Dedifferentiation in the metastatic progression of prostate carcinoma

Unraveling dedifferentiation and metastasis traces in pancreatic ductal adenocarcinoma ductal cells: Insights from single-cell RNA sequencing analysis of ITGB4 and C19orf33

Pancreatic Ductal Adenocarcinoma (PDAC) ranks among the most prevalent gastrointestinal malignancies, with risk factors including smoking, alcohol abuse, diabetes mellitus, obesity, age, family history, and genetic predisposition. Extensive research has focused on unraveling biomarkers and molecular intricacies associated with PDAC. Leveraging data from the Gene Expression Omnibus microarray and single-cell RNA sequencing datasets, our study identified ITGB4 and C19orf33 as potentially differentially expressed genes in PDAC samples when contrasted with non-malignant tissues. Notably, these genes exhibited a strong correlative expression pattern, primarily within ductal cells. Gene Expression Profiling Interactive Analysis corroborated our findings, further confirming the correlation between ITGB4 and C19orf33. Additionally, we conducted experiments involving two pivotal PDAC-related cell lines, MIA PaCa-2 and PANC-1, treated with oxaliplatin and 5-Fluorouracil. We also assessed the expression of these candidate genes in PDAC samples in comparison to adjacent normal tissues. Our findings revealed that C19orf33 is upregulated in PDAC samples, and treatment of PDAC cells with chemotherapeutic agents led to a correlated decrease in the expression of both ITGB4 and C19orf33. These co-expressed and correlated genes are implicated in relevant signaling pathways, suggesting shared biological activities that may contribute to the promotion of metastasis within malignant ductal cells. This study identifies ITGB4 and C19orf33 as key genes potentially shedding light on the molecular mechanisms driving tumorigenesis and metastasis in PDAC. These genes hold promise as potential diagnostic and therapeutic targets, offering valuable insights into the management of this challenging disease.

CRSP8 promotes thyroid cancer progression by antagonizing IKKα-induced cell differentiation

CRSP8 plays an important role in recruiting mediators to genes through direct interaction with various DNA-bound transactivators. In this study, we uncovered the unique function of CRSP8 in suppressing thyroid cancer differentiation and promoting thyroid cancer progression via targeting IKKα signaling. CRSP8 was highly expressed in human thyroid cancer cells and tissues, especially in anaplastic thyroid cancer (ATC). Knockdown of CRSP8 suppressed cell growth, migration, invasion, stemness, and induced apoptosis and differentiation in ATC cells, while its overexpression displayed opposite effects in differentiated thyroid cancer (DTC) cells. Mechanistically, CRSP8 downregulated IKKα expression by binding to the IKKα promoter region (-257 to -143) to negatively regulate its transcription. Knockdown or overexpression of IKKα significantly reversed the expression changes of the differentiation and EMT-related markers and cell growth changes mediated by CRSP8 knockdown or overexpression in ATC or DTC cells. The in vivo study also validated that CRSP8 knockdown inhibited the growth of thyroid cancer by upregulating IKKα signaling in a mouse model of human ATC. Furthermore, we found that CRSP8 regulated the sensitivity of thyroid cancer cells to chemotherapeutics, including cisplatin and epirubicin. Collectively, our results demonstrated that CRSP8 functioned as a modulator of IKKα signaling and a suppressor of thyroid cancer differentiation, suggesting a potential therapeutic strategy for ATC by targeting CRSP8/IKKα pathway.

Neuroendocrine Differentiation in Metastatic Conventional Prostate Cancer Is Significantly Increased in Lymph Node Metastases Compared to the Primary Tumors

Neuroendocrine serum markers released from prostate cancers have been proposed for monitoring disease and predicting survival. However, neuroendocrine differentiation (NED) in various tissue compartments of metastatic prostate cancer is poorly described and its correlation with specific tumor features is unclear. NED was determined by Chromogranin A expression on immunostains from a tissue microarray of 119 nodal positive, hormone treatment-naïve prostate cancer patients who underwent radical prostatectomy and extended lymphadenectomy. NED in the primary cancer and in the metastases was correlated with tumor features and survival. The mean percentage of NED cells increased significantly (p < 0.001) from normal prostate glands (0.4%), to primary prostate cancer (1.0%) and nodal metastases (2.6%). In primary tumors and nodal metastases, tumor areas with higher Gleason patterns tended to display a higher NED, although no significance was reached. The same was observed in patients with a larger primary tumor volume and higher total size and number of metastases. NED neither in the primary tumors nor in the metastases predicted outcome significantly. Our data suggest that (a) increasing levels of neuroendocrine serum markers in the course of prostate cancer might primarily derive from a poorly differentiated metastatic tumor component; and (b) NED in conventional hormone-naïve prostate cancers is not significantly linked to adverse tumor features.

NFIB Mediates BRN2 Driven Melanoma Cell Migration and Invasion Through Regulation of EZH2 and MITF

While invasion and metastasis of tumour cells are the principle factor responsible for cancer related deaths, the mechanisms governing the process remain poorly defined. Moreover, phenotypic divergence of sub-populations of tumour cells is known to underpin alternative behaviors linked to tumour progression such as proliferation, survival and invasion. In the context of melanoma, heterogeneity between two transcription factors, BRN2 and MITF, has been associated with phenotypic switching between predominantly invasive and proliferative behaviors respectively. Epigenetic changes, in response to external cues, have been proposed to underpin this process, however the mechanism by which the phenotypic switch occurs is unclear. Here we report the identification of the NFIB transcription factor as a novel downstream effector of BRN2 function in melanoma cells linked to the migratory and invasive characteristics of these cells. Furthermore, the function of NFIB appears to drive an invasive phenotype through an epigenetic mechanism achieved via the upregulation of the polycomb group protein EZH2. A notable target of NFIB mediated up-regulation of EZH2 is decreased MITF expression, which further promotes a less proliferative, more invasive phenotype. Together our data reveal that NFIB has the ability to promote dynamic changes in the chromatin state of melanoma cells to facilitate migration, invasion and metastasis.

