Laboratory predictors to intravesical BCG therapy response in patients with non-muscle invasive bladder cancer

Abstract

Introduction. Transurethral resection of bladder tumor (TURBT) is the gold standard treatment for patients with non-muscle invasive bladder cancer (NMIBC). However, the high recurrence rate after TURBT makes necessary not only regular following to reveal recurrence disease timely, but it also talks about a necessity of adjuvant antitumor therapy in some cases, that allows to prevent disease recurrence and progression. In this regard, patients belonging to high- and sometimes intermediate- risk progression groups are shown to undergo postoperative adjuvant intravesical Bacillus Calmette–Guérin (BCG) therapy. Despite the long experience of using BCG therapy for NMIBC treatment the question of the existence of possible prognostic markers and response predictors to intravesical BCG therapy remains open.Objective. To review cutting-edge data on different markers that can be used as predictive response markers to ongoing intravesical BCG therapy in NMIBC-patients.Materials and methods. A literature search was conducted using PubMed/ Medline and Google Scholar databases. We used terms 'bladder cancer', 'non-muscle-invasive bladder cancer' in conjunction with 'recurrence', 'progression', 'BCG', 'intravesical therapy', 'immune response', 'molecular markers' to choose relevant articles published between 2000 and 2022.Results. Clinical and pathological characteristics of the tumor and the patient himself remain leading in predicting the response to intravesical BCG therapy in NMIBC-patients. However, to improve the effectiveness of assessing the risk of developing adverse BC outcomes and choosing the most appropriate strategy for monitoring and treatment in each case, it is necessary to introduce additional assessment parameters. Molecular and genetic markers could be considered as such parameters, make it possible to reveal differences between tumors at a deeper level.Conclusion. Currently, there are no markers that have high-evidence in predicting response to intravesical BCG therapy in NMIBC-patients compared with the cliniсal and pathological characteristics of the tumor and the patient himself. The clearer awareness of molecular genetic pathways of BC pathogenesis, the mechanism of BCG antitumor effect will make it possible to competently select markers that have the highest specificity for BC, which will increase the predictive ability of currently existing tools to assess the risks of BC recurrence and progression.