Focal irreversible electroporation for prostate cancer: functional outcomes and short-term oncological control

BACKGROUND

Current data on the use of irreversible electroporation (IRE) in the treatment of prostate cancer (PCa) is limited. We aim to evaluate the safety, short-term functional and oncological outcomes of focal IRE in low-intermediate risk PCa.

METHODS

Between February 2013 and May 2014, 32 consecutive men underwent IRE at a single centre. Patients with low-intermediate risk PCa who had not received previous PCa treatment were included for analysis. The tumour was ablated using 3-6 electrodes, ensuring a minimum 5-mm safety margin around the visible magnetic resonance imaging (MRI) lesion. Follow-up included recording Clavien complications, Expanded Prostate Cancer Index Composite (EPIC) questionnaires (baseline, 1.5, 3, 6 months), 6-month multi-parametric MRI (mp-MRI) and 7-month biopsy. Findings on mp-MRI and biopsy were sub-divided into infield, adjacent or outfield of the treatment zone.

RESULTS

Twenty-five men were included for final analysis. Safety follow-up revealed one Clavien Grade 3 complication and five Grade 1 complications. Functional follow-up confirmed no significant change in American Urological Association urinary symptom score, sexual or bowel function. Infield, there were no suspicious findings on mp-MRI (n=24) or biopsy (n=21) in all patients. Adjacent to the treatment zone, five (21%) had suspicious findings on mp-MRI with four (19%) proving to be significant on biopsy. Outfield, there were two (8%) with suspicious findings on mp-MRI and one (5%) significant finding on biopsy. For the five patients with significant findings on follow-up biopsy, one is awaiting repeat IRE, one had radical prostatectomy and three remained on active surveillance.

CONCLUSIONS

In selected patients with low-intermediate risk PCa, focal IRE appears to be safe with minimal morbidity. There were no infield recurrences and 76% of patients were histologically free of significant cancer at 8 months. Almost all recurrences were adjacent to the treatment zone, and this was addressed by widening the treatment margins.

Presence of mouse mammary tumour-like virus gene sequences may be associated with morphology of specific human breast cancer

BACKGROUND

Mouse mammary tumour virus (MMTV) has a proven role in breast carcinogenesis in wild mice and genetically susceptible in-bred mice. MMTV-like env gene sequences, which indicate the presence of a replication-competent MMTV-like virus, have been identified in some human breast cancers, but rarely in normal breast tissues. However, no evidence for a causal role of an MMTV-like virus in human breast cancer has emerged, although there are precedents for associations between specific histological characteristics of human cancers and the presence of oncogenic viruses.

AIM

To investigate the possibility of an association between breast cancer and MMTV-like viruses.

METHODS

Histological characteristics of invasive ductal human breast cancer specimens were compared with archival MMTV-associated mammary tumours from C3H experimental mice. The presence of MMTV-like env DNA sequences in the human breast cancer specimens was determined by polymerase chain reaction and confirmed by Southern hybridisation.

RESULTS

MMTV-like env gene sequences were identified in 22 of 59 (37.3%) human breast cancer specimens. Seventeen of 43 (39.5%) invasive ductal carcinoma breast cancer specimens and 4 of 16 (25%) ductal carcinoma in situ specimens had some histological characteristics, which were similar to MMTV-associated mouse mammary tumours. However, these similarities were not associated with the presence or absence of MMTV-like gene sequences in the human breast tumour specimens. A significant (p = 0.05) correlation was found between the grade of the human breast cancer and similarity to the mouse mammary tumours. The lower the grade, the greater the similarity.

CONCLUSION

Some human breast cancer specimens, in which MMTV-like env DNA sequences have been identified, were shown to have histological characteristics (morphology) similar to MMTV-associated mouse mammary tumours. These observations are compatible with, but not conclusive of, an association between the presence of MMTV-like env DNA sequences and some human breast cancers.

