Clinical Management of Premalignant Lesions of the Prostate

High-grade prostatic intraepithelial neoplasia and atypical small acinar proliferation on initial 21-core extended biopsy scheme: incidence and implications for patient care and surveillance

PURPOSE

To evaluate the incidence of high-grade prostatic intraepithelial neoplasia (HGPIN) and atypical small acinar proliferation (ASAP) in an initial 21-core extended biopsy scheme and to determine the prostate cancer detection rate in the repeated biopsy.

METHODS

Between 2002 and 2008, 2,006 patients underwent a first 21-core extended biopsy scheme. Incidences of cancer, ASAP and HGPIN were studied. Cancer detection rate in the repeated 21-core extended biopsy for ASAP and HGPIN was reported and compared with those obtained on repeated biopsy for clinico-biological indications.

RESULTS

Incidences of HGPIN and ASAP were 1.7 and 1.1%, respectively. The 6-core and 12-core biopsy schemes detecting HGPIN would have missed the diagnosis of cancer in 10 and 3.6% of cases, compared to a 21-core biopsy protocol, respectively. The cancer detection rate on repeated biopsy for HGPIN was 19% and not significantly different compared with the detection rate on repeated biopsy for clinico-biological indications (16.8%, p = 0.77). Seven prostate cancers were found among the 17 re-biopsies for ASAP revealing a detection rate of 41.2% (p = 0.01). All detected cancers were organ confined. No clinico-pathological data were independent predictor of cancer on repeated biopsy.

CONCLUSION

Our report demonstrates the different risk profiles for HGPIN and ASAP in a 21-core extended biopsy scheme. The presence of HGPIN does not imply a higher risk for cancer detection at immediate re-biopsy compared to other patients for whom repeated biopsies were indicated for increasing or persistently increased PSA levels. Repeated biopsy is warranted when ASAP is diagnosed because of a high risk of prostate cancer.

High-grade prostatic intraepithelial neoplasia is an independent predictor of outcome after radical prostatectomy

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.

Development and external validation of an extended repeat biopsy nomogram

PURPOSE

We hypothesized that the outcome of repeat biopsy could be accurately predicted. We tested this hypothesis in a contemporary cohort from 3 centers.

MATERIALS AND METHODS

The principal cohort of 1,082 men from Hamburg, Germany was used for nomogram development as well as for internal 200 bootstrap validation in 721 and external validation in 361. Two additional external validation cohorts, including 87 men from Milan, Italy and 142 from Seattle, Washington, were also used. Predictors of prostate cancer on repeat biopsy were patient age, digital rectal examination, prostate specific antigen, percent free prostate specific antigen, number of previous negative biopsy sessions and sampling density. Multivariate logistic regression models were used to develop the nomograms.

RESULTS

The mean number of previous negative biopsies was 1.5 (range 1 to 6) and the mean number of cores at final repeat biopsy was 11.1 (range 10 to 24). Of the men 370 (30.2%) had prostate cancer. On multivariate analyses all predictors were statistically significant (p < or =0.028). After internal validation the nomogram was 76% accurate. External validation showed 74% (Hamburg), 78% (Milan) and 68% (Seattle) accuracy.

CONCLUSIONS

Relative to the previous nomograms (10 predictors or 71% accuracy) our tool relies on fewer variables (6) and shows superior accuracy in European men. Accuracy in American men is substantially lower. Racial, clinical and biochemical differences may explain the observed discrepancy in predictive accuracy.

Validity of primary care patient self-report of abnormal (but not cancer) prostate biopsy results

PURPOSE

We assessed the validity of patient self-report of abnormal (but not cancer) prostate biopsy results, ie, atypical cells or prostatic intraepithelial neoplasia.

MATERIALS AND METHODS

We compared survey responses and pathology records for 156 men from a multicenter, prospective cohort study, which was designed to evaluate the impact of a suspicious prostate cancer screening test followed by benign prostate biopsy.

RESULTS

Of the 156 subjects 45 (29%) reported having had atypical cells or prostatic intraepithelial neoplasia and 38 (24%) had a pathology report with atypia or prostate intraepithelial neoplasia. The sensitivity of the self-report was 87%, specificity was 90%, positive predictive value was 73% and negative predictive value was 95%. The kappa statistic was 0.7.

CONCLUSIONS

Men in this study reported this complex result accurately. However, it was concerning that 5 men (13%) appeared unaware of an abnormal prostate biopsy result, especially given the substantial residual risk of prostate cancer conferred by this result.

Production of serum-free and total prostate-specific antigen due to prostatic intraepithelial neoplasia

OBJECTIVE

High serum total prostate-specific antigen (PSA) levels have proven to be predictive of concurrent cancer but the role of prostatic intraepithelial neoplasia (PIN) in the production of total (t) and free (f) PSA is still the subject of research. In this study we wanted to discover whether variations in serum fPSA and tPSA levels are caused by PIN.

MATERIAL AND METHODS

We reviewed the medical records of 87 patients: in 32 of them the diagnosis of isolated PIN was made from surgical samples (simple prostatectomy, n = 19; radical cystectomy, n = 13); in 30 patients a diagnosis of benign prostatic hyperplasia (BPH) without PIN or prostatic carcinoma was made after simple prostatectomy (n = 20) or radical cystectomy (n = 10); and in 25 patients a clinically significant prostatic cancer was diagnosed and these patients underwent radical prostatectomy. All patients underwent a standard preoperative evaluation, including serum fPSA and tPSA determinations and PSA density.

RESULTS

The frequency of isolated PIN in simple prostatectomy specimens was 6.3%. The mean f/t PSA ratios were 17.66% in the 32 patients with PIN, 19.2% in the 8 patients with low-grade PIN, 17.6% in the 24 patients with high-grade PIN, 24.2% in patients with BPH and 13% in patients who underwent radical prostatectomy.

CONCLUSIONS

We believe that to make a definitive diagnosis of isolated PIN without carcinoma, study of the whole prostate gland is necessary, in order to definitively exclude the presence of concurrent neoplastic foci. Our data show that PIN does not contribute to tPSA levels and density; however, it may be responsible for a slight reduction in the f/t PSA ratio, with a significant reduction in cases with high-grade PIN (17.6%) compared to those with BPH (24.2%).

Effect of androgen deprivation therapy on prostatic intraepithelial neoplasia

There is a marked decrease in the prevalence and extent of high-grade prostatic intraepithelial neoplasia (PIN) in men with prostate cancer after androgen deprivation therapy (ADT) when compared with untreated cases. Basal cell hyperplasia, cytoplasmic clearing, and prominent atrophy of benign acini, with decreased ratio of acini to stroma, accompany this decrease. These findings indicate that the benign and dysplastic prostatic epithelium is androgen dependent. In the normal prostatic epithelium, luminal secretory cells are more sensitive to the absence of androgen than basal cells, and the proliferative cells of high-grade PIN share this androgen sensitivity. The loss of some normal, hyperplastic, and dysplastic epithelial cells with ADT is probably because of acceleration of programmed single-cell death. Remarkably little is known about the comparative effect of different forms of chemical ADT on PIN and cancer, although there appears to be a limited and consistent repertoire of morphologic responses to all forms of this therapy. Conversely, blockade of 5alpha-reductase with finasteride has little or no effect on PIN (or benign epithelium and cancer), unlike other forms of ADT. A recent international consensus conference sponsored by the World Health Organization concluded that identification of high-grade PIN offered the possibility of chemoprevention with hormonal therapy to block the development of clinical cancer. Multiple chemoprevention trials are planned or under way to address this hypothesis.