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NFIB mediates a slow cycling, highly invasive/migratory melanoma cell phenotype downstream of BRN2.

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NFIB increases EZH2 expression downstream of BRN2, which further decreases MITF levels.

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NFIB expression is defined by an invasive gene signature and colocalises with BRN2 in primary and metastatic human melanoma tumours.

Melanoma is a heterogeneous cancer, made up of many cellular populations that differ in their ability to induce tumour growth or invasion throughout the body (metastasis). These populations have been found to switch back and forth to drive invasion and progression. This process appears to be controlled by an inverse axis between two genes, MITF and BRN2. BRN2 drives metastatic spread, but the process by which it acts is not well characterized and cannot be targeted clinically. This study has uncovered a role for the gene NFIB in driving invasion downstream of BRN2. Importantly, it appears to drive this process through EZH2, which can be targeted therapeutically to reduce metastasis.

Lymph node staging in prostate cancer: perspective for the pathologist

Pelvic lymph node dissection (PLND) currently represents the gold standard method for nodal staging in the setting of localised prostate cancer and may also have a therapeutic benefit in certain patients. The histopathological evaluation of PLND specimens plays a critical role in accurate lymph node staging, however there is currently a lack of consensus regarding the optimum approach and no quality parameters are in place. In addition, there are no guidelines as to the handling of less commonly encountered nodal specimens such as those identified within the anterior fat pad. This summary provides an overview of pertinent issues regarding lymph node staging in prostate cancer, with a focus on the histopathological evaluation of resected nodal specimens. We hope that this review will further the discussion on how to achieve a more standardised approach to the processing and reporting of PLND specimens in the setting of prostate cancer.

Delay from biopsy to radical prostatectomy influences the rate of adverse pathologic outcomes

BACKGROUND

We sought to determine maximum wait times between biopsy diagnosis and surgery for localized prostate cancer, beyond which the rate of adverse pathologic outcomes is increased.

METHODS

We retrospectively reviewed 4,610 patients undergoing radical prostatectomy between 1990 and 2011. Patients were stratified by biopsy Gleason score and PSA value. For each stratification, χ2 analysis was used to determine the smallest 15-day multiple of surgical delay (e.g., 15, 30, 45…180 days) for which adverse pathologic outcomes were significantly more likely after the time interval than before. Adverse outcomes were defined as positive surgical margins, upgrading from biopsy, upstaging, seminal vesicle invasion, or positive lymph nodes.

RESULTS

Two thousand two hundred twelve patients met inclusion criteria. Median delay was 64 days (mean 76, SD 47). One thousand six hundred seventy-five (75.7%), 537 (24.3%), and 60 (2.7%) patients had delays of <=90, >90, and >180 days, respectively. Twenty-six percent were upgraded on final pathology and 23% were upstaged. The positive surgical margin rate was 24.2% and the positive lymph node rate was 1.1%. Significant increases in the proportion of adverse pathological outcomes were found beyond 75 days in the overall cohort (P = 0.03), 150 days for patients with Gleason <=6, and PSA 0-10 (P = 0.038), 60 days for patients with Gleason 7 and PSA >20 (P = 0.032), and 30 days for patients with Gleason 8-10 and PSA 11-20 (0.041).

CONCLUSION

In low-risk disease, there is a considerable but not unlimited surgical delay which will not adversely impact the rate of adverse pathologic features found. In higher risk disease, this time period is considerably shorter.

[¹¹C]Choline PET/CT predicts survival in hormone-naive prostate cancer patients with biochemical failure after radical prostatectomy

PURPOSE

Over the last decade, PET/CT with radiolabelled choline has been shown to be useful for restaging patients with prostate cancer (PCa) who develop biochemical failure. The limitations of most clinical studies have been poor validation of [(11)C]choline PET/CT-positive findings and lack of survival analysis. The aim of this study was to assess whether [(11)C]choline PET/CT can predict survival in hormone-naive PCa patients with biochemical failure.

METHODS

This retrospective study included 302 hormone-naive PCa patients treated with radical prostatectomy who underwent [(11)C]choline PET/CT from 1 December 2004 to 31 July 2007 because of biochemical failure (prostate-specific antigen, PSA, >0.2 ng/mL). Median PSA was 1.02 ng/mL. PCa-specific survival was estimated using Kaplan-Meier curves. Cox regression analysis was used to evaluate the association between clinicopathological variables and PCa-specific survival. The coefficients of the covariates included in the Cox regression analysis were used to develop a novel nomogram.

RESULTS

Median follow-up was 7.2 years (1.4 - 18.9 years). [(11)C]Choline PET/CT was positive in 101 of 302 patients (33%). Median PCa-specific survival after prostatectomy was 14.9 years (95% CI 9.7 - 20.1 years) in patients with positive [(11)C]choline PET/CT. Median survival was not achieved in patients with negative [(11)C]choline PET/CT. The 15-year PCa-specific survival probability was 42.4% (95% CI 31.7 - 53.1%) in patients with positive [(11)C]choline PET/CT and 95.5% (95% CI 93.5 - 97.5 %) in patients with negative [(11)C]choline PET/CT. In multivariate analysis, [(11)C]choline PET/CT (hazard ratio 6.36, 95% CI 2.14 - 18.94, P < 0.001) and Gleason score >7 (hazard ratio 3.11, 95% CI 1.11 - 8.66, P = 0.030) predicted PCa-specific survival. An internally validated nomogram predicted 15-year PCa-specific survival probability with an accuracy of 80%.

CONCLUSION

Positive [(11)C]choline PET/CT after biochemical failure predicts PCa-specific survival in hormone-naive PCa patients. Prospective studies are warranted to confirm our results before more extensive use of [(11)C]choline PET/CT for prognostic stratification of PCa patients.

