Genomic analyses of tropical beef cattle fertility based on genotyping pools of Brahman cows with unknown pedigree

We introduce an innovative approach to lowering the overall cost of obtaining genomic EBV (GEBV) and encourage their use in commercial extensive herds of Brahman beef cattle. In our approach, the DNA genotyping of cow herds from 2 independent properties was performed using a high-density bovine SNP chip on DNA from pooled blood samples, grouped according to the result of a pregnancy test following their first and second joining opportunities. For the DNA pooling strategy, 15 to 28 blood samples from the same phenotype and contemporary group were allocated to pools. Across the 2 properties, a total of 183 pools were created representing 4,164 cows. In addition, blood samples from 309 bulls from the same properties were also taken. After genotyping and quality control, 74,584 remaining SNP were used for analyses. Pools and individual DNA samples were related by means of a "hybrid" genomic relationship matrix. The pooled genotyping analysis of 2 large and independent commercial populations of tropical beef cattle was able to recover significant and plausible associations between SNP and pregnancy test outcome. We discuss 24 SNP with significant association ( < 1.0 × 10) and mapped within 40 kb of an annotated gene. We have established a method to estimate the GEBV in young herd bulls for a trait that is currently unable to be predicted at all. In summary, our novel approach allowed us to conduct genomic analyses of fertility in 2 large commercial Brahman herds managed under extensive pastoral conditions.

Using CRP to predict anastomotic leakage after open and laparoscopic colorectal surgery: is there a difference?

AIM

C-reactive protein (CRP) has proven to be a useful adjunct in early diagnosis of anastomotic leak (AL) after colorectal surgery. It would be of considerable value to examine whether modality of surgery has influence upon postoperative CRP serum levels and their predictive value in the diagnosis of AL.

METHODS

All patients undergoing elective colorectal surgery with anastomosis were enrolled into a prospective database between 2011 and 2014. AL was defined with strict operative and radiological criteria. Outcomes between open and laparoscopic resections were assessed statistically and Receiver Operating Characteristic (ROC) curve analysis performed.

RESULTS

Seven hundred twenty-seven patients with an intestinal anastomosis were identified including 468 laparoscopic procedures (468/727; 64 %). There were 58 anastomotic leaks (58/727; 7.9 %) of which 29 (6.2 %) were laparoscopic and 29 (11.2 %) were open. Mean CRP levels were significantly higher in patients after open surgery compared with laparoscopic both with AL (p = 0.013), and without (p = 0.02). ROC curve analysis revealed postoperative day 3 (cut-off CRP 209) and day 4 (cut-off CRP 123.5) to be most predictive of leak in the open group with an area under the curve (AUC) 0.794 (sensitivity 80 %, specificity 80 %) and AUC 0.806 (sensitivity 94 %, specificity 60 %), respectively. In the laparoscopic group, day 2 proved to be the most accurate day for detection of leak with a cut-off CRP of 146.5 showing 75 % sensitivity and a 70 % specificity (AUC 0.766).

CONCLUSION

CRP levels are higher after open surgery compared with laparoscopic surgery, both with and without AL. AL generates a significant detectable increase in CRP within 2-4 days after surgery.

Analysis of the genetic phylogeny of multifocal prostate cancer identifies multiple independent clonal expansions in neoplastic and morphologically normal prostate tissue

Genome-wide DNA sequencing was used to decrypt the phylogeny of multiple samples from distinct areas of cancer and morphologically normal tissue taken from the prostates of three men. Mutations were present at high levels in morphologically normal tissue distant from the cancer, reflecting clonal expansions, and the underlying mutational processes at work in morphologically normal tissue were also at work in cancer. Our observations demonstrate the existence of ongoing abnormal mutational processes, consistent with field effects, underlying carcinogenesis. This mechanism gives rise to extensive branching evolution and cancer clone mixing, as exemplified by the coexistence of multiple cancer lineages harboring distinct ERG fusions within a single cancer nodule. Subsets of mutations were shared either by morphologically normal and malignant tissues or between different ERG lineages, indicating earlier or separate clonal cell expansions. Our observations inform on the origin of multifocal disease and have implications for prostate cancer therapy in individual cases.

