INTRODUCTION: To evaluate the association of perineural invasion (PNI) with disease progression in men with prostate cancer (PCa) on active surveillance (AS).
METHODS: Retrospective analysis of 302 men on AS for low-risk PCa (T1c-T2a), Gleason ≤ 6, ≤ 3 cores positive, ≤ 50% of any core involved, prostate-specific antigen ≤ 11ng/ml in the reduction by dutasteride of clinical progression events in expectant management (REDEEM) study. Patients underwent study-mandated biopsies at 18- and 36-months after enrollment. Disease progression was divided in pathological (≥4 positive cores, ≥50% core involvement or Gleason >6 on follow-up biopsy), therapeutic (any therapeutic PCa intervention) or clinical (either pathological or therapeutic progression). Time to disease progression was analyzed with Cox models adjusting for age, race, baseline PSA, and number of sampled and involved cores, tumor length and treatment.
RESULTS: A total of 11 (4%) patients had PNI on baseline biopsy. PNI was not associated with any baseline features (all P>0.05). During the study, 125 (41%) patients developed clinical progression (95 pathological progression). The 1, 2 and 3-year clinical progression-free survival for men with PNI was 82%, 27%, and 27%, respectively; vs. 93%, 67%, and 58% among men without PNI (P< 0.05). On multivariable analyses, PNI was associated with clinical (HR=2.39, 95%CI=1.16-4.94, P=0.019) and pathological progression (HR=2.21, 95%CI=0.92-5.33, P=0.076).
CONCLUSION: Among patients with PCa on AS, PNI was associated with increased risk of clinical progression. The 2-year risk of clinical progression with PNI was 73%. If these results are confirmed, patients with PNI may not be good AS candidates.
Moreira DM, Fleshner NE, Freedland SJ. Are you the author?
Department of Urology, Mayo Clinic, Rochester, MN, USA; Division of Urology, Princess Margaret Hospital, University Health Network, Toronto, ON, Canada; Division of Urology, Department of Surgery, University of Toronto, Toronto, ON, Canada; Division of Urology, Department of Surgery and the Samuel Oschin Comprehensive Cancer Institute, Cedars Sinai Medical Center, Los Angeles, CA, USA; Urology Section, Veterans Affairs Medical Center, Durham, NC, USA.
Reference: J Urol. 2015 May 16. pii: S0022-5347(15)04011-2.