Can Prostate Cancer Patients on AS Delay Surgery at Progression?

Among men with clinically localized prostate cancer who continued active surveillance (AS) after biopsy progression, delaying surgery did not significantly reduce recurrence-free survival (RFS) rates or increase the risk of adverse pathology, researchers reported.

In a prospectively followed cohort, men on AS who underwent early radical prostatectomy (RP) had a 3-year RFS rate of 80%, as compared with 87% for those who underwent late RP (P=0.64), reported Meera R. Chappidi, MD, MPH, of the University of California San Francisco (UCSF), and colleagues.

Rates of adverse pathology were not significantly different between groups either, at 55% for the early RP group (within 6 months of biopsy progression) and 53% for the late RP group (beyond 6 months and up to 5 years from progression; P=0.74), nor were there differences in grade group (P=0.15), they wrote in the Journal of Urology.

“There was a very low rate of metastatic disease in this cohort,” wrote Chappidi and coauthors. “These findings suggest some patients may be able to safely delay definitive management after biopsy progression.”

Previous research has shown that about 30% of prostate cancer patients on AS will develop disease progression and decide to have definitive treatment within 5 years of their diagnosis, the researchers explained. However, a significant percentage of patients on AS who progress continue on AS without treatment. The team, therefore, wanted to characterize the cohort of patients who continue on AS after progression and determine the oncologic impact.

The prospective study included participants enrolled in AS at UCSF who were initially diagnosed with grade group 1, localized prostate cancer, with prostate-specific antigen (PSA) levels less than 20 ng/mL and who subsequently progressed to grade group 2 or higher, and underwent further surveillance via biopsy, imaging, or PSA testing.

Patients were stratified by post-progression follow-up into three groups: continuing AS untreated, early RP, and late RP.

Of 551 patients with biopsy progression from grade group 1 disease, 40% remained untreated, 24% underwent late RP, and 36% had early RP.

Among the 317 patients who underwent early or late RP, 45 had a recurrence in the 3-year follow-up period.

Undergoing late RP was not associated with worse RFS in either univariable (HR 0.90, 95% CI 0.57-1.41) or multivariable (HR 1.04, 95% CI 0.64-1.68) models.

The only predictor of a higher risk of recurrence identified in the multivariable model was a higher Cancer of the Prostate Risk Assessment Post-Surgical (CAPRA-S) score (HR 1.42, per point 95% CI 1.24-1.64). CAPRA-S was associated with higher risk of recurrence in both the early RP and late RP groups.

Four patients developed metastases after RP at a median time of 44 months, with three in the early RP group.

The current findings, do not help in further risk stratifying this subset of patients, the researchers noted.

“This is an area for future research, especially genomic testing,” Chappidi told MedPage Today in an e-mail. “In our cohort, about 50% of patients did not have genomic testing, so that limits our ability to identify whether this would be a good predictor moving forward. Another important limitation is the short- to intermediate-term outcomes, so we will need to see what happens long-term as the data matures.”