The addition of chemotherapy to radiation therapy in patients with bladder cancer significantly reduced recurrence of the disease, according to a study that will be presented Nov. 1 at the annual meeting for the American Society of Radiation Oncology (ASTRO) in San Diego.
Bladder cancer affects 70,000 Americans each year while resulting in a five-year survival rate of 40 percent. The most common treatment for advanced bladder cancer in the U.S. is the complete removal of the bladder (cystectomy).
The present study sought to evaluate whether the addition of chemotherapy to radiation therapy improved loco-regional disease-free survival in patients with advanced muscle invasive bladder cancer compared to radiation therapy alone. The researchers also examined whether the reduction of radiation dose in bladder areas immediately surrounding the tumor reduced toxicity and effected local control.
The study followed 458 patients treated at 45 British hospitals for a median follow-up period of 40 months. One hundred eighty-two patients were treated with radiation and chemotherapy while 178 were treated with radiotherapy alone (other patient groups included 108 treated with standard dose radiotherapy and 111 with reduced high-dose volume radiation; 30 percent of all patients received neoadjuvant chemotherapy).
Two-year disease-free survival rates for patients treated with chemotherapy and radiation therapy were 67 percent compared with 54 percent for patients treated with radiotherapy alone. After 40 months of followup, the radiation plus chemotherapy cohort had a hazard ratio of 0.61.
The researchers observed no significant effect to either tumor control or toxicity with reduced radiation doses to the surrounding bladder. The overall cystectomy rate was 10 percent, with no significant difference observed between treatment groups.
"The trial shows that this treatment offers improved control of cancer within the bladder with acceptable long-term side effects and is therefore a viable alternative to radical surgery in patients with muscle invasive bladder cancer," said lead researcher Nicholas James, MD, a medical oncologist at University of Birmingham in Birmingham, England. "This may shift the balance from surgery to chemo-radiotherapy as the primary treatment for many patients with invasive bladder cancer."