Better models needed for predicting bladder Ca recurrence

Current National Comprehensive Cancer Network (NCCN) guidelines are comparable to European models for predicting nonmuscle-invasive bladder cancer recurrence and progression. But better models are needed, according to a recent study.

“A fair amount of urology involves caring for oncology patients, and urologist are definitely at the frontlines in these conversations [with nonmuscle-invasive bladder cancer patients],” said senior author Tracy M. Downs, MD, of the University of Wisconsin School of Medicine and Public Health, Madison. “What I think this study shows is that we need better predictive models…, and the less complicated NCCN guidelines are equally as helpful and had the same limitations as the more rigorous EORTC and CUETO models.”

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For the study, which was published in the Journal of Urology (2017; 198:824-31), Dr. Downs and colleagues retrospectively studied the electronic medical records of 1,333 nonmuscle-invasive bladder cancer patients. In an average follow-up of 37 months, they evaluated recurrence-free and progression-free survival at 1 and 5 years with the European Organisation for Research and Treatment of Cancer (EORTC) and Club Urologico Espanol de Tratamiento Oncologico (CUETO) guidelines; then, compared that to the predictive power of NCCN’s guidelines.

This is the first external validation study of the European models in a U.S. population of nonmuscle-invasive bladder cancer patients at multiple centers and comparing the predictive ability of those models to that of the NCCN guidelines, according to the authors.

The authors reported that 573 patients recurred in the study-a 28% cumulative probability of recurrence at 1 year and 47% at 5 years. The recurrence c-index of EORTC was 0.59 and 0.56 for CUETO at 5 years. For progression, EORTC was 0.74 and CUETO 0.72. NCCN’s model showed a c-index of 0.56 for recurrence and 0.75 for progression.

Next: Three take-home points

The big three take-home points from the study, according to Dr. Downs, are: All three models were best at predicting recurrence and progression in low-risk bladder cancer patients. All three models overestimated the cancer progressing to a higher stage in high-risk individuals. And all three models were not very good at predicting recurrence in the growing body of patients who receive bacillus Calmette-Guérin therapy.

“In our highest risk patients, where we want to be even more accurate, that’s where these models are not very good. Yet, these models perform better in our low-risk patients,” Dr. Downs said.

Dr. Downs said he believes that, even though these models have some limitations, their use should not be disregarded.

“I use them as a starting point for conversations with patients and with other colleagues,” he said.

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One example: The EORTC model has a risk calculator application that urologists can download on their smartphones. They can plug in a patient’s age, cancer grade, and number of tumors, and the app will calculate the information in terms of the percentage of patients who will recur in a given time frame and who will progress, according to Dr. Downs.

“What I have found helpful in the management of nonmuscle-invasive bladder cancer patients, is to step back and ask yourself a few simple questions: Are we managing the patient to prevent the cancer from coming back (ie, recurrence)? Or are we managing the patient’s cancer from progressing?” Dr. Downs said.

Being able to share this information with the patient is very powerful, because when they hear the word “cancer,” most patients think of the most aggressive form of a cancer that can lead to death, according to Dr. Downs.

“In many instances, for patients diagnosed with low-risk or intermediate-risk bladder cancer, we are managing the risk of the cancer recurring. When making treatment recommendations for a patient with low-risk nonmuscle-invasive bladder cancer in the clinic, I can share that we are managing the frequency of the cancer coming back or eliminating it from coming back altogether. But this isn’t one that’s going to spread and become lethal,” he said. “That’s how I use these tools-as starting points.”

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