Clinical Significance of Intraductal Carcinoma of the Prostate After High-Dose Brachytherapy With External Beam Radiation Therapy: A Single Institution Series and an Updated Meta-Analysis

BACKGROUND

We compared oncological outcomes between prostate cancer (PCa) patients with and without intraductal carcinoma of the prostate (IDC-P) after high-dose-rate brachytherapy (HDR-BT) with external beam radiation therapy (EBRT).

METHODS

We performed a retrospective analysis of 138 patients with clinically high-risk, very high-risk, or locally advanced PCa who received HDR-BT with EBRT. Of these, 70 (50.7 %) patients were diagnosed with IDC-P; 68 (49.3 %) patients with acinar adenocarcinoma of prostate. The oncological outcomes, including biochemical recurrence-free survival (BCRFS) and clinical progression-free survival (CPFS), were assessed using Kaplan-Meier curves. Additionally, Cox proportional hazards models were used to identify significant prognostic indicators or biochemical recurrence (BCR). Meta-analysis of existing literatures was performed to evaluate the risk of BCR in patients with IDC-P after radiation therapy, compared to those without IDC-P.

RESULTS

Kaplan-Meier curves demonstrated significantly inferior BCRFS and CPFS in patients with IDC-P. Multivariate analysis revealed that IDC-P and Grade Group 5 status were associated with increased BCR risk. in our meta-analysis, IDC-P was associated with BCR (HR = 2.13, P = .003).

CONCLUSION

Amongst the patients who received HDR-BT, patients with IDC-P displayed significantly more rapid disease progression, compared with patients who did not have IDC-P.

Molecular complexity of intraductal carcinoma of the prostate

Intraductal carcinoma of the prostate (IDC-P) is an aggressive subtype of prostate cancer characterized by the growth of tumor cells within the prostate ducts. It is often found alongside invasive carcinoma and is associated with poor prognosis. Understanding the molecular mechanisms driving IDC-P is crucial for improved diagnosis, prognosis, and treatment strategies. This review summarizes the molecular characteristics of IDC-P and their prognostic indications, comparing them to conventional prostate acinar adenocarcinoma, to gain insights into its unique behavior and identify potential therapeutic targets.

Appl1, Sortilin and Syndecan-1 immunohistochemistry on intraductal carcinoma of the prostate provides evidence of retrograde spread

The presence of intraductal carcinoma of the prostate (IDCP) correlates with late-stage disease and poor outcomes for patients with prostatic adenocarcinoma, but the accurate and reliable staging of disease severity remains challenging. Immunohistochemistry (IHC) has been utilised to overcome problems in assessing IDCP morphology, but the current markers have only demonstrated limited utility in characterising the complex biology of this lesion. In a retrospective study of a cohort of patients who had been diagnosed with IDCP, we utilised IHC on radical prostatectomy sections with a biomarker panel of Appl1, Sortilin and Syndecan-1, to interpret different architectural patterns and to explore the theory that IDCP occurs from retrograde spread of high-grade invasive prostatic adenocarcinoma. Cribriform IDCP displayed strong Appl1, Sortilin and Syndecan-1 labelling patterns, while solid IDCP architecture had high intensity Appl1 and Syndecan-1 labelling, but minimal Sortilin labelling. Notably, the expression pattern of the biomarker panel in regions of IDCP was similar to that of adjacent invasive prostatic adenocarcinoma, and also comparable to prostate cancer showing perineural and vascular invasion. The Appl1, Sortilin, and Syndecan-1 biomarker panel in IDCP provides evidence for the model of retrograde spread of invasive prostatic carcinoma into ducts/acini, and supports the inclusion of IDCP into the five-tier Gleason grading system.

