The impact of tumor locations on local recurrences in prostate cancer patients receiving cryoablation

Purpose: To evaluate the impact of tumor locations on local recurrences in prostate cancer patient who received cryoablation

Materials and Methods: A total 255 patients with prostate cancer who received primary cryoablation in National Taiwan University Hospital between January 2008 and December 2012 were enrolled. During follow-up, biochemical failure (Phoenix criteria) would trigger prostate biopsies. Local recurrence refers to pathologically proven prostate cancer in prostate and seminal vesicles. The prostate was defined into eight areas: left lateral (LL), left medial (LM), left apex (LA), right lateral (RL), right medial (RM), right apex (RA), anterior and midline posterior (PM). The seminal vesicles also defined as one area each: left seminal vesicle (LSV), right seminal vesicle (RSV). We analyzed the prostate cancer recurrence rate of each area after primary cryoablation.

Results: A total of 46 (18.0%) patients had local recurrences during a median follow-up duration of 5 years. In the primary tumor areas, local recurrence rates were 7.1% (RM), 3.4% (RA), 2.4% (RSV), 2.6% (LSV), 1.1% (LM), 2.1% (LL), and 0 (RL, anterior, PM, LA). For the areas with negative results for malignancy in pre-operative prostate biopsies, local recurrence rates were 2.4% (RSV), 1.1% (RL) and 0 (other areas). For patients whose anterior and PM areas were not routinely examed in pre-operative prostate biopsy, local recurrence rates were 3.3% (anterior) and 1.7% (PM). Multivariate analysis revealed higher tumor stages, and tumor locations at RM, and anterior areas were associated with higher risk of local recurrence. Those patients with previously proved cancer distribution at the right medial had highest recurrence rate at this area.

Conclusion: Limited to the nature of cryoablation and preservation of vital organs nearby, tumor locations in prostate would interfere with the successful rate of prostate cryoablation. To improve oncological outcomes, detailed and accurate tumor locations is essential for prostate patients who plan to receive cryoablation.