Prognosis of patients with pelvic lymph node (LN) metastasis after radical prostatectomy: value of extranodal extension and size of the largest LN metastasis

OBJECTIVE

To assess the prognostic role of extranodal extension (ENE) and the size of the largest lymph node (LN) metastasis in predicting early biochemical relapse (eBCR) in patients with LN metastasis after radical prostatectomy (RP).

PATIENTS AND METHODS

We evaluated BCR-free survival in men with LN metastases after RP and pelvic LN dissection performed in six high-volume centres. Multivariable Cox regression tested the role of ENE and diameter of largest LN metastasis in predicting eBCR after adjusting for clinicopathological variables. We compared the discrimination of multivariable models including ENE, the size of largest LN metastasis and the number of positive LNs.

RESULTS

Overall, 484 patients were included. The median (interquartile range, IQR) follow-up was 16.1 (6-27.5) months. The median (IQR) number of removed LNs was 10 (4-14), and the median (IQR) number of positive LNs was 1 (1-2). ENE was present in 280 (58%) patients, and 211 (44%) had their largest metastasis >10 mm. Patients with ENE and/or largest metastasis of >10 mm had significantly worse eBCR-free survival (all P < 0.01). On multivariable analysis, number of positive LNs (≤2 vs >2) and the diameter of LN metastasis (≤10 vs >10 mm), but not ENE, were significant predictors of eBCR (all P < 0.003). ENE and diameter of LN metastasis increased the area under the curve of a baseline multivariable model (0.663) by 0.016 points.

CONCLUSIONS

The diameter of the largest LN metastasis and the number of positive LNs are independent predictors of eBCR. Considered together, ENE and the diameter of the largest LN metastasis have less discrimination than the number of positive LNs.

When is prostate cancer really cancer?

Several investigators have challenged the idea that low-grade cancers are a cause for concern, suggesting that the term cancer should not be applied to these tumors. This article reviews the defining features of cancer, and the diagnostic and prognostic classification systems currently used for prostate cancer. Logical, morphologic, and molecular evidence is presented to show that low-grade prostate cancers are correctly classified as cancer. The authors suggest, however, that 6 out of 10 on an aggressiveness scale is inappropriate for indolent cancer, and that a proposed reinterpretation of Gleason grading categories is a more logical way to address overtreatment.

Clinical activity of abiraterone acetate in patients with metastatic castration-resistant prostate cancer progressing after enzalutamide

BACKGROUND

Abiraterone acetate and enzalutamide both improve outcomes in patients with metastatic castration-resistant prostate cancer (mCRPC). Optimal sequencing for these agents and whether cross-resistance occurs is unknown.

METHODS

Multicentre review of patients with mCRPC treated with abiraterone acetate and prednisone after progressing on enzalutamide. Primary objective was to determine abiraterone acetate response.

RESULTS

Thirty patients identified from four North American centres. At abiraterone initiation, median age was 70 years (56-84 years); 70% had ECOG performance status of 0-1; all had prior docetaxel. Median prior enzalutamide treatment duration was 41 weeks (6-95 weeks), with 70% (21 of 30) having a ≥30% prostate-specific antigen (PSA) decline. Median abiraterone acetate treatment duration was 13 weeks (1-52). No objective radiographic responses were observed. Median abiraterone time to progression (PSA, objective or symptomatic) was 15.4 weeks [95% confidence interval (CI) 10.7-20.2]. Median overall survival was 50.1 weeks (95% CI 28.3-72.0). Three patients had a ≥30% PSA decline with abiraterone. Two of these patients had PSA progression as best response with prior enzalutamide.

CONCLUSIONS

In this study of patients progressing after enzalutamide, treatment with abiraterone was associated with a modest response rate and brief duration of effect. Primary progression on enzalutamide may not preclude a response to abiraterone.

Importance and determinants of Gleason score undergrading on biopsy sample of prostate cancer in a population-based study

Background

In this population-based study, we investigated the degree of concordance between Gleason scores obtained from prostate biopsies and those obtained from prostatectomy specimens, as well as the determinants of biopsy understaging.

Methods

We considered for this study all 371 prostate cancer patients recorded at the Geneva Cancer Registry diagnosed from 2004 to 2006 who underwent a radical prostatectomy. We used the kappa statistic to evaluate the Gleason score concordance from biopsy and prostatectomy specimens. Logistic regression was used to determine the parameters that predict the undergrading of the Gleason score in prostate biopsies.

Results

The kappa statistic between biopsy and prostatectomy Gleason score was 0.42 (p < 0.0001), with 67% of patients exactly matched, and 26% (n = 95) patients with Gleason score underestimated by the biopsy. In a multi-adjusted model, increasing age, advanced clinical stage, having less than ten biopsy cores, and longer delay between the two procedures, were all independently associated with biopsy undergrading. In particular, the proportion of exact match increased to 72% when the patients had ten or more needle biopsy cores. The main limitation of the study is that both biopsy and prostatectomy specimens were examined by different laboratories.

Conclusions

The data show that concordance between biopsy and prostatectomy Gleason scores lies within the classic clinical standards in this population-based study. The number of biopsy cores appears to strongly impact on the concordance between biopsy and radical prostatectomy Gleason score.

Lymph node-positive prostate cancer: current issues, emerging technology and impact on clinical outcome

Lymph node metastasis in patients with prostate cancer indicates a poorer prognosis compared with patients without lymph node metastasis; however, some patients with node-positive disease have long-term survival. Many studies have attempted to discern what characteristics of lymph node metastasis are prognostically significant. These characteristics include nodal tumor volume, number of positive lymph nodes, lymph node density, extranodal extension, lymphovascular invasion and tumor dedifferentiation. Favorable characteristics of regional lymph node involvement included a smaller tumor size and smaller tumor volume. However, the current staging system for prostate cancer does not provide different subclassifications for patients with node-positive prostate cancer. In recent years numerous advanced technologies for the detection of lymph node metastasis have been developed, including molecular imaging techniques and the CellSearch Circulating Tumor Cell System. With the increased detection of patients with prostate cancer, emergence of new technology to identify lymph node metastasis and the number of radical prostatectomies being performed on the rise, subclassifying patients with lymph node-positive disease is imperative. Subclassification would provide a better picture of patient prognosis and allow for a better understanding of targeted therapies to treat patients with lymph node metastasis.

