Management and Oncologic Outcomes of Incidental Prostate Cancer After Transurethral Resection of the Prostate in Denmark.

Purpose: Approximately 1 in 10 patients without prior prostate biopsy undergoing surgery for lower urinary tract symptoms harbors incidental prostate cancer; however, practice guidelines do not provide recommendations for its management. We aimed at describing the oncologic outcomes of patients with Grade Group (GG) 1 and GG2 prostate cancer diagnosed at transurethral resection of the prostate (TURP).

Materials and methods: This was a nationwide, population-based, observational study of patients undergoing TURP in Denmark from 2006 to 2022 using the Danish Prostate Registry. We estimated the cumulative incidence of further biopsies and MRI, curative treatment, endocrine treatment, and cause-specific mortality with competing risk analyses.

Results: Among 24,494 patients who underwent TURP, there were 1016 men with GG1 and 381 with GG2 prostate cancer. The 5-year cumulative incidence of further MRIs or biopsies was 36% (95% CI 33%-39%) for GG1 and 30% (95% CI 25%-34%) for GG2 disease. Fifteen-year prostate cancer mortality was 8.4% (95% CI 5.3%-11%) for GG1 and 14% (7.5%-21%) for GG2. A total of 270 men with GG1 disease underwent a biopsy after the TURP, and 162 (60%) had no cancer; in this group, prostate cancer mortality after 15 years was 0.6% (95% CI 0%-1.8%). Men with post-TURP biopsy ≥ GG2 had a prostate cancer mortality of 30% (95% CI 9%-50%) 15 years post TURP. The major limitation was the heterogeneous follow-up, which could lead to an overestimation of prostate cancer mortality compared to a more standardized follow-up.

Conclusions: We observed high prostate cancer mortality after TURP with GG1 or GG2, likely due to unsampled high-grade cancer in the peripheral zone. Patients with incidental prostate cancer should be further investigated to rule out high-grade cancer. For patients with GG1 on TURP, once a subsequent biopsy does not show cancer, follow-up should be lessened similar to that of patients with an initial nonmalignant biopsy.