Potential markers of aggressiveness in prostatic intraepithelial neoplasia detected by fluorescence in situ hybridization

Population-based study of the incidence and survival for intraductal carcinoma of the prostate

PURPOSE

The degree to which intraductal carcinoma of the prostate (IDC-P) affects clinical course remains poorly understood owing to small sample sizes from single-center studies. We sought to determine prognostic factors and outcomes associated with IDC-P in radical prostatectomy (RP) specimens.

MATERIALS AND METHODS

This is a retrospective study of RP during 2004 to 2013 using Surveillance, Epidemiology, and End Results to compare IDC-P with non-IDC-P. The effect of IDC-P on overall and disease-specific survival was assessed using Cox regression with a median follow-up of 4.8 years (interquartile range [IQR]: 2.6-7.0y; P = 0.01). Median prostate-specific antigen at diagnosis in IDC-P vs. non-IDC-P was similar (P = 0.23) at 6.2 (IQR: 4.6-13.0) vs. 6.1ng/ml (IQR: 4.6-9.8).

RESULTS

We identified 159,777 RP from 2004 to 2013, and 242 (0.002%) had IDC-P pathologic features. IDC-P was associated with a greater likelihood of extraprostatic stage, pT3/T4, 45.9% vs. 21.6% (P<0.001), higher grade, GS≥ 7, 79.3% vs. 62.7% (P<0.001), lymph node metastases, 5.8% vs. 2.4% (P<0.001), and positive surgical margins, 25.6% vs. 19.5% (P = 0.02). IDC-P was associated with a 3-fold increase in prostate cancer-specific mortality relative to non-IDC-P (hazard ratio = 3.0, 95% CI: 1.5-5.7; P<0.01). Limitations include retrospective design and potential underreporting of IDC-P that leads to underestimation of the true effect size.

CONCLUSIONS

The significance of IDC-P features has been recently recognized by the World Health Organization and it is associated with high-grade, extraprostatic features, and worse prostate cancer-specific mortality. Understanding its prognostic significance better guides adjuvant therapies and clinical trials.

Precursors of prostate cancer

High-grade prostatic intraepithelial neoplasia (PIN) is the only accepted precursor of prostatic adenocarcinoma, according to numerous studies of animal models and man; other proposed precursors include atrophy and malignancy-associated changes (with no morphologic changes). PIN is characterized by progressive abnormalities of phenotype and genotype that are intermediate between benign prostatic epithelium and cancer, indicating impairment of cell differentiation and regulatory control with advancing stages of prostatic carcinogenesis. The only method of detection of PIN is biopsy because it does not significantly elevate serum prostate-specific antigen concentration and cannot be detected by ultrasonography. The mean incidence of PIN in biopsies is 9% (range, 4%-16%), representing about 115,000 new cases of isolated PIN diagnosed each year in the United States. The clinical importance of PIN is its high predictive value as a marker for adenocarcinoma, and its identification warrants repeat biopsy for concurrent or subsequent carcinoma, especially when multifocal or observed in association with atypical small acinar proliferation (ASAP). Carcinoma develops in most patients with PIN within 10 years. Androgen deprivation therapy and radiation therapy decrease the prevalence and extent of PIN, suggesting that these forms of treatment may play a role in prevention of subsequent cancer. Multiple clinical trials to date of men with PIN have had modest success in delaying or preventing subsequent cancer.

Intraductal carcinoma of the prostate without invasive carcinoma on needle biopsy: emphasis on radical prostatectomy findings

PURPOSE

Limited information is available on radical prostatectomy findings in men with intraductal carcinoma of the prostate on needle core biopsy in the absence of invasive prostate cancer.

MATERIALS AND METHODS

From the consulting files of one of us we identified 83 men in whom biopsy showed only intraductal prostate cancer. Followup was available in 66 cases. We reviewed slides in 21 radical prostatectomy cases.

RESULTS

Treatment was radical prostatectomy in 23 men, radiation therapy in 15, hormone therapy in 8 and radiation plus hormone therapy in 15 while 5 underwent no treatment or repeat biopsy. Of the 21 radical prostatectomies available for review findings revealed pathological stage pT3a in 8 (38%), pT3b in 3 (13%), pT2 in 8 (38%) and intraductal carcinoma without identifiable invasive cancer in 2 (10%). One patient with pT3a had a positive lymph node at surgery. Average Gleason score was 7.9. Three patients (14%) experienced post-prostatectomy biochemical failure and another (5%) had bone metastases 2.5 years after prostatectomy. In 15 prostatectomies (71%) there was extensive intraductal carcinoma, defined as greater than 10% of tumor being intraductal, including the 2 cases of intraductal carcinoma only. Of the 19 prostatectomies with invasive adenocarcinoma 16 (84%) were conventional acinar adenocarcinoma, 2 (11%) ductal adenocarcinoma, and 1 (5%) mixed ductal and acinar adenocarcinoma.