Lessons learnt in the management of primary invasive penile cancer in an Australian tertiary referral centre: clinical outcomes with a minimum 48 months follow-up study

Purpose

To report on lessons learnt in the management of primary invasive penile cancer in a major tertiary hospital in Australia.

Materials and Methods

Medical records for all patients who underwent surgery for primary invasive penile cancer between January 2000 and January 2011 were obtained. Patient demographics, clinical status of inguinal node, cancer stage and clinical outcomes were reviewed. All patients were followed up for a minimum of 48 months postoperative unless patient deceased within the first 48 months from the time of penile cancer surgery.

Results

Over the 11-year period, a total of 23 cases of invasive penile cancer were identified. Partial penectomy was the most common form of organ preserving surgery and the majority of patients have pT1b disease. Of the 9 patients with clinically palpable inguinal nodes, 7 patients were diagnosed with pN3 disease following inguinal lymphadenectomy. The Kaplan-Meier cancer-specific survival at 72 months showed decreasing survival based on tumour stage (83% in pT1, 79% in pT2, and 64% in pT3 disease) and nodal disease (100% in node negative, 50% in superficial inguinal lymphadenopathy, and 38% in patients with deep inguinal and/or pelvic lymphadenopathy) (p=0.082). The Kaplan-Meier cancer-specific survival revealed statistically significant difference in survival outcome in patients with local recurrence vs. systemic metastasis disease (33% vs. 17%, p=0.008).

Conclusions

The presence of high risk features such as tumour stage, lymph node involvement and distant metastasis carries a significant higher risk of death and tumour recurrence in patients with penile cancer and inguinal lymph node metastasis.

Development of synchronous VHL syndrome tumors reveals contingencies and constraints to tumor evolution

BACKGROUND

Genomic analysis of multi-focal renal cell carcinomas from an individual with a germline VHL mutation offers a unique opportunity to study tumor evolution.

RESULTS

We perform whole exome sequencing on four clear cell renal cell carcinomas removed from both kidneys of a patient with a germline VHL mutation. We report that tumors arising in this context are clonally independent and harbour distinct secondary events exemplified by loss of chromosome 3p, despite an identical genetic background and tissue microenvironment. We propose that divergent mutational and copy number anomalies are contingent upon the nature of 3p loss of heterozygosity occurring early in tumorigenesis. However, despite distinct 3p events, genomic, proteomic and immunohistochemical analyses reveal evidence for convergence upon the PI3K-AKT-mTOR signaling pathway. Four germline tumors in this young patient, and in a second, older patient with VHL syndrome demonstrate minimal intra-tumor heterogeneity and mutational burden, and evaluable tumors appear to follow a linear evolutionary route, compared to tumors from patients with sporadic clear cell renal cell carcinoma.

CONCLUSIONS

In tumors developing from a germline VHL mutation, the evolutionary principles of contingency and convergence in tumor development are complementary. In this small set of patients with early stage VHL-associated tumors, there is reduced mutation burden and limited evidence of intra-tumor heterogeneity.

Do we need a different organ allocation system for kidney transplants using donors after circulatory death?

BACKGROUND

There is no national policy for allocation of kidneys from Donation after circulatory death (DCD) donors in the UK. Allocation is geographical and based on individual/regional centre policies. We have evaluated the short term outcomes of paired kidneys from DCD donors subject to this allocation policy.

METHODS

Retrospective analysis of paired renal transplants from DCD's from 2002 to 2010 in London. Cold ischemia time (CIT), recipient risk factors, delayed graft function (DGF), 3 and 12 month creatinine) were compared.

