Recommended primary treatment for non-muscle invasive micropapillary urothelial carcinoma (MPBC) is often foregone in community cancer centers and academic centers, according to a study presented at the American Urological Association (AUA) Annual Meeting (May 12-16, 2017; Boston, MA).
MPBC is a rare and aggressive histologic subtype of bladder cancer. Current recommendations call for early radical cystectomy to treat non-muscle invasive disease, rather than commonly-used bacillus Calmette-Guerin (BCG) therapy.
Kyle Scarberry, MD, Urology Institute, University Hospitals Case Medical Center (Cleveland, OH), and colleagues conducted a study that analyzed the management of non-muscle invasive MPBC in the US. Using the National Cancer Database, researchers identified 777 patients diagnosed with MPBC — 270 (34.7%) of whom having non-muscle invasive disease — between 2003 and 2013. Treatment trends and pathological upstaging were recorded and compared with patients without the histologic variant.
Among the patient population, BCG therapy was administered as initial therapy in 25.1% of patients of non-muscle invasive MPBC and in 14.3% of patients without non-MPBC (P < .001). Radical cystectomy was administered as initial therapy in 19.6% of patients with non-muscle invasive MPBC and in 2.3% of patients with non-MPBC (P < .001).
Patients with MPBC who underwent primary radical cystectomy were more likely to experience upstaging from non-muscle invasive disease to T2-T4 disease (33%) compared with those who had non-MPBC (11.1%). Similarly, upstaging pathologic N1-3 disease was observed in 33.3% of patients with MPBC compared with 11.1% of patients with non-MPBC.
Researchers also observed that radical cystectomy for non-muscle invasive MPBC was more likely to be performed at academic cancer centers (29.6%) compared to community cancer centers (11.3%).
Multivariate analyses showed that adjusting for patient age, sex, race, comorbidities, disease stage, and care at academic centers were associated with higher odds of having radical cystectomy as initial therapy compared with community centers (OR, 3.11; 95% CI, 1.53-6.29).
BCG was not found to be used any more frequently between academic centers (26.2%) and community centers (23.7%).
Researchers concluded that BCG is overused as a primary treatment for non-muscle invasive MPBC. Patients with this rare histologic variant are much more likely to be treated with guideline-recommended radical cystectomy in an academic center compared with a community center, but neither type cancer treatment center shows high adherence to treatment guidelines. — Zachary Bessette