Jul 18, 2023
By Jane Brown
Bladder removal is life-altering, but for some patients with muscle-invasive bladder cancer, it has been the only option offered.
It’s not because there is no other way to treat it than with what is also known as radical cystectomy, but because until recently there was limited data on the success of a second option known as trimodality therapy.
Trimodality therapy involves endoscopically removing the tumour, and then treating the patient with systemic chemotherapy and radiotherapy administered on the area from where it was removed.
Now, there is potentially game-changing research that trimodality therapy is as effective as bladder removal for select patients with muscle invasive bladder cancer.
A new study co-led by Dr. Alexandre Zlotta, Director of Uro-Oncology at Mount Sinai Hospital, part of Sinai Health, and staff in the Department of Surgical Oncology at University Health Network, where the multidisciplinary bladder cancer clinic is held, has now provided the most robust comparison between trimodality therapy and bladder removal.
It shows that trimodality therapy, which was typically only offered to patients with significant comorbidities where removal of the bladder isn’t possible, has equal results in terms of five-year metastasis-free survival, cancer-specific survival, or disease-free survival, as bladder removal (for select patients with muscle invasive bladder cancer). These represent roughly 30-percent of candidate patients.
The specific characteristics of these ideal candidates for bladder sparing include the number and size of the tumours (there can only be one, and it has to be smaller than 7 centimetres).
“For those specific patients who have those specific characteristics, it’s time to move on,” Dr. Zlotta tells Zoomer Radio‘s Jane Brown, “We cannot only propose to remove the bladder if there is another treatment which is equally effective. Patients should be able to discuss and choose among various option if they are candidates for them.”
Listen to Jane Brown’s entire conversation with Dr. Zlotta here:
Published in June in the journal Lancet Oncology, and co-led by Dr. Jason Efstathiou, radiation oncologist from Harvard Medical School and Massachusetts General Hospital, the study, “Radical cystectomy versus trimodality therapy for muscle invasive bladder cancer: a multi-institutional propensity score matched and weighted analysis,” retrospectively looked at 722 patients who were treated at university centres in the United States (Boston and Los Angeles) and Canada (Toronto) between Jan. 1, 2005, and Dec. 31, 2017.
The researchers decided to pursue this study, the largest ever analysis comparing these two treatment options for patients who would be eligible for either treatment, Dr. Zlotta notes, to fill a hole in the available data. There have been attempts at randomized controlled studies that compared these two treatments, but none was able to accrue patients, he says. This is why they chose the retrospective approach with two robust statistical methods when randomized studies are not possible, he explains.
Dr. Zlotta says what makes the research so strong is that it was a large multi-institutional study, that it demonstrates that the outcomes were the same for either option regardless of which centre the patient was treated at which supports the generalizability of the results, and that it shows that both treatment options were equal for these select patients.
“It’s not that the bladder preservation was good because surgery was bad,” he explains, as outcomes after surgery were in keeping with the best available published results. Patients treated with trimodality therapy need stringent and diligent follow-up though, so this implies a real commitment.
As for next steps, Dr. Zlotta says they would like to look at using biomarkers and genetics to predict a patient’s response to each type of treatment, and they would also like to study what the results would be if they compared the two options for people who have more than one tumour in their bladder.
“We know that for patients with single muscle invasive tumors less than 7 cm, trimodality performs equally well than surgery. But we don’t know what is the sweet spot and whether if we push it, say to two or three tumours, how far can we go.” he explains.
“But still, if 30 percent of all patients can be offered trimodality therapy, that’s huge.”