PSA-detected prostate cancer and the potential for dedifferentiation--estimating the proportion capable of progression

The aims were to determine whether prostate-specific antigen (PSA)-detected prostate cancers progress to higher Gleason score during the preclinical screen-detectable phase, and, if so, to estimate the proportion of tumours with progressive potential. We developed two multi-state Markov chain models to represent the natural history of two tumour populations, one with (Model I) and the other without (Model II) the potential for progression. For each, we derived the transition rates between the states and used these estimates to calculate the expected prevalence of preclinical low and intermediate-to-high Gleason score prostate cancers, using data from the Prostate Testing for Cancer and Treatment (ProtecT) study on 2,310 prostate cancers detected by PSA testing in 71,511 men 50-69 years. We compared the expected prevalence for each tumour population to that of the observed based on ProtecT and the European Randomised Study on Screening for Prostate Cancer (ERSPC)-Rotterdam Centre's first round screening data, the latter allowing independent assessment of the two models. The overall expected proportion of low Gleason score tumours was 0.56 under Model I and 0.81 under Model II, whereas the observed proportion based on either ProtecT or ERSPC-Rotterdam was 0.69. Using the observed prevalence from ERSPC-Rotterdam, we estimated that 22, 33 and 66% of the tumours in men aged 55-59, 60-64 and 65-69 years, respectively, had the potential for progression in the preclinical phase. PSA-detected prostate cancers are a mixture of progressive and non-progressive tumours with respect to Gleason score. The former may potentially benefit from screening. Identifying cancers with the potential for progression is important to target screening.

Multifocal prostate cancer: biologic, prognostic, and therapeutic implications

Prostatic adenocarcinoma is the most common cancer diagnosed in men and is often multifocal. Ongoing controversy exists about the most appropriate system of tumor classification and grading and the optimal curative treatment approaches. This review examines recent progress in the pathogenesis of multifocal prostatic adenocarcinoma and its biologic, pathologic, prognostic, and therapeutic implications. Prostatic cancer multifocality makes accurate clinical staging difficult, and repeated revisions have been undertaken in an effort to optimize prognostic accuracy. Although the 2010 revision represents an improvement over the previous systems, the clinical significance of the T2 substaging is questionable. Also discussed is the potential impact of tumor multifocality and clonal heterogeneity on the oncologic efficacy of novel focal ablative approaches. The clinical significance of smaller secondary tumors and the relationship between extent of chromosomal abnormalities and the metastatic potential of an individual tumor focus were reviewed.

Survival in surgically treated, nodal positive prostate cancer patients is predicted by histopathological characteristics of the primary tumor and its lymph node metastases

BACKGROUND

Histopathological risk factors for survival stratification of surgically treated nodal positive prostate cancer patients are poorly defined as reflected by only one category for nodal metastases.

METHODS

We evaluated biochemical recurrence-free survival (RFS), disease-specific survival (DSS), and overall survival (OS) in 102 nodal positive, hormone treatment-naïve prostate cancer patients (median age: 65 years, range: 45-75 years; median follow-up 7.7 years, range: 1.0-15.9 years) who underwent radical prostatectomy and standardized extended lymphadenectomy.

RESULTS

A significant stratification was possible, with the Gleason score of the primary and virtually all nodal parameters favoring patients with better differentiated primaries and metastases, lower nodal tumor burden, and without extranodal extension of metastases. In multivariate analyses, diameter of the largest metastasis (< or =10 mm vs. >10 mm) was the strongest independent predictor for RFS (P < 0.001), DSS (P < 0.001), and OS (P < 0.001) with a more than quadrupled relative risk of cancer related deaths for patients with larger metastases (Hazard ratio: 4.2, Confidence interval: 2.0-8.9; 5-year RFS/DSS/OS: 18%/57%/54%). The highest 5-year survival rates were seen in patients with micrometastases only (RFS/DSS/OS: 47%/94%/94%).

CONCLUSION

The TNM classification's current allocation of only one category for nodal metastases in prostate cancers is unsatisfactory since subgroups with significantly different prognoses can be identified. The diameter of the patient's largest metastasis (< or =10 mm vs. >10 mm) should be used for substaging because of its independent prognostic value. The substage "micrometastasis only" is also useful in nodal positive prostate cancer since it designates the subgroup with the most favorable outcome.

Do Intraindividual Variation in Disease Progression and the Ensuing Tight Window of Opportunity Affect Estimation of Screening Benefits?

Background . The effects of variation in disease progression between individuals on the effectiveness of screening have been assessed extensively in the literature. For several diseases, progression may also vary within individuals over time. The authors study the effects of intraindividual variation and the combined effects of inter- and intraindividual variation in disease progression on the effectiveness of screening. Methods . The authors investigated the risk reduction of aneurysmal subarachnoid hemorrhage (SAH) achieved by screening for intracranial aneurysms in a simulation study as a function of the inter- and intraindividual variation in the risk of aneurysm rupture. They also extended a previously constructed Markov model for the cost-effectiveness analysis of screening for new aneurysms in patients with clipped aneurysms after SAH. A time-varying risk of aneurysm rupture was introduced, and the influence of this variation on cost-effectiveness was assessed. Results . The risk reduction provided by screening decreased with increasing intraindividual variation in disease progression. The expected number of prevented instances of SAH was overestimated by 58% in this simulation study when high degrees of inter- and intraindividual variation were present. Interindividual variation alone resulted in up to 33% overestimation and intraindividual variation in up to 43% overestimation. In the extended Markov model, screening benefits were overestimated by 24% when a high degree of intraindividual variation was present but ignored. Conclusions . If intraindividual variation in disease progression is ignored in decision models, subsequent cost-effectiveness analyses of screening strategies will overestimate the benefits provided by screening. This bias is comparable to, but partially independent of, the bias caused by ignoring interindividual heterogeneity.

