February 6, 2012 (San Francisco, California) — In muscle-invasive bladder cancer, local resection and chemoradiation results in long-term survival benefits equivalent to standard treatment involving radical cystectomy, say researchers here at the 2012 Genitourinary Cancers Symposium.
For patients with less advanced bladder cancer, the use of radiation therapy combined with chemotherapy provides a viable option to surgical removal of the bladder, according to presenting author Raymond Mak, MD, from the Brigham and Women's Hospital and the Dana-Farber Cancer Institute in Boston, Massachusetts.
"We found that [initial complete] response to combined-modality therapy with radiation and clinical T stage are important predictors of beneficial long-term survival outcomes," Dr. Mak said. He noted that 72% of patients in the pooled analysis of 6 studies had a complete response to bladder-preserving therapy.
In the study, researchers performed an analysis of long-term outcomes from 6 phase 2 and phase 3 studies involving 486 patients treated with bladder-preserving combined-modality therapy with radiation. After a median follow-up of 4.3 years for all patients and 7.8 years for long-term survivors (n = 205), results indicated that the rate of overall survival at 5 years was 57% and at 10 years was 36%. The rate of disease-specific survival at 5 years was 71% and at 10 years was 61%.
However, when the researchers analyzed their results, those with a higher clinical T stage (T3 and T4) experienced decreased disease-specific and overall survival, compared with those with T2 disease. The rate of 5-year disease-specific survival in those with T2 disease was 74%; in those T3 and T4 disease, it was 66%. The 10-year disease-specific survival was 69% in those with T2 disease and 60% in those with T3 and T4 disease (P = .05)
When the researchers looked at overall survival, they found that those with clinical T2 disease had more favorable outcomes with bladder-preserving therapy including radiation. The rate of 5-year overall survival in those with T2 disease was 62% and in those with T3 or T4 disease was 49%; the rate of 10-year overall survival was 41% and 30%, respectively (P = .002).
Thus, in selected patients — those with earlier and less bulky disease — bladder-preserving combined-modality therapy with radiation can be a viable option, Dr. Mak said.
The majority of recurrences experienced by patients in the study were nonmuscle-invasive local failures and distant metastases. Local failure involving muscle-invasive disease occurred in 13% of patients and that involving local recurrences with nonmuscle-invasive disease occurred in 31%. Distant metastases occurred in 31% of patients at 5 years and 35% at 10 years.
"The higher recurrence rate of nonmuscle-invasive disease underscores the need for careful posttreatment surveillance with cystoscopy and further study of novel systemic therapies," Dr. Mak said.
"This study shows us that, in selected patients, bladder preservation is safe and leads to long-term cures," said Nicholas Vogelzang, MD, from the Comprehensive Cancer Centers of Las Vegas and professor of medicine at the University of Nevada. He noted that the study's strengths include its multicenter design and the fact that all patients were categorized and treated in a similar way. "But all patients in the analysis were treated by experts at leading medical centers, so it may be hard to extrapolate these results to real life," he added.
From the study results, clinicians can conclude that T2 patients treated with bladder-preserving combined-modality therapy with high-dose radiation therapy can achieve good results, Dr. Vogelzang said. He cautioned that combined-modality bladder-preservation therapy with radiation is not appropriate for those with T3 or T4 disease, nor is it the standard of care for bladder cancer.
"I don't recommend bladder radiation to my patients more often than 4 or 5 times a year," Dr. Vogelzang said. "Most of the time I recommend bladder removal, because the bladder is a damaged organ in those with bladder cancer and there may be late side effects of radiation," he added.
For some patients with less advanced disease who don't want their bladder removed, combined-modality therapy with radiation is a viable option, Dr. Vogelzang said.
"This study does not really change practice, but it reinforces the fact that radiation is safe and can control bladder cancer in the long term," he said.
The study was funded by grants from the National Cancer Institute. Dr. Mak and Dr. Vogelzang have disclosed no relevant financial relationships.
2012 Genitourinary Cancers Symposium (GUCS): Abstract 264. Presented February 3, 2012.
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