1715 - National Small Cell Bladder Cancer Audit: Results from 26 UK institutions

Background

Small cell bladder cancer (SCBC) is rare and accounts for <1% of all bladder carcinomas. It is aggressive and outcomes are poor due to early metastatic spread. Owing to its rarity, there is currently no standardised UK management pathway and treatments vary between institutions.

Methods

We conducted a retrospective analysis of all patients presenting with SCBC across 26 UK institutions between 1/1/2006 - 1/1/2016. We report on the patient characteristics, treatment received and clinical outcome. Data cut-off date is 1/2/2018.

Results

409 eligible patients (pts) from 26 UK institutions were identified. 75.1% were male. Median age was 71 years (range 35 - 96). 189/409 pts (46.2%) had pure small cell cancer. At data cut-off, 301/409 pts (73.6%) have died. Median overall survival (OS) was 15.9 months (range 9 - 4230 days). 200/409 pts (48.9%) presented with bladder only disease (N0 M0). Median OS of N0 M0 disease was 28.3 months vs. 12.7 months in N+/ M+ disease. Within the N0 M0 group, 61/200 pts (30.5%) had cystectomy and 104/200 pts (52.0%) had radiotherapy. The most common radiotherapy dose schedules used were 64Gy in 32 fractions and 55Gy in 20 fractions. Median OS of the cystectomy group was 26.7 months vs 30.0 months for radiotherapy. 247/409 pts (60.4%) received primary chemotherapy. Median time from diagnosis to first chemotherapy date was 47 days (range 5 - 124 days). The regimens used include carboplatin and etoposide (54.6%), cisplatin and etoposide (17.0%), cisplatin and gemcitabine (14.2%), carboplatin and gemcitabine (5.3%), other (3.6%). Median OS of pts who received primary chemotherapy was 21.6 months vs. 11.3 months in those who received no chemotherapy. Only 6 pts (1.5%) were identified to have brain metastases.

Conclusions

This is the largest retrospective study of unselected small cell cancer bladder population to date. These patients have a poor prognosis and brain metastases were rare (1.5%). Median OS was better in the chemotherapy than the non-chemotherapy group. Our results are in keeping with other studies which showed similar outcome between cystectomy and radiotherapy in patients with bladder only disease. UK national consensus guidelines are now being set up to standardise therapeutic approach for this rare disease entity.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.