Downregulation of KAI1 mRNA in localised prostate cancer and its bony metastases does not correlate with p53 overexpression

Recent data have proposed that transcription of the KAI1 metastasis suppressor gene is directly mediated by p53 and that loss of KAI1 expression in advanced prostate cancer is simply due to loss of p53 function after mutation. To investigate this possibility, we have examined KAI1 mRNA (by in situ hybridisation) and p53 protein expression (by immunohistochemistry) as an indicator of wildtype or mutant p53, in a series of 77 paraffin-embedded prostate tissue samples, including post-mortem normal prostates (2), benign prostatic hyperplasia (10), localised cancer (grades 4-6, 25; grades 7-9, 21) and prostate-derived bony metastases (19). Overall, we confirmed that expression of KAI1 mRNA decreased from normal tissue, through localised cancer to bony metastases (P=0.055, tending to significance), while levels of p53 staining significantly increased with cancer progression (P=0.046). These were consistent with the possibility that loss of p53 function might be responsible for loss of KAI1 mRNA. However, by close examination of KAI1 and p53 in adjacent tissue sections, we found no correlation between decreased levels of KAI1 mRNA and overexpression of p53 protein (P=0.497). In addition, high levels of KAI1 mRNA could be identified in samples irrespective of p53 staining. Our data suggest that mutation of p53 is independent of the loss of KAI1 mRNA, and do not support a role for p53 in regulating the expression of KAI1.

Prognostic significance of pathologic features in localized prostate cancer treated with radical prostatectomy: implications for staging systems and predictive models

PURPOSE

Although predicting outcome for men with clinically localized prostate cancer (PC) has improved, the staging system and nomograms used to do this are based on results from the North American health system. To be internationally applicable, these models require testing in cohorts from a variety of different health systems based on the predominant PC case identification methods used.

PATIENTS AND METHODS

We studied 732 men with localized PC treated with radical prostatectomy and no preoperative therapy between 1986 and 1999 at one Australian institution to determine the effect of clinicopathologic features on disease-free survival.

RESULTS

Preoperative serum prostate-specific antigen (PSA) concentration, Gleason score, pathologic stage, and year of surgery were independent predictors of outcome. Although margin status demonstrated only a trend toward significance in multivariate modeling overall, it proved to be independent in subgroups based on later year of surgery (1986 to 1994 v 1995 to 1998), preoperative PSA of less than 10 ng/mL, and Gleason score > or = 7. Adjuvant radiation therapy improved disease-free survival rates in patients with multiple surgical margin involvement.

CONCLUSION

This work confirms the prognostic significance of pathologic stage, Gleason score, and preoperative serum PSA. In the context of a contemporaneous screening effect in Australia, these findings may have implications for methods that predict outcome following surgery as screening becomes more prevalent in a population. The independent prognostic effect of margin status may alter with an increase in the proportion of screening-identified PCs. Staging systems and nomograms that predict outcome following surgery require validation in cohorts with different health practices before being universally applied.

Frequent loss of estrogen receptor-beta expression in prostate cancer

The role of estrogen and its receptors in the etiology and progression of prostate cancer (PC) is poorly understood. In normal and malignant human prostate, estrogen receptor-alpha is expressed only in the stroma, whereas estrogen receptor-beta (ERbeta) is present in both normal stroma and epithelium. Because loss of ERbeta expression is associated with prostate hyperplasia in ERbeta-null mice, this study determined patterns of ERbeta expression in normal, hyperplastic, and malignant human prostate and associations with clinical outcome. Five normal prostates from organ donors and 159 radical prostatectomy specimens from patients with clinically localized PC were assessed for ERbeta expression using immunohistochemistry. ERbeta-positivity was defined as > or =5% of cells demonstrating nuclear immunoreactivity. All of the five normal prostates showed strong ERbeta-nuclear staining in >95% of the epithelium and 35% of the stromal cells. The number of ERbeta-positive cases declined to 24.2% (38/157) in hyperplasia adjacent to carcinoma and 11.3% (18/159) in PCs. ERbeta-positivity was related to decreased relapse-free survival (log-rank P = 0.04). Thus, loss of ERbeta expression is associated with progression from normal prostate epithelium to PC, whereas those cancers that retained ERbeta expression were associated with a higher rate of recurrence. These data identify the need to further investigate the potential role of ERbeta in the regulation of prostate epithelial cell proliferation and the functional consequences of decreased ERbeta expression in the evolution of PC.