RESULTS

Complete data was available on 129 paired kidneys.115 pairs were transplanted in the same centre and 14 pairs transplanted in different centres. There was a significant increase in CIT in kidneys transplanted second when both kidneys were accepted by the same centre (15.5 ± 4.1 vs 20.5 ± 5.8 hrs p<0.0001 and at different centres (15.8 ± 5.3 vs. 25.2 ± 5.5 hrs p=0.0008). DGF rates were increased in the second implant following sequential transplantation (p=0.05).

CONCLUSIONS

Paired study sequential transplantation of kidneys from DCD donors results in a significant increase in CIT for the second kidney, with an increased risk of DGF. Sequential transplantation from a DCD donor should be avoided either by the availability of resources to undertake simultaneous procedures or the allocation of kidneys to 2 separate centres.

Patients' perceptions of surgical registrars' training in the private hospital setting

What's known on the subject? and What does the study add? The Australian private health sector is increasingly being recognised as an opportunity for advanced surgical training. Little is known about what the patients think of urology training in the private sector. Patients perceptions on the place of urology registrars in the Australian private sector are assessed for the first time. We can confirm that there appears to be acceptance of urology training in the private sector.

OBJECTIVE

• To determine the acceptance of surgical trainees in a private hospital setting.

METHOD

• This was an ethics approved prospective study using a written survey. • A total of 177 consecutive patients presenting for private consultation were recruited. A self-administered written survey was completed by each patient in the waiting room prior to consultation.

RESULTS

• Only 36.8% of subjects (confidence interval 29.6-44.1) initially understood the term registrar which significantly increased to 75% (confidence interval 68.4-81.6, P < 0.05) after reading explanatory notes. • Perceived differences between private and public hospitals were choice of surgeon (28%), waiting times for an operation (28%), standard of care (17%), cost (16%) and waiting times for an appointment (11%). • Patients' acceptance of registrar involvement with either a small part of an operation, a large part of an operation, the whole operation and assistance only were 34%, 16%, 13% and 37%.

CONCLUSIONS

• Patients have a poor understanding of the term registrar. • Acceptance of registrars in private hospitals is increased if consultant involvement is emphasized. • Surgical assistance and performance of minor parts of surgery by trainees is well accepted.

Human papillomavirus in benign prostatic hyperplasia and prostatic adenocarcinoma patients

The aim of this study was to determine the prevalence of human papillomavirus (HPV) types in tissue and HPV antibodies in prostatic disease. Prostate tissue samples were collected from 51 patients diagnosed with adenocarcinoma and 11 with benign prostatic hyperplasia (BPH). All tissue samples were confirmed by histology. Plasma samples were available for 52 prostate patients. We investigated HPV DNA prevalence by PCR, and PCR positive samples were HPV type determined by sequencing. Prevalence of antibodies against twenty-seven HPV proteins from fourteen different HPV types was assessed in the plasma samples. The HPV DNA prevalence in the tissue samples was 14% (7/51) for prostate cancer samples and 27% (3/11) for BPHs. HPV-18 was the only type detected in tissue samples (10/62). No significant difference in HPV prevalence between the prostate cancer and BPH samples was found. HPV-positive cells were identified in eight of our thirteen prostate tissue slides (3/3 BPH and 5/10 adenocarcinoma) by in situ hybridisation, and the positive cells were found in epithelial cells and peripheral blood cells. Serology data showed no significant increase in levels of antibodies against any of the HPV-18 proteins tested for in prostatic disease patients. Antibodies against HPV-1, HPV-4, HPV-6 and HPV-11 were significantly higher in the group of males with prostatic disease. Our study did not show an association between prostatic disease and either presence of HPV DNA in samples or previous exposure of high-risk HPV.

