Objective: To examine the relationship between the presence of high-grade prostatic intraepithelial neoplasia (HGPIN) in retropubic radical prostatectomy (RP) specimens and cancer-specific outcomes, including pathological variables and biochemical disease-free survival (bDFS), as HGPIN shares many histopathological characteristics with prostate carcinoma and has been considered a precursor lesion to prostate cancer.
Patients and methods: The Columbia University Urologic Oncology Database was reviewed; 3460 patients were identified who underwent RP between 1988-2006, and 2133 with or without HGPIN and >12 months of follow-up were included in the analysis. Analysis of variance methods were used to evaluate the relationship between HGPIN and pathological stage, Gleason sum, perineural invasion, multifocality, extraprostatic extension, margin and nodal status. Kaplan-Meier analysis with the log-rank test and a multivariate Cox proportional hazard model fitted for preoperative prostate-specific antigen (PSA) level, Gleason sum and pathological stage were used to assess differences in bDFS.
Results: In all, 1885 (88.4%) patients had HGPIN in the RRP specimen and 248 (11.6%) had no HGPIN. There was no significant difference in the distribution of PSA level (P = 0.27), pathological stage (P = 0.18) or Gleason sum (P = 0.84) between patients with and with no HGPIN. The HGPIN-positive group had higher rates of perineural invasion (69.9 vs 57.5%; P = 0.003) and multifocality (63.0 vs 38.4%; P < 0.001). Patients with no HGPIN had a better bDFS, at 87.3% vs 81.0% at a median follow-up of 50 months, and 73.6% vs 67.0% at 9 years (P = 0.045). The risk of biochemical failure was 1.9 times greater in the HGPIN-positive group than the negative group (P = 0.006) when controlling for PSA level, pathological stage and Gleason sum.
Conclusions: In addition to traditional pathological prognostic variables, the absence of HGPIN in RRP specimens, although found in a minority of patients, denotes a significantly lower rate of tumour multifocality, perineural invasion and ultimately biochemical recurrence.