Feasibility study of ADCs targeting TROP-2, HER2, and CD46 in Ductal Adenocarcinoma and Intraductal Carcinoma of the prostate.

BACKGROUND: Ductal Adenocarcinoma (DAC) and Intraductal Carcinoma of the Prostate (IDC-P) respond poorly to all the currently available conventional therapies. Given their accurate and efficient elimination of cancer cells, Antibody-Drug Conjugates (ADCs) have become one of the most promising anticancer treatments. However, no ADCs have so far been approved for Prostate Cancer (PCa) treatment. This study investigated TROP-2, HER2, and CD46 expression in DAC/IDC-P samples, indirectly analyzing their preliminary feasibility as therapeutic targets for future treatment of the two conditions. PATIENTS AND METHODS: We conducted a retrospective study involving 184 participants (87 DAC/IDC-P patients and 97 Prostatic Acinar Adenocarcinoma (PAC) patients with a Gleason score ≥ 8) without prior treatment between August 2017 and August 2022. Immunohistochemical staining was employed to detect the differential protein expressions of TROP-2, HER2, and CD46 in DAC/IDC-P, PAC, and normal prostate tissues. RESULTS: Compared to pure PAC tissues, TROP-2 expression was significantly higher in DAC/IDC-P and DAC/IDC-P-adjacent PAC tissues (H-score 68.8 vs. 43.8, p < 0.001, and 59.8 vs. 43.8, p = 0.022, respectively). No significant differences in HER2 expression were observed across different cancer tissues. Compared to both DAC/IDC-P-adjacent PAC and pure PAC tissues, CD46 expression was significantly higher in DAC/IDC-P tissues (42.3 vs. 28.6, p = 0.041, and 42.3 vs. 24.3, p = 0.0035, respectively). CONCLUSIONS: Herein, TROP-2 and CD46 expression was higher in DAC/IDC-P tissues than in pure PAC and normal prostate tissues. This finding implies that ADCs targeting the two proteins hold significant promise as potential future treatments for DAC/IDC-P.

Unveiling the Genomic Landscape of Intraductal Carcinoma of the Prostate Using Spatial Gene Expression Analysis.

Intraductal carcinoma of the prostate (IDCP) has recently attracted increasing interest owing to its unfavorable prognoses. To effectively identify the IDCP-specific gene expression profile, we took a novel approach of characterizing a typical IDCP case using spatial gene expression analysis. A formalin-fixed, paraffin-embedded sample was subjected to Visium CytAssist Spatial Gene Expression analysis. IDCP within invasive prostate cancer sites was recognized as a distinct cluster separate from other invasive cancer clusters. Highly expressed genes defining the IDCP cluster, such as MUC6, MYO16, NPY, and KLK12, reflected the aggressive nature of high-grade prostate cancer. IDCP sites also showed increased hypoxia markers HIF1A, BNIP3L, PDK1, and POGLUT1; decreased fibroblast markers COL1A2, DCN, and LUM; and decreased immune cell markers CCR5 and FCGR3A. Overall, these findings indicate that the hypoxic tumor microenvironment and reduced recruitment of fibroblasts and immune cells, which reflect morphological features of IDCP, may influence the aggressiveness of high-grade prostate cancer.

Correlations of PTEN and ERG Immunoexpression in Prostate Carcinoma and Lesions Related to Its Natural History: Clinical Perspectives.

Purpose: The aim of our study was to observe the associations between the ETS-related gene (ERG) and the phosphatase and tensin homolog gene (PTEN) immunoexpression in prostate cancer and related lesions and highlight the clinical significance of these findings. Methods: We evaluated the immunohistochemical expression of ERG and PTEN in a series of 151 invasive prostate adenocarcinomas, including low-grade (Gleason grade pattern 3) and high-grade (Gleason grade patterns 4, 5) morphological patterns which corresponded to 45.5% and 54.4% of the cases, respectively. Additionally, we evaluated the immunoexpression of the two markers both in foci of high-grade prostatic intraepithelial neoplasia (HGPIN), as a precursor lesion of cancer, and in foci of intraductal carcinoma of the prostate (IDCP). Finally, to ensure the malignant nature of the prostate glands examined, we employed p63 and alpha-methylacyl-CoA racemase (AMACR) expression. Results: We found that PTEN loss was observed in 50.7%, and ERG positivity was detected in 41.8% of our cancerous samples. In HGPIN, PTEN loss appeared to be linked with a high-grade adjacent invasive carcinoma component which also displayed PTEN loss. As far as IDCP is concerned, ERG immunonegativity was correlated with adjacent high-grade invasive cancer, which was also ERG immunonegative. Conclusions: Our findings suggest that the clonal expansion of invasive cancer appears to be associated with distinct immunophenotypic cellular alterations of both early and late cancer-related histological lesions. Patients with PTEN loss in HGPIN in prostate biopsies should be closely monitored due to the increased likelihood of having an associated invasive high-grade carcinoma that may have not been sampled. Given the clinical significance that derives from PTEN expression in HGPIN lesions, we suggest the routine use of PTEN immunohistochemistry in prostate cancer biopsies in which HGPIN is the only finding.

