Prostatic ductal adenocarcinoma presenting as a urethral polyp: a clinicopathological study of eight cases of a lesion with the potential to be misdiagnosed as a benign prostatic urethral polyp

Prevalence of prostate cancer in men with haematuria: a systematic review and meta-analysis

OBJECTIVES

To investigate the prevalence of prostate cancer in men attending evaluation for haematuria, as this could help healthcare providers to determine whether men with haematuria should have prostate examinations performed.

METHODS

The study was performed according to a pre-specified protocol uploaded to the International Prospective Register of Systematic Reviews (PROSPERO; CRD42022299383). A systematic search of MEDLINE, Ovid and Google Scholar was performed in December 2021. Two independent researchers evaluated all titles, available abstracts, and full texts. We included studies on adult men (aged ≥18 years) describing haematuria and prostate cancer.

RESULTS

We screened 4252 titles and abstracts when available and assessed 350 studies in full text. In total, 65 studies were included and 42 was summarised in a meta-analysis. In total, 18 752 men with haematuria were included, and the pooled prevalence (95% confidence interval [CI]) of prostate cancer was 3.0% (2.0-4.1%). In men with macroscopic haematuria, the pooled prevalence (95% CI) of prostate cancer was 5.9% (2.9-9.9%; n = 265/5373). In men with microscopic haematuria, the pooled prevalence (95% CI) of prostate cancer was 1.4% (0.8-2.2%; n = 71/6642).

CONCLUSION

Our findings indicate that the prevalence of prostate cancer is considerable in men attending evaluation for haematuria. Therefore, digital rectal examination and prostate-specific antigen measurement should become a standard procedure for all men with haematuria, especially for men with macroscopic haematuria.

Optimizing the diagnosis and management of ductal prostate cancer

Ductal adenocarcinoma (DAC) is the most common variant histological subtype of prostate carcinoma and has an aggressive clinical course. DAC is usually characterized and treated as high-risk prostatic acinar adenocarcinoma (PAC). However, DAC has a different biology to that of acinar disease, which often poses a challenge for both diagnosis and management. DAC can be difficult to identify using conventional diagnostic modalities such as serum PSA levels and multiparametric MRI, and the optimal management for localized DAC is unknown owing to the rarity of the disease. Following definitive therapy for localized disease with radical prostatectomy or radiotherapy, the majority of DACs recur with visceral metastases at low PSA levels. Various systemic therapies that have been shown to be effective in high-risk PAC have limited use in treating DAC. Although current understanding of the biology of DAC is limited, genomic analyses have provided insights into the pathology behind its aggressive behaviour and potential future therapeutic targets.

Tumour-like lesions of the urinary bladder

There are a number of benign epithelial proliferations in the bladder that may be difficult to distinguish from carcinomas, including urothelial carcinoma and its variants, squamous cell carcinoma and adenocarcinoma. If misdiagnosed, there is the potential for over treatment, with its attendant risk of complications, as well as errors relating to prognostic assessment. In the case of the misdiagnosis of high grade proliferative lesions that mimic invasive carcinoma, unnecessary radical surgery, chemotherapy and radiotherapy may result. Similarly, the misdiagnosis of lesions that have the appearance of low grade carcinoma can prompt a lifetime of radiological investigation and cystoscopies. In this review, we discuss a variety of entities that may be diagnostically challenging and emphasise the importance of identifying key morphological features that have diagnostic utility. We also highlight the importance of relevant clinical information and the clinical settings in which these lesions may occur. In this review we have divided the lesions on the basis of morphology in order to facilitate discussion relating to the differential diagnosis. The architectural patterns we discuss include papillary lesions (polypoid/papillary cystitis and papillary urothelial hyperplasia), pseudocarcinomatous proliferations (pseudocarcinomatous urothelial hyperplasia, florid proliferation of von Brunn nests and fibroepithelial polyps), glandular lesions (intestinal metaplasia and müllerianosis) and lesions with several different patterns (prostatic type urethral polyps and nephrogenic adenoma or metaplasia).

