Prostate cancer (PCa) patients on active surveillance (AS) who experience disease reclassification are more likely to have adverse pathology at radical prostatectomy (RP) than those undergoing surgery for other reasons, a new study confirms.
Furthermore, disease reclassification by certain criteria may signal a worse prognosis than others.
“These findings may aid in clarifying criteria used to define reclassification in future studies of patients on AS, and may allow more patients to safely continue in AS programs despite potential evidence of disease progression,” lead author Adam C. Reese, MD, of Temple University School of Medicine in Philadelphia, and colleagues wrote in a paper published online ahead of print in Urology.
The investigators studied pathologic outcomes in 130 of 1,086 mostly Caucasian men who underwent RP after a median 2 years on AS at Johns Hopkins. The patients met original Epstein criteria at AS enrollment (i.e., clinical stage T1, PSA density less than 0.15 ng/mL, biopsy Gleason Score 6 or lower, 2 or fewer positive biopsy cores, and less than 50% tumor involvement in any 1 core).
Three-quarters of the men had evidence of disease reclassification. The most common reason was a follow-up biopsy yielding more than 2 positive cores. Men with reclassification also tended to have higher Gleason Scores.
Rates of adverse pathology varied from 24% for men with more than 2 positive biopsy cores to 45% in men reclassified by Gleason score. Adverse pathology was defined as stage T3a disease or greater, Gleason score 4+3 or higher, or positive lymph nodes. The researchers found no association between longer time on AS and adverse pathology.
“This suggests that certain types of disease reclassification are not as ominous as others when predicting the risk of adverse pathology, and that some men, particularly the elderly or those with significant medical comorbidities, can safely remain on AS despite evidence of disease reclassification.”
Whether different criteria should be used to define reclassification versus AS enrollment requires further study in larger groups of patients. The researchers also noted that not all pathologic T3a tumors carry the same recurrence risk, with non-focal extraprostatic extension more worrisome than focal.