In-Depth Comparison of Genetic Variants Demonstrates a Close Relationship Between Invasive and Intraductal Components of Prostate Cancer.

Intraductal carcinoma (IDC) of the prostate is often associated with concurrent high-grade invasive prostate cancer (PCa) and poor clinical outcomes. In this context, IDC is thought to represent the retrograde spread of invasive prostatic adenocarcinoma into the acini and ducts. Prior studies have demonstrated a concordance of PTEN loss and genomic instability between the IDC and high-grade invasive components of PCa, but larger genomic association studies to solidify our understanding of the relationship between these 2 lesions are lacking. Here, we evaluate the genomic relationship between duct-confined (high-grade prostatic intraepithelial neoplasia and IDC) and invasive components of high-grade PCa using genetic variants generated by whole exome sequencing. High-grade prostatic intraepithelial neoplasia and IDC were laser-microdissected, and PCa and nonneoplastic tissue was manually dissected from 12 radical prostatectomies. A targeted next-generation sequencing panel was used to identify disease-relevant variants. Additionally, the degree of overlap between adjacent lesions was determined by comparing exome-wide variants detected using whole exome sequencing data. Our results demonstrate that IDC and invasive high-grade PCa components show common genetic variants and copy number alterations. Hierarchical clustering of genome-wide variants suggests that in these tumors, IDC is more closely related to the high-grade invasive components of the tumor compared with high-grade prostatic intraepithelial neoplasia. In conclusion, this study reinforces the concept that, in the context of high-grade PCa, IDC likely represents a late event associated with tumor progression.

Clinical significance of IDC-P as predictive factor after intensity-modulated radiation therapy.

The clinical significance of intraductal carcinoma of the prostate (IDC-P) in men with nonmetastatic prostate cancer (PCa) treated with high-dose external-beam radiation therapy remains unclear. The aim of this study was to evaluate the impact of IDC-P in men who received intensity-modulated radiation therapy (IMRT) for nonmetastatic PCa. All patients with high-risk (H-R) and very high-risk (VH-R) PCa who received IMRT between September 2000 and December 2013 at our institution were analyzed retrospectively. We re-reviewed biopsy cores for the presence of IDC-P. Treatment consisted of IMRT (median: 78 Gy at 2 Gy per fraction) plus 6-month neoadjuvant hormonal therapy (HT). In total, 154 consecutive patients with H-R and VH-R PCa were analyzed. Intraductal carcinoma of the prostate was present in 27.9% (n = 43). The median follow-up period was 8.4 years. The 10-year PCa-specific survival, biochemical failure (BF), clinical failure, and castration-resistant PCa rates were 90.0%, 47.8%, 27.5%, and 24.5% in patients with IDC-P, and 96.6%, 32.6%, 10.8%, and 7.0% in those without IDC-P, respectively (p = 0.12, 0.04, 0.0031, and 0.012, respectively). In multivariable analysis, IDC-P was not identified as an independent predictive factor for BF (p = 0.26). The presence of IDC-P was correlated with a significantly higher incidence of disease progression in men with H-R and VH-R PCa who received IMRT, although it was not identified as an independent predictive factor for BF. Further investigations are needed to determine the significance of IDC-P as an independent predictive factor for survival outcomes.

MRI-detectability and histological factors of prostate cancer including intraductal carcinoma and cribriform pattern.