Assigning trait adjectives in an evaluative context: quicker, more consistent, and less equivocal

The objective was to examine the social conditions under which subjects could attribute trait adjectives to an unknown person, the paradigm of impression-formation at zero acquaintance. The situation on which the subject had to base his judgement was a 90-sec. film clip with sound of an individual reading a weather forecast. Analysis showed traits were attributed more quickly and consistently when instructions stipulated subject should evaluate the social utility of an individual (evaluator-recruiter type instructions) rather than describe personality (psychologist-type instructions). Traits were attributed more rapidly, with more consistency and greater certainty. Interpretation of results, which generally corroborate other research, is that the judgement of another person based on a first impression is an evaluation of the social utility of that person.

ProsCan for men: randomised controlled trial of a decision support intervention for men with localised prostate cancer

Background

Prostate cancer is the most common male cancer in the Western world but is highly heterogeneous in disease progression and outcomes. Consequently, the most substantial morbidity may actually arise from the adverse psychosocial impact of distress in decision-making and long term quality of life effects such as impotence. This paper presents the design of a randomised controlled trial of a decision support/psychosocial intervention for men newly diagnosed with localised prostate cancer.

Methods/Design

350 men per condition (700 men in total) have been recruited after diagnosis and before treatment through urology private practices and hospital outpatient clinics and randomised to 1) a tele-based nurse delivered five session decision support/psychosocial intervention or 2) a usual care control group. Two intervention sessions are delivered before treatment that address decision support, stress management and preparation for treatment. Three further sessions are provided three weeks, seven weeks and five months after treatment that focus on adjustment to cancer, problem solving and coping with treatment side effects. Participants are assessed at baseline (before treatment) and 2, 6, 12, 24 and 36 months post-treatment. Outcome measures include: cancer threat appraisal; decision-related distress and bother from treatment side effects; involvement in decision making; satisfaction with health care; heath care utilisation; use of health care resources; and a return to previous activities.

Discussion

The study will provide recommendations about the efficacy of early decision support to facilitate adjustment after prostate cancer. As well the study will identify men diagnosed with localised prostate cancer at risk of poorer long term psychosocial adjustment.

Trial Registration

ACTRN012607000233426.

Estimated donor glomerular filtration rate is the most important donor characteristic predicting graft function in recipients of kidneys from live donors

We hypothesized that predictors of outcome in live donor transplants were likely to differ significantly from deceased donor transplants, in which cold ischaemia time, cause of donor death and other donor factors are the most important predictors. The primary aim was to explore the independent predictors of graft function in recipients of live donor kidneys (LDK). Our secondary aim was to determine which donor characteristics are the most useful predictors. A retrospective analysis was undertaken of all patients receiving live donor (n = 206) renal transplants at our institution between 31 May 1994 and 15 October 2002. Twelve patients were excluded from the analysis. Follow-up was completed on all patients until graft loss, death or 22 November 2003. We explored predictors of Nankivell glomerular filtration rate (GFR) at 6 months by multivariate linear regression. In the 194 patients studied, the mean recipient 6-month Nankivell GFR was 59 +/- 15 ml/min/1.73 m(2). Independent predictors of recipient GFR in at 6 months were donor Cockcroft-Gault GFR (CrCl; beta 0.16; CI 0.13 to 0.29; P < 0.0001), steroid resistant rejection (beta-6.07; CI -12.05 to -0.09; P = 0.006) and delayed graft function (DGF) (beta-10.0; CI -19.52 to -0.49; P = 0.039). Renal function in an LDK transplant recipients is predicted by donor GFR, episodes of steroid resistant rejection and DGF. Importantly, donor Cockcroft-Gault GFR is the most important characteristic for predicting the recipient renal function.

