Prostatic Intraepithelial Neoplasia is Risk Factor for Adenocarcinoma: Predictive Accuracy in Needle Biopsies

Prostate adenocarcinoma detected after high-grade prostatic intraepithelial neoplasia or atypical small acinar proliferation

OBJECTIVE

To review specific histological variables in patients with prostate cancer who previously had diagnoses of high-grade prostatic intraepithelial neoplasia (HGPIN) and/or atypical small acinar proliferation (ASAP), compared with those who had no such diagnoses.

PATIENTS AND METHODS

The histological characteristics of prostate cancers which were detected after a previous diagnosis of HGPIN and/or ASAP during 1998-2005 were investigated and correlated with the biopsies from patients with prostate cancer but with no such previous diagnoses.

RESULTS

HGPIN was followed by prostate cancer on repeat biopsy in 16.8% of patients, and ASAP in 26.7%. The mean age of patients with HGPIN or ASAP was higher than in those with no such diagnoses (P < 0.001). Similarly, patients with these previous diagnoses had a lower Gleason score (P = 0.017 and <0.001, respectively) and lower tumour volume variables (fewer tumour foci, P = 0.033 and 0.041, respectively) and shorter cancer (P = 0.048 and 0.030) in core biopsies than those without.

CONCLUSIONS

Patients with prostate cancer who had previous biopsies with HGPIN or ASAP were older and has lower grade- and volume-cancers than those who had not.

The proportion of cores with high-grade prostatic intraepithelial neoplasia on extended-pattern needle biopsy is significantly associated with prostate cancer on site-directed repeat biopsy

OBJECTIVE

To determine whether the predictive value of isolated high-grade prostatic intraepithelial neoplasia (HGPIN) for an unsampled prostate cancer on an extended biopsy is lower due to more thorough prostate sampling, and whether the proportion of cores with HGPIN is associated with prostate cancer, as isolated HGPIN on sextant prostate biopsy is associated with a 27-57% risk of prostate cancer on repeat biopsy.

PATIENTS AND METHODS

All extended prostate biopsies taken by one urologist over 6 years were reviewed for patients with isolated HGPIN on initial biopsy. Biopsies were evaluated for histological features and the proportion of cores with HGPIN. The clinical characteristics and pathological findings from subsequent biopsies were determined.

RESULTS

Of 577 men having extended biopsies, 48 had isolated HGPIN, followed by one to four site-directed repeat biopsies. Although only 10 (21%) had cancer on the first repeat biopsy, overall 15 (31%) had cancer. Those with cancer on repeat biopsy had a significantly higher proportion of cores with HGPIN, i.e. 29% vs 15%, cancer vs no cancer, respectively (P = 0.04).

CONCLUSIONS

Isolated HGPIN on extended biopsy conferred a 31% risk of unsampled prostate cancer. The proportion of cores with HGPIN on initial biopsy was significantly associated with the risk of cancer. The same was not true for age, race, prostate-specific antigen level, or the findings on digital rectal examination. The significant association between the proportion of cores with HGPIN and the risk of cancer suggests that patients with unifocal HGPIN on extended biopsy be managed expectantly, whereas those with multifocal HGPIN be re-biopsied.

Prostate cancer detection in men with an initial diagnosis of atypical small acinar proliferation

OBJECTIVE

To determine the subsequent prostatic adenocarcinoma detection rate amongst men with an initial diagnosis of atypical small acinar proliferation (ASAP).

PATIENTS AND METHODS

We reviewed the Illawarra Prostate Pathology Database over a 10-year period (January 1994 to January 2004) for specimens diagnosed as ASAP. These specimens were re-reviewed and clinical data obtained.

RESULTS

Of 61 cases of ASAP, there were complete follow-up data for 31. In this group nine patients had no further biopsies at our institution; the other 22 had at least one repeat biopsy. The incidence of prostatic adenocarcinoma in this group was 17/31 (55%). This included 13 diagnoses on second biopsy, three on third biopsy and one diagnosed at another institution.