BACKGROUND: Histopathological characteristics affecting the detectability of clinically significant prostate cancer (csPCa) on magnetic resonance imaging (MRI) remain unclear. This study aimed to compare the histopathology between MRI-detectable and MRI-undetectable cancers, emphasizing intraductal carcinoma of the prostate (IDC-P) and predominant Gleason pattern 4 subtype. METHODS: This single-center retrospective study enrolled 153 consecutive patients with 191 lesions who underwent preoperative multiparametric MRI and subsequent radical prostatectomy. MRI/histopathological findings and area fractions of histological components (cancer cells, stroma, and luminal spaces) of MRI-detectable and MRI-undetectable cancers were compared. Data were analyzed using Fisher's exact, independent t, or Mann-Whitney U tests. RESULTS: Overall, 148 (77%) and 43 (23%) cancers were MRI-detectable and MRI-undetectable, respectively. MRI-detectable cancers were significantly larger than MRI-undetectable cancers (p = 0.03). The percentage of lesions in Grade Group 3 or higher was significantly higher among MRI-detectable cancers than among MRI-undetectable cancers (p = 0.02). MRI detectability of csPCa was associated with increases in relative area fractions of cancer cells (p < 0.001) and decreases in those of stroma (p < 0.001) and luminal spaces (p < 0.001) in prostate cancer (PCa) than the percentage of Gleason pattern 4 (p = 0.09). The percentage of lesions containing IDC-P was similar for MRI-detectable and MRI-undetectable cancers (40% vs. 33%; p = 0.48). The distribution of cribriform gland subtypes was not significantly different between MRI-detectable and MRI-undetectable Gleason pattern 4 subtype cancers (p > 0.99). Contrarily, the ratio of fused gland subtype was significantly higher in MRI-detectable than in MRI-undetectable cancers (p = 0.03). Furthermore, the ratio of poorly-formed gland subtype was significantly higher in MRI-undetectable than in MRI-detectable cancers (p = 0.01). CONCLUSIONS: MRI detectability of csPCa is strongly associated with the relative area fractions of cancer cells, stroma, and luminal spaces in PCa rather than conventional histopathological parameters. Neither the presence nor the percentage of IDC-P affected MRI detectability.

Circulating tumour DNA reveals genetic traits of patients with intraductal carcinoma of the prostate.

OBJECTIVES: To investigate the genetic alterations of patients with prostate cancer (PCa) with and without intraductal carcinoma of the prostate (IDC-P). PATIENTS AND METHODS: We performed targeted sequencing of plasma cell-free DNA on 161 patients with prostate adenocarcinoma (PAC) with IDC-P and 84 without IDC-P. Genomic alterations were compared between these two groups. The association between genetic alterations and patients' survival outcomes was also explored. RESULTS: We identified that 29.8% (48/161) and 21.4% (18/84) of patients with and without IDC-P harboured genomic alterations in DNA repair pathways, respectively (P = 0.210). Pathogenic germline DNA repair alterations were frequently detected in IDC-P carriers compared to IDC-P non-carriers (11.8% [19/161] vs 2.4% [two of 84], P = 0.024). Germline BReast CAncer type 2 susceptibility protein (BRCA2) and somatic cyclin-dependent kinase 12 (CDK12) defects were specifically identified in IDC-P carriers relative to PAC (BRCA2: 8.7% [14/161] vs 0% and CDK12: 6.8% [11/161] vs 1.2% [one of 84]). Patients with IDC-P had a distinct androgen receptor (AR) pathway alteration, characterised by an enrichment of nuclear receptor corepressor 2 (NCOR2) mutations compared with patients with pure PAC (21.1% [34/161] vs 6.0% [five of 84], P = 0.004). Increased AR alterations were detected in patients harbouring tumours with an IDC-P proportion of ≥10% vs those with an IDC-P proportion of <10% (6.4% [five of 78] vs 18.1% [15/83], P = 0.045). For IDC-P carriers, tumour protein p53 (TP53) mutation was associated with shorter castration-resistant-free survival (median 10.9 vs 28.9 months, P = 0.026), and BRCA2 alteration was related to rapid prostate-specific antigen progression for those receiving abiraterone treatment (median 9.1 vs 11.9 months, P = 0.036). CONCLUSION: Our findings provide genomic evidence explaining the aggressive phenotype of tumours with IDC-P, highlighting the potential therapeutic strategies for this patient population.

Androgen receptor enhancer amplification in matched patient-derived xenografts of primary and castrate-resistant prostate cancer.

Amplifications of the androgen receptor (AR) occur in up to 80% of men with castration-resistant prostate cancer (CRPC). Recent studies highlighted that these amplifications not only span the AR gene but usually encompass a distal enhancer. This represents a newly recognised, non-coding mechanism of resistance to AR-directed therapies, including enzalutamide. To study disease progression before and after AR amplification, we used tumour samples from a castrate-sensitive primary tumour and castrate-resistant metastasis of the same patient. For subsequent functional and genomic studies, we established serially transplantable patient-derived xenografts (PDXs). Whole genome sequencing showed that alterations associated with poor prognosis, such as TP53 and PTEN loss, existed before androgen deprivation therapy, followed by co-amplification of the AR gene and enhancer after the development of metastatic CRPC. The PDX of the primary tumour, without the AR amplification, was sensitive to AR-directed treatments, including castration, enzalutamide, and apalutamide. The PDX of the metastasis, with the AR amplification, had higher AR and AR-V7 expression in castrate conditions, and was resistant to castration, apalutamide, and enzalutamide in vivo. Treatment with a BET inhibitor outperformed the AR-directed therapies for the metastasis, resulting in tumour regression for some, but not all, grafts. Therefore, this study provides novel matched PDXs to test potential treatments that target the overabundance of AR in tumours with AR enhancer amplifications. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The heterogeneity of intraductal carcinoma of the prostate is associated with different efficacy of standard first-line therapy for patients with metastatic castration-resistant prostate cancer.

