Health costs could be reduced by more appropriate use of cardiac stress testing with imaging

In a new study recently published in the Annals of Internal Medicine, researchers at NYU Langone Medical Center concluded that overuse of cardiac stress testing with imaging has led to rising healthcare costs and unnecessary radiation exposure to patients.

In what is believed to be the first comprehensive examination of trends in cardiac stress testing utilizing imaging, researchers also showed that there are no significant racial or ethnic health disparities in its use. They also made national estimates of the cost of unnecessary cardiac stress testing with imaging and the health burden of this testing, in terms of cancer risk due to radiation exposure.

Cardiac stress testing, particularly with imaging, has been the focus of debate about rising health care costs, inappropriate use, and patient safety in the context of radiation exposure. Joseph Ladapo, MD, PhD, assistant professor in the Departments of Medicine and Population Health at NYU Langone, and the lead author of the study, and colleagues wanted to determine whether U.S. trends in cardiac stress testing with imaging may be attributable to population shifts in demographics, risk factors, and provider characteristics, and to evaluate whether racial/ethnic disparities exist in physician decision making.

They designed their study utilizing data from the National Ambulatory Medical Care Survey (NAMCS) and National Hospital Ambulatory Medical Care Survey (NHAMCS) from 1993 to 2010. Patients chosen for the study were adults without coronary heart disease who were referred for cardiac stress tests.

Between 1993 to 1995 and 2008 to 2010, the annual number of ambulatory visits in the U.S. in which a cardiac stresstest was ordered or performed increased by more than 50%. Cardiac stress tests with imaging comprised a growing portion of all of these tests – increasing from 59% in 1993 to 1995 to 87% in 2008 to 2010. At least 34.6% – or one million tests – were probably inappropriate, the researchers concluded, with associated annual costs and harms of $501 million and 491 future cases of cancer.

The authors also concluded that there was no evidence of a lower likelihood of black patients receiving a cardiac stresstest with imaging (odds ratio, 0.91 [95% CI, 0.69 to 1.21]) than their white counterparts – although some modest evidence of disparity in Hispanic patients was found (odds ratio, 0.75 [CI, 0.55 to 1.02]).

The investigators concluded that the national growth in cardiac stress testing can be attributed largely to population and provider characteristics – but the use of imaging cannot. Physician decision making about cardiac stress testing also does not result in racial/ethnic disparities in cardiovascular disease.

“Cardiac stress testing is an important clinical tool,” says Dr. Ladapo, “but we are over using imaging for reasons unrelated to clinical need. This is causing preventable harm and increasing healthcare costs.

“Reducing unnecessary testing also will concomitantly reduce the incidence of radiation related cancer,” he adds. “We estimate that about 500 people get cancer each year in the US from radiation received during a cardiac stress test when, in fact, they most probably didn’t need any radiological imaging in the first place. While this number might seem relatively small, we must remember that ‘first, do no harm’ is one of the guiding principles in medicine.”

So what can be done to reduce unnecessary cardiac stress testing with imaging? “More efforts, such as clinical decision support, are needed to reduce unnecessary cardiac stress testing,” Dr. Ladapo concludes, suggesting greater use ofstress testing without radiological imaging, such as regular exercise treadmill tests or stress testing with ultrasoundimaging as opposed to CT imaging.

As to the reason why certain racial and ethnic minorities have poorer rates of treatment for cardiovascular disease and generally have poorer cardiovascular health outcomes compared to white patients, Dr. Ladapo concludes that no one has really explored whether there could be disparities in cardiac stress testing, which is a mainstay of diagnosing patients with heart disease in this country. “If we know that one minority group has a higher incidence of poorer outcomes from heart disease, perhaps we need to examine if they would benefit from more appropriate use of cardiac stress testing,” he offers. “Perhaps one contributing reason they have poorer outcomes is because we are not testing them appropriately.”

http://www.medicalnewstoday.com/releases/283694.php

 

Exercise can enhance tumor-shrinking effects of chemotherapy

New research published in the American Journal of Physiology, suggests exercise may boost the tumor-shrinking effects of chemotherapy.

In a study of mice with melanoma, scientists from the University of Pennsylvania (Penn) in Philadelphia, found that chemotherapy shrank more tumors when combined with exercise.

Senior author Joseph Libonati, an associate professor in Penn’s School of Nursing, and colleagues were originally trying to find out if exercise could protectcancer patients against the heart damage that can result from use of the common cancer drug doxorubicin.

Although the drug is effective against a variety of cancers, one of its side effects is the potential damage it can do to heart cells. In the long term, this can causeheart failure.

Prof. Libonati says at first, all cancer patients are concerned about is the cancer, “and they’ll do whatever it takes to get rid of it.”