Overexpression of the cell cycle inhibitor p16INK4A in high-grade prostatic intraepithelial neoplasia predicts early relapse in prostate cancer patients

Prostate cancer (PC) is the most commonly diagnosed male cancer in industrialized societies. No molecular markers of PC progression or outcome with proven clinical utility have been described. Because the loss of normal cell cycle control is an early event in the evolution of cancer, we sought to determine whether changes in expression of the cyclin-dependent kinase inhibitor, p16INK4A, predicted outcome in this disease. We screened a cohort of 206 patients with clinically localized PC treated with radical prostatectomy for overexpression of the INK4A gene, the product of which inactivates the G1-phase cyclin dependent kinases, Cdk4 and Cdk6. p16INK4A protein expression was evaluated by immunohistochemistry in areas of high-grade intraepithelial neoplasia (HGPIN), a precursor to invasive disease, and of cancer in the same specimen. Data were evaluated for disease relapse using the Kaplan-Meier method and in a Cox proportional hazards model by assessing p16INK4A status in areas of HGPIN and cancer with other variables of known clinical relevance. Overexpression of p16INK4A in HGPIN and cancer was correlated with, but independent of, pathological stage and was associated with early relapse in PC patients treated with radical prostatectomy (log-rank test, P < 0.001). In a multivariate model adjusted for Gleason grade, pretreatment prostate-specific antigen levels, pathological stage, and margin status, overexpression of p16INK4A in HGPIN was an independent predictor of disease relapse and increased the risk of recurrence 2.24-fold (95% confidence interval, 1.28-3.93). These data provide the first evidence for a prognostic marker in HGPIN. The clinical utility of p16INK4A status in stratifying patients for aggressive treatment very early in the disease process, potentially several years prior to the onset of invasive disease, requires further investigation.

Altered expression of androgen receptor in the malignant epithelium and adjacent stroma is associated with early relapse in prostate cancer

The molecular basis of androgen-independent prostate cancer is unknown; however, functional androgen receptor (AR) signaling is maintained after the acquisition of hormone-refractory disease. Because normal and malignant prostate epithelial cell proliferation is regulated by androgen stimulation via both the AR-positive stroma and epithelium, we sought to evaluate patterns of AR expression in these cells and to determine any relationships with prostate cancer progression. AR expression in the malignant epithelium and associated periepithelial and nonperiepithelial stroma was measured in a cohort of 96 patients with clinically localized prostate cancer treated with radical prostatectomy. Data were evaluated for disease relapse using the Kaplan-Meier method and in a Cox proportional hazards model with other variables of known clinical relevance, including Gleason score, pathological stage, clinical stage, and pretreatment prostate-specific antigen concentration. Concurrent overexpression of AR (> or = 70% positive nuclei) in the malignant epithelium and loss of AR immunoreactivity in the adjacent periepithelial stroma (< or = 30%) was associated with higher clinical stage (P = 0.01), higher pretreatment prostate-specific antigen level (P = 0.03), and earlier relapse after radical prostatectomy (log-rank P = 0.009). These data identify a pattern of AR expression in malignant epithelium and adjacent stroma that is associated with a poor clinical outcome in prostate cancer. Equally important, they identify the need to further investigate the mechanistic basis of loss of AR expression in the malignant stroma and its potential role in deregulation of prostate epithelial cell proliferation.

