Adam B. Murphy

Targeted antimicrobial prophylaxis using rectal swab cultures in men undergoing transrectal ultrasound guided prostate biopsy is associated with reduced incidence of postoperative infectious complications and cost of care.

PURPOSE We evaluated targeted antimicrobial prophylaxis in men undergoing transrectal ultrasound guided prostate biopsy based on rectal swab culture results. MATERIALS AND METHODS From July 2010 to March 2011 we studied differences in infectious complications in men who received targeted vs standard empirical ciprofloxacin prophylaxis before transrectal ultrasound guided prostate biopsy. Targeted prophylaxis used rectal swab cultures plated on selective media containing ciprofloxacin to identify fluoroquinolone resistant bacteria. Patients with fluoroquinolone susceptible organisms received ciprofloxacin while those with fluoroquinolone resistant organisms received directed antimicrobial prophylaxis. We identified men with infectious complications within 30 days after transrectal ultrasound guided prostate biopsy using the electronic medical record. RESULTS A total of 457 men underwent transrectal ultrasound guided prostate biopsy, and of these men 112 (24.5%) had rectal swab obtained while 345 (75.5%) did not. Among those who received targeted prophylaxis 22 (19.6%) men had fluoroquinolone resistant organisms. There were no infectious complications in the 112 men who received targeted antimicrobial prophylaxis, while there were 9 cases (including 1 of sepsis) among the 345 on empirical therapy (p=0.12). Fluoroquinolone resistant organisms caused 7 of these infections. The total cost of managing infectious complications in patients in the empirical group was

The landscape of recombination in African Americans

13,219. The calculated cost of targeted vs empirical prophylaxis per 100 men undergoing transrectal ultrasound guided prostate biopsy was

Genome-wide association study of prostate cancer in men of African ancestry identifies a susceptibility locus at 17q21

1,346 vs

Genome-wide meta-analyses of smoking behaviors in African Americans

5,598, respectively. Cost-effectiveness analysis revealed that targeted prophylaxis yielded a cost savings of

Chronic prostatitis: management strategies.

4,499 per post-transrectal ultrasound guided prostate biopsy infectious complication averted. Per estimation, 38 men would need to undergo rectal swab before transrectal ultrasound guided prostate biopsy to prevent 1 infectious complication. CONCLUSIONS Targeted antimicrobial prophylaxis was associated with a notable decrease in the incidence of infectious complications after transrectal ultrasound guided prostate biopsy caused by fluoroquinolone resistant organisms as well as a decrease in the overall cost of care.

Characterizing Genetic Risk at Known Prostate Cancer Susceptibility Loci in African Americans

Recombination, together with mutation, gives rise to genetic variation in populations. Here we leverage the recent mixture of people of African and European ancestry in the Americas to build a genetic map measuring the probability of crossing over at each position in the genome, based on about 2.1 million crossovers in 30,000 unrelated African Americans. At intervals of more than three megabases it is nearly identical to a map built in Europeans. At finer scales it differs significantly, and we identify about 2,500 recombination hotspots that are active in people of West African ancestry but nearly inactive in Europeans. The probability of a crossover at these hotspots is almost fully controlled by the alleles an individual carries at PRDM9 (P value < 10−245). We identify a 17-base-pair DNA sequence motif that is enriched in these hotspots, and is an excellent match to the predicted binding target of PRDM9 alleles common in West Africans and rare in Europeans. Sites of this motif are predicted to be risk loci for disease-causing genomic rearrangements in individuals carrying these alleles. More generally, this map provides a resource for research in human genetic variation and evolution.

Identification, replication, and fine-mapping of Loci associated with adult height in individuals of african ancestry.

In search of common risk alleles for prostate cancer that could contribute to high rates of the disease in men of African ancestry, we conducted a genome-wide association study, with 1,047,986 SNP markers examined in 3,425 African-Americans with prostate cancer (cases) and 3,290 African-American male controls. We followed up the most significant 17 new associations from stage 1 in 1,844 cases and 3,269 controls of African ancestry. We identified a new risk variant on chromosome 17q21 (rs7210100, odds ratio per allele = 1.51, P = 3.4 × 10−13). The frequency of the risk allele is ∼5% in men of African descent, whereas it is rare in other populations (<1%). Further studies are needed to investigate the biological contribution of this allele to prostate cancer risk. These findings emphasize the importance of conducting genome-wide association studies in diverse populations.