Comedonecrosis within conventional prostatic adenocarcinoma vs. intraductal carcinoma of the prostate: their clinical significance is not comparable

It remains controversial if Gleason grade should be assigned to intraductal carcinoma of the prostate (IDC-P) and if the prognostic value of comedonecrosis associated with IDC-P is equivalent to that in conventional/invasive prostatic adenocarcinoma (CPA) as a Gleason grade 5 pattern. We herein assessed radical prostatectomy findings and postoperative outcomes in 287 patients with CPA exhibiting any Gleason pattern 5. Our cases were divided into 4 cohorts according to the absence or presence of necrosis within CPA and/or IDC-P: Cohort-1) no necrosis in CPA/IDC-P (n = 179; 62.4%); Cohort-2) necrosis only in CPA (n = 25; 8.7%); Cohort-3) necrosis only in IDC-P (n = 62; 21.6%); and Cohort-4) necrosis in both CPA and IDC-P (n = 21; 7.3%). Univariate analysis revealed patients with necrosis only in IDC-P (P < .001) or both CPA and IDC-P (P = .001) had a higher risk of progression than those with necrosis only in CPA, while the prognosis was comparable between the no necrosis group vs. the CPA only necrosis group (P = .680) or the IDC-P only necrosis group vs. the CPA/IDC-P necrosis group (P = .715). In a subgroup of patients exhibiting IDC-P (n = 198), the presence of IDC-P necrosis was still associated with a significantly higher progression risk, compared with CPA necrosis only. In multivariable analysis, necrosis only in IDC-P (vs. necrosis only in CPA) showed significantly worse progression-free survival (HR = 3.193, P = .003). IDC-P necrosis, as an independent predictor, was thus found to be associated with significantly worse oncologic outcomes, compared with necrosis only in CPA, and might therefore be better not to be simply considered as a grade 5 pattern.

Nomogram Models for Distinguishing Intraductal Carcinoma of the Prostate From Prostatic Acinar Adenocarcinoma Based on Multiparametric Magnetic Resonance Imaging

OBJECTIVE

To compare multiparametric magnetic resonance imaging (MRI) features of intraductal carcinoma of the prostate (IDC-P) with those of prostatic acinar adenocarcinoma (PAC) and develop prediction models to distinguish IDC-P from PAC and IDC-P with a high proportion (IDC ≥ 10%, hpIDC-P) from IDC-P with a low proportion (IDC < 10%, lpIDC-P) and PAC.

MATERIALS AND METHODS

One hundred and six patients with hpIDC-P, 105 with lpIDC-P and 168 with PAC, who underwent pretreatment multiparametric MRI between January 2015 and December 2020 were included in this study. Imaging parameters, including invasiveness and metastasis, were evaluated and compared between the PAC and IDC-P groups as well as between the hpIDC-P and lpIDC-P subgroups. Nomograms for distinguishing IDC-P from PAC, and hpIDC-P from lpIDC-P and PAC, were made using multivariable logistic regression analysis. The discrimination performance of the models was assessed using the receiver operating characteristic area under the curve (ROC-AUC) in the sample, where the models were derived from without an independent validation sample.

RESULTS

The tumor diameter was larger and invasive and metastatic features were more common in the IDC-P than in the PAC group (P < 0.001). The distribution of extraprostatic extension (EPE) and pelvic lymphadenopathy was even greater, and the apparent diffusion coefficient (ADC) ratio was lower in the hpIDC-P than in the lpIDC-P group (P < 0.05). The ROC-AUCs of the stepwise models based solely on imaging features for distinguishing IDC-P from PAC and hpIDC-P from lpIDC-P and PAC were 0.797 (95% confidence interval, 0.750-0.843) and 0.777 (0.727-0.827), respectively.

CONCLUSION

IDC-P was more likely to be larger, more invasive, and more metastatic, with obviously restricted diffusion. EPE, pelvic lymphadenopathy, and a lower ADC ratio were more likely to occur in hpIDC-P, and were also the most useful variables in both nomograms for predicting IDC-P and hpIDC-P.

Cribriform pattern and intraductal carcinoma of the prostate can have a clinicopathological impact, regardless of their percentage and/or number of cores

