Radiation Raises Women’s Risk of Heart Disease Only Slightly, Study Finds

Story First Appeared on The Wall Street Journal

Radiation treatment for breast cancer can increase a woman’s risk of heart disease, doctors have long known. But the size of the added risk has not been clear.

Now, a new study offers a way to estimate the risk. It finds that for most women the risk is modest, and that it is outweighed by the benefit from the treatment, which can halve the recurrence rate and lower the death rate from breast cancer by about one-sixth.

According to the study, a 50-year-old woman with no cardiovascular risk factors has a 1.9 percent chance of dying of heart disease before she turns 80. Radiation treatment for breast cancer would increase that risk to between 2.4 percent and 3.4 percent, depending on how much radiation hits the heart.

“It would be a real tragedy if this put women off having radiotherapy for breast cancer,” said Sarah Darby, a professor of medical statistics at the University of Oxford in Britain, and the lead author of the study, published Wednesday in The New England Journal of Medicine.

Dr. Silvia Formenti, the chairwoman of radiation oncology at New York University Langone Medical Center, said she worried that women with cancer would misconstrue the findings to mean that radiation is dangerous and that they should have their breasts removed instead of having lumpectomies, in order to avoid radiation.

“There is a wave toward mastectomy in this country,” Dr. Formenti said.

But at the same time, she and other experts say that the cardiovascular risk is real and that when radiation is given, every effort should be made to minimize exposure of the heart.

In addition, women who have had radiation treatment need to be especially vigilant about controlling other factors that increase the odds of heart disease, like high blood pressureand cholesterol.

Dr. Lori Mosca, the director of preventive cardiology at NewYork-Presbyterian Hospital/Columbia University Medical Center, who was not involved in the study, said the findings meant that a history of breast irradiation should be added to the list of risk factors for heart disease and taken into consideration by all doctors who are treating such patients.

“We absolutely need to put on our radar screen that prior radiation to the breast may