“But then when you get over that hump you have to deal with the long-term elevated risk of cardiovascular disease,” he adds.

There is evidence that taking up regular exercise before undergoing chemotherapy can protect heart cells from the damaging effects of doxorubicin. But not many have investigated whether there is any benefit from exercising during chemotherapy.

For their study, the team picked four groups of mice and induced them with melanoma. Over the next 2 weeks, two of the groups received two injections of doxorubicin, and two received placebo injections.

At the same time, mice in one of the chemotherapy groups and one of the placebo groups were placed on exercise regimens. The other mice did not exercise during the treatment period. The exercising mice walked on treadmills for 45 minutes a day on 5 days of each week.

Exercise helped chemotherapy shrink tumors but did not change effect on heart

After the 2-week period, the team found the mice that received chemotherapy – regardless of whether they had exercised or not – showed signs of heart damage. The damage consisted of reduced heart function and increased fibrosis or tissue thickening.

As Prof. Libonati says, “exercise didn’t do anything to the heart – it didn’t worsen it, it didn’t help it.”

But he and his team were amazed when they looked at the tumors. They found the mice that had received chemotherapy and exercised had much smaller tumors after 2 weeks than the sedentary mice on chemotherapy.

They conclude that in mice with melanoma, exercise appears to boost the tumor-shrinking effects of doxorubicin, without having an effect on the damage the drug can do to the heart.

They suggest further studies should now look into exactly how exercise boosts the effects of chemotherapy. Perhaps a reason is because exercise improves blood flow, which allows more of the drug to reach the cancer cells.

Prof. Libonati adds, “If exercise helps in this way, you could potentially use a smaller dose of the drug and get fewer side effects.”

He explains that we are only just beginning to understand the effect exercise can have on drug- taking:

“People don’t take a drug and then sit down all day. Something as simple as moving affects how drugs are metabolized.”

Finding out more about how exercise affects the body could lead to drugs that mimic the effects of exercise.

Funds for the study came from the National Cancer Institute, the National Heart Lung and Blood Institute, the National Center for Research Resources, the National Center for Advancing Translational Sciences, and the Biobehavioral Research Center at Penn.

Meanwhile, Medical News Today recently learned of a study published in Science Translational Medicine that showed how tumors shrank following a bacteria injection. The researchers shrank cancer tumors in rats, dogs and also one human patient, by directly injecting the tumors with a modified version of Clostridium novyi to trigger targeted anti-cancer responses.

Written by Catharine Paddock PhD

Copyright: Medical News Today

http://www.medicalnewstoday.com/articles/282767.php

 

 

UCLA scientists unlock protein that can accelerate recovery in cancer patients following radiation and chemotherapy

Scientists from UCLA’s Jonsson Comprehensive Cancer Center (JCCC) have shown for the first time how a unique protein found in human bone marrow can drive stem cells to repair our blood system after an injury. These groundbreaking findings provide a roadmap to make existing radiation and chemotherapy treatments more effective for patients with cancer and other blood-related diseases.

Led by Dr. John Chute, UCLA professor of hematology and radiation oncology and JCCC member, the nearly two-year study was published online ahead of print in the Journal of Clinical Investigation.

Millions of cancer patients worldwide currently receive some form of radiation therapy or chemotherapy in hopes of curing the disease, and most will suffer damage to the blood system as a result. Current therapeutic regimens are also cyclical (generally requiring a 30-day wait period between treatments) to allow the blood system time to heal and repair.

Hematopoietic stem cells (HSCs) are cells in our body that can change and become any other type of blood cell (such as red or white blood cells). Scientists have long used HSCs in the laboratory to study how the bone marrow in our body can regulate and instruct these blood stem cells to regenerate and repair themselves, and thus help our bodies to recover after an injury or stress (such as following radiation or chemotherapy).

In his prior research, Dr. Chute discovered that specific cells that make up the lining of blood vessels in our bone marrow (called endothelial cells) play a key role in telling HSCs how to renew and repair themselves. He further theorized that following an injury or stress to our body, the blood system as a whole will benefit as the activities and functions happening in our bone marrow directly drive HSCs to promote and accelerate recovery.

In this new study, Dr. Chute and colleagues built upon their research to specifically identify a new protein called pleiotrophin. They discovered that the protein binds to HSCs, and that it is this process that activates recovery of blood stem cells and our entire blood system.

Dr. Chute’s team conducted experiments in mouse models to administer pleiotrophin after a normally lethal dose of radiation. Results showed that HSCs and the blood system recovered faster, and in two thirds of the cases the animal survived.

