In men with biochemical recurrence (BCR) after radical surgery for prostate cancer, magnetic resonance imaging (MRI) of the prostatectomy bed might provide information useful for treatment, investigators suggest.
Investigators identified 896 patients with PSA of 0.2 ng/mL or higher or rising PSA after RP. At baseline, the men had no known distant metastases or salvage treatment with androgen deprivation therapy and/or radiation. On pelvic MRI, 441 (49%) had a locally recurrent lesion in the prostatectomy bed and 455 patients (51%) did not.
On univariate analysis, positive vs negative MRI findings were significantly associated with a 3.1-fold higher risk for cancer-specific death, Takashi Tanaka, MD, of Mayo Clinic in Scottsdale, Arizona, and colleagues reported in The Journal of Urology. Larger lesion size was also significantly associated with an increased risk of cancer-specific death. Progression-free survival was significantly worse among patients with negative MRI. Men with negative findings may have had occult metastases, according to the investigators, and might have benefited from positron emission tomography (PET) with a prostate cancer-specific radiotracer.
On multivariable analysis, pathologic Gleason scores of 7 and higher independently predicted progression. Compared with pathologic Gleason score 6 or less, a score of 7 and 8-10 was significantly associated with approximately 3.0- and 5.6-fold greater likelihood of positive MRI findings. However, MRI results, PSA doubling time, and time from RP to BCR did not appear prognostic.
“MRI has higher spatial resolution than molecular PET imaging and allows for the precise localization of local recurrence in the prostatectomy bed for subsequent [salvage radiation] or focal ablative therapy,” Dr Tanaka’s team noted. “Patients with positive MRIs, which were associated with shorter PCa-specific survival, could benefit from subsequent salvage therapies which would improve PCa-specific survival although further study remains necessary.”
Tanaka T, Kawashima A, Rangel LJ, et al. Long term risk of clinical progression utilizing MRI findings of locally recurrent prostate cancer in patients with biochemical recurrence following radical prostatectomy. J Urol. Published online January 4, 2022. doi:10.1097/JU.0000000000002421