Bladder-sparing treatments show noninferior OS vs radical cystectomy in BCG-unresponsive NMIBC

Patients who underwent bladder-sparing treatment (BST) for Bacillus Calmette-Guerin (BCG) unresponsive non-muscle invasive bladder cancer (NMIBC) were not found to have inferior long-term survival outcomes compared with those who underwent early radical cystectomy (RC). The data were presented at the 2023 American Urological Association Annual Meeting in Chicago, Illinois.¹

Patients who underwent RC were more likely to have T1 disease, with 52.6% of RC patients presenting with T1 disease compared with 35.0% of patients who underwent BST.

“Radical cystectomy is the recommended treatment for BCG-unresponsive non muscle invasive bladder cancer. However, a lot of patients are quite reluctant to undergo radical cystectomy, and sometimes they seek alternatives such as bladder-sparing approaches… What we wanted to evaluate is, “Are we sacrificing cancer outcomes in our attempts to preserve the bladder?” said lead author Wei Shen Tan, MD, during a presentation on the results. Tan is a urologic oncology fellow at MD Anderson Cancer Center in Houston, Texas.

In total, 118 patients who were diagnosed with BCG-unresponsive NMIBC at MD Anderson Cancer Center between January 2000 and September 2021 were retrospectively identified for analysis. Of these, 76 underwent BST and 38 underwent early RC. In the BST group, treatments included additional BCG (36.8%), BCG interferon (28.9%), gemcitabine/docetaxel (21.1%), and other (13.2%).

Patients who underwent RC were more likely to have T1 disease, with 52.6% of RC patients presenting with T1 disease compared with 35.0% of patients who underwent BST (P = .048). Further, 10.5% of patients who were treated with RC had lymphovascular invasion, compared with 0% of patients who were treated with bladder-sparing options (P = .003). Patients receiving BST had more prior BCG instillations, with 93.4% of this group having received ≥10 instillations vs 34.2% in the RC group (P < .001). Patients in the BST arm were more likely to be ex- or current smokers at 73.7% vs 50% in the RC group (P = .012).

For the study, the investigators compared patients who underwent early RC versus BST, as well as patients who underwent early RC versus delayed RC. The primary end points were overall survival (OS) and cancer-specific survival (CSS). Median follow-up for patients who underwent BST was 72.1 months.

There was no significant difference found in overall survival (HR, 1.34; P = .429) outcomes nor cancer-specific survival (HR, 0.84; P = .803) outcomes between patients who underwent RC and patients who underwent BST.

Patients who underwent BST had a high-grade regression-free survival of 37% and a progression-free survival of 84%. In total, avoidance of RC was achieved in 81% of patients.

“Specifically for patients undergoing bladder-sparing treatments, a significant number of patients actually go on to have high-grade recurrence–nearly 60% of them–and this tails out after 48 months. So, even though we did show there is no significant difference in survival outcomes, it's important to understand that a fair number of these patients actually go on to have high-grade recurrence, and it's very important to promptly address high-grade recurrence and recommend radical treatment where indicated,” Tan said during the presentation.

Among patients receiving BST, current smokers had a higher risk of high-grade recurrence compared with non-smokers (P = .005) upon multivariable analysis.

Among the patients who underwent RC, median time to early RC was 2.1 months, and median time to delayed RC was 15.8 months. Those who underwent early RC had an OS of 58%, compared with 54% among those with delayed RC (HR, 1.17; P = .717). Patients in both groups had a CSS of 81% (HR, 1.07; P = .927).

“Our results suggest that bladder-sparing treatments may be a safe approach in selected patients. Survival outcomes were not inferior compared to early radical cystectomy. Some of our results may be useful in counseling patients and physicians and allaying fears that the bladder-sparing approach may be appropriate in selected patients,” Tan concluded.

Reference

1. Shen Tan W, Grajales V, Contieri R, et al. Bladder sparing treatment in patients with BCG unresponsive non-muscle invasive bladder cancer: An analysis of long-term survival outcomes. Presented at: American Urological Association Annual Meeting, April 28-May 1, Chicago. Abstract PD13-12. doi:10.1097/JU.0000000000003260.12