BACKGROUND: To explore whether metastatic castration-resistant prostate cancer (mCRPC) patients with distinct intraductal carcinoma of the prostate (IDC-P) subtypes respond differently to abiraterone and docetaxel treatment. METHODS: We retrospectively analyzed data of 170 mCRPC patients receiving abiraterone or docetaxel as first-line therapy. PSA response, PSA progression-free survival (PSA-PFS), radiographic progression-free survival (rPFS), and overall survival (OS) were analyzed based on the presence of IDC-P and its subpatterns. RESULTS: IDC-P was confirmed in 91/170 (53.5%) patients. Among them 36/91 (39.6%) and 55/91 (60.4%) harbored IDC-P patterns 1 and 2, respectively. Patients with IDC-P pattern 1 shared similar clinical outcomes to those without IDC-P in both abiraterone and docetaxel treatment. However, against cases without IDC-P or with IDC-P pattern 1, patients with IDC-P pattern 2 had markedly poorer prognosis in either abiraterone (mPSA-PFS: 11.9 vs. 11.1 vs. 6.1 months, p < 0.001; mrPFS: 18.9 vs. 19.4 vs. 9.6 months, p < 0.001) or docetaxel (mPSA-PFS: 6.2 vs. 6.6 vs. 3.0 months, p < 0.001; mrPFS: 15.1 vs. 12.6 vs. 5.5 months, p < 0.001) treatment. For patients without IDC-P, docetaxel had comparable therapeutic efficacy with abiraterone. However, the efficacy of docetaxel was significantly inferior to abiraterone in patients with either IDC-P pattern 1 (mPSA-PFS: 6.6 vs. 11.1 months, p = 0.021; mrPFS: 12.6 vs. 19.4 months, p = 0.027) or pattern 2 (mPSA-PFS: 3.0 vs. 6.1 months, p = 0.003; mrPFS: 5.5 vs. 9.6 months, p = 0.007). CONCLUSION: Compared to docetaxel, abiraterone exhibited better efficacy in patients with IDC-P of either pattern. However, IDC-P pattern 2 responded unsatisfactorily to either abiraterone or docetaxel therapy. Novel therapeutic strategies for IDC-P pattern 2 need further investigations.

Association of intraductal carcinoma of the prostate detected by initial histological specimen and neuroendocrine prostate cancer: A report of three cases.

We present three cases of neuroendocrine prostate cancer (NEPC) and histologically investigate the association of intraductal carcinoma of the prostate (IDC-P) and NEPC. Case 1 was a 76-year-old man who had NEPC identified by repeated biopsy specimens when his prostate-specific antigen (PSA) level became elevated 8 years after the initiation of androgen deprivation therapy (ADT). Case 2 was a 70-year-old man who had NEPC detected when multiple bone metastases were found 3 years after the initiation of ADT. Case 3 was a 70-year-old man who was diagnosed with NEPC based on histological examination of transurethral resected specimens. The histological findings in these three cases showed mixed neuroendocrine carcinoma-acinar adenocarcinoma with various proportions of both components. In all three cases, the neuroendocrine carcinoma components were positive for synaptophysin and chromogranin A, whereas the adenocarcinoma components were positive for PSA and NKX3.1. When we retrospectively reviewed the initial hematoxylin and eosin-stained slides, IDC-P was detected in all three cases. Furthermore, we collected nine additional cases of NEPC and found that all six cases with initial biopsy specimens available had an IDC-P component. Detecting IDC-P on initial histological specimens of the prostate may predict transformation to NEPC.

The influence of the presence of intraductal carcinoma of the prostate on the grade group system's prognostic performance.

BACKGROUND: Although the presence of intraductal carcinoma of the prostate (IDC-P) influences biochemical failure in radical prostatectomy patients, no data are available regarding the impact of its integration into the classification grade group system. Thus, the aim of this study was to enhance the utility of the grade group system by integrating the presence of IDC-P. METHODS: This study was a retrospective evaluation of 1019 patients with prostate cancer who underwent radical prostatectomy between 2005 and 2013 without neoadjuvant or adjuvant therapy. The data on age, prostate-specific antigen (PSA) level at diagnosis, pathological T stage (pT), presence of Gleason pattern 5 (GP5), presence of IDC-P, and surgical margin status were analyzed to predict PSA recurrence after prostatectomy. RESULTS: The median patient age was 67 (range, 45-80) years and the median initial PSA level was 6.8 (range, 0.4-82) ng/mL. The median follow-up period was 82 (range, 0.7-148) months. IDC-P was detected in 157 patients (15.4%). Among these patients, the increase in the positive rate of IDC-P correlated with tumor upgrading. The grade groups (GGs) were as follows: GG1 without IDC-P, 16.0% (n = 163); GG2 without IDC-P, 46.1% (n = 470); GG3 without IDC-P, 15.7% (n = 160); GG4 without IDC-P, 2.6% (n = 27); GG5 without IDC-P, 4.1% (n = 42); any GG with IDC-P, 15.4% [n = 157; GG 2 (n = 29); GG3 (n = 60); GG4 (n = 13); GG5 (n = 55)]. Any grade Group with IDC-P showed significantly worse prognosis than any other group without IDC-P (P < 0.0001). In a multivariate analysis, integration of the IDC-P into the Grade Groups, the PSA level at diagnosis, and the surgical margin status were significant prognostic predictors (P < 0.0001, < 0.0001 and < 0.0001, respectively). CONCLUSIONS: Integrating the presence of IDC-P into the grade group system will result in more accurate predictions of patient outcome.