Histopathological characteristics of lymph node metastases predict cancer-specific survival in node-positive prostate cancer

OBJECTIVE

To correlate the histopathological characteristics of lymph node metastases in prostate cancer with cancer-specific survival (CSS).

PATIENTS AND METHODS

The histopathological slides from 142 patients who had had a pelvic lymph node dissection for node-positive prostate cancer were reviewed. For each patient we recorded the number of lymph nodes removed, the number of positive nodes, the diameter of the largest metastasis and extranodal extension (ENE). The lymph node metastases were graded according to the Gleason system. These variables were correlated with CSS.

RESULTS

The mean age of the patients was 62.4 years and the mean preoperative prostate-specific antigen level was 40.2 ng/mL. The median follow-up was 77.5 months, and the median overall and CSS were 91 and 112 months, respectively. On univariable analysis the following variables correlated with poor CSS: a nodal Gleason score of >7 (hazard ratio 2.4, P < 0.001), a diameter of the largest metastasis of >3 mm (2.2, P = 0.025), more than two lymph node metastases (2.0, P = 0.003), and ENE in more than one lymph node (1.9, P = 0.014). Multivariable analysis showed only the nodal Gleason score and the diameter of the largest metastasis to be independent predictors of CSS (1.8, P = 0.021, and 2.2, P = 0.046, respectively).

CONCLUSION

The histopathological characteristics of lymph node metastases in prostate cancer have predictive value for the clinical outcome. The nodal Gleason score and the diameter of the largest metastasis are independent predictors of survival.

Change in prostate cancer grade over time in men followed expectantly for stage T1c disease

PURPOSE

We assessed whether the Gleason grade changes in men followed expectantly with nonpalpable prostate cancer diagnosed on needle biopsy (stage T1c).

MATERIALS AND METHODS

We studied 241 men with stage T1c prostate cancer who were treated expectantly with repeat yearly needle biopsy sampling to assess for cancer progression. Following the initial cancer diagnosis all men had at least 1 other biopsy demonstrating cancer.

RESULTS

Median patient age was 66 years. The number of biopsies showing cancer over time was 2 in 119 (49.4%), 3 in 74 (30.7%), 4 in 33 (13.7%) and 5 or greater in 15 (6.2%). The average followup for those without progression was 32.3 months. Of 241 cases 45 (18.7%) showed a significant change in grade from Gleason score 6 or less to Gleason score 7 or greater (Gleason score 7 in 41 cases, Gleason score 8 in 4 cases). Of 45 (53.5%) cases 24 that showed progression did so within 24 months of diagnosis.

CONCLUSIONS

Within the first 3 years after diagnosis of Gleason score 6 prostate cancer, there is a relatively low risk of grade progression. Within the first 3 years, our data suggest that in most cases tumor grade did not evolve but rather that the higher grade component was not initially sampled since most grade changes occurred relatively soon after biopsy. Grade progression does appear to occur in some men with long-term followup who had multiple biopsies showing Gleason score 6 followed by higher grade cancer.

Choices for Surgery

Surgical treatment of prostate cancer has seen many improvements in the past two decades, including laparoscopy, robotic surgery, and better assessment of quality of life and functional results. The limits of surgery for locally advanced disease and after failure of radiotherapy have been better defined, together with the roles of neoadjuvant and adjuvant treatment. Patients with clinically organ-confined prostate cancer, reasonable life expectancy, and little or no co-morbidity are the best candidates for radical prostatectomy. This chapter reviews the different technical options for the treatment of prostate cancer, with their respective indications and functional and oncological results.

Percentage of Gleason pattern 4 and 5 predicts survival after radical prostatectomy

BACKGROUND

Morphologic and clinical heterogeneity within tumor grades is well recognized in prostate cancer. The objective of the current study was to determine whether the combined percentage of Gleason patterns 4 and 5 in radical prostatectomy specimens is an independent predictor of cancer-specific survival in prostate cancer patients.

METHODS

The radical prostatectomy specimens were analyzed from 504 consecutive prostate cancer patients who were treated at Indiana University Medical Center between 1990 and 1998. Various clinical and pathologic characteristics were analyzed.

RESULTS

A higher combined percentage of Gleason patterns 4 and 5 was associated with older age, higher preoperative serum prostate-specific antigen level, higher pathologic stage, positive surgical margins, extraprostatic extension of tumor, higher Gleason score, perineural invasion, and lymph node metastasis. In the multivariate Cox regression model, the combined percentage of Gleason patterns 4 and 5 was found to be an independent predictor of cancer-specific survival (P = .04).

CONCLUSIONS

The combined percentage of Gleason patterns 4 and 5 is a powerful predictor of prostate cancer-specific survival. Assessment of high-grade cancer amounts may allow for better stratification of patients into appropriate prognostic groups and treatment protocols.

