MicroRNAs in prostate cancer: from biomarkers to molecularly-based therapeutics

MicroRNAs (miRNAs) are effective regulators of gene expression that have a significant role in the pathogenesis of prostate and various other cancers. The high prevalence of aberrant miRNA expression in prostate cancer, and miRNAs' distinctive properties, give much hope that they can be used as biomarkers and next generation of molecular anticancer therapeutics. Herein, we review the literature on miRNA involvement in prostate cancer pathogenesis and the current understanding of their role as oncogenes, tumor suppressors and metastasis-regulators. We also review the latest research on miRNAs in prostate cancer preclinical studies and clinical trials, and highlight the advantages and challenges of possible miRNA-based therapies. The emerging information regarding the biology of miRNAs in prostate cancer is promising, and may lead to a role(s) for these molecules as diagnostic/prognostic markers and effective therapeutic tools for better molecularly targeted treatment of prostate cancer.

Got central prostate pathology review? A cross-sectional audit of 2009 versus 2003 outcomes

196

Background: Prostate cancer is the most common non-cutaneous cancer in Canadian men; over 24,000 will be newly diagnosed and 4,300 will die from it in 2010. Estimating an individual's risk of disease spreading across the capsule and probability of recurrence with different treatment modalities is common practice in prostate cancer management and often drive the choice or extent of treatment options. A strong predictor of recurrence and organ confined disease is tumor grade. The literature recognizes differences in grading prostate cancer between genitourinary and non-specialized pathologists; we previously reported a 30% change in risk category (Low, GS 2-6; Int., GS 7; High, GS 8-10). However, this report was based on data from 2003/2004. A repeat audit was necessary given Gleason grading practice changes following the 2005 ISUP Consensus Conference.

Methods: Log books from 2009/10 where our Genitourinary Pathologists (GUP) reviewed prostate needle core biopsies were used to identify cases; a retrospective chart review was completed. The following variables were extracted: 1° Gleason score; 2° Gleason score; number of sites; % Gleason 4/5 pattern (overall); perineural invasion (present/absent); extracapsular extension (present/absent). Descriptive statistics were used to summarize the results.

Results: The charts of 132 patients having a GUP biopsy review were extracted. Seventeen percent (22/132) of cases changed risk category. Of the 47 low risk cases, 23% (11/47) were up-graded in risk category (21% by 1 category; 2% by 2 categories). Of the 46 intermediate risk cases, 15% (7/46) were up-graded and 2% (1/46) were down-graded. Of the 39 high risk cases, only 8% (3/39) were down-graded by 1 risk category. Comparatively, there was a 43% reduction in risk category change between 2003/04 (30%) and 2009/10 (17%).

Conclusions: Despite this reduction, a clinically significant proportion of patients changed pathologic risk category upon GUP review. Thus, it is recommended that prostate cancer pathology be routinely reviewed by a GUP as a best practice to optimize management and quality of care. Strategies are still needed to address disparities in pathologic grading and represent a potential area for further investigation.

No significant financial relationships to disclose.

Three-dimensional ultrasound-based spectroscopic imaging for detection of prostate cancer in men

57

Background: The objective of this translational research was to investigate the use of real-time novel three-dimension, quantitative ultrasound-based spectroscopic imaging of the prostate as a means of cancer detection.

Methods: Ten patients with T2-3 prostate cancer underwent a 6-9 MHz trans-rectal ultrasound scan of the prostate prior to radical prostatectomy. Equally spaced axial ultrasound images (0.5 cm separation) corresponding elasticity and spectroscopy data were collected in each patient. Colour-coded spectroscopic parametric maps of 0-Mhz intercept (0-Mhz), mid-band fit (MBF) and slope of line of best fit (slope) were generated indicating where the disease in the prostate gland is hypothetically located. Quantitative data (% volume of cancer over the prostate gland) were compared to whole-mount radical prostatectomy histopathology maps to determine the sensitivity and accuracy in parametrically delineating prostate cancer.

Results: Representative data indicate spectral changes were associated with the presence of co-incident disease as located on correlative histopathology whole mount sections. Of the 10 patients enrolled, 7 have been analyzed and presented here. The mean % difference between 0-MHz and MBF, with H&E, was 14% (SD 38%) and 21% (SD 24%), respectively. Gross areas of disease were readily visualized in ultrasound parametric maps and corresponded to a maximum 10dB decrease in 0-MHz or MBF. Parametric maps generated from the spectral slope offered no discrimination of disease.