PTEN loss in prostatic adenocarcinoma correlates with specific adverse histologic features (intraductal carcinoma, cribriform Gleason pattern 4 and stromogenic carcinoma).

BACKGROUND: The loss of PTEN tumor suppressor gene is one of the most common somatic genetic aberrations in prostate cancer (PCa) and is frequently associated with high-risk disease. Deletion or mutation of at least one PTEN allele has been reported to occur in 20% to 40% of localized PCa and up to 60% of metastases. The goal of this study was to determine if somatic alteration detected by PTEN immunohistochemical loss of expression is associated with specific histologic features. METHODS: Two hundred sixty prostate core needle biopsies with PCa were assessed for PTEN loss using an analytically validated immunohistochemical assay. Blinded to PTEN status, each tumor was assessed for the Grade Group (GG) and the presence or absence of nine epithelial features. Presence of stromogenic PCa was also assessed and defined as grade 3 reactive tumor stroma as previously described: the presence of carcinoma associated stromal response with epithelial to stroma ratio of greater than 50% reactive stroma. RESULTS: Eight-eight (34%) cases exhibited PTEN loss while 172 (66%) had intact PTEN. PTEN loss was significantly (P < 0.05) associated with increasing GG, poorly formed glands (74% of total cases with loss vs 49% of intact), and three well-validated unfavorable pathological features: intraductal carcinoma of the prostate (IDC-P) (69% of total cases with loss vs 12% of intact), cribriform Gleason pattern 4 (38% of total cases with loss vs 10% of intact) and stromogenic PCa (23% of total cases with loss vs 6% of intact). IDC-P had the highest relative risk (4.993, 95% confidence interval, 3.451-7.223, P < 0.001) for PTEN loss. At least one of these three unfavorable pathological features were present in 67% of PCa exhibiting PTEN loss, while only 11% of PCa exhibited PTEN loss when none of these three unfavorable pathological features were present. CONCLUSIONS: PCa with PTEN loss demonstrates a strong correlation with known unfavorable histologic features, particularly IDC-P. This is the first study showing the association of PTEN loss with stromogenic PCa.

Atypical intraductal proliferation detected in prostate needle biopsy is a marker of unsampled intraductal carcinoma and other adverse pathological features: a prospective clinicopathological study of 62 cases with emphasis on pathological outcomes.

AIMS: Intraductal proliferations of the prostate with more complexity and/or cytological atypia than high-grade prostate intra-epithelial neoplasia (HGPIN), but falling short of intraductal carcinoma (IDC-P), are described as 'atypical intraductal proliferation' (AIP). When present in needle biopsy (NBX) without IDC-P, the clinical significance is not known. METHODS AND RESULTS: Sixty-two NBX cases were diagnosed as AIP over 7 years with estimated incidence of 1%. AIP was characterised by loose cribriform architecture (90%) or non-cribriform architecture exhibiting significant nuclear atypia that fell short of IDC-P. Fifty patients had concomitant PCa (20% grade group (GG) 1, 48% GG2, 14% GG3, 8% GG4 and 10% GG 5), and 12 had AIP alone. Of 40 patients who were candidates for no therapy (AIP alone) or active surveillance (AIP with GG1 or GG2 PCa without cribriform pattern 4), 20 had subsequent follow-up pathology [seven NBXs and 13 radical prostatectomy (RP)]. Of the 12 AIP only patients, six had a subsequent biopsy diagnosis of: benign prostate (two), IDC-P with PCa (one) and PCa (three). One or more adverse pathological features at subsequent RP were present in 93% of patients with AIP and GG1 or GG2 PCa, defined as: GG ≥ 3 (15%), IDC-P (77%), cribriform Gleason pattern 4 (69%), pT3a (77%) or pT3b (8%). CONCLUSIONS: AIP in NBX may be a marker of unsampled IDC-P and/or other adverse pathological features in suspected low- to intermediate-risk PCa. AIP should be considered distinct from HGPIN for risk assessment and warrant consideration for further work-up to detect unsampled high-risk PCa.

