Blue light flexible cystoscopy (BLFC) with hexaminovulinate is frequently used to detect cancer lesions in the operating room (OR). While the FDA approved surveillance in the OR in 2018, its use outside the OR has not yet enjoyed the same status. However, a study published in the Journal of Urology may hasten its arrival as a widely used, reimbursed procedure for outpatient cystoscopic surveillance.
The 2018 study compared surveillance of patients at intermediate or high risk of non-muscle invasive bladder cancer (NMIBC) using both white and blue light cystoscopy. 20.6 percent of malignancies were identified only by blue light cystoscopy.
“Blue light cystoscopy in the surveillance setting clearly identifies tumors that would otherwise have gone undetected with conventional white light cystoscopy alone,” said Matthew Resnick, M.D., a genitourinary oncologist at Vanderbilt University Medical Center and coauthor on the study. Resnick explains it will be critically important to characterize the population that will most benefit from this new technology.
Study Results for BLFC and WLFC
The study was the Phase III arm of a multicenter, prospective, controlled trial. 304 patients with a history of multiple, recurrent or high-grade bladder tumors were enrolled and randomized to either undergo surveillance via white light flexible cystoscopy (WLFC) only or WLFC followed by BLFC. Patients with suspicious lesions were referred to the OR for repeat cystoscopy. A total of 103 patients (66 percent) had suspicious lesions and 63 (41 percent) had confirmed bladder cancer. The false positive rate was 9.1 percent in both arms.
Thirteen (20.6%) of the patients whose suspicious lesions were identified only through BLFC had confirmed bladder cancer. In only one case did WLFC identify a malignant lesion BLFC did not. The study provides further evidence that WLFC falls considerably short of 100 percent sensitivity.
Considerations for Outpatient Applications
Patients with high-risk NMIBC undergo frequent cystoscopy for surveillance, starting every three months for several years. “Patients tolerate it well,” Resnick says, “and are reassured with the addition of BLFC, given its high sensitivity for the detection of recurrent tumors.”
“Patients tolerate it well, and are reassured with the addition of BLFC, given its higher sensitivity.”
At the same time he cautions that aggregate false positive rates of WLFC and BLFC constitute a downside. “The goal of treatment is to mitigate the likelihood of downstream morbidity and treatment intensity,” Resnick said. “We need to balance identifying, at the earliest point, tumors that may progress, while minimizing the likelihood of false positive results driving unnecessary trips to the OR.”
The implications of a false positive in the OR vs. the clinical setting are different, Resnick says. In the OR, it means an additional biopsy while someone is asleep with little, if any, downstream morbidity. In the clinical setting, someone may be subjected to an additional anesthetic and more tests. BLFC requires an extra step of instillation, more time, increased resources, and a higher initial expense.
“The bottom line is that this emerging technology looks valuable as an adjunct to white light cystoscopy in identifying disease recurrence in patients that are high risk,” Resnick said. Resnick now recommends BLFC to support NMIBC outpatient surveillance. “It will help minimize the risk of downstream treatment intensity for these patients, with the hope of improving outcomes.”