Intravesical recurrence after bladder sparing treatment of small cell carcinoma of the bladder: Characteristics, treatment, and outcome.

Introduction: Small cell carcinoma of the bladder (SCCB) is a rare and lethal disease. Previously, we and others have reported a bladder sparing strategy with platinum-etoposide-based chemotherapy followed by radiotherapy of the bladder. Little is known on frequency and treatment of intravesical recurrence following this approach. The objective of this study is to describe the incidence of intravesical recurrences and their management.

Materials And Methods: Retrospective study including all patients with SCCB treated at a single institution from 1993 until 2016. All patients with limited disease (LD) SCCB who had a bladder sparing approach with sequential chemotherapy and radiotherapy were identified. Intravesical and overall recurrence rate, overall and disease specific survival, salvage treatment options and their results were retrieved.

Results: Of the 110 patients with SCCB (82% male) with a mean age of 65 years and a median follow up of 48 months, 89 patients (81%) had LD-SCCB. Of these, 65 were treated with chemotherapy and radiotherapy, with a median overall recurrence free survival of 22 months (CI: 14-30). Of 65 patients, 23 (35%) progressed to distant metastasis without intravesical recurrence after a median of 9 months (CI: 8-11), whereas 14 patients (22%) developed isolated intravesical recurrence at a median of 24 months (CI: 14-34). Local recurrence contained SCCB, urothelial carcinoma, and carcinoma in situ and was treated with various local salvage treatments including TURB, cystectomy, neoadjuvant chemotherapy, and BCG. Following salvage treatment a complete response was seen in 64%. Median overall survival for intravesical vs. systemic recurrence was different, with 28 (CI: 9-47) and 8 (CI: 5-11) months, respectively (P<0.001).

Conclusion: SCCB is a serious potentially lethal disease. Even in patients with LD-SCCB a high percentage rapidly develops systemic disease. This suggests that systemic therapy is more important than the type of local treatment to control the disease but small sample sizes limit the ability to distinguish between different treatment options in this study. A bladder sparing approach can be a reasonable alternative to major surgery. However, in those surviving long enough isolated intravesical recurrence occurs even after many years. Our results indicate that long term follow up is required because salvage therapy can be successful in the majority of patients.