CONCLUSIONS

At radical prostatectomy men in whom prior biopsies showed only intraductal carcinoma of the prostate typically have high grade (Gleason score 7 or greater) invasive adenocarcinoma and most have advanced stage disease (pT3). Definitive therapy is recommended in men with intraductal carcinoma of the prostate on needle biopsy even in the absence of pathologically documented invasive prostate cancer.

The 3-dimensional structure of isolated and small foci of prostatic adenocarcinoma: the morphologic relationship between prostatic adenocarcinoma and prostatic intraepithelial neoplasia

BACKGROUND

Transitional histopathologic changes from high-grade prostatic intraepithelial neoplasia (HGPIN) into early prostatic adenocarcinoma (PAC) have not been well studied to date. To investigate the histogenesis of PAC, we examined isolated and small foci of PAC (ISPAC) found in prostatectomy specimens and the 3-dimensional structure of these foci.

DESIGN

Twelve consecutive radical prostatectomy specimens having ISPAC, performed for peripheral zone PAC (10 cases) and for transitional zone PAC (2 cases), of Gleason score were studied. One to 2 tissue blocks with representative sections were used.

RESULTS

Eight ISPAC, with Gleason score 3 + 3 had complete serial sections of the entire lesion. PAC consisted of continuous, tortuous and branching tubules and acini arising from benign ducts displaying: (a) HGPIN in 5 ISPAC and (b) no HGPIN in 3 ISAPC. At the junctions between benign epithelia with or without HGPIN and malignant epithelia, there were transitional lesions with HGPIN involving small ducts and acini.

CONCLUSIONS

PAC develops as a result of multiple outpouchings of the epithelium with formation of small ducts and acini showing cytologic atypia and gradual or abrupt loss of basal cells. Grade 3 ISPAC consists of a system of continuous duct pushing into the stroma. There is also evidence suggestive of HGPIN as being both a precursor lesion and an accompanying lesion of PAC.

Basal prostate epithelial cells stimulate the migration of prostate cancer cells

Carcinoma cells in PIN are situated above a layer of basal epithelial cells, which shield the tumor cells from stimulation by factors from the prostate stroma. During progression to invasive carcinoma, the basal cell layer becomes disrupted and tumor cells adhere to the basement membrane. The close proximity of basal epithelial cells to tumor cells in the early stages of prostate oncogenesis raises the possibility that basal epithelial cells participate in tumor cell invasion. Here, we investigated the migration-promoting activity of secreted factors from basal epithelial cells on BPH-1 cells, which we used as an in vitro model of preinvasive prostate cancer cells. We showed that the conditioned medium of basal epithelial cells (PEC-CM) contains adhesion proteins and chemotactic factors that stimulate adhesion, planar polarization, migration, and phosphorylation of Akt and that LY294002 and Wortmannin partially inhibit PEC-CM-triggered migration. We identified laminin-5 as a major migration-stimulating protein for BPH-1 cells in PEC-CM. Laminin-5 induced migration is completely inhibited by LY294002 or Wortmannin. In addition, antibody-depletion of laminin-5 from PEC-CM significantly diminishes the migration of BPH-1 cells. These results demonstrated, that laminin-5 is secreted by basal prostate epithelial cells in vivo and in vitro and stimulates migration of BPH-1 cells through a PI3-kinase dependent mechanism. Altogether, the possibility that basal epithelial cells assist in the invasion of in situ carcinoma cells is supported by the results from our in vitro system.

High-grade prostatic intraepithelial neoplasia

High-grade prostatic intraepithelial neoplasia (PIN) is now accepted as the most likely preinvasive stage of adenocarcinoma, almost two decades after its first formal description. PIN has a high predictive value as a marker for adenocarcinoma, and its identification warrants repeat biopsy for concurrent or subsequent invasive carcinoma. The only method of detection is biopsy; PIN does not significantly elevate serum prostate-specific antigen (PSA) concentration or its derivatives and cannot be detected by current imaging techniques, including ultrasound. Most patients with PIN will develop carcinoma within 10 years. PIN is associated with progressive abnormalities of phenotype and genotype, which are similar to cancer rather than normal prostatic epithelium, indicating impairment of cell differentiation with advancing stages of prostatic carcinogenesis. Androgen deprivation therapy decreases the prevalence and extent of PIN, suggesting that this form of treatment may play a role in chemoprevention.