Laminin, VEGF, and bone matrix protein expression in uroepithelial bone induction--a canine model

A biological and embryological bone induction from epithelial-mesenchymal cell interactions has been noticed in some developing tissues. However, the mechanism for bone formation induced by the epithelial-mesenchymal cell interactions is not clear. The aim of our study was to reveal the role of laminin, vascular endothelial growth factor (VEGF), and bone matrix proteins in mesenchymal cell differentiation during uroepithelial bone induction using a well-established canine model. In this model, a myoperitoneal muscle flap from the abdominal rectus sheath was transplanted into the bladder wall. After 6 weeks, the bladder samples were removed and assessed by histology and immunohistochemistry. This study demonstrated that bone formation occurred in two different directions with two distinct mechanisms. We noted that bone-forming cells in two types of bone formation derived from mesenchymal stem cell differentiation induced either from uroepithelium or bone autoinduction. Laminin was only expressed in peripheral regions of uroepithelium bone formation. Type II collagen was expressed both intracellularly and extracellularly around hypertrophic chondrocytes, whereas VEGF was mostly expressed in proliferating chondrocytes. This study indicates that components in basement membrane like laminin play a role in transitional epithelium-induced differentiation of mesenchymal cells to chondrocytes in muscle tissue. The sequential expression of bone matrix proteins by differentiated osteogenetic cells indicates a subsequent sequence of bone autoinduction.

Development of an isolate-specific marker for tracking Phaeomoniella chlamydospora infection in grapevines

Petri disease causes decline of grapevines worldwide. The grapevine endophyte Phaeomoniella chlamydospora is the most important fungal pathogen associated with this disease. Epidemiological studies of this pathogen have been hampered by its common occurrence in the internal tissue of apparently healthy vines. Development of a molecular marker for a single strain would overcome this limitation and aid experiments designed to answer key questions about the biology of this pathogen. Genetic variation analysis of New Zealand and Italian strains of P. chlamydospora detected a potential molecular marker in New Zealand isolate A21. Characterization of the 1010 bp marker band showed that it had 50% identity to moxY, a gene involved in the aflatoxin biosynthetic pathway of Aspergillus parasiticus. Sequencing of the region flanking the 1010 bp product revealed a single nucleotide polymorphism in the 3' border of the marker band. Primers were designed to amplify a 488 bp fragment encompassing this polymorphic site and cleavage of this product with the restriction enzyme BsrI produced three bands only in isolate A21 and two bands in all other isolates tested. The sensitivity of the PCR-RFLP protocol was increased with a nested PCR approach and the protocol optimized for soil and wood samples. When the nested PCR/RFLP procedure was used to determine the persistence of viable and nonviable spores in soil, the results showed that nonviable spores were undetected after 8 wk whereas viable spores still could be detected at 17 wk.

Comparative Analysis of Caspase Activation and Apoptosis in Renal Tubular Epithelial Cells and Renal Cell Carcinomas

BACKGROUND/AIMS

Treatment of renal cell carcinoma (RCC) is limited by its resistance to conventional chemotherapies. This may occur, in part, from resistance to apoptosis. The role of caspase activation in apoptosis resistance in treated RCCs was investigated.

METHODS

Two human RCC cell lines (ACHN and SN12K1) and renal tubular epithelial cells (HK2) were treated with 5-fluorouracil (0.2-20 microg/ml) or cisplatin (1-100 microM). Activation of caspase-3 and -2 was analysed and compared with levels of apoptosis. Caspase function was analysed using pan-caspase inhibition (z-VAD-fmk) and caspase-2 inhibition (z-VDVAD-fmk).

RESULTS

RCC apoptosis was significantly lower (p < 0.05) than in HK2s after treatment, confirming their chemoresistance. Pro-caspase-3 (32 kDa) was detected in all cell lines. Cleaved caspase-3 (19 kDa) was not detected by Western immunoblots in treated RCCs and only minimal activated caspase-3 was detected in treated RCCs using immunohistochemistry. All cells had pro-caspase-2 (48 kDa) and the activated form (33 kDa) appeared in all treated cells. Caspase inhibition caused a reduction in, but not negation of, therapy-induced apoptosis in HK2s and RCCs (p < 0.05 for HK2s and ACHN cells), indicating that a caspase activation pathway must occur in RCC apoptosis but this pathway does not act via caspase-3 cleavage. Inhibition of caspase-2 reduced apoptosis only in HK2s, indicating that the activated caspase-2, identified in treated RCCs, was not responsible for their apoptosis induction.

