CHEMORADIOTHERAPY FOR BLADDER PRESERVATION

Adding chemotherapy with fluorouracil and mitomycin to radiotherapy improves locoregional control, salvage cystectomy rate, and bladder cancer-specific survival compared with radiation treatment alone in muscle-invasive bladder cancer, according to a study presented at the 2017 Genitourinary Cancers Symposium.1

The multicenter, phase 3 BC2001 trial (ClinicalTrials.gov Identifier: NCT00024349) demonstrated that chemoradiotherapy significantly improved locoregional control rates vs radiotherapy alone in muscle-invasive bladder cancer. Reduced high dose volume radiation treatment did not, however, significantly reduce late adverse events compared with standard radiotherapy.

In this updated analysis, results showed that the addition of fluorouracil and mitomycin to radiation significantly reduced the risk of a locoregional event by 41% compared with radiotherapy alone after adjusting for confounding factors (hazard ratio [HR], 0.59; 95% CI, 0.41-0.83; P = .003). Chemoradiotherapy also lowered the risk of an invasive locoregional event by 48% vs radiotherapy (HR, 0.52; 95% CI, 0.33-0.81).

The risk of bladder cancer-specific death was 27% lower for patients treated with chemoradiotherapy (HR, 0.73; 95% CI, 0.54-0.99; P = .04). There was no significant difference in overall survival between the 2 arms.

Receipt of fluorouracil plus mitomycin was associated with a significantly lower rate of salvage cystectomy compared with radiation alone (HR, 0.54; 95% CI, 0.31-0.95; P = .03).

"With 10 years follow-up, an improvement in locoregional control and a reduced salvage cystectomy rate is confirmed with chemoradiotherapy," said lead statistician Emma Hall, PhD. "After adjustment for known prognostic factors, there was an improvement in bladder cancer-specific survival."

Despite additional follow-up, the study continued to show a reduced risk of toxicity with the radiotherapy volume modification. There was no evidence, however, of an increase in the local failure rate with lower dose radiation (HR, 0.82; 95% CI, 0.51-1.31; P = .42).

Dr Hall concluded: "these updated results support the use of chemoradiotherapy with fluorouracil plus mitomycin and confirm that this should be a standard of care in muscle-invasive bladder cancer."