Precancerous lesions and conditions of the prostate: from morphological and biological characterization to chemoprevention

Prostatic intraepithelial neoplasia (PIN) is composed of dysplastic cells with a luminal cell phenotype, expressing the androgen receptor as well as prostate-specific antigen. PIN is characterized by progressive abnormalities of phenotype that are intermediate between normal prostatic epithelium and cancer, indicating impairment of cell differentiation and regulatory control with advancing stages of carcinogenesis. High-grade PIN is considered the most likely precursor of prostatic carcinoma, according to virtually all available evidence. Androgen deprivation decreases the prevalence and extent of PIN and the degree of capillary vascularization (e.g., angiogenesis) in the surrounding stroma via suppression of vascular endothelial growth factor production. Prostatic carcinoma is also likely to arise from precursor lesions other than high-grade PIN such as low-grade PIN, atypical adenomatous hyperplasia, malignancy-associated foci, and atrophy.

Current status of flow cytometry in cell and molecular biology

This review summarizes recent developments in flow cytometry (FC). It gives an overview of techniques currently available, in terms of apparatus and sample handling, a guide to evaluating applications, an overview of dyes and staining methods, an introduction to internet resources, and a broad listing of classic references and reviews in various fields of interest, as well as some recent interesting articles.

Morphological identification of the patterns of prostatic intraepithelial neoplasia and their importance

High grade prostatic intraepithelial neoplasia (PIN) is the most likely precursor of prostatic carcinoma. PIN has a high predictive value as a marker for carcinoma, and its identification in biopsy specimens warrants repeat biopsy for concurrent or subsequent carcinoma. The only methods of detection are biopsy and transurethral resection; PIN does not greatly raise the concentration of serum prostate specific antigen (PSA) or its derivatives, does not induce a palpable mass, and cannot be detected by ultrasound. Androgen deprivation decreases the prevalence and extent of PIN, suggesting that this form of treatment might play a role in chemoprevention. Radiotherapy is also associated with a decreased incidence of PIN.

Cribriform carcinoma of the prostate and cribriform prostatic intraepithelial neoplasia: incidence and clinical implications

Cribriform neoplasia of the prostate can be recognized easily. However, controversy persists regarding terminology, particularly with the intraductal spread of cribriform neoplasia; some consider this "intraductal carcinoma," whereas consensus meetings defined these lesions as high-grade cribriform prostatic intraepithelial neoplasia (HGCP). This study attempts to identify the incidence and clinical significance of HGCP and cribriform carcinoma (CC) by evaluating 114 radical prostatectomy specimens. Cases were divided into three histologic groups for statistical analysis: (1) pure acinar carcinoma: infiltrating acinar carcinoma without evidence of cribriform neoplasia; (2) CC: acinar carcinoma with CC; and (3) HGCP: acinar carcinoma with HGCP. High-grade cribriform prostatic intraepithelial neoplasia was defined as the presence of neoplastic cells spanning the entire lumen in a cribriform configuration in which a basal cell layer could be shown by immunohistochemistry. Similar areas in which no basal cell layer could be seen were diagnosed as CC. The incidence of cribriform neoplasia was 38% (43 of 114). The incidences of HGCP and CC were 13% (15 of 114) and 25% (28 of 114), respectively. Univariate analysis showed a strong association between HGCP and CC both and several preoperative and final pathology results, including digital rectal examination, pathology tumor stage, extraprostatic extension, surgical margin positivity, high Gleason sum (GS), and high tumor volume. Kaplan-Meier analysis showed HGCP to have a 61% cumulative prostate-specific antigen (PSA) failure rate in contrast with CC and pure acinar cancer, which had cumulative PSA failure rates of 15% and 13%, respectively (p = 0.0001, log-rank test). Multivariate Cox's proportional-hazards analysis found preoperative serum PSA, GS, tumor stage, and volume to be important predictors of PSA failure. In a second regression model that included serum PSA, GS, and pathology tumor stage, HGCP was an independent predictor of PSA failure. Both HGCP and CC are closely associated with several poor prognostic indicators, including advanced pathology tumor stage, a high GS, and serum PSA. Multivariate analysis showed HGCP as an independent prognostic indicator. The close association between high tumor volume and HGCP supports the theory that the development of HGCP is a late event in tumor progression, more compatible with the intraductal spread of tumor than dysplasia.