Ten-year outcomes for pathologic node-positive patients treated in RTOG 75-06

Area of Science:

• Oncology
• Radiation Oncology

Background:

• Prostate cancer with pelvic nodal involvement is associated with a poorer prognosis.
• Radiation therapy is a standard treatment modality for localized prostate cancer.

Purpose of the Study:

• To determine the long-term cancer-free survival rate in patients with biopsy-proven nodal involvement treated with radiation therapy.
• To assess the fraction of node-positive prostate cancer patients who achieve a cure 10 years after radiation treatment.

Main Methods:

• Analysis of data from RTOG protocol #75-06, including 90 patients with biopsy-proven pelvic nodal involvement treated with radiation.
• Continuous follow-up of patients since treatment.
• Solicitation of prostate-specific antigen (PSA) levels from patients clinically cancer-free (no evidence of disease, NED) at 10 years to confirm cure.

Main Results:

• The 10-year overall survival rate was 29%.
• The 10-year clinical no evidence of disease (NED) survival rate was 7%.
• Two patients with confirmed cures had PSA levels < 0.8 ng/ml. These patients had clinical stage T-3, Gleason Score 6 and 8, with 1 or 2 positive nodes. Multivariate analysis indicated Gleason sum significantly correlated with disease-free survival.

Conclusions:

• A small fraction of node-positive prostate cancer patients (2 of 90 by PSA, 3 of 90 by clinical endpoints) are cured 10 years after radiation therapy.
• Innovative treatment strategies are necessary to improve cure rates for node-positive prostate cancer patients.