Prognostic role of TSPAN1, KIAA1324 and ESRP1 in prostate cancer.

The aim of this study was to validate prostate cancer-associated genes on transcript level and to assess the prognostic value of the most promising markers by immunohistochemistry. Based on differentially expressed genes found in a previous study, 84 genes were further validated using mRNA expression data and follow-up information from the Cancer Genome Atlas (TCGA) prostate cancer cohort (n = 497). Immunohistochemistry was used for validation of three genes in an independent, clinically annotated prostatectomy patient cohort (n = 175) with biochemical relapse as endpoint. Also, associations with clinicopathological variables were evaluated. Eleven protein-coding genes from the list of 84 genes were associated with biochemical recurrence-free survival on mRNA expression level in multivariate Cox-analyses. Three of these genes (TSPAN1, ESRP1 and KIAA1324) were immunohistochemically validated using an independent cohort of prostatectomy patients. Both ESRP1 and KIAA1324 were independently associated with biochemical recurrence-free survival. TSPAN1 was univariately prognostic but failed significance on multivariate analysis, probably due to its strong correlation with high Gleason scores. Multistep filtering using the publicly available TCGA cohort, data of an earlier expression profiling study which profiled 3023 cancer-associated transcripts in 42 primary prostate cancer cases, identified two novel candidate prognostic markers (ESRP1 and KIAA1324) of primary prostate cancer for further study.

Somatic alterations detected in diagnostic prostate biopsies provide an inadequate representation of multifocal prostate cancer.

BACKGROUND: The majority of clinical prostate cancers are multifocal with morphological and molecular heterogeneity. Adequate tissue representation is crucial for the clinical utility of multigene panel sequencing of core needle biopsies. The aim of this study was to evaluate the genomic heterogeneity in multifocal prostate cancer and to analyze how representative preoperative biopsies are of spatially separated tumor foci. METHODS: We analyzed at least 2 tumor foci and 1 to 3 preoperative biopsy cores from 11 patients. Diagnostic biopsies, as well as fresh frozen and formalin-fixed paraffin-embedded samples, from major tumor foci of radical prostatectomy specimens were macrodissected for the enrichment of tumor tissue. DNA was extracted and sequenced. We analyzed structural alterations, mutations, and copy number variations and compared the genomic profiles of tumor foci with those of preoperative biopsies. RESULTS: Alterations were rarely shared between foci, indicating a high degree of genomic heterogeneity. In 8 of 11 men at least 1 tumor focus was represented by the biopsies defined as harboring at least 1 common clonal somatic event. In only one case, somatic alterations from two spatially separate tumors were identified in the biopsies. Of the mutations and structural variants detected in fresh frozen or formalin-fixed paraffin-embedded prostatectomy material, only an average of 19% (range 0-44) and 55% (range 0-100), respectively, were found in preoperative biopsies where a common somatic origin was established. CONCLUSIONS: Multifocal prostate cancer is a somatically heterogeneous disease in which systematic needle biopsies do not provide sufficient molecular representation of the somatic alterations detected in spatially distinct tumor areas. Targeted biopsies, directed at separate tumor foci, could potentially improve tissue representation of these heterogeneous foci in preoperative biopsies.

Prognostic significance and biopsy characteristics of prostate cancer with seminal vesicle invasion on radical prostatectomy: a nationwide population-based study.

The objective of this study was to evaluate the prognostic significance of seminal vesicle invasion (SVI, pT3b) compared with extraprostatic extension (EPE) alone (pT3a) after radical prostatectomy, and to correlate pre-operative biopsy pathology with SVI and EPE. The National Prostate Cancer Register includes all prostate cancers diagnosed in Sweden. We analysed 4063 cases with stage category pT3a and 1371 cases with pT3b at radical prostatectomy between 2000 and 2012. Associations between pT3a and pT3b and progression were evaluated and adjusted for year, age, biopsy grade and s-PSA. Needle biopsy findings in these stages were compared. Patients with pT3b (n=1371) had a higher risk of death from prostate cancer (HR 2.3, 95% CI 1.5-3.3, p<0.001) and death from any cause (HR 1.5, 95% CI 1.2-1.8, p<0.001) than those with pT3a (n=4063). They were also more likely to be treated with post-operative radiotherapy (HR 1.5, 95% CI 1.4-1.7, p<0.001) or androgen deprivation therapy (HR 3.0, 95% CI 2.5-3.7, p<0.001), indicating clinical progression. Yet, disease-specific survival of patients with stage pT3b was 94% after 6 years. Median cancer extent in pre-operative biopsies of pT3a and pT3b was 14 and 24 mm (p<0.001), number of positive cores was four and five, (p<0.001) and biopsy Gleason score was 8-10 in 11.6% and 27.3%, respectively (p<0.001). SVI of prostate cancer is associated with worse outcome after radical prostatectomy than EPE alone. However, few patients with SVI die within 6 years from surgery, suggesting that radical prostatectomy may be curative in locally advanced cancers.