CONCLUSION

Specific differences in caspase-3 and -2 activation were identified in renal tubular epithelium and RCCs after chemotherapy. Identification of RCC-specific caspase inactivation or redundancy may explain, in part, the resistance of RCCs to cancer therapies and may be useful in targeting apoptotic pathways to overcome RCC resistance to treatment.

Altered messenger RNA and protein expressions for insulin-like growth factor family members in clear cell and papillary renal cell carcinomas

BACKGROUND

The purpose of the present paper was to describe the pattern of expression of insulin-like growth factor (IGF-I) and its regulatory binding proteins (IGFBP) in renal cell carcinoma (RCC).

METHODS

The expressions of mRNA and protein for various IGF members were assessed in 24 paired normal and malignant human renal tissues (16 clear cell and 8 papillary RCC) using semiquantitative reverse transcription-polymerase chain reaction and immunohistochemistry. Paired tissue samples were also obtained from six patients with oncocytoma in order to compare the specificity of changes in IGF/IGFBP expression between tumors derived from proximal (RCC) and distal (oncocytoma) tubular epithelium.

RESULTS

Clear cell RCC were characterized by significant increases in the mRNA expression of IGF-I, IGFBP-3 and IGFBP-6 while papillary RCC exhibited down-regulated expression of IGF-I, IGFBP-4 and IGFBP-5. The IGFBP-2, IGFBP-4 and IGFBP-5 mRNA were down-regulated in oncocytomas. Semiquantitative assessment of immunohistochemical staining demonstrated significant increases in epithelial associated IGF-I and IGFBP-3 in clear cell RCC, increased IGFBP-5 protein in papillary RCC and no significant changes in IGF/IGFBP protein expression in oncocytoma.

CONCLUSIONS

The expression of IGF-I and certain IGFBP is significantly altered in RCC compared with normal renal tissue and oncocytomas. This altered expression is differentially regulated according to the histologic subtype of RCC, and suggests that the IGF/IGFBP axis may play an important role in determining the malignant phenotype of RCC.

Are patents for methods of medical treatment contrary to the ordre public and morality or "generally inconvenient"?

"No one has advanced a just and logical reason why reward for service to the public should be extended to the inventor of a mechanical toy and denied to the genius whose patience, foresight, and effort have given a valuable new [discovery] to mankind" (Katopis CJ. Patents v patents: policy implications of recent patent legislation. St John's Law Review 1997;71:329). The law around the world permits the granting of patents for drugs, medical devices, and cosmetic treatment of the human body. At the same time, patentability for a method of treatment of the same body is denied in some countries on various public policy grounds. Is there any logical justification for this distinction? Are methods of medical treatment not as vital to the health or even to the life of a patient as drugs or medical devices? Why is a cosmetic result patentable and a curative result not?

Haemodynamic assessment following inferior vena cava resection without replacement

BACKGROUND

Treatment of bulky retroperitoneal malignancy may require en bloc resection of the infrarenal inferior vena cava. A number of reconstructive options are available to the surgeon but objective haemodynamic assessment of the peripheral venous system following resection without replacement is lacking. The aim of the present paper was thus to determine the symptomatic and haemodynamic effects of not reconstructing the resected infrarenal inferior vena cava.

METHODS

A retrospective descriptive study was carried out at Princess Alexandra Hospital in Queensland. Five patients underwent resection of the thrombosed infrarenal inferior vena cava as part of retroperitoneal lymph node dissection for testicular cancer (n = 3), radical nephrectomy for renal cell carcinoma (n = 1) and thrombosed inferior vena cava aneurysm (n = 1). Clinical effects were determined via the modified venous clinical severity score and venous disability score. Haemodynamic data were obtained postoperatively using venous duplex ultrasound and air plethysmography.

