Post-Surgical Radiation Therapy Cuts Pelvic Relapse Risk in High-Risk Bladder Cancer

Results of a phase III clinical trial presented today at the American Society for Radiation Oncology (ASTRO) Annual Meeting indicated that adding radiation therapy after bladder removal surgery may sharply lower the risk of cancer returning in the pelvis for patients with high-risk, muscle-invasive bladder cancer.

The Bladder Adjuvant RadioTherapy (BART) trial, conducted across centers in India, found that post-operative radiation reduced pelvic relapses without increasing serious side effects.

“This is one of the first and largest randomized trials to show that post-operative radiation therapy can meaningfully reduce pelvic relapses in bladder cancer,” said Vedang Murthy, MD, principal investigator and professor of radiation oncology at Tata Memorial Hospital in Mumbai. “Pelvic relapse can be devastating for patients – extremely painful and almost impossible to treat. Our research shows that modern radiation therapy offers a safe way to prevent many of these recurrences and improve patients’ quality of life.”

Trial Results

The trial enrolled 153 patients with locally advanced bladder cancer from 2016 to 2024. All had bladder removal surgery, and most received chemotherapy. Patients were randomized to receive either radiation (50.4 Gy in 28 fractions) or observation.

At nearly four years of follow-up, only 8% of patients in the radiation group experienced pelvic recurrence compared to 26% in the observation group. Two-year locoregional recurrence-free survival was 91.2% with radiation versus 76.4% without.

“Bladder cancer is aggressive, and surgery and chemotherapy alone are not enough to prevent pelvic recurrence,” said Dr. Murthy. “But in our trial, very few people who received radiation had a locoregional relapse within two years.”

Disease-free survival also trended higher with radiation (77.6% vs. 64.4%), though rates of distant metastases remained similar, underscoring the systemic nature of the disease.

Side effects were low and comparable in both groups. Severe late complications occurred in fewer than 11% of patients overall. Subgroup analyses suggested greater benefit for patients with larger tumors or node-positive disease.

Two-year overall survival was higher with radiation (68% vs. 57%), though not statistically significant. Dr. Murthy said his team is planning a meta-analysis with trials from France and Egypt to confirm survival impact.

Murthy added, “Radiation therapy is already used safely after surgery for gynecologic cancers in the same region,” he said. “These results suggest it could also become a standard option for high-risk bladder cancer. The two treatments act differently, and there’s no reason we shouldn’t be studying them together.”