Tracking the origin of metastatic prostate cancer.

UNLABELLED: Metastatic prostate cancer is a monoclonal disease. We previously failed to identify a common somatic denominator between primary tumor tissue and two lymph-node metastases by exome sequencing [Lindberg J, et al. Eur Urol 2013;63:702-8]. To track the seeding clone we performed copy-number alteration analysis on 34 morphologically distinct tissue areas in one prostatectomy specimen. Using break-point regions to infer phylogenetic relationships, the clone most closely related to the metastases was found in intraductal carcinoma of the prostate. Although the majority of tumor areas harbored events also found in the metastases, three carried none. This emphasizes the importance of intraprostatic tumor heterogeneity for prediction of prognosis. These findings also support recent evidence that intraductal carcinoma is a marker of aggressive disease. PATIENT SUMMARY: We identified the area in the prostate that gave rise to metastases by searching for metastatic-specific DNA alterations in multiple regions of the prostate. The metastasizing component grew within prostatic ducts, suggesting that intraductal cancer should be reported when found in needle biopsies. It is also important to be aware of tumor heterogeneity when assessing somatic changes linked to tumor aggressiveness.

Seminal vesicle intraepithelial involvement by prostate cancer: putative mechanism and clinicopathological significance.

We have recently shown seminal vesicle intraepithelial involvement of prostate cancer in cases with seminal vesicle invasion (pT3b). Based on the manner of seminal vesicle invasion, there could be 2 possible mechanisms of seminal vesicle intraepithelial involvement: direct intraepithelial invasion from prostate carcinoma in the muscular wall of seminal vesicles or intraepithelial involvement of cancer from the invaginated extraprostatic space (IES)/ejaculatory duct system to extraprostatic seminal vesicle. We aimed to clarify the manner and clinicopathological significance of seminal vesicle intraepithelial involvement. Of 1629 consecutive radical prostatectomies, 109 cases (6.7%) showed seminal vesicle invasion in whole-mounted radical prostatectomy specimens. In these pT3b cases, 18 (17%) showed seminal vesicle intraepithelial involvement by prostate cancer. Stromal invasion of the IES/ejaculatory duct system and ejaculatory duct intraepithelial invasion by prostate cancer were identified in 62 and 5 of 109 pT3b cases, respectively. However, the presence/absence of IES/ejaculatory duct system involvement by prostate cancer does not predict seminal vesicle intraepithelial involvement. No statistically significant correlation was observed between all pathologic parameters/biochemical recurrence and the presence/absence of seminal vesicle intra-epithelial involvement in the pT3b cases. These findings suggest that seminal vesicle intraepithelial involvement is more likely due to direct invasion of carcinoma from the muscular wall of seminal vesicles rather than intraepithelial extension from the ejaculatory duct system in the IES. Further studies with a substantially greater case number are needed to clarify the clinicopathological significance of seminal vesicle intraepithelial involvement in a better manner.

Prognostic significance of patterns of seminal vesicle invasion in prostate cancer.

AIMS: We aimed to evaluate the prognostic significance of histopathological patterns of seminal vesicle invasion (SVI) after radical prostatectomy. METHODS AND RESULTS: Seminal vesicles of 1050 radical prostatectomy specimens from the Karolinska Hospital, from 1998 to 2005, were reviewed. Extraprostatic SVI was found in 60 cases (5.7%). Associations between histopathological characteristics of SVI and biochemical recurrence were analysed. The SVI component of the tumour always had a Gleason score of 7 or higher. Invasion of seminal vesicle (SV) mucosa was seen in 68.3%, and was always accompanied by muscle wall invasion. SVI was associated with biochemical recurrence [HR 1.7 (95% CI 1.1-2.6), P = 0.015], while intraprostatic SVI was not. SV mucosal invasion was associated with adverse outcome [HR 4.2 (95% CI 1.2-14.2), P = 0.021], while only 15.8% of tumours with muscle wall invasion alone recurred. Other features of SVI such as the Gleason score of the SV component, laterality, invasion route, measures of extent and local margin status in the SV did not predict outcome. CONCLUSIONS: The prognosis of patients with SVI is not uniformly poor. Invasion of the SV mucosa portends a higher risk of recurrence than invasion of the muscle wall alone. There is no evidence that other histopathological features of SVI need to be reported.