Gleason score, age and screening: modeling dedifferentiation in prostate cancer

Tumor differentiation as measured by the Gleason score is highly predictive of the course of prostatic cancer after diagnosis. Since the introduction of the prostate-specific antigen (PSA) test tumors are diagnosed with a favorable tumor stage and differentiation grade. Does screening with PSA just detect more tumors with favorable characteristics or is dedifferentiation actually being prevented by early detection and consequent treatment? The latter option implies that tumors dedifferentiate in the preclinical screen-detectable phase. To model the natural history of prostate cancer, we analyzed the age-specific distribution of clinical stage and Gleason score of 2,204 tumors diagnosed in the ERSPC-Rotterdam trial. We fitted 2 MISCAN simulation models to the observed data: Model I where tumors dedifferentiate before becoming screen-detectable and Model II where dedifferentiation occurs during the screen-detectable preclinical phase. The hypothesis of dedifferentiation during the screen-detectable phase was tested by a goodness of fit test of both models. In ERSPC-Rotterdam, we observed a significantly more favorable distribution of Gleason scores in screen-detected cancers compared to cancers found in the control arm, and in cancers detected in the second round compared to cancers detected in the first round of screening. Also, a significant association between Gleason score and age at diagnosis was found, most notably in cancers detected in the first round of screening. These findings were reproduced by Model II and less so by Model I, with a significant difference in goodness of fit between the 2 models (p < 0.001). This study provides epidemiological evidence of dedifferentiation as a major mechanism of progression in prostate cancer. Tumors dedifferentiate during the screen-detectable phase and consequently screening with PSA and early treatment can possibly prevent dedifferentiation.

Prognostic factors in lymph node-positive prostate cancer

OBJECTIVES

To characterize lymph node metastasis of prostate cancer (PCa) and identify the parameters associated with patient outcome. The incidence of clinically localized PCa with concurrent lymph node metastasis has decreased to less than 1% in the United States but is between 10% and 15% in other countries.

METHODS

Our study cohort of 1148 patients underwent radical prostatectomy in Ulm, Germany, between 1986 and 2002, and 201 (18%) had lymph node-positive PCa.

RESULTS

The metastases showed growth architecture resembling primary PCa. We assigned a Gleason pattern and evaluated for size, extranodal extension, and lymphovascular invasion (LVI). Of 201 patients, 155 had original pathology slides available; 36 of the 155 were excluded because of preoperative hormonal ablation therapy. Of the remaining 119 patients, 22 (19%) were assigned Gleason pattern 3, 93 (78%) Gleason pattern 4, and 4 (3%) Gleason pattern 5. Extranodal extension was present in 66 (55%) of 119 patients and LVI in 29 (25%). An increased risk of prostate-specific antigen (PSA) recurrence was found for Gleason pattern 4/5 (hazard ratio [HR] 2.5, P = 0.038), LVI in the lymph nodes (HR 1.9, P = 0.038), and nuclear grade of the primary tumor (HR 2, P = 0.025). Independent predictors of PSA recurrence included LVI and nuclear grade (HR 1.9, P = 0.03 and HR 2, P = 0.03, respectively).

CONCLUSIONS

Lymph node metastases of PCa are heterogeneous and have a close relation to the corresponding primary tumor. Most patients with lymph node-positive PCa remained disease free for up to 13 years after radical prostatectomy. Independent predictors of PSA recurrence among those with lymph node-positive PCa included LVI in the lymph nodes and the nuclear grade of the primary tumor. These parameters may be useful in predicting PSA recurrence in lymph node-positive PCa and could be included in patient follow-up.

Prognostic factors and reporting of prostate carcinoma in radical prostatectomy and pelvic lymphadenectomy specimens

This paper, based on the activity of the Morphology-Based Prognostic Factors Committee of the 2004 World Health Organization-sponsored International Consultation, describes various methods of handling radical prostatectomy specimens for both routine clinical use and research purposes. The correlation between radical prostatectomy findings and postoperative failure is discussed in detail. This includes issues relating to pelvic lymph node involvement, detected both at the time of frozen section and in permanent sections. Issues of seminal vesicle invasion, including its definition, routes of invasion and relationship to prognosis, are covered in detail. The definition, terminology and incidence of extra-prostatic extension are elucidated, along with its prognostic significance relating to location and extent. Margins of resection are covered in terms of their definition, the etiology, incidence and sites of positive margins, the use of frozen sections to assess the margins and the relationship between margin positivity and prognosis. Issues relating to grade within the radical prostatectomy specimen are covered in depth, including novel ways of reporting Gleason grade and the concept of tertiary Gleason patterns. Tumor volume, tumor location, vascular invasion and perineural invasion are the final variables discussed relating to the prognosis of radical prostatectomy specimens. The use of multivariate analysis to predict progression is discussed, together with proposed modifications to the TNM system. Finally, biomarkers to predict progression following radical prostatectomy are described, including DNA ploidy, microvessel density, Ki-67, neuroendocrine differentiation, p53, p21, p27, Bcl-2, Her-2/neu, E-cadherin, CD44, retinoblastoma proteins, apoptotic index, androgen receptor status, expression of prostate-specific antigen and prostatic-specific acid phosphatase and nuclear morphometry.

Local and systemic therapy for patients with metastatic prostate cancer: should the primary tumor be treated?

Data from well-designed, prospective clinical trials are lacking to support treatment of primary tumor in men diagnosed with metastatic prostate cancer. However, a growing body of evidence suggests that treatment of the primary tumor may enhance cancer control and survival in some men. This evidence is examined and recommendations are made for identifying patients with metastatic prostate cancer who may benefit from definitive treatment of the prostate tumor.

The Combined Percentage of Gleason Patterns 4 and 5 Is the Best Predictor of Cancer Progression After Radical Prostatectomy

Purpose

Clinical outcome is variable in prostate cancer patients treated with radical prostatectomy. The Gleason histologic grade of prostatic adenocarcinoma is one of the strongest predictors of biologic aggressiveness of prostate cancer. We evaluated the significance of the relative proportion of high-grade cancer (Gleason patterns 4 and/or 5) in predicting cancer progression in prostate cancer patients treated with radical prostatectomy.

Patients and Methods

Radical prostatectomy specimens from 364 consecutive prostate cancer patients were totally embedded and whole mounted. Various clinical and pathologic characteristics were analyzed. All pathologic data, including Gleason grading variables, were collected prospectively.