RESULTS

None of the present patients scored >2 (out of 30) on the modified venous clinical severity score or >1 (out of 3) on the venous disability score. Haemodynamic studies showed only minor abnormalities.

CONCLUSIONS

Not reconstructing the resected thrombosed infrarenal inferior vena cava results in minor signs and symptoms of peripheral venous hypertension and only minor abnormalities on haemodynamic assessment.

Molecular subclassification of kidney tumors and the discovery of new diagnostic markers

We analysed the expression profiles of 70 kidney tumors of different histological subtypes to determine if these subgroups can be distinguished by their gene expression profiles, and to gain insights into the molecular mechanisms underlying each subtype. In all, 39 clear cell renal cell carcinomas (RCC), seven primary and one metastatic papillary RCC, six granular RCC from old classification, five chromophobe RCC, five sarcomatoid RCC, two oncocytomas, three transitional cell carcinomas (TCC) of the renal pelvis and five Wilms' tumors were compared with noncancerous kidney tissues using microarrays containing 19,968 cDNAs. Based on global gene clustering of 3560 selected cDNAs, we found distinct molecular signatures in clear cell, papillary, chromophobe RCC/oncocytoma, TCC and Wilms' subtypes. The close clustering in each of these subtypes points to different tumorigenic pathways as reflected by their histological characteristics. In the clear cell RCC clustering, two subgroups emerged that correlated with clinical outcomes, confirming the potential use of gene expression signatures as a predictor of survival. In the so-called granular cell RCC (terminology for a subtype that is no longer preferred), none of the six cases clusters together, supporting the current view that they do not represent a single entity. Blinded histological re-evaluation of four cases of 'granular RCC' led to their reassignment to other existing histological subtypes, each compatible with our molecular classification. Finally, we found gene sets specific to each subtype. In order to establish the use of some of these genes as novel subtype markers, we selected four genes and performed immunohistochemical analysis on 40 cases of primary kidney tumors. The results were consistent with the gene expression microarray data: glutathione S-transferase alpha was highly expressed in clear cell RCC, alpha methylacyl racemase in papillary RCC, carbonic anhydrase II in chromophobe RCC and K19 in TCC. In conclusion, we demonstrated that molecular profiles of kidney cancers closely correlated with their histological subtypes. We have also identified in these subtypes differentially expressed genes that could have important diagnostic and therapeutic implications.

Prostatic and peripheral blood selenium levels after oral supplementation

PURPOSE

The dietary trace element selenium has been proposed to be a potential chemopreventive agent for prostate cancer. Epidemiological studies have suggested an inverse association between blood selenium and prostate cancer incidence. However, to our knowledge no study to date has examined selenium absorption by the prostate. Therefore, we determine whether oral selenium supplementation alters selenium levels within the prostate and/or peripheral blood.

MATERIALS AND METHODS

In this prospective trial 51 men undergoing transurethral resection of the prostate for benign prostatic hyperplasia were randomly assigned to serve as controls or receive 200 microg selenium daily orally for 1 month. Sample size was calculated to detect a difference of 30 ng/gm in prostate tissue with a power of 80%. Peripheral blood was obtained at enrollment and subsequently at surgery, when prostate tissue was also sampled. Selenium levels were determined using inductively coupled plasma mass spectrometry.

RESULTS

Baseline erythrocyte selenium was within the standard reference range. Supplementation increased erythrocyte (initial median 173 and final median 209 ng/ml, p = 0.008) and prostate (supplement median 241 and control median 196 ng/gm, p = 0.016) levels. Erythrocyte levels at surgery correlated poorly with prostate levels in the control (r = 0.18) and supplement (r = 0.07) groups.

CONCLUSIONS

Oral selenium supplementation increases prostatic and peripheral blood levels in men in a nonselenium deficient population. Blood and prostate levels correlated poorly, suggesting that peripheral blood measurements are a poor indicator of prostatic selenium content.