Conclusions: Initial results suggest that there is good correlation between spectroscopic maps with disease on whole-mount specimens. This method may ultimately permit ultrasound-guided targeted biopsies to improve detection rates and non-invasive assessment of disease for radiotherapy planning.

No significant financial relationships to disclose.

How much does Gleason grade of follow-up biopsy differ from that of initial biopsy in untreated, Gleason score 4-7, clinically localized prostate cancer?

OBJECTIVE

To compare histologic grades between an initial biopsy and a follow-up biopsy in untreated, Gleason score (GS) 4-7, clinically localized prostate cancer.

METHODS AND MATERIALS

In a prospective single-arm cohort study, clinically localized, GS 4-7, prostate cancer was managed with active surveillance alone, provided that a pre-defined definition of disease progression was not met. One hundred five (63%) of a total of 168 eligible patients underwent a follow-up prostate biopsy during surveillance. Median time to a follow-up biopsy was 22 months (range: 7-81). Histologic grades between these two biopsies were compared to evaluate the extent of histologic grade change.

RESULTS

On the follow-up biopsy, GS was unchanged in 33 patients (31%), upgraded in 37 (35%), and downgraded in 34 (32%). Eleven (10%) had upgrading by 2 Gleason points or more. Eight (8%) had upgrading to GS 8 (none to GS 9 or 10); of these, six were among those with upgrading by 2 Gleason points or more. Twenty-seven (26%) had no malignancy on the follow-up biopsy. Negative follow-up biopsy was more prevalent in patients with a small volume of malignancy in the initial biopsy and a low baseline PSA.

CONCLUSIONS

No consistent change in histologic grade was observed on the follow-up biopsy at a median of 22 months in untreated, GS 4-7, clinically localized prostate cancer. Upgrading to GS > or =8 or by 2 Gleason points or more was relatively uncommon.

Expression of the TMPRSS2:ERG fusion gene predicts cancer recurrence after surgery for localised prostate cancer

The prostate-specific gene, TMPRSS2 is fused with the gene for the transcription factor ERG in a large proportion of human prostate cancers. The prognostic significance of the presence of the TMPRSS2:ERG gene fusion product remains controversial. We examined prostate cancer specimens from 165 patients who underwent surgery for clinically localised prostate cancer between 1998 and 2006. We tested for the presence of TMPRSS2:ERG gene fusion product, using RT–PCR and direct sequencing. We conducted a survival analysis to determine the prognostic significance of the presence of the TMPRSS2:ERG fusion gene on the risk of prostate cancer recurrence, adjusting for the established prognostic factors. We discovered that the fusion gene was expressed within the prostate cancer cells in 81 of 165 (49.1%) patients. Of the 165 patients, 43 (26.1%) developed prostate-specific antigen (PSA) relapse after a mean follow-up of 28 months. The subgroup of patients with the fusion protein had a significantly higher risk of recurrence (58.4% at 5 years) than did patients who lacked the fusion protein (8.1%, P<0.0001). In a multivariable analysis, the presence of gene fusion was the single most important prognostic factor; the adjusted hazard ratio for disease recurrence for patients with the fusion protein was 8.6 (95% CI=3.6–20.6, P<0.0001) compared to patients without the fusion protein. Among prostate cancer patients treated with surgery, the expression of TMPRSS2:ERG fusion gene is a strong prognostic factor and is independent of grade, stage and PSA level.