Two susceptibility loci identified for prostate cancer aggressiveness

The identification and exploration of genetic loci that influence smoking behaviors have been conducted primarily in populations of the European ancestry. Here we report results of the first genome-wide association study meta-analysis of smoking behavior in African Americans in the Study of Tobacco in Minority Populations Genetics Consortium (n=32 389). We identified one non-coding single-nucleotide polymorphism (SNP; rs2036527[A]) on chromosome 15q25.1 associated with smoking quantity (cigarettes per day), which exceeded genome-wide significance (β=0.040, s.e.=0.007, P=1.84 × 10−8). This variant is present in the 5′-distal enhancer region of the CHRNA5 gene and defines the primary index signal reported in studies of the European ancestry. No other SNP reached genome-wide significance for smoking initiation (SI, ever vs never smoking), age of SI, or smoking cessation (SC, former vs current smoking). Informative associations that approached genome-wide significance included three modestly correlated variants, at 15q25.1 within PSMA4, CHRNA5 and CHRNA3 for smoking quantity, which are associated with a second signal previously reported in studies in European ancestry populations, and a signal represented by three SNPs in the SPOCK2 gene on chr10q22.1. The association at 15q25.1 confirms this region as an important susceptibility locus for smoking quantity in men and women of African ancestry. Larger studies will be needed to validate the suggestive loci that did not reach genome-wide significance and further elucidate the contribution of genetic variation to disparities in cigarette consumption, SC and smoking-attributable disease between African Americans and European Americans.

Vitamin D deficiency predicts prostate biopsy outcomes

The National Institutes of Health (NIH) has redefined prostatitis into four distinct entities. Category I is acute bacterial prostatitis. It is an acute prostatic infection with a uropathogen, often with systemic symptoms of fever, chills and hypotension. The treatment hinges on antimicrobials and drainage of the bladder because the inflamed prostate may block urinary flow. Category II prostatitis is called chronic bacterial prostatitis. It is characterized by recurrent episodes of documented urinary tract infections with the same uropathogen and causes pelvic pain, urinary symptoms and ejaculatory pain. It is diagnosed by means of localization cultures that are 90% accurate in localizing the source of recurrent infections within the lower urinary tract. Asymptomatic inflammatory prostatitis comprises NIH category IV. This entity is, by definition, asymptomatic and is often diagnosed incidentally during the evaluation of infertility or prostate cancer. The clinical significance of category IV prostatitis is unknown and it is often left untreated. Category III prostatitis is called chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). It is characterized by pelvic pain for more than 3 of the previous 6 months, urinary symptoms and painful ejaculation, without documented urinary tract infections from uropathogens. The syndrome can be devastating, affecting 10–15% of the male population, and results in nearly 2 million outpatient visits each year. The aetiology of CP/CPPS is poorly understood, but may be the result of an infectious or inflammatory initiator that results in neurological injury and eventually results in pelvic floor dysfunction in the form of increased pelvic muscle tone. The diagnosis relies on separating this entity from chronic bacterial prostatitis. If there is no history of documented urinary tract infections with a urinary tract pathogen, then cultures should be taken when patients are symptomatic. Prostatic localization cultures, called the Meares-Stamey 4 glass test, would identify the prostate as the source for a urinary tract infection in chronic bacterial prostatitis. If there is no infection, then the patient is likely to have CP/CPPS.For healthcare providers, the focus of therapy is symptomatic relief. The first therapeutic measure is often a 4- to 6-week course of a fluoroquinolone, which provides relief in 50% of men and is more efficacious if prescribed soon after symptoms begin. Second-line pharmacotherapy involves anti-inflammatory agents for pain symptoms and α-adrenergic receptor antagonists (α-blockers) for urinary symptoms. Potentially more effective is pelvic floor training/biofeedback, but randomized controlled trials are needed to confirm this. Third-line agents include 5α-reductase inhibitors, glycosaminoglycans, quercetin, cernilton (CN-009) and saw palmetto. For treatment refractory patients, surgical interventions can be offered. Transurethral microwave therapy to ablate prostatic tissue has shown some promise.The treatment algorithm provided in this review involves a 4- to 6-week course of antibacterials, which may be repeated if the initial course provides relief. Pain and urinary symptoms can be ameliorated with anti-inflammatories and α-blockers. If the relief is not significant, then patients should be referred for biofeedback. Minimally invasive surgical options should be reserved for treatment-refractory patients.

Genome-wide Scan of 29,141 African Americans Finds No Evidence of Directional Selection since Admixture

GWAS of prostate cancer have been remarkably successful in revealing common genetic variants and novel biological pathways that are linked with its etiology. A more complete understanding of inherited susceptibility to prostate cancer in the general population will come from continuing such discovery efforts and from testing known risk alleles in diverse racial and ethnic groups. In this large study of prostate cancer in African American men (3,425 prostate cancer cases and 3,290 controls), we tested 49 risk variants located in 28 genomic regions identified through GWAS in men of European and Asian descent, and we replicated associations (at p≤0.05) with roughly half of these markers. Through fine-mapping, we identified nearby markers in many regions that better define associations in African Americans. At 8q24, we found 9 variants (p≤6×10−4) that best capture risk of prostate cancer in African Americans, many of which are more common in men of African than European descent. The markers found to be associated with risk at each locus improved risk modeling in African Americans (per allele OR = 1.17) over the alleles reported in the original GWAS (OR = 1.08). In summary, in this detailed analysis of the prostate cancer risk loci reported from GWAS, we have validated and improved upon markers of risk in some regions that better define the association with prostate cancer in African Americans. Our findings with variants at 8q24 also reinforce the importance of this region as a major risk locus for prostate cancer in men of African ancestry.