Oncologic outcomes of Bacillus Calmette-Guérin therapy in elderly patients with non-muscle-invasive bladder cancer: A meta-analysis

Introduction: There is a challenge on the medical efficacy of intravesical Bacillus Calmette-Guérin (BCG) therapy and the power of the immune system boosting, which can be influenced by the age of the non-muscle-invasive bladder cancer (NMIBC) patients. This meta-analysis evaluates the efficacy of BCG therapy among aged (>70) and younger patients with non-muscle-invasive bladder cancer (NMIBC). Methods: The central database of PubMed, Scopus, and Web of Science were queried until August 4, 2021, by using "BCG," "Bladder Cancer," "AGE," and "efficacy" keywords. After excluding duplicated results, titles and abstracts were evaluated by two independent reviewers. The exclusion criteria included non-English studies, conference abstracts, reviews, editorials, letters, and comments. Three main outcomes, disease-free survival (DFS), progression-free survival (PFS), and cancer-specific survival (CSS), were considered. The statistical analysis was performed using STATA (version 14; Stata Corp, College Station, Texas, USA). Results: From 1115 found documents, the 24 research articles were recruited in the systematic review, and 10 were the candidate for meta-analysis. The overall estimate of H.R. revealed that BCG therapy in those over age 70 is significantly associated with an improved risk of progression and cancer-specific death in studied patients. However, this association was not statistically significant for DFS (1.04 (95% CI: 0.85,1.26)). Conclusion: The BCG maintenance therapy improved CSS and PFS oncological outcomes in elderly patients with NMIBC. BCG therapy did not significantly change the DSF.