[The subgroup analysis of the prognostic value of the intraductal carcinoma of the prostate in patients with metastatic prostate cancer].

Objective: To determine the prognostic value of the intraductal carcinoma of the prostate IDC-P in metastatic prostate cancer (mPCa) patients of different subgroups. Methods: Data of 582 de novo mPCa patients between January 2011 and December 2017 diagnosed at Departments of Urology, West China Hospital, Sichuan University were retrospectively analyzed. The age was (70±8) years (range: 45 to 89 years). IDC-P was identified from 12-core prostate biopsy. The prognostic role of IDC-P was assessed by Kaplan-Meier curves and Cox regression. Subgroup analysis was conducted by the forest plot. The endpoints were castration-resistant prostate cancer free survival (CFS) and overall survival (OS). Results: In total, 177/582 (30.4%) patients harbored IDC-P. Patients with IDC-P had poorer CFS and OS than those without IDC-P (mCFS: 12.1 months vs. 16.9 months, P=0.000; mOS: 39.7 months vs. not reached, P=0.000). Multivariate Cox regression analysis indicated that, the existence of IDC-P was an independent prognosticator of both CFS (HR=1.40, 95% CI: 1.10 to 1.79, P=0.006) and OS (HR=1.51, 95% CI: 1.02 to 2.25, P=0.041). Subanalysis indicated that, in most subgroups, IDC-P was an adverse prognosticator of both CFS and OS. Even in subgroups with adverse clinicopathological features, e.g. Gleason score 9 to 10 (CFS: HR=1.467, P=0.007; OS: HR=1.807, P=0.013), baseline prostate specific antigen≥50 µg/L (CFS: HR=1.616, P=0.000; OS: HR=1.749, P=0.006), anemia (CFS: HR=1.653, P=0.036; OS: HR=2.100, P=0.038), alkaline phosphatase≥160 U/L (CFS: HR=1.326, P=0.038; OS: HR=1.725, P=0.010) or abnormal lactate dehydrogenase level (CFS: HR=1.614, P=0.001; OS: HR=1.900, P=0.003), IDC-P was still closely associated with shorter CFS and OS. Conclusions: The presence of IDC-P was closely related to poor survival outcomes for patients with mPCa. IDC-P was an adverse prognosticator in most subgroup patients. The description of IDC-P in the pathological report of prostate biopsy would help clinicians to evaluate the prognosis of mPCa patients more accurately and make better treatment choices.

Prognostic parameter for high risk prostate cancer patients at initial presentation.

BACKGROUND: High-risk prostate cancer can be defined by a patient's Gleason score (GS), prostate-specific antigen (PSA) level, and clinical T (cT) stage, but a novel marker is needed due to heterogeneity of the disease. In this study, we evaluated whether intraductal carcinoma of the prostate (IDC-P) confirmed by needle biopsy is an adverse prognostic parameter for progression-free survival (PFS) and cancer-specific survival (CSS) in patients with high-risk prostate cancer. METHODS: We retrospectively evaluated 204 patients with high-risk prostate cancer treated by radical prostatectomy from 1991 to 2005 at Nagoya University and its affiliated hospitals. Data on each patient's PSA level, biopsy GS, cT stage, presence of Gleason pattern 5, presence of IDC-P, percentage of the core involved with cancer, and maximum percentage of the core involved with cancer were analyzed. RESULTS: The median follow-up period was 108 months (range, 11-257 months). Forty-eight patients (24%) showed disease progression. Thirty-four patients (17%) died of the disease during follow-up. The IDC-P component was detected in 74 (36%) needle biopsy samples. The 5-, 10-, and 15-year CSS rates of the IDC-P-negative cases were 3.2%, 9.0%, and 23.7%; the corresponding rates of the IDC-P-positive cases were 23.9%, 33.7%, and 52.7%, respectively (P = 0.0001). In the Fine and Gray's model for PFS, IDC-P, maximum percentage of the core involved with cancer, and cT stage were significantly associated (P = 0.013, P = 0.003, P = 0.007). In the Fine and Gray's model for CSS, only IDC-P was significant (P = 0.027). In a multivariate Cox regression analysis, IDC-P (P = 0.04; hazard ratio [HR], 1.95) and maximum percentage of the core involved with cancer (P = 0.021; HR, 0.43) were significant factors in predicting overall survival (OS). CONCLUSIONS: The presence of IDC-P in a needle biopsy was a prognostic factor for PFS, CSS, and OS in patients with high-risk prostate cancer who underwent radical prostatectomy. Multimodal pre-and/or post- surgical therapy may be needed when IDC-P is found in a needle biopsy specimen.

