|The following article features coverage from the ASCO Genitourinary Cancers Symposium 2022. Click here to read more of Cancer Therapy Advisor’s conference coverage.|
Trimodal therapy (TMT) may be an effective alternative to radical cystectomy (RC) for select patients with muscle-invasive bladder cancer (MIBC), according to researchers.
A retrospective study showed similar metastasis-free survival with TMT and RC, but cancer-specific and overall survival results favored TMT.
These results were presented at the ASCO Genitourinary Cancers Symposium 2022 by Alexander R. Zlotta, MD, PhD, of Mount Sinai Hospital and University of Toronto in Ontario, Canada.
Dr Zlotta noted that previous randomized controlled trials comparing bladder preservation with RC for MIBC closed early due to lack of accrual, indicating that future trials are unlikely.
In the absence of level 1 data, Dr Zlotta and colleagues conducted a retrospective study to compare RC and TMT in matched cohorts of patients treated at 3 institutions between 2005 and 2017.
The study initially included 703 patients with clinical stage T2-T3/4aN0M0 MIBC. There were 282 patients treated with TMT and 421 patients who underwent RC. TMT consisted of complete transurethral resection of the bladder tumor, followed by radiotherapy with radio-sensitizing chemotherapy.
All patients would have been eligible for either treatment approach, had solitary tumors smaller than 7 cm, had no or unilateral hydronephrosis, and had no extensive carcinoma in situ.
The researchers then used treatment propensity scores to match patients 3:1 with replacement. The covariates were age, sex, clinical T stage, hydronephrosis, adjuvant/neoadjuvant chemotherapy, body mass index, smoking history, and performance status.
The matched cohort consisted of 1116 patients — 834 in the RC group and 282 in the TMT group.
The primary endpoint was metastasis-free survival, and there was no significant difference between the groups. The 5-year metastasis-free survival rate was 73% in the RC group and 78% in the TMT group (P =.07).
Likewise, there was no significant difference between the RC and TMT groups for 5-year distant failure-free survival — 78% and 82%, respectively (P =.14).
However, cancer-specific survival and overall survival favored TMT. The 5-year cancer-specific survival rate was 78% with RC and 85% with TMT (P =.02). The 5-year overall survival rate was 66% and 78%, respectively (P <.001).
In the TMT cohort, 13% of patients had undergone salvage cystectomy. The researchers analyzed 5-year cancer-specific survival by salvage cystectomy status and found no significant difference between patients who had salvage cystectomy and those who did not — 83% and 84%, respectively (P =.77).
“We believe this is probably the largest multi-institutional contemporary study to provide the best evidence possible to date in the absence of a randomized study … supporting that TMT is a very valid option for select patients with muscle-invasive bladder cancer,” Dr Zlotta said in closing.
“Oncologic outcomes seem to be equivalent between TMT and radical cystectomy,” he added. “We do believe that TMT should be offered as an effective alternative for these patients.”
Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
Read more of Cancer Therapy Advisor’s coverage of ASCO GU 2022 by visiting the conference page.
Zlotta AR, Ballas LK, Niemierko A, et al. Multi-institutional matched comparison of radical cystectomy to trimodality therapy for muscle-invasive bladder cancer. Presented at ASCO GU 2022; February 17-19, 2022. Abstract 433.