CONCLUSION

This study showed a detection rate for prostatic adenocarcinoma of 55% after an initial diagnosis of ASAP, which indicates that an initial diagnosis of ASAP mandates re-biopsy.

Cytosolic overexpression of p62 sequestosome 1 in neoplastic prostate tissue

AIMS

To investigate the expression of p62 in various prostatic tissues, and to demonstrate different immunohistochemical patterns of p62 expression in distinct pathological entities of the prostate. The p62 sequestosome 1 (SQSTM1) gene product is a multifunctional protein with ubiquitous expression in normal adult tissue.

METHODS AND RESULTS

Overexpression of p62 was detected in prostate cancer cell lines and tissues by reverse transcriptase-polymerase chain reaction. Immunohistochemical staining for p62 was performed on 73 cases of paraffin-embedded prostatic tissue. p62 was negative or weakly positive only in the nucleus (pattern N) of prostatic gland epithelium in nine normal and hyperplastic prostate specimens, whilst most cancerous tissue showed intense, uniform staining for p62 in the cytoplasm (pattern C). Of the prostate cancer specimens, 91% showed positive pattern C immunoreactivity. Of the cases with high-grade prostatic intraepithelial neoplasia (PIN) around cancer, 77% showed pattern C. However, in specimens from the patients without prostate cancer PIN displayed pattern C in only 32% of cases. Western blot analysis showed that all cancer cell lines expressed p62 in the cytoplasm but there was little nuclear expression.

CONCLUSION

Cytosolic overexpression of p62 is a novel immunohistochemical characteristic in prostatic adenocarcinoma and high-grade PIN, suggesting that p62 might be a novel marker for prostatic malignancy.

Do all patients with high-grade prostatic intraepithelial neoplasia on initial prostatic biopsy eventually progress to clinical prostate cancer?

OBJECTIVE

To assess the clinical outcome of patients with a diagnosis of high-grade prostatic intraepithelial neoplasia (PIN) on initial prostatic biopsy, with a minimum of 5 years of follow-up, as such patients are at greater risk of having prostate cancer on subsequent biopsy.

PATIENTS AND METHODS

Between November 1992 and October 1998, 21 patients were identified as having PIN on their initial transrectal ultrasonography-guided prostate biopsy. None of these patients had a focus of cancer on the initial biopsy. Their medical data were reviewed retrospectively to determine the natural history of PIN in these patients. Patients who were not identified as having cancer were followed every 6-12 months with prostate-specific antigen (PSA) testing and digital rectal examinations (DRE).

RESULTS

A mean (range) of 7 (2-8) cores were taken at initial biopsy; the mean age of the patients was 63 (53-77) years and mean PSA level 9.1 (4.9-17.6) ng/mL. Six patients had an abnormal DRE at presentation. A mean of 8 (7-10) cores were obtained on the second biopsy; six patients were diagnosed with cancer, with a mean Gleason score of 6 (5-7), while three were diagnosed with persistent PIN. These three patients had a third prostate biopsy which showed cancer of Gleason score 6 in one and benign prostatic hyperplasia in two. After a mean follow-up of 72.2 (60-84) months, none of the remaining 12 patients was diagnosed with clinically significant cancer. Five of these patients went on to a third prostate biopsy, with no evidence of cancer. One patient died from unrelated causes during this period.

CONCLUSION

This study affirms our current practice of following patients with PIN conservatively if a second or third subsequent prostate biopsy is negative. Whether PIN is a premalignant lesion or merely a lesion associated with cancer needs to be addressed in multicentre studies with a follow-up of > 10 years.

The possibility of 'de novo' cancer in the prostate

BACKGROUND

To investigate the possibility of 'de novo' prostate cancer by analyzing the relationship between high grade prostatic intraepithelial neoplasia (HGPIN) and latent prostate cancer.