Relationship between expression of the KAI1 metastasis suppressor and other markers of advanced bladder cancer

Expression of a newly described inhibitor of tumour metastasis, KAI1, was examined in bladder cancer progression and compared with the expression of p53 and pRb, which are markers of advanced disease. KAI1 mRNA (by in situ hybridization) and protein levels (by immunohistochemistry) were examined in 135 paraffin-embedded bladder tissue sections. Significant decreases in KAI1 mRNA and protein levels were detected between normal and tumour tissue (p<0.001 and p=0.026, respectively), and between non-invasive and invasive tumours (p=0.046 and p<0.001, respectively). Loss of KAI1 protein expression was accompanied by a shift in staining pattern from a uniform distribution to a weaker, membranous or heterogeneous pattern. Normal tissue and low-grade tumours showed little p53 protein staining. High level staining (indicative of mutant p53) was associated with increased grade in non-invasive tumours (p=0.031) but was not significantly higher in invasive tumours. Whilst p53 protein staining increased with malignant progression and KAI1 mRNA expression decreased, there was no significant correlation between the two patterns (p=0.33, adjusted for group, p=0.18) or when only cancer samples were analysed (p=0.065, adjusted for group, p=0.26), even when taking into account overexpression of MDM-2 protein as a pathway for inactivation of p53. There was no correlation between loss of KAI1 mRNA expression and gain of abnormal pRb staining (p=0. 30, or adjusted for tumour samples only, p=0.59). These results suggest that loss of KAI1 expression is associated with invasive bladder cancer, but is not related to mutation of p53 or to loss of normal pRb expression.

Prognostic significance of p53 nuclear accumulation in localized prostate cancer treated with radical prostatectomy

The role of p53 in the pathogenesis of, and as a predictive biomarker for, localized prostate cancer (PCa) is contested. Recent work has suggested that patterns of p53 nuclear accumulation determined by immunohistochemistry are prognostic, whereas studies using other methods question the role of p53 mutations in predicting outcome. We studied 263 men with localized PCa treated with radical prostatectomy to determine whether p53 nuclear accumulation predicts relapse and disease-specific mortality. We combined two p53 immunohistochemistry scoring systems: (a) percentage of p53-positive tumor nuclei in all major foci of cancer within the prostate; and (b) clustering, where the presence of 12 or more p53-positive cells within a x 200 power field was deemed "cluster positive." Analysis was undertaken using chi2, Kruskal-Wallis, and Mann-Whitney tests for clinicopathological variables and the Kaplan-Meier method, log-rank test, and univariate and multivariate Cox regression modeling for evaluation of contribution to relapse and disease-specific survival. At mean follow-up of 55.1 months (range, 4.9-123.0 months), 39% (102 of 263) of patients had relapsed and 2.3% (6 of 253) had died of PCa. Pretreatment serum prostate-specific antigen concentration, pathological tumor stage, lymph node involvement, Gleason score, and p53 nuclear accumulation, as determined by either percentage score or cluster status, were independent predictors of relapse in multivariate analysis. Clustering of p53-positive cells distinguished between favorable and poor prognosis patients within the lowest p53-positive stratum (>0 to <2%) and was the most discriminatory threshold for predicting relapse in the entire cohort. p53 status predicted outcome in patients with a Gleason score of 5 and above but not those with a score of 4 and below. In patients treated with neoadjuvant hormonal therapy, p53 cluster positivity carried a 90% (19 of 21) risk of relapse by 36 months. All six patients who died from PCa in the period of the study exhibited p53 nuclear accumulation in 20% or more tumor nuclei. This study demonstrates strong relationships between p53 nuclear accumulation and relapse and disease-specific mortality in a large series of localized PCas. Furthermore, the presence of clusters of p53-positive nuclei delineates a group of patients with poor prognosis not identified by traditional scoring methods and supports the hypothesis that p53 dysfunction within PCa may exist in foci of tumor cells that are clonally expanded in metastases.

Case report 870. Schneckenbecken dysplasia, possibly a new variant

We report the case of a newborn with a lethal newborn skeletal dysplasia, in whom skeletal and morphologic findings resembled those in schneckenbecken dysplasia except that the projection of bone from the medial aspect of the iliac bones, resembling the "snail's" head, was absent. This could be accounted for by variability or genetic heterogeneity.

