Topography of Prostate Cancer Recurrence: A Single-centre Analysis of Salvage Radical Prostatectomy Specimens and Implications for Focal Salvage Treatments

BACKGROUND: Most prostate cancer (PCa) recurrences after nonsurgical first-line treatment are managed with androgen deprivation therapy (ADT). When local treatment is indicated, salvage focal treatment (FT) may achieve outcomes similar to those after salvage radical prostatectomy (sRP), with lower morbidity. However, descriptions of the topography of PCa recurrence are scarce. OBJECTIVE: To describe the characteristics and topography of recurrent PCa at sRP. DESIGN, SETTING, AND PARTICIPANTS: We performed a review of the final pathology for consecutive men undergoing sRP at a single centre between 2007 and 2021. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Clinical and pathological outcomes and recurrence localisation (standardised map) were recorded. Suitability for salvage FT was evaluated using criteria defined a priori. RESULTS AND LIMITATIONS: We included 41 men who underwent sRP after whole-gland treatment (82.9% primary radiotherapy). Of these, 68.3% had grade group ≥3 and 46.3% had pT3 disease, including nine men (22%) with seminal vesicle involvement >1 cm. The pN+ rate was 29.3%. Surgical margins were positive in 39% (mostly at the apex, 21.9%). PCa was located at <3 mm from the apex in 68% of cases. The segment most frequently involved was the mid-gland (93%). The median prostate and index lesion (IL) volume was 31.4 cm(3) (interquartile range [IQR] 23–37) and 2 cm(3) (IQR 0.5–6), respectively. A solitary IL was present in 63.4% of cases, while 7.3% had whole-gland PCa involvement. Overall, 56% of the men (n = 23) were deemed suitable for salvage FT (although seven had pN+ disease). The sample size, single-centre retrospective design, and unavailability of magnetic resonance imaging data are the main limitations. CONCLUSIONS: According to sRP pathology, radiorecurrent PCa is an aggressive disease, frequently showing extraprostatic extension, positive margins, and apical involvement. The majority of cases still harbour a solitary index lesion and a consistent proportion may be suitable for a gland-preserving strategy. PATIENT SUMMARY: In this report we looked at the location of prostate cancer recurrence within the prostate gland after radiotherapy or ablation, in which energy (such as heat, cold, or laser energy) is used to kill cells. We found that although these recurrences are often high-grade locally advanced disease, around half of cases might be suitable for a gland-preserving salvage treatment.