A recent study from Fox Chase Cancer Center has found that in patients treated with radical cystectomy - removal of the bladder - those with cT1 micropapillary bladder cancer had similar or worse oncological outcomes compared with patients with cT2 conventional urothelial carcinoma.

Results from this study will be presented at the virtual American Urological Association 2021 Annual Meeting.

The designations cT1 and cT2 refer to the stages at which the cancer has developed, an important step in helping physicians determine the appropriate treatment.

“Micropapillary bladder cancer is a rare and often aggressive variant of bladder cancer, which poses a very difficult treatment dilemma when diagnosed in the non-muscle invasive stage because it often presents at an advanced stage. When it’s caught at an early stage, it’s very difficult to know what to do with it because it is such an aggressive variant,” said Kevin Ginsburg, MD, lead author on the study and second-year fellow in the Urologic Oncology Fellowship Program at Fox Chase.

To help determine the best course of treatment for this cancer, the researchers reviewed the National Cancer Database for patients undergoing radical cystectomy for cT1 micropapillary bladder cancer and conventional cT1/cT2 urothelial carcinoma from 2004 to 2016.

Researchers were able to find more than 25,000 patients who underwent cystectomy in the database, including only 125 who had been diagnosed with cT1 micropapillary bladder cancer.

“We compared patients with cT1 micropapillary bladder cancer with cT1 and cT2 conventional urothelial cell carcinoma. The point was to find out whether someone who’s being treated with a cystectomy with cT1 micropapillary cancer behaves like someone who has a cystectomy for cT1 urothelial carcinoma or whether they have outcomes more like someone who has cT2 urothelial cell carcinoma,” said Ginsburg, who conducted the study with colleagues from the Division of Urology and Urologic Oncology at Fox Chase.

In examining the data, the researchers found that despite having earlier-stage disease, patients who had cT1 micropapillary bladder cancer had very similar survival to patients who had cT2 urothelial cell carcinoma.

“About 40% of these patients had lymph node involvement, compared with 11% of patients that had cT1 and 19% of patients that had cT2 conventional urothelial cell carcinoma, which suggests this is a very aggressive variant despite the fact that it’s at an earlier stage,” said Ginsburg.

Additionally, he said that when the researchers looked at other outcomes such as being upstaged to non-organ-confined disease, they found that 31% of cT1 micropapillary patients were upstaged compared with 18% and 20% of cT1 and cT2 conventional urothelial cell carcinoma patients.

“This is just another piece of information that physicians can use when discussing the aggressiveness of early stage micropapillary bladder cancer with their patients. Physicians can also use it to explain to patients that an aggressive treatment, such as bladder removal, may be necessary because cT1 micropapillary bladder cancer may behave like cT2 urothelial cell bladder cancer,” Ginsburg said.

“The standard of care for cT2 urothelial cell bladder cancer is often treated with complete bladder removal and we should consider treating this early stage micropapillary bladder cancer in the same aggressive manner.”

The study was published in The Journal of Urology.

Source: Fox Chase Cancer Center