Long-term Follow-up of a Matched Cohort Study Evaluating the Role of Adjuvant Radiotherapy for Organ-confined Prostate Cancer With a Positive Surgical Margin.

Abstract

OBJECTIVE:

To evaluate if adjuvant radiation therapy (ART) is associated with improved long-term oncologic outcomes for pT2N0R1 prostate cancer (PCa).

METHODS:

Men with pT2N0 PCa and a single positive surgical margin following radical prostatectomy and pelvic lymphadenectomy were identified (1987-1996). Men who received ART were matched 1:1 to men who did not receive ART based on age, year of surgery, Gleason score, preoperative prostate-specific antigen, site of positive surgical margin, and DNA ploidy. Biochemical recurrence (BCR), local recurrence, distant metastasis, and overall survival (OS) were compared between groups in time-to-event analyses.

RESULTS:

The cohort included 152 men (76 per group) with a median follow-up of 20 years (interquartile range 19,22). ART was associated with a lower cumulative incidence of BCR (25% vs 52%; P <.001) and local recurrence (3% vs 12%; P = .03), but no significant differences in cumulative incidence of distant metastasis (10% vs 7%; P = .44) or in probability of OS (56% vs 68%; P = .08) at 20 years. In competing risks models, receipt of ART was associated with reduced risks of BCR (hazard ratio [HR] = 0.40; 95% confidence interval [CI] 0.23-0.70; P <.001) and local recurrence (HR = 0.21; 95% CI .05-0.98; P = .05), but not distant metastasis (HR = 1.56; 95% CI 0.51-4.75; P = .43). In the Cox model, ART was not associated with improved OS (HR = 1.56; 95% CI 0.94-2.57; P = .08).

CONCLUSION:

ART was associated with reduced risks of BCR and local recurrence for men with pT2N0R1 PCa. However, ART was not significantly associated with metastasis-free or OS benefits, as recurrences in these patients generally followed an indolent trajectory with 20 years of median follow-up.

• Authors: Bimal Bhindi, Rachel E Carlson, Ross J Mason, Phillip J Schulte, Matthew T Gettman, Igor Frank, Matthew K Tollefson, R Houston Thompson, Stephen A Boorjian, Bradley C Leibovich, R Jeffrey Karnes
• Journal: Urology (Urology) Vol. 109 Pg. 145-152 (11 2017) ISSN: 1527-9995 [Electronic] United States
• PMID: 28823636 (Publication Type: Journal Article)
• Copyright: Copyright © 2017 Elsevier Inc. All rights reserved.

Topics

• Aged
• Cohort Studies
• Follow-Up Studies
• Humans
• Male
• Margins of Excision
• Middle Aged
• Prostatectomy
• Prostatic Neoplasms (pathology, radiotherapy, surgery)
• Radiotherapy, Adjuvant
• Time Factors
• Treatment Outcome