Proposal for an Expanded "R" Classification: Impact of Positive Surgical Margin Length on Biochemical Recurrence...

Area of Science:

• Urology
• Pathology
• Oncology

Background:

• Radical prostatectomy is a primary treatment for prostate cancer.
• Positive surgical margins (PSM) are associated with increased risk of biochemical recurrence (BCR).
• Current staging systems may not fully capture prognostic information from PSM.

Purpose of the Study:

• To evaluate the effect of positive surgical margin (PSM) length on predicting postoperative biochemical recurrence (BCR) after radical prostatectomy.
• To propose an enhanced R subclassification for the TNM-R system based on PSM length.

Main Methods:

• Retrospective analysis of 353 patients undergoing robot-assisted radical prostatectomy with PSM.
• Quantitative measurement of PSM length by a uropathologist.
• Definition of BCR as two consecutive PSA levels ≥0.2 ng/mL.

Main Results:

• BCR occurred in 27.1% of patients.
• A PSM length of 3.5 mm was identified as a significant cut-off for predicting BCR (p < 0.001).
• Patients with PSM ≥ 3.5 mm had a significantly higher BCR rate (54.3%) compared to those with PSM < 3.5 mm (9.8%). PSM length was an independent prognostic factor for BCR.

Conclusions:

• Quantitative PSM length is an independent predictor of BCR after radical prostatectomy.
• A proposed subclassification of R1 margins into R1a (<3.5 mm) and R1b (≥3.5 mm) may improve prognostic accuracy.
• This refined pathological reporting can aid in better patient management and risk stratification.