Immunohistochemical profile of ductal adenocarcinoma of the prostate

Ductal adenocarcinoma of the prostate (DAC) is considered to be an aggressive subtype of prostate cancer with greater risk of progression than acinar adenocarcinoma (AC). It has been debated whether DAC is a distinct subtype or a morphological variant of AC. Our aim was to examine the protein expression of DAC and to compare the results with AC. A tissue microarray was constructed from 60 DAC and 46 AC matched by Gleason score. The slides were stained for 28 immunomarkers (estrogen, progesterone and androgen receptor, prolactin, PSA, prostein, PSMA, PSAP, CDX2, lysozyme, villin, monoclonal CEA, CK7, CK20, HMWCK, p63, p504s, c-myc, EGFR, Ki-67, p16, p21, p27, p53, PTEN, ERG, PAX-2, and PAX-8). HMWCK was positive in 8.5 % of DAC, but negative in all cases of AC (p = 0.045). p16 was positive in 53.3 % of DAC and in 26.1 % of AC (p = 0.005). p53 was positive in 42.4 % of DAC and 26.7 % of AC (p = 0.031). A distinct patchy positivity of CK20 was seen in 23.7 % of DAC, and this pattern was also seen in 9.1 % of AC (p = 0.047). Villin was positive in 3.4 % of DAC while expression was negative in AC. Ki-67 labeling index was significantly higher in DAC than in AC (mean 9.2 % [95 % CI 6.4-12.0] and 2.6 % [1.9-3.4], p < 0.001). While there is some overlap in the immunohistochemical expression of DAC and AC, the differences between these two morphotypes of prostatic carcinoma are consistent with DAC having a more aggressive phenotype than AC.

Ductal adenocarcinoma of the prostate: increased mortality risk and decreased serum prostate specific antigen

PURPOSE

The clinical significance of ductal prostatic carcinoma is not well-defined. In a population based cancer registry we identified a large group of patients with ductal carcinoma to characterize the impact of the ductal subtype on presentation and survival in men with prostate cancer.

MATERIALS AND METHODS

We used a national cancer registry to identify incident cases of ductal and acinar adenocarcinoma from 1996 to 2006. We analyzed clinicopathological variables and performed Cox multivariate survival analysis. Prostate specific antigen values were available for 2004 to 2006 and used to assess differences in Gleason grade and serum prostate specific antigen between ductal and acinar cancer cases at diagnosis.

RESULTS

We identified 442,881 acinar and 371 ductal cases. Ductal cases were more likely to present with distant disease (12% vs 4%, p <0.001) and be poorly differentiated (50% vs 32%, p <0.001). Ductal histology was associated with a 30% decrease in geometric mean prostate specific antigen (adjusted coefficient 0.7, 95% CI 0.6-0.8) and more than 2-fold increased odds of prostate specific antigen less than 4.0 ng/ml (OR 2.4, 95% CI 1.4-4.0) independent of other clinicopathological variables. In men with nondistant disease at diagnosis ductal histology was associated with 2.2-fold (CI 1.4-3.5) increased disease specific mortality.

CONCLUSIONS

In what is to our knowledge the largest series of this histological subtype ductal cancer cases were more likely to present with advanced stage cancer and lower prostate specific antigen, suggesting that timely disease detection is a significant challenge. Also, men with locoregional disease were more likely to die of the disease.

Cancer biomarker discovery: the entropic hallmark

Background

It is a commonly accepted belief that cancer cells modify their transcriptional state during the progression of the disease. We propose that the progression of cancer cells towards malignant phenotypes can be efficiently tracked using high-throughput technologies that follow the gradual changes observed in the gene expression profiles by employing Shannon's mathematical theory of communication. Methods based on Information Theory can then quantify the divergence of cancer cells' transcriptional profiles from those of normally appearing cells of the originating tissues. The relevance of the proposed methods can be evaluated using microarray datasets available in the public domain but the method is in principle applicable to other high-throughput methods.

Methodology/Principal Findings

Using melanoma and prostate cancer datasets we illustrate how it is possible to employ Shannon Entropy and the Jensen-Shannon divergence to trace the transcriptional changes progression of the disease. We establish how the variations of these two measures correlate with established biomarkers of cancer progression. The Information Theory measures allow us to identify novel biomarkers for both progressive and relatively more sudden transcriptional changes leading to malignant phenotypes. At the same time, the methodology was able to validate a large number of genes and processes that seem to be implicated in the progression of melanoma and prostate cancer.

Conclusions/Significance

We thus present a quantitative guiding rule, a new unifying hallmark of cancer: the cancer cell's transcriptome changes lead to measurable observed transitions of Normalized Shannon Entropy values (as measured by high-througput technologies). At the same time, tumor cells increment their divergence from the normal tissue profile increasing their disorder via creation of states that we might not directly measure. This unifying hallmark allows, via the the Jensen-Shannon divergence, to identify the arrow of time of the processes from the gene expression profiles, and helps to map the phenotypical and molecular hallmarks of specific cancer subtypes. The deep mathematical basis of the approach allows us to suggest that this principle is, hopefully, of general applicability for other diseases.