Additionally, Dr. Chute’s team found in further testing that by doing the opposite and actually blocking pleiotrophin (thereby preventing it from functioning), the blood stem cells saw no advantage in recovery. This highly suggests that the protein is key in accelerating recovery of the blood system.

“We have now discovered the mechanism by which pleiotrophin can instruct blood stem cells to regenerate,” said Dr. Chute. “By modeling it for potential use in human patients, this opens the door for tremendous therapeutic possibilities.”

Dr. Chute and his team are currently pursuing a Phase I clinical trial, with the goal of accelerated recovery for patients undergoing all types of radiation and chemotherapy as well as lessened delays between treatments.

“With this discovery, we hope to provide the basis for improving outcomes for patients with cancer or other blood-related diseases and who are undergoing highly toxic treatments,” said Dr. Chute.

This research was supported by funding from the National Institute of Allergy and Infectious Diseases and National Heart, Lung, and Blood Institute. Additional funding was provided by the UCLA Broad Stem Cell Research Center.

http://www.medicalnewstoday.com/releases/283036.php

 

 

Combined therapy improves survival for patients with liver cancer who are not suitable for surgery

The mature results from a trial conducted by the Asia-Pacific Hepatocellular Carcinoma Trials Group led by the National Cancer Centre Singapore (NCCS) and Singapore General Hospital (SGH) have shown that patients who suffer from inoperable advanced hepatocellular carcinoma (HCC) may have a chance to live significantly longer by using a combined therapy.

The multi-centre phase II clinical trial was conducted at four Asia Pacific tertiary medical centres to evaluate the efficacy of combining two existing treatment modalities, Sorafenib and Selective Internal Radiation Therapy (SIRT). The combination therapy involves starting patients on SIRT using SIR-Spheres microspheres, a medical device that contains radioactive microspheres labeled with yttrium-90 for short range high energy radiation therapy, followed by systemic therapy with an oral chemotherapy drug, Sorafenib, 14 days later.

The mature results of the trial published recently in a peer-reviewed journal, PLOS ONE, show that median overall survival was 20.3 months for patients with intermediate stage HCC and 8.6 months for patients with advanced liver cancer. These final results were better than the preliminary data released in 2010.

Led by Prof Pierce Chow, Senior Consultant Surgeon at NCCS and SGH, the investigator-initiated trial, which commenced in June 2008, recruited 29 patients from four countries namely Malaysia, Myanmar, Singapore and South Korea.

“Hepatocellular carcinoma is the most common type of liver cancer with limited treatment options. About 1 million individuals are diagnosed with the condition annually and only 20 per cent of them are eligible for potentially curative treatment. This is a major concern and we aim to change that,” said Prof Chow.

“It is through collaboration with hospitals and medical centres in the region that we can further our understanding of this disease that is so prevalent in the Asian population. This multi-centre phase II clinical trial, which showed that the combination therapy improves survival, is an example of how patients can benefit from the collaboration.”

The trial also revealed that median time to progression was 15.2 months and 9 months for patients with locally advanced HCC and patients with metastatic liver cancer respectively. This means that patients are able to enjoy better quality of life for a longer period, from the time therapy starts till the disease progresses.

The results of the trial also compare favorably with the known outcomes of current monotherapy treatments such as the overall survival following transarterial embolization in Asia-Pacific patients with intermediate or advanced HCC (median 18.2 and 6.8 months, respectively).

“This is an improvement of the initial result in 2010, which were already better than treatment with either therapy alone. It is very encouraging as it justifies our perseverance in seeking a deeper understanding of how we can treat this form of cancer to achieve the best results for our patient, ” said Prof Soo Khee Chee, Director of NCCS who is also involved in the Phase II study.

The trial also demonstrated that patients with locally advanced HCC can also be downstaged to receive potentially curative treatment. In the trial two patients were downstaged to receive radio-frequency ablation. Outside of this phase II trial, four other clinical patients became amendable to surgery after treatment with SIRT and another became amendable to liver transplantation after receiving combination SIRT and sorafenib therapy. Potentially curative treatment such as surgical resection, transplantation and radiofrequency ablation are otherwise not options for patients with advanced HCC. If left untreated, they have a median survival of about 4 to 8 months.

HCC, a form of liver cancer, is the 5th most common cancer worldwide. Almost 80 per cent of HCC cases are found in the Asia-Pacific region. As the majority of patients with liver cancer do not develop any symptoms, only one in five of them can potentially be cured by surgery when diagnosed.

In view of the success of the phase II trial, the phase III multi-centre trial has commenced to determine if SIRT would help patients survive longer and would potentially be the first line therapy for advanced HCC.

http://www.medicalnewstoday.com/releases/282225.php