Study Shows Encouraging Results for Patients With Invasive Bladder Cancer
Radiation plus immunotherapy may help some patients with invasive bladder cancer keep their bladders.
Patients with localized muscle-invasive bladder cancer (MIBC), or bladder cancer that has spread through the lining of the bladder and into the muscle wall or beyond it, are commonly treated by removing the entire bladder, known as a radical cystectomy. While it is typically effective, it is an invasive procedure that can have lasting impacts on a patient’s life.
New research, however, indicates that radiation plus combination immunotherapy may help to preserve the bladder in some patients. The study was published in Clinical Cancer Research, a journal of the American Association for Cancer Research (AACR).
“While this is an early exploratory study, the results are encouraging and highlight the potential of radiotherapy plus combination immunotherapy to improve quality of life without compromising survival,” said the study’s senior author, Xavier Garcia-del-Muro, MD, PhD, a professor of medical oncology at the University of Barcelona and the Institut Català d’Oncologia in Spain.
How To Preserve a Bladder
Patients with MIBC have reported self-consciousness and discomfort from urostomy bags and complications from reconstructed neobladders, among other issues, leading researchers to look for new ways to treat MIBC noninvasively to improve patients’ quality of life. According to Dr. Garcia-del-Muro, “multimodal treatments,” or therapies that combine more than one method of treatment, “offer a promising conservative alternative that deserves further exploration.”
Preclinical studies have suggested that a combination of two types of immunotherapies called immune checkpoint inhibitors (ICI) that target different immune checkpoints—durvalumab, which targets PD-L1, and tremelimumab, which targets CTLA-4—may pair effectively with radiotherapy and result in fewer side effects than chemotherapy. Further, radiotherapy can trigger cancer cells to release danger signals and other cytokines that can stimulate the immune system, potentially making ICIs more effective, Dr. Garcia-del-Muro explained.
Dr. Garcia-del-Muro and colleagues enrolled and treated 32 patients with stage T2-T4A disease with no metastases or lymph node involvement who had not previously received immunotherapy or radiotherapy to the bladder. Patients were either ineligible for or did not want to undergo cystectomy. Enrolled patients received three courses of the immunotherapy combination. Treatments were given four weeks apart with concurrent radiotherapy.
Among the 28 evaluable patients, 26 (93%) had a complete response. In the overall population, after two years of follow-up, five patients (16%) had experienced a metastatic recurrence, six patients (19%) had experienced a recurrence of muscle-invasive disease, and one patient (3%) had experienced a recurrence of non-muscle invasive disease.
After a median follow-up of 27 months, 30 patients were able to preserve their bladders, while two patients underwent radical cystectomy due to recurrence.
The estimated two-year overall survival and distant metastasis-free survival rates were 84% and 83%, respectively.
“This multimodal bladder-preserving approach is feasible, showing high efficacy in terms of response and long-term bladder preservation,” Dr. Garcia-del-Muro said. He and his colleagues aim to confirm these findings in larger studies with more patients, a longer follow-up, and direct comparisons to other treatment regimens including radiation plus chemotherapy.