Cystic hamartoma of the renal pelvis

We describe three hitherto undocumented cases of renal lesion in the adult age group that share a similar site and histological features. They are three adult women, with a short clinical history of pain and an abdominal mass. A partial or complete nephrectomy resulted in clinical cure. All cases showed an intrarenal multicystic mass situated adjacent to the pelvicalyceal system. These vaguely circumscribed lesions had no true capsule and blended in with the adjacent renal parenchyma. The histological appearance was distinctive and characterised by disorderly biphasic proliferation of epithelial and mesenchymal elements. The epithelial component consisted of tubules and cysts lined by cuboidal and columnar epithelium showing focal oncocytic changes. The stroma was cellular and predominantly fibroblastic with scattered bundles of smooth muscle cells. Despite extensive sampling, blastemal cells were not identified. The tubular epithelium was positive for CAM 5.2, epithelial membrane antigen, carcinoembryonic staining, and vimentin immunostaining. The stroma stained positively for vimentin and smooth muscle bundles for alpa smooth muscle actin and desmin. The cytological appearances of these lesions were benign. We propose that these are benign hamartomatous lesions arising as a result of faulty focal embryogenesis. They are distinct from well recognised lesions such as multilocular cysts, partially differentiated nephroblastomas, mesoblastic nephromas, and nephrogenic adenofibromas.

Multifocal endometrial type carcinoma involving 5 primary sites in the pelvis

A case of widespread endometrioid carcinoma is reported. The concept of multifocal carcinoma in the pelvis is discussed.

Metastatic adenocarcinoma of the cervix presenting as an inflammatory breast lesion

The occurrence of an inflammatory breast lesion and wide-spread venous thrombosis in a woman with metastatic adenocarcinoma of the endocervix is reported. Examination of biopsy specimens showed the inflammatory breast mass to be histologically consistent with metastasis from the endocervix. Recurrent venous thrombosis requiring large doses of heparin for control of the phlebitis was also a feature of this patient's illness. The disease was associated with elevation of serum CA 125 levels that did not parallel the patient's clinical course.

Widespread pulmonary fibrosis as a major clinical manifestation of chronic graft-versus-host disease

A 20-year-old Chinese male given an HLA-identical sibling bone marrow transplant for severe aplastic anemia, who had previously had chronic graft-versus-host disease (GVHD) of the mouth, developed myasthenia gravis and widespread pulmonary infiltrates with cough and exertional dyspnea at day 820 post-transplant. There was nothing to suggest aspiration pneumonia. Lung histology at day 940 showed some areas of dense pulmonary fibrosis, some areas of normal parenchyma, and some areas of widening of the interstitium and a mild lymphocytic infiltrate. Evidence of infection was not found. Treatment with cyclosporin and prednisone resulted in slow partial resolution of the infiltrates over 5 months. The myasthenia gravis was controlled with pyridostigmine. In view of the association with myasthenia gravis, of the absence of infectious agents and the response to immunosuppression, we conclude that widespread pulmonary fibrosis can be a major clinical manifestation of chronic GVHD. Examination of lung tissue to distinguish this from infective interstitial pneumonitis is essential.

Spermatocytic seminoma of testis with sarcomatous transformation. A report of five cases

Five cases of spermatocytic seminoma of the testis associated with a sarcomatous component, one of them of rhabdomyosarcomatous type, are presented. No recognizable teratomatous structures were identified in any of the cases. The presence of the sarcomatous elements transformed the usually innocuous spermatocytic seminoma into a highly aggressive neoplasm, which led to the patients' death in at least two cases. The sarcomatous elements may represent a nonseminomatous germ cell component, but we prefer to view them as an expression of anaplastic transformation of the tumors, analogous to that seen in tumors in other organs.

Antihypertensive effect of plasma volume expansion in pregnancy-associated hypertension

Plasma and total extracellular fluid volume expansion was confirmed in normal pregnant women in the third trimester of pregnancy. The plasma volume contraction of pregnancy-associated hypertension (pre-eclampsia) was found to be associated with an increase in the interstitial compartment of extracellular fluid volume. The infusion of a plasma volume expander produced significant amelioration of hypertension for 48 h associated with partial reversal of the disturbance of fluid distribution. This finding confirms the central place of volume contraction in maintenance of elevated blood pressure in pregnancy-associated hypertension.