The impact of intraductal carcinoma of the prostate on the site and timing of recurrence and cancer-specific survival.

BACKGROUND: To investigate the effect of intraductal carcinoma of the prostate (IDC-P) in radical prostatectomy (RP) specimens in the context of the site of recurrence, time to recurrence, and cancer-specific survival in two academic cohorts of locally, regionally, or distantly recurrent prostate cancer. METHODS: Our cohort included men enrolled into two academic tissue repositories from 1993 to 2011, who were treated with first-line RP who later experienced local recurrence, regional recurrence, or distant metastasis (together termed clinical recurrence, CR). RP material was reviewed to identify IDC-P and to update grading to current standards. The primary endpoint was the initial location of CR. Secondary endpoints included time to CR and cancer-specific survival. Pearson's chi-square, Welch's t-test, Mann-Whitney U test and Fisher's exact test were performed for univariate analyses. Multinomial logistic regression was used for multivariate analyses. Cancer-specific survival was analyzed with the generalized Wilcoxon test and Cox regression. RESULTS: Eighty-five patients with CR were included in the analysis. IDC-P was present in 78.5% of patients from Center 1 and 70.0% from Center 2 (P = 0.547). IDC-P was independently associated with distant metastasis at initial CR (multivariate odds ratio = 6.27, P = 0.015). IDC-P status did not affect time to recurrence; median survival without recurrence was at 53 months for IDC-P(+) and at 50 months for IDC-P(-) (P = 0.441). Distant metastases at the initial CR event had a 36% reduction of cancer-specific survival compared to local recurrences (P = 0.007). Additionally, prostatic-bed radiotherapy (adjuvant or salvage for biochemical recurrence before distant metastasis) was associated with a 25% reduction in cancer-specific mortality compared to no radiotherapy (P = 0.023). Similar reduction in cancer-specific mortality was observed in the subgroup of patients with distant metastasis and IDC-P when treated with radiotherapy (29%, P = 0.050). CONCLUSIONS: In our cohort, presence of IDC-P was an independent factor for distant metastasis at initial CR, but did not have a significant impact on time to CR. Furthermore, metastatic patients showed statistically reduced cancer-specific mortality when treated with radiotherapy. This reduction in cancer-specific mortality was also identified in patients with IDC-P. Future large scale validation studies should take into account the presence of IDC-P and confirm its impact on disease progression.

Intraductal carcinoma of the prostate can evade androgen deprivation, with emergence of castrate-tolerant cells.

OBJECTIVE: To determine the relevance of intraductal carcinoma of the prostate (IDC-P) in advanced prostate cancer by first examining whether IDC-P was originally present in patients who later developed advanced prostate cancer and then using patient-derived xenografts (PDXs) to investigate the response of IDC-P to androgen deprivation therapy (ADT). MATERIALS AND METHODS: We conducted a retrospective pathology review of IDC-P in primary prostate biopsy or surgery specimens from 38 men who subsequently developed advanced prostate cancer. Overall survival was calculated using the Kaplan-Meier method. To demonstrate the response of IDC-P to ADT, we established PDXs from seven patients with familial and/or high-risk sporadic prostate cancer. After castration and testosterone restoration of host mice, we measured the volume and proliferation of IDC-P within PDX grafts. RESULTS: We found that IDC-P was a prominent feature in the primary prostate specimens, present in 63% of specimens and often co-existing with poorly differentiated adenocarcinoma. Overall survival was similar in patients with or without IDC-P. In the PDXs from all seven patients, IDC-P was identified and present at a similar volume to adenocarcinoma. Residual IDC-P lesions persisted after host castration and, similar to castrate-tolerant adenocarcinoma, testosterone restoration led to tumour regeneration. CONCLUSION: The study showed that IDC-P is prevalent in aggressive prostate cancer and contains cells that can withstand androgen deprivation. Thus, IDC-P appears functionally relevant in advanced prostate cancer. The presence of IDC-P may be a trigger to develop innovative clinical management plans.

Efficacy of docetaxel in castration-resistant prostate cancer patients with intraductal carcinoma of the prostate.