A genome-wide association screen identifies regions on chromosomes 1q25 and 7p21 as risk loci for sporadic prostate cancer

We conducted a genome-wide association study of 3090 sporadic prostate cancer patients and controls using the Affymetrix 10 000 SNP GeneChip. Initial screening of 40 prostate cancer cases and 40 non-cancer controls revealed 237 SNPs to be associated with prostate cancer (P<0.05). Among these SNPs, 33 were selected for further association analysis of 2069 men who had undergone a cancer-screening prostate biopsy. Results identified five loci as being significantly associated with increased prostate cancer risk in this larger sample (rs 1930293, OR=1.7, P=0.03; rs 717809-2p12, OR=1.3, P=0.03; rs 494770-4q34, OR=1.3, P=0.01; rs 2348763-7p21, OR=1.5, P=0.01; rs 1552895-9p22, OR=1.5, P=0.002). To validate these association data, 61 additional HapMap tagSNPs spanning the latter five loci were genotyped in this subject cohort and an additional 1021 men (total subject number=3090). This analysis revealed tag SNP rs 4568789 (chromosome 1q25) and tag SNP rs 13225697 (chromosome 7p21) to be significantly associated with prostate cancer (P-values 0.009 and 0.008, respectively). Haplotype analysis revealed significant associations of prostate cancer with two allele risk haplotypes on both chromosome 1q25 (adjusted OR of 2.7 for prostate cancer, P=0.0003) and chromosome 7p21 (adjusted OR of 1.3, P=0.0004). As linkage data have identified a putative prostate cancer gene on chromosome 1q25 (HPC1), and microarray data have revealed the ETV1 oncogene to be overexpressed in prostate cancer tissue, it appears that chromosome 1q25 and 7p21 may be sites of gene variants conferring risk for sporadic and inherited forms of prostate cancer.

Comparison of histologic grade between initial and follow-up biopsy in untreated, low to intermediate grade, localized prostate cancer

OBJECTIVE

To examine the change of histologic grade of untreated, low to intermediate grade, clinically localized prostate cancer over time on repeat prostate biopsy.

METHODS AND MATERIALS

In a prospective single-arm cohort study, patients were managed with observation alone unless they met pre-defined criteria of disease progression (PSA, clinical or histologic progression). Sixty-seven (54%) of a total of 123 eligible patients underwent follow-up prostate biopsy. Median time to the follow-up biopsy was 22 months (range: 7-60).

RESULTS

On the follow-up biopsy, Gleason score was unchanged in 20 patients (30%), upgraded in 19 (28%), and downgraded in 27 (40%). Twenty-one (31%) had no malignancy on the follow-up biopsy. Sixteen (37%) of 43 patients with < or = 2 positive cores on the initial biopsy had negative follow-up biopsy, while only 2 (11%) out of 18 with > or = 3 positive cores on the initial biopsy did. Five (7%) patients were upgraded to Gleason score 8. There was no correlation between the extent of grade change and baseline variables (age, clinical stage, and initial PSA) as well as PSA doubling time.

CONCLUSIONS

There was no consistent histologic upgrade on the follow-up biopsy at a median of 22 months in untreated, low to intermediate grade, clinically localized prostate cancer.

Is there a progression of histologic grade from radical prostatectomy to local recurrence in patients with clinically isolated local recurrence following surgery?

OBJECTIVE

To evaluate whether there is any histologic progression from radical prostatectomy (RP) to local recurrence in patients with clinically isolated local recurrence following RP.

METHODS AND MATERIALS

A total of 43 patients with clinically isolated, biopsy proven, local recurrence following RP were retrospectively analyzed with respect to the change in Gleason score (GS) from RP to local recurrence. Central pathology review was undertaken for both RP and local recurrence biopsy specimens. The changes in primary and secondary Gleason grade (GG), and any potential correlation between the extent of GS change and other variables were also examined.

RESULTS

Median age at the time of local recurrence was 67 years (range: 55-78). Median interval between RP and local recurrence was 3.6 years (range: 0.3-17.7). Eight had a short course (<3 months) of hormone therapy prior to RP. Initial GS of RP specimens was 5, 6, 7, 8, and 9 in 1, 3, 29, 1, and 9 patients, respectively. At the time of local recurrence, GS was upgraded in 13, unchanged in 23, and downgraded in 7. The extent of GS change was correlated with the interval between RP and local recurrence, but not with pathological T stage or age.

CONCLUSION

There was no statistically significant change in GS from RP to local recurrence, although there was a trend toward a higher GS at the time of local recurrence. The extent of GS change was associated positively with the elapsed time to local recurrence.

