Toxicity With Prostate-Only vs Prostate and Pelvic Lymph Node Intensity-Modulated Radiation Therapy
In a UK national population-based study reported in the Journal of Clinical Oncology, Parry et al found virtually no difference in gastrointestinal or genitourinary toxicity associated with prostate-only (PO-IMRT) vs prostate and pelvic lymph node intensity-modulated radiation therapy (PPLN-IMRT) in patients with high-risk localized or locally advanced prostate cancer.
The study involved data from patients with high-risk localized or locally advanced prostate cancer treated with PPLN-IMRT (n = 780) or PO-IMRT (n = 3,065) in the English National Health Service between 2010 and 2013. Follow-up was available through the end of 2015. A competing-risks regression analysis adjusting for patient and tumor characteristics provided estimated subdistribution hazard ratios (sHRs) comparing gastrointestinal and genitourinary complications with PPLN-IMRT vs PO-IMRT.
Treatment-Related Toxicity
The 3-year cumulative incidence of toxicity was 14% in the PPLN-IMRT group vs 14% in the PO-IMRT group for gastrointestinal toxicity and 9% vs 8% for genitourinary toxicity. There was no significant difference between the PPLN-IMRT group vs PO-IMRT group in severe gastrointestinal toxicity (adjusted sHR = 1.00, P = .97) or severe genitourinary toxicity (adjusted sHR = 1.10, P = .50).
The investigators concluded, “Including pelvic lymph nodes in radiation fields for high-risk or locally advanced prostate cancer is not associated with increased gastrointestinal or genitourinary toxicity at 3 years. Additional follow-up is required to answer questions about its impact on late genitourinary toxicity. Results from ongoing trials will provide insight into the anticancer effectiveness of pelvic lymph node irradiation.”
Matthew G. Parry, MSc, of the Clinical Effectiveness Unit, Royal College of Surgeons of England, London, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was funded by NHS England and the Welsh Government. For full disclosures of the study authors, visit jco.ascopubs.org.
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