MATERIALS AND METHODS

Latent prostate cancers found at autopsy were examined and 55 cancer foci with a poorly (Gleason grade 4 and 5) or moderately (Gleason grade 3) differentiated component were selected. The 55 foci were separated into two groups: (i) foci with either a poorly or moderately differentiated component only (single differentiation group, SDG); and (ii) mixed foci with two or more types of differentiation components (mixed differentiation group, MDG). High grade intraepithelial neoplasia was defined as positive if it was observed within 2 mm from the edge of the cancer focus and the relationship between HGPIN and the two groups was investigated.

RESULTS

The MDG had 39 cancer foci (71.0%) and there were 16 in the SDG (29.0%). There were 31 foci that were small-volume cancers (<0.2 mL). In the MDG, 13 small-volume cancer foci were HGPIN positive, but in the SDG, none of the small-volume cancers were HGPIN positive.

CONCLUSIONS

Small-volume cancer foci without HGPIN in the SDG may be candidates for de novo prostate cancers.

Should high-grade prostatic intraepithelial neoplasia change our approach to infravesical obstruction?

OBJECTIVES

To investigate whether coexistence of high-grade prostatic intraepithelial neoplasia (HPIN) should change our therapeutic approach to infravesical obstruction.

MATERIAL AND METHODS

Of 505 patients who underwent sextant transrectal ultrasonography (TRUS)-guided prostate biopsy, 65 (12.8%) had HPIN and 29 of them underwent prostatectomy (23 transurethral resection of prostate (TURP), 6 open) due to obstructive urinary symptoms. Patients without carcinoma were followed up with semiannual prostate-specific antigen (PSA) and digital rectal examination. After a follow-up of 24.8 +/- 11.0 months, 19 of 29 patients who accepted our call had another sextant biopsy.

RESULTS

Mean age and initial mean PSA values of 29 patients were 67.6 +/- 6.7 years and 9.26 +/- 5.91 ng/ml, respectively. The final pathological evaluation of the surgical specimens revealed 2 prostatic adenocarcinomas both in the TURP group. The remaining 27 (93.2%) patients were found to have benign prostatic hyperplasia (BPH) and their serum PSA levels declined from 9.26 +/- 5.91 to 4.59 +/- 2.0 ng/ml 3 months after prostatectomy. Of the 19 patients who had another biopsy with a mean PSA value of 4.06 +/- 4.61 ng/ml, 15 and 4 of them had BPH and HPIN respectively.

CONCLUSIONS

Our preliminary data indicate that the presence of HPIN on TRUS-guided biopsies is not a factor to delay an indicated surgical intervention for infravesical obstruction.

Effectiveness of percent free prostate specific antigen as a predictor of prostate cancer detection on repeat biopsy

BACKGROUND

The aim of this study was to identify predictors that can increase the accuracy of detecting prostate cancer on subsequent biopsies.

METHODS

Between 1998 and 2003, a total of 235 men with prostate specific antigen (PSA) levels between 4.0 and 20 ng/mL underwent one or more systematic needle biopsies of the prostate. Of these men, 73 (31.1%) underwent one repeat biopsy and 26 (11.1%) underwent two or more repeat biopsies. We evaluated the results of prostate biopsies in relation to the morbidity of prostate cancer detected on repeat biopsies.

RESULTS

Of the 73 men who underwent repeat biopsy, 16 (21.9%) had prostate cancer. Twenty-six men with one negative re-biopsy underwent two or more repeat biopsies, and five of these patients were found to have early stage prostate cancer. On repeat biopsy, there was a significant difference in percent free PSA between the cancer-detected group and the no-cancer-detected group (P < 0.01). A receiver operating characteristics (ROC) curve gave an optimal cut-off value for percent free PSA of 11%, demonstrating a significant difference in the cancer detection rate on repeat biopsy (P = 0.0009). Analysis of the data for re-biopsies showed that cancer-detected cases showed a raised PSA value and a simultaneously reduced percent free PSA (these differences were statistically significant).

CONCLUSIONS

A low percent free PSA level increased the probability of a positive result in repeat biopsy. An increase in the accuracy of detecting cancer, especially on repeat biopsy, will promote the detection of more early stage prostate cancer.