Results

A multiple-factor analysis was performed that included the combined percentage of Gleason patterns 4 and 5, Gleason score, tumor stage, surgical margin status, preoperative prostate-specific antigen (PSA), extraprostatic extension, and total tumor volume. Using Cox regression analysis with bootstrap resampling for predictor selection, we identified the combined percentage of Gleason patterns 4 and 5 (P < .0001) and total tumor volume (P = .009) as significant predictors of PSA recurrence.

Conclusion

The combined percentage of Gleason patterns 4 and 5 is one of the most powerful predictors of patient outcome, and appears superior to conventional Gleason score in identifying patients at increased risk of disease progression. On the basis of our results, we recommend that the combined percentage of Gleason patterns 4 and 5 be evaluated in radical prostatectomy specimens. The amount of high-grade cancer in a prostatectomy specimen should be taken into account in therapeutic decision making and assessment of patient prognosis.

Loss of 14-3-3sigma in prostate cancer and its precursors

PURPOSE

The 14-3-3 family proteins are highly conserved over many mammalian species. The sigma isoform (also called HME-1 or stratifin) is expressed in epithelial cells. Loss of 14-3-3sigma is associated with failure to arrest the cell cycle at the G(2)-M phase checkpoint after DNA damage that leads to increased G(2)-type chromosomal aberrations. The role of 14-3-3sigma in prostatic carcinogenesis is uncertain.

EXPERIMENTAL DESIGN

We studied one hundred and eleven specimens of invasive prostate adenocarcinoma with paired, adjacent high-grade prostatic intraepithelial neoplasia and normal prostate epithelium. Immunohistochemistry was used to detect the expression of 14-3-3sigma. The findings were correlated with various clinical pathological parameters.

RESULTS

14-3-3sigma is ubiquitously expressed at high levels in normal prostate epithelium. Its expression is significantly decreased in prostatic intraepithelial neoplasia and prostatic adenocarcinoma. Ninety percent of samples of prostatic intraepithelial neoplasia had no or low 14-3-3sigma expression. Ninety-seven percent of invasive adenocarcinomas had no or low 14-3-3sigma expression. In most specimens (90%), suppression of 14-3-3sigma expression occurred during the development of prostatic intraepithelial neoplasia from normal epithelium.

CONCLUSIONS

Our data suggest that loss of 14-3-3sigma contributes to the development of prostate adenocarcinoma. 14-3-3sigma expression is significantly decreased during the progression of normal prostatic epithelium to prostatic intraepithelial neoplasia and invasive cancer.

Predictors of metastatic disease in men with biochemical failure following radical prostatectomy

PURPOSE

We determined clinical and pathological predictors of positive bone scans and computerized tomography (CT) in patients with biochemical recurrence after radical prostatectomy (RP).

MATERIALS AND METHODS

A retrospective analysis of patients treated with RP at West Los Angeles Veterans Affairs Medical Center and University of California-Los Angeles Medical Center was performed to identify men with biochemical recurrence. All postoperative bone scans and pelvic CT following recurrence and prior to the initiation of hormone ablation therapy were reviewed. Preoperative clinical variables, pathological findings, serum prostate specific antigen (PSA) at postoperative imaging and postoperative PSA doubling time were compared between patients with positive and negative imaging study results.

RESULTS

A total of 128 patients with biochemical recurrence after RP who had postoperative pelvic CT or bone scans available were identified. A total of 97 bone scans were obtained, of which 11 (11%) were positive, and 71 CT scans were obtained, of which 5 (7%) were positive. Men with PSA doubling time less than 6 months were at increased risk of a positive bone scan (26% vs 3%) or positive CT (24% vs 0%) relative to men with longer PSA doubling time. In men with PSA doubling time less than 6 months the risk of a positive study highly depended on PSA at the time of imaging. In men with PSA less than 10 ng/ml the incidence of a positive study was 0% for pelvic CT and 11% for bone scan. In men with PSA greater than 10 ng/ml the risk of a positive study was 57% for pelvic CT and 46% for bone scan. In men with PSA doubling time greater than 6 months no clear relationship to PSA was seen, although the number of patients with a positive study was extremely low (positive bone scans 3% and positive CT 0%). However, none of the 6 imaging studies performed in men with PSA doubling times greater than 6 months and a markedly elevated PSA of 20 to 90 ng/ml was positive.

CONCLUSIONS

The risk of detecting metastatic disease by bone scan or pelvic CT in men with biochemical recurrence following RP with PSA doubling time greater than 6 months is low despite marked PSA increases up to 90 ng/ml. In men with PSA doubling time less than 6 months the risk of detecting metastatic disease markedly increases when PSA is greater than 10 ng/ml. These results have important implications for the timing of imaging in patients with biochemical recurrence following RP.

Upregulation and nuclear recruitment of HDAC1 in hormone refractory prostate cancer

BACKGROUND

Histone deacetylase 1 (HDAC1) is a co-repressor involved in differentiation and proliferation control. It is upregulated in malignant compared to benign tissue, and targets a number of transcription factors including p53.

METHODS

By immunohistochemistry, HDAC1 protein expression was investigated in human prostate specimens and the CWR22 mouse xenograft model. Flow cytometry and deconvolution immunofluorescence were also performed.

RESULTS

HDAC1 was upregulated in pre-malignant and malignant lesions, with the highest increase in expression in hormone refractory (HR) cancer. Using the CWR22 xenograft model we showed androgen dependent regulation of HDAC1. HDAC1 overexpression led to a significant increase in proliferation and a shift towards the undifferentiated cytokeratin (CK) profile in a PC3M derivative clone constitutively expressing HDAC1.

CONCLUSION

This study underlines the importance of HDAC1 in cell proliferation and the development of prostate cancer (CaP) and proposes a mechanism for HDAC1 nuclear recruitment. HDAC1 may constitute a crucial therapeutic target particularly in the most lethal phase of androgen independence.

