG-non responsive (BCG-N). BCG-R have no evidence of tumour recurrence or advancement after 1 year of BCG immunotherapy, but BCG-N have recurrence of tumour after 3-6month cycles of BCG instillation, as determined by cystoscopy. In all groups, we measured the levels of oxidative stress markers- malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), and catalase (CAT).

Results

Our findings revealed that the levels of the oxidative stress markers (MDA, NO, and SOD) in the BCG-N group were significantly higher (p < 0.001) than in the BCG-R group. Furthermore, the data demonstrate a significant correlation between oxidative stress marker and NMIBC T1 high grade and tumour size >2.5cm, but no significant difference was found with CAT.

Conclusions

The findings suggest that the carcinogenesis of NMIBC is associated with oxidative damage of biomolecules and indicates the involvement of oxidative stress markers in the development and recurrence of NMIBC; therefore, it is critical to ensure a management for T1 high grade and tumour size of >2.5cm to ensure antioxidant protection.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Indian Council of Medical Research.

Disclosure

All authors have declared no conflicts of interest.