Predicting progression in IgA nephropathy

Immunoglobulin A (IgA) nephropathy is one of the most common primary types of glomerulonephritis to progress to end-stage renal disease. Its variable and often long natural history makes it difficult to predict outcome. We investigated the association of the rate of renal function decline based on the slope of creatinine clearance over time with demographic, clinical, laboratory, and histological data from 298 patients with biopsy-proven IgA nephropathy with a mean follow-up of 70 months. Using univariate analysis, urinary protein excretion at baseline and Lee pathological grading, as well as mean arterial pressure (MAP) and urinary protein excretion during follow-up, were associated with the rate of deterioration in renal function. Of these, only MAP and urinary protein excretion during follow-up were identified as independent factors by multiple linear regression analysis. The combination of best accuracy of prediction and shortest observation time using these two parameters was reached between the second and third years of follow-up. A semiquantitative method of estimating the rate of progression by using these factors was developed. These results indicate that MAP and severity of proteinuria over time are the most important prognostic indicators of IgA nephropathy. The potential relevance of the algorithm in patient management is shown.

Pre-natal and peri-natal exposures and risk of testicular germ-cell cancer

The present case-control study was undertaken to investigate the association between exposure to maternal hormones and risk of testicular germ-cell cancer by histologic subgroups. Cases were males, aged 16 to 59 years, diagnosed with testicular germ-cell cancer in Ontario between 1987 and 1989. Histologic review was performed on all eligible cases for the purpose of categorizing cases as seminoma or non-seminoma (the latter classified 2 ways, with and without tumors containing seminoma). Risk factor data were collected on 502 cases, 346 case mothers, 975 age-matched controls, and 522 control mothers. Exogenous hormone exposure was associated with elevated risk (OR = 4.9, 95% CI 1.7-13.9). Several additional risk factors were associated with risk of testicular cancer: bleeding and threatened miscarriage (OR = 0.6, 95% CI 0.3-1.0), maternal cigarette smoking (12+ cigarettes/day OR = 0.6, 95% CI 0. 4-1.0). pre-term birth (OR = 1.6, 95% CI 1.0-2.5), and treatment for undescended testicle (OR = 8.0, 95% CI 3.2-20.0). First births were associated with elevated risk (OR = 1.7, 95% CI 1.0-2.8) among mothers below the age of 24 years at conception. There was little evidence that risk factors differed by histologic subgroup. We found evidence that exposure to maternal hormones, particularly estrogens, is associated with testicular germ-cell cancer risk. Not only does exposure to elevated levels (exogenous hormone use, pre-term birth, and first births among young mothers) increase risk but also exposure to relatively lower levels (heavy cigarette consumption and, perhaps, bleeding and threatened miscarriage) may decrease cancer risk.

Development of focal segmental glomerulosclerosis in the renal allograft of a patient with lupus

Nephritis has been a recognized complication of systemic lupus erythematosus since the early 1900s. Almost all lupus patients have some degree of renal involvement related to their condition, but a considerably smaller proportion of these patients actually progress to end-stage renal disease (ESRD). However, lupus patients are also susceptible to other primary renal insults that may significantly contribute to the deterioration in their renal function. We present a case of a patient with clinical and pathological evidence of lupus nephritis that progressed to ESRD and subsequently developed "recurrent" focal segmental glomerulosclerosis in her transplant kidney. Retrospective clinicopathologic correlation suggested the possibility of more than 1 primary renal process that eventually led to her dialysis-dependent state. This case illustrates the importance of meticulously examining both clinical and renal biopsy data in patients with lupus nephritis and considering the presence of co-existing renal pathologies to resolve an otherwise discordant picture of disease progression. These considerations may have important therapeutic and prognostic implications.

Prognostic factors for relapse in stage I testicular seminoma treated with surveillance

PURPOSE

We sought to identify prognostic factors predictive of disease progression in patients with clinical stage I seminoma on surveillance following orchiectomy.

MATERIALS AND METHODS

Between January 1981 and December 1993, 201 patients 20 to 86 years old (median age 34) with clinical stage I seminoma were placed on surveillance following orchiectomy. The potential prognostic factors studied included age, tumor size, mitotic count, S phase fraction, ploidy, presence of small vessel invasion, syncytiotrophoblasts and tumor infiltrating lymphocytes, expression of beta-human chorionic gonadotropin and low molecular weight keratin on immunohistochemistry.

