Bladder mucosal apoptosis index and quality of life after adjuvant intravesical BCG therapy for non-muscle-invasive bladder cancer: a retrospective propensity-score-matched study

Objective To evaluate the association of adjuvant intravesical Bacillus Calmette-Guérin (BCG) immunotherapy after transurethral resection of bladder tumor (TURBT) with bladder mucosal apoptosis index, recurrence-related outcomes, progression-free survival, and 12-month quality of life in patients with non-muscle-invasive bladder cancer (NMIBC). Methods A retrospective analysis was conducted on 114 NMIBC patients who underwent TURBT at our hospital from January 2022 to December 2024, including 57 patients receiving postoperative intravesical BCG immunotherapy (BCG group) and 57 patients receiving TURBT alone without postoperative adjuvant intravesical therapy (control group). Tumor recurrence rates, progression-free survival (PFS), bladder mucosal apoptosis index, and quality of life (QOL-BREF) scores were compared between groups. Results Baseline characteristics of both groups were balanced via propensity score matching (PSM) (P>0.05). The BCG group exhibited a significantly higher bladder mucosal apoptosis index (32. 13 ± 5.61) compared to the control group (18.72 ± 4.29) (P<0.001). Six-month and one-year recurrence rates were markedly lower in the BCG group (2 cases, 3.51%; 8 cases, 14.04%) versus the control group (9 cases, 15.79%; 21 cases, 36.84%) (P<0.001), with median PFS extended to 25 months (control group: 13 months, P<0.001). Pearson correlation analysis showed a positive correlation between apoptosis index and PFS (r=0.61, P<0.001), and multivariable Cox regression further indicated that a higher apoptosis index was independently associated with a lower risk of recurrence or progression. Preoperative QOL-BREF scores showed no significant difference between groups (54. 11 ± 5.96 vs. 54.03 ± 6.27, P>0.05), while postoperative scores were significantly higher in the BCG group (71.95 ± 8.23 vs. 63.47 ± 8.22) (P<0.001). Conclusion In this retrospective propensity-score-matched cohort, adjuvant intravesical BCG immunotherapy after TURBT was associated with a higher bladder mucosal apoptosis index, lower recurrence risk, longer progression-free survival, and better 12-month QOL-BREF scores. These findings support the clinical relevance of apoptosis index and QOL assessment in postoperative NMIBC management.