Cribriform pattern and intraductal carcinoma of the prostate (IDC-P) are widely accepted as poor prognostic factors in prostate cancer. However, it remains unclear to what extent the presence of these morphological features in prostate biopsy specimens, as diagnosed by hematoxylin-eosin-stained specimens only, affects the clinicopathological impact. In this study, we summarized the characteristics of the cribriform pattern and IDC-P in 850 prostate biopsy cases. The results showed a statistically significant increase in the incidence of cribriform pattern and IDC-P as grade group (GG) increased (especially in cases ≥ GG4, Chi-square test P < 0.001). The independent risk factors for cribriform pattern and IDC-P in biopsy specimens in the multivariate logistic regression analysis were the former GG, presence of IDC-P, lesion length of the highest GG core, latter GG, presence of the cribriform pattern, number of biopsies obtained, and number of highest GG core. Overall, 125 cases in which radical prostatectomy was conducted after biopsy were selected for further analysis. Multivariate logistic regression analysis using biopsy and surgical specimens confirmed that the presence of the cribriform pattern and IDC-P in biopsy specimens were independent risk factors for lymph node metastasis (odds ratios [95% confidence interval] were 6.54 [1.15-37.05] for the cribriform pattern and 23.71 [1.74-322.42] for IDC-P). The presence of the cribriform pattern and/or IDC-P in a biopsy specimen was a significant factor, even if only partially present, indicating lymph node metastasis. However, further validation is required to predict poor prognostic factors more accurately.

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.

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.

Intraductal Carcinoma of the Prostate: Pathogenesis and Molecular Perspectives

Intraductal carcinoma of the prostate (IDC-P), a clinicopathological entity characterized by malignant prostatic epithelial cells growing within ducts and/or acini, has a distinct architectural pattern, cytological features, and biological behavior. Whereas most IDC-P tumors could be derived from adjacent high-grade invasive cancer via retrograde spreading of cancer cells along benign ducts and acini, a small subset of IDC-P may arise from the transformation and intraductal proliferation of precancerous cells induced by various oncogenic events. These isolated IDC-P tumors possess a distinct mutational profile and may function as a carcinoma in situ lesion with de novo intraductal outgrowth of malignant cells. Further molecular characterization of these two types of IDC-P and better understanding of the mechanisms underlying IDC-P formation and progression could be translated into valuable biomarkers for differential diagnosis and actionable targets for therapeutic interventions. PATIENT SUMMARY: Intraductal carcinoma of the prostate is an aggressive type of prostate cancer associated with high risk for local recurrence and distant metastasis. In this review, we discussed pathogenesis, biomarkers, differential diagnoses, and therapeutic strategies for this tumor.

[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.

Intraductal carcinoma of prostate: a comprehensive and concise review

Intraductal carcinoma of the prostate (IDC-P) is defined as a proliferation of prostate adenocarcinoma cells distending and spanning the lumen of pre-existing benign prostatic ducts and acini, with at least focal preservation of basal cells. Studies demonstrate that IDC-P is strongly associated with high-grade (Gleason grades 4/5), large-volume invasive prostate cancers. In addition, recent genetic studies indicate that IDC-P represents intraductal spread of invasive carcinoma, rather than a precursor lesion. Some of the architectural patterns in IDC-P exhibit architectural overlap with one of the main differential diagnoses, high-grade prostatic intraepithelial neoplasia (HGPIN). In these instances, additional diagnostic criteria for IDC-P, including marked nuclear pleomorphism, non-focal comedonecrosis (>1 duct showing comedonecrosis), markedly distended normal ducts/acini, positive nuclear staining for ERG, and cytoplasmic loss of PTEN by immunohistochemistry, can help make the distinction. This distinction between IDC-P and HGPIN is of critical importance because IDC-P has an almost constant association with invasive carcinoma and has negative clinical implications, including shorter relapse-free survival, early biochemical relapse, and metastatic failure rate after radiotherapy. Therefore, IDC-P should be reported in prostate biopsies and radical prostatectomies, regardless of the presence of an invasive component. This article will review the history, diagnostic criteria, molecular genetics, and clinical significance of IDC-P.

Prostatic Adenocarcinoma, Prostatic Intraepithelial Neoplasia, and Intraductal Carcinoma

Prostate carcinoma (PCa) exhibits a wide range of architectural and cytological features. Gleason grading remains as one of the most powerful histological prognostic parameters. However, it has evolved considerably. High-grade prostatic intraepithelial neoplasia (high-grade PIN) is accepted as a precursor lesion to PCa. Its detection in prostate biopsy is also considered as a risk factor for detecting cancer in subsequent biopsies. Such risk, however, has significantly decreased in recent studies. Intraductal carcinoma of the prostate (IDC-P) represents the intraductal spread of invasive cancer and constitutes a poor histologic parameter. This article reviews the key histological features of PCa, high-grade PIN and IDC-P, as well as the Gleason grading system that was most recently updated in 2005.