Phenotypic heterogeneity of end-stage prostate carcinoma metastatic to bone

To better understand the clinical and pathologic features of end-stage, androgen-independent carcinoma of the prostate (CaP), we performed rapid autopsies on 14 men who died of progressive CaP and recorded relevant clinical data. The timing of tumor progression varied widely. The median time to androgen independence was 2 years (range, 4 months to 13.6 years). The median survival after androgen independence was 1 year (range, 1 month to 3.6 years). Because osseous metastases are prevalent in progressive CaP, up to 20 bone sites were systematically sampled in each patient. Bone metastases were widespread; tumor filled the marrow in an average of 14 bone sites. Tumor histology and expression of prostate-specific antigen (PSA) and chromogranin A (CGA) were examined in all metastases and were compared with the primary tumor. Five histological patterns of metastatic tumor were observed: solid (10 patients), macroacinar (1 patient), microacinar (1 patient), clear cell (1 patient), and comedocarcinoma (1 patient). Gleason grade of the primary tumor did not predict the histological pattern of the metastases. Although >70% of tumor cells expressed PSA, the fraction of PSA-positive cells varied widely in separate metastases in some patients (standard deviation >25). Likewise, the fraction of neuroendocrine (NE) (CGA-positive) tumor cells in different metastases varied widely. For example, between 0 and 95% of tumor cells in different metastases in 1 patient had a NE phenotype. The present study highlights the heterogeneity--histologically and immunophenotypically--of metastatic CaP. Consequently, therapy directed to the phenotype of 1 metastasis may have no effect on other metastases in the same patient because of phenotypic heterogeneity.

Pathologic assessment of the surgical specimen

Despite the wealth of information obtained by conventional histology, long-term studies are needed to provide novel information on the correlation of pathologic findings with prognosis. Findings need to be correlated not only with PSA progression but with the more clinically important parameters of distant metastases and survival. Although conventional histology still will have a role in the evaluation of prostate cancer at radical prostatectomy and its correlation with outcome, it undoubtedly will be augmented by newer techniques. These developments must be approached critically and rationally to determine whether they provide additional prognostic information beyond that currently available using more conventional parameters.

Risk of prostate carcinoma death in patients with lymph node metastasis

BACKGROUND

The presence of lymph node metastasis is a poor prognostic sign for patients with prostate carcinoma. Results of published reports on survival among patients with lymph node metastasis are difficult to assess because of treatment selections. The extent to which lymph node status will have an impact on a patient's survival is uncertain.

METHODS

The authors analyzed 3463 consecutive Mayo Clinic patients who underwent radical prostatectomy and bilateral pelvic lymphadenectomy for prostate carcinoma between 1987 and 1993. Of these patients, 322 had lymph node metastasis at the time of surgery, and 297 lymph node positive patients also received adjuvant hormonal therapy within 90 days of surgery. The progression free rate and the cancer specific survival rate were used as outcome endpoints in univariate and multivariate Cox proportional hazards models. The median follow-up was 6.3 years. Progression was defined by elevation of serum prostate specific antigen (PSA) > or = 0.4 ng/mL after surgery, development of local recurrence, or distant metastasis documented by biopsy or radiographic examination.

RESULTS

The 5-year and 10-year progression free survival rates (+/- standard error [SE]) for patients with lymph node metastasis were 74% +/- 2% and 64% +/- 3%, respectively, compared with 77% +/- 1% and 59% +/- 2%, respectively, for patients without lymph node metastasis. The 5-year and 10-year cancer specific survival rates were 94% +/- 1% and 83% +/- 4%, respectively, compared with 99% +/- 0.1% and 97% +/- 0.5%, respectively, for patients without lymph node metastasis. Among patients with a single lymph node metastasis, the 5-year and 10-year cancer specific survival rates were 99% +/- 1% and 94% +/- 3%, respectively. After adjustment for extraprostatic extension, seminal vesicle invasion, Gleason grade, surgical margins, DNA ploidy, preoperative serum PSA concentration, and adjuvant therapy, the hazard ratio for death from prostate carcinoma among patients with a single lymph node metastasis compared with patients who were without lymph node metastasis was 1.5 (95% confidence interval, 0.5-5.0; P = 0.478), whereas the hazard ratio for death from prostate carcinoma was 6.1 (95% confidence interval, 1.9-19.6; P = 0.002) for those with two positive lymph nodes and 4.3 (95% confidence interval, 1.4-13.0; P = 0.009) for those with three or more positive lymph nodes. There was no significant difference in the progression free survival rate among patients with or without lymph node metastasis in multivariate analysis after controlling for all relevant variables, including treatments (hazard ratio,1.0; 95% CI, 0.7-1.3; P = 0.90).

CONCLUSIONS

Patients with prostate carcinoma who have multiple regional lymph node metastases had increased risk of death from disease, whereas patients with single lymph node involvement appeared to have a more favorable prognosis after radical prostatectomy and immediate adjuvant hormonal therapy. Excellent local disease control was achieved by using combined surgery and adjuvant hormonal therapy in patients with positive lymph nodes.

Metastatic, sarcomatoid, and PSA- and PAP-negative prostatic carcinoma: diagnosis by fine-needle aspiration

Fine-needle aspiration of prostatic carcinoma usually yields an acinar carcinoma that is immunoreactive for prostatic-specific antigen (PSA) and prostatic acid phosphatase (PAP). We report on two FNAs of metastatic sarcomatoid prostatic carcinoma that were PSA- and PAP-negative. Our methods included a review of the medical records and pathology results. Both cases presented with elevated serum PSA levels and prostate needle biopsies with Gleason score 8 and 9 tumors, respectively. Both cases developed retroperitoneal/pelvic lymphadenopathy, and fine-needle aspirations were performed. These showed high-grade, sarcomatoid tumors with marked anisonucleosis. Immunocytochemical staining for PSA and PAP was negative in both cases. Clinical and radiologic evaluation failed to reveal any other potential primary sites. Metastatic, sarcomatoid, PSA- and PAP-negative prostatic carcinoma is a rare diagnosis of exclusion that should be considered in the characteristic clinical setting.