The University of Michigan Medical Center, Ann Arbor, MI.The Ann Arbor Veteran Affairs Medical System, Ann Arbor, MI.
To assess the prognostic value of perineural invasion (PNI) for patients treated with dose-escalated external-beam radiation therapy for prostate cancer.
Outcomes were analyzed for 651 men treated for prostate cancer with EBRT to a minimum dose ≥75 Gy. We assessed the impact of PNI as well as pretreatment and treatment-related factors on freedom from biochemical failure (FFBF), freedom from metastasis (FFM), cause-specific survival (CSS), and overall survival.
PNI was present in 34% of specimens at biopsy and was significantly associated with higher Gleason score (GS), T stage, and prostate-specific antigen level. On univariate and multivariate analysis, the presence of PNI was associated with worse FFBF (hazard ratio = 1.7, p < 0.006), FFM (hazard ratio = 1.8, p < 0.03), and CSS (HR = 1.4, p < 0.05) compared with absence of PNI; there was no difference in overall survival. Seven-year rates of FFBF, FFM, and CCS were 64% vs. 80%, 84% vs. 92%, and 91% vs. 95% for those patients with and without PNI, respectively. On recursive partitioning analysis, PNI predicted for worse FFM and CSS in patients with GS 8-10, with FFM of 67% vs. 89% (p < 0.02), and CSS of 69% vs. 91%, (p < 0.04) at 7 years for those with and without PNI, respectively.
The presence of PNI in the prostate biopsy predicts worse clinical outcome for patients treated with dose-escalated external-beam radiation therapy. Particularly in patients with GS 8-10 disease, the presence of PNI suggests an increased risk of metastasis and prostate cancer death.
Feng FY, Qian Y, Stenmark MH, Halverson S, Blas K, Vance S, Sandler HM, Hamstra DA. Are you the author?
Reference: Int J Radiat Oncol Biol Phys. 2011 Aug 4. Epub ahead of print.