Compared with other treatment approaches, definitive surgical extirpation provides the best survival outcomes in patients with invasive, non-urachal adenocarcinoma of the bladder, results of a recent study suggest.
Compared with other treatment approaches, definitive surgical extirpation provides the best survival outcomes in patients with invasive, non-urachal adenocarcinoma of the bladder, results of a recent analysis suggest.
Five-year survival approached 40% for patients with these rare bladder cancers who underwent cystectomy, and on multivariate analysis, cystectomy was the only factor associated with improved survival, according to results of the retrospective analysis of more than 800 patients.
However, only about one-third of the patients underwent surgery, suggesting this guideline-recommended treatment strategy is underutilized, investigator Zachary Hamilton, MD, and colleagues reported in the World Journal of Urology (July 20, 2018 [epub ahead of print]).
“Even if it looks like they have aggressive disease, doing a cystectomy potentially is going to increase their survival benefit, based on the retrospective study we’ve done,” Dr. Hamilton said in an interview with Urology Times.
The findings bolster expert opinion, and reinforce results of earlier, smaller studies suggesting surgery is the optimal choice for patients with these rare bladder cancers, according to Dr. Hamilton and colleagues.
“I think we should feel encouraged that, if a patient can undergo surgery, it's probably in their best interest to get that done in an expeditious manner, given the rarity of this disease and the poor prognosis associated with it,” said Dr. Hamilton, of Saint Louis University, St. Louis.
The analysis by Dr. Hamilton and co-investigators focused on 851 patients with invasive (cT2-T4) non-urachal bladder adenocarcinoma in the U.S. National Cancer Database between 2004 and 2015.
Out of those patients, nearly half (398, or 47.8%) received no definitive treatment, while 298 (35.8%) underwent cystectomy, investigators found. Another 124 (14.9%) received external beam radiation therapy (EBRT) and 31 (3.7%) had EBRT plus cystectomy.
At the 5-year time point, overall survival was 39.1% for cystectomy, which was significantly improved in comparison to no treatment, EBRT, and EBRT plus cystectomy, which had 5-year overall survivals of 15.5%, 14.4%, and 24.7%, respectively (log-rank p<.001), Kaplan-Meier analysis showed.
Continue to the next page for more.The only treatment with an independent beneficial effect on overall mortality was surgical extirpation including cystectomy, with a hazard ratio of 0.584 (95% CI, 0.471-0.724; p<.001) in multivariable analysis including patients with metastatic disease, and 0.593 (95% CI, 0.472-0.744; p<.001) when metastatic disease was excluded.
Charlson score and treatment at a low-volume center were associated with worsened survival, according to investigators, who defined low volume as those centers that see 500 or fewer newly diagnosed cancer cases per year.
Adenocarcinoma is rare, representing 0.5% to 2% of all bladder cancer diagnoses, and thus suffers from a lack of randomized data to guide treatment, Dr. Hamilton and co-authors said in their report.
Based on this new retrospective report, they said, clinicians could consider surgical treatment when technically feasible.
“Certainly, this places emphasis on the current expert opinions and provides more data to support them. That being said, probably more research is needed for all these variant histologies of the bladder, just to ensure we are doing the right thing,” Dr. Hamilton said in the interview.