RESULTS

With a median followup of 6.1 years (range 1.3 to 12.3) 31 patients had relapse for an actuarial 5-year relapse-free rate of 84.9%. The 5-year actuarial survival rate was 97.1% and the cause specific survival rate was 99.5%. On univariate analysis factors predictive of relapse were tumor size (5-year relapse-free rate 88 and 67% for tumors 6 cm. or less and greater than 6 cm., respectively, p = 0.004), age (5-year relapse-free rate 79 and 91% for age 34 years or younger versus older than 34 years, respectively, p = 0.009) and presence of small vessel invasion (5-year relapse-free rate 86 versus 69%, p = 0.01). On multivariate analysis age and tumor size were predictive of relapse, while small vessel invasion approached statistical significance. The risk of relapse in 57 patients with none of the 3 adverse prognostic factors (age greater than 34 years, tumor 6 cm. or smaller and no small vessel invasion) was 6%.

CONCLUSIONS

We identified age, size of the primary tumor and small vessel invasion as important prognostic factors for relapse in patients with stage I seminoma treated with surveillance. Further followup and assessment of biological factors are needed to optimize selection of patients at a high risk for relapse who should receive immediate postoperative therapy.

alpha-smooth muscle actin and collagen deposition in dysfunctional renal transplants

In normal kidneys, alpha-smooth muscle actin and collagen type III expression is restricted to vascular smooth muscle cells and perivascular fibrous tissues, respectively, but in pathological conditions their expression or deposition is more extensive. Using immunohistochemistry, we examined the expression of alpha-smooth muscle actin and type III collagen in 31 human renal transplant biopsy specimens obtained from patients with graft dysfunction. We found that dysfunctional renal transplants have increased alpha-smooth muscle actin and collagen III expression in the glomerulus and interstitium, but only glomerular alpha-smooth muscle actin expression correlates with graft function and prognosis.

Diagnosis and management of urethral sarcoidosis

We report on a woman with urethral sarcoidosis with obstructive urinary symptoms and previously known systemic sarcoidosis. The diagnosis of this rare lesion and management are discussed, and the genitourinary manifestations of sarcoidosis are reviewed.

Successful removal of an unusual cystic mass of the heart

A patient presented with a very unusual multicystic cardiac mass that echocardiographically mimicked an echinococcal cyst. The management of this patient is highlighted, including the clinical diagnosis, investigation, surgical management, pathological studies and review of the relevant literature.

Giant fibroepithelial polyps of the female urethra: two case reports and review of the literature

Fibroepithelial polyps are one of the less common obstructive lesions of the female urethra. The authors describe two cases of giant fibroepithelial polyps in paraplegic women. Both patients had a history of long-term indwelling catheterization to manage neurogenic bladder. The chronic irritation caused by the catheters was thought to be responsible for the development of the polyps. Resection is required in these cases to relieve the urethral obstruction and eliminate the possibility of malignant disease.

A study of post-orchiectomy surveillance in stage I testicular seminoma

A study of post-orchiectomy surveillance without radiation therapy was done in patients with histologically pure seminoma apparently confined to the testicle. Criteria for study entry included a negative physical examination, chest x-ray, bipedal lymphogram, excretory urogram, abdomino-pelvic computerized tomography scan and serum alpha-fetoprotein. Followup consisted of frequent clinical examination, repeat lymphograms, abdominal computerized tomography scans, chest x-rays and serum markers. The purpose of this study was to determine the percentage of patients cured by orchiectomy alone, percentage who ultimately required therapy for occult metastases beyond the testicle, sites of relapse, factors predictive of relapse, and over-all cure rate and treatment morbidity. Of 81 patients followed for 3 to 43 months (median 19 months) only 3 had relapse at 3, 5 and 18 months after orchiectomy with nonbulky retroperitoneal disease: 1 patient had disease 17 months after salvage infradiaphragmatic radiation therapy, 1 had an increase in beta-human chorionic gonadotropin 11 months after radiation therapy, presumably due to occult nonseminoma, and he is receiving chemotherapy, and 1 has not yet completed treatment. Further followup is necessary to determine ultimate survival, since a risk for later relapse exists. However, to date it does not appear as if the outcome has been compromised when surveillance was applied in place of routine adjuvant radiotherapy.

Nephrotic syndrome and renal failure secondary to lithium carbonate therapy

Images