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Family history increases cardiac arrest risk in dialysis patients NephrologyNews.com ... for Sudden Cardiac Arrest in ESRD,” will be published in an upcoming issue of the Journal of the American Society of Nephrology (JASN), and appears online ahead of print. http://jasn.asnjournals.org/content/early/2015/04/16/ASN.2014090881.abstract. Higher Risk of Cardiac Arrest in Dialysis May Be Genetic Monthly Prescribing Reference all 2 news articles »

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(HealthDay News) — Genes may play a role in cardiac arrest risk among kidney patients who are on dialysis, new research suggests. The study was published online April 16 in the Journal of the American Society of Nephrology.

The researchers analyzed data from 647,457 dialysis patients, focusing on 5,117 pairs of patients from the same family. Each patient was then matched to an unrelated control patient. Cardiac arrest was the cause of death in both patients in 4.3% of the family pairs, compared with 2.6% of unrelated pairs of patients.

Compared with unrelated pairs, the risk of dual cardiac arrest was 88% higher among genetically-related family members who did not live together, and 66% higher among genetically-related family members who did live together. Dialysis patients who were spouses were not at increased risk for cardiac arrest.

"These findings advance the science because they suggest that genetic factors – or differences in DNA sequence – contribute to the high risk of sudden death among patients on dialysis," study author Kevin Chan, MD, from Massachusetts General Hospital in Boston, said in a journal news release. "It paves the way for more detailed genetic studies in the dialysis population to find specific genes that could explain the high risk of cardiac arrest and potentially new treatments for these patients."

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Severe lower urinary tract symptoms (LUTS) are associated with an increased risk of developing bladder cancer, new findings suggest.

In a study of 30,183 men in the Health Professionals Follow-up Study (HPFS), men with severe LUTS had a 64% higher relative risk of bladder cancer compared with men who did not have LUTS in multivariate analysis. Men who had both voiding and storage dysfunction had a significant 60% higher risk of bladder cancer. 

In addition, among individual urinary symptoms, urinary hesitancy was strongly associated with bladder cancer risk. Men who had urinary hesitancy at least 50% of the time had a 2.2 times increased risk, a team led by Dominique S. Michaud, ScD, of Tufts University Medical School in Boston, reported online ahead of print in Urology.

Dr. Michaud and her colleagues concluded that their findings suggest that urinary voiding symptoms may raise the risk of bladder cancer. “If this association is confirmed,” they wrote, “LUTS might be used as a simple test to identify men who are at higher risk of bladder cancer.”

The investigators pointed out that about 15%–60% of men older than 40 years report suffering from LUTS in various studies, with the prevalence and severity increasing with age.

Investigators used a slightly modified American Urological Association Symptom Score Index (AUA-7) to assess LUTS information. The index consists of 7 questions assessing storage and voiding dysfunction symptoms. Each question is scored on a 0–5 scale, with 0, 1, 2, 3, 4, 5 corresponding, respectively, to 0%, 10%, 25%, 50%, 75%, and almost 100% of the time that a symptom was experienced. The maximum possible total score is 35. Patients with AUA-7 scores greater than 1 but not more than 7, higher than 7 but not more than 19, and higher than 19 had mild, moderate, and severe LUTS, respectively.

At baseline, 1,892 men reported experiencing urinary hesitance for at least 50% of the time, among which 1,069 men (56.5%) had mixed storage and voiding dysfunctions and 642 (33.9%) had isolated voiding dysfunction, according to the investigators. Men reporting experiencing hesitance for at least 50% of the time had the highest overall total AUA-7 score.

“These results suggest that the presence of severe urinary hesitancy might indicate higher volume of post-void residual urine, which can increase the contact time of potential carcinogens in urine and the bladder urothelium and the risk of bladder cancer,” they wrote.

Previous studies have revealed bladder wall thickening and bladder mass increases among men with LUTS, Dr. Michaud's group noted.

The researchers found that men who urinated 3 or more times per night had a nonsignificant 18% decreased risk of bladder cancer compared with men who had no nighttime urination.

Initiated in 1986, the HPFS enrolled 51,529 male health professionals aged 40–75 years from across the United States.

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(HealthDay News) -- If genetic tests are only done on cancer tissue, as many as half of patients may not receive the most appropriate treatment for their cancer, according to research published in Science Translational Medicine.

Victor Velculescu, M.D., Ph.D., a professor of oncology and pathology at the Johns Hopkins University School of Medicine in Baltimore, and colleagues compared the genetic information of tumor and normal tissue from 815 patients. These patients had a variety of cancers, including breast, brain, renal, gastric, lung, pancreatic, and blood cancers and melanoma. 

Three-quarters of patients had genetic mutations for which approved therapies or clinical trials had been designed, suggesting that DNA analysis could steer these people to targeted therapy, Velculescu told HealthDay. However, a comparison of cancerous and normal tissue found that about 2/3 of all the mutations uncovered by DNA scans "were a part of the patient's normal inherited genetic variation," he said.

The researchers then looked specifically at mutations in genes for which a drug or cancer therapy has already been identified. They found that nearly a third of these changes also were false positives -- harmless genetic variations that had nothing to do with a person's cancer. Each patient had multiple harmless genetic mutations, according to Velculescu. Overall, he said, the false positives affected almost 1 in every 2 patients.

Based on these findings, the researchers argued that doctors should begin obtaining DNA analysis of both normal and cancer tissue from patients. That would allow doctors to screen out normal genetic variations and more accurately determine the causes of a person's cancer. 

"Of course we all want precision medicine, but one conclusion from these analyses is that we cannot have precision medicine without precision genomics," Velculescu said. "We can't expect physicians to provide the right therapy to the right patients if we can't obtain accurate results in our diagnostic tests."

Source

1. Sian, J, et al. Sci. Transl. Med, April 2015; doi: 10.1126/scitranslmed.aaa7161.

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