BACKGROUND: This study aimed to investigate the efficacy of docetaxel in castration-resistant prostate cancer (CRPC) patients with intraductal carcinoma of the prostate (IDC-P). PATIENTS AND METHODS: We retrospectively identified 79 CRPC patients with distant metastasis at initial diagnosis from June 2002 to January 2014. All patients received initial androgen deprivation therapy and 46 received docetaxel chemotherapy after progressing to CRPC. The primary outcome of interest was cancer-specific survival (CSS) from the time of CRPC diagnosis. The Cox regression model was used to confirm whether IDC-P and docetaxel would act as independent factors for prognosis. RESULTS: IDC-P was found in 62 of 79 patients. The median CSS in the IDC-P-present group was 18.2 versus 45.6 months in the IDC-P-absent group (HR 2.67; 95% CI 1.18 to 6.06; P = 0.019). Docetaxel was administered to 36 patients with IDC-P and 10 patients without IDC-P, with a median CSS of 20.5 versus 53.2 months, respectively (HR 2.98; 95% CI 1.02 to 8.64; P = 0.044). Multivariate analysis demonstrated that the presence of IDC-P and docetaxel were independent prognostic factors for CSS (P = 0.026 and 0.005, respectively) and overall survival (OS) (P = 0.029 and 0.001, respectively). CONCLUSION: The presence of IDC-P is an independent prognostic factor in CRPC patients with distant metastases and IDC-P in needle biopsies at the time of initial diagnosis. Docetaxel may prolong CSS and OS in CRPC patients with distant metastases and IDC-P in needle biopsies at the time of initial diagnosis.

Atypical intraductal proliferation and intraductal carcinoma of the prostate on core needle biopsy: a comparative clinicopathological and molecular study with a proposal to expand the morphological spectrum of intraductal carcinoma.

AIMS: Atypical intraductal proliferation (AIP) of the prostate is histologically worse than high-grade prostate intraepithelial neoplasia, but lacks the diagnostic criteria of intraductal carcinoma of the prostate (IDC-P). The aim of this study was to compare the clinicopathological and molecular characteristics (ERG overexpression and PTEN loss) of AIP and IDC-P in core needle biopsies. METHODS AND RESULTS: One hundred and six [84 (5.6%) of 1480 consecutive and 22 retrospectively collected] cases met the criteria: AIP only (2.4%), IDC-P only (1.3%), and IDC-P coexisting with AIP (2%). Invasive adenocarcinoma [prostate adenocarcinoma (PCa)] was present in 96% and 97% cases of AIP and IDC-P, respectively. The mean number of glands/focus and the largest gland diameter for AIP and IDC-P were 7.6 (range, 2-27) and 11.7 (range, 1-51), and 0.59 mm (range, 0.2-1.1 mm) and 0.75 mm (range, 0.2-1.8 mm), respectively. For AIP, loose cribriform architecture was the most common (93%) morphology. IDC-P-associated PCa had more aggressive pathology, including the highest combined Gleason score (GS), high-grade GS ≥ 4 + 3, and largest percentage involvement of core by PCa and percentage positive cores, than AIP-associated PCa (P < 0.05). Within the AIP group, ERG status and PTEN status were similar to those of adjacent PCa in 97% and 88% of cases, respectively. Within the IDC-P group, ERG status and PTEN status were similar among IDC-P, AIP and PCa in 96% and 91% of cases, respectively. PTEN loss was frequently heterogeneous in PCa, and localized adjacent to AIP or IDC-P. CONCLUSIONS: AIP represents a lower-grade morphological spectrum of IDC-P, associated with intermediate-risk PCa. Patients with only AIP need an immediate repeat biopsy to rule out clinically significant PCa.

[SIGNIFICANCE OF INTRADUCTAL CARCINOMA OF THE PROSTATE IN POST-OPERATIVE BIOCHEMICAL RECURRENCE].

(Objective) We investigated the prognostic significance of intraductal carcinoma of the prostate (IDC-P) in radical prostatectomy specimens. (Materials and methods) We evaluated 441 patients treated with radical prostatectomy and analyzed data on IDC-P, lymph node metastases, Gleason score, seminal vesicle invasion, extraprostatic extension, surgical margin, total cancer volume, and zonal origin of dominant cancer focus in radical prostatectomy specimens. The median follow-up was 50 months (range 6-164 months). (Results) We identified IDC-P in 112 cases (25.4%). The five-year biochemical progression-free survival rate in patients with IDC-P was significantly lower than for those without IDC-P (35.8% vs 69.6%; p<0.0001). In a univariate analysis, IDC-P (p<0.0001), lymph node metastases (p=0.0022), Gleason score (p<0.0001), seminal vesicle invasion (p<0.0001), extraprostatic extension (p<0.0001), surgical margin (p<0.0001) and total cancer volume (p<0.0001) were significantly associated with the biochemical progression-free survival. In a multivariate analysis, Gleason score (p<0.0001), IDC-P (p=0.0002), seminal vesicle invasion (p=0.0011), extraprostatic extension (p=0.0012), surgical margin (p=0.0019) and lymph node metastases (p=0.0402) were significantly associated with biochemical progression-free survival. (Conclusions) The presence of IDC-P is an independent factor of biochemical recurrence in prostate cancer patients treated with radical prostatectomy. We therefore recommend that the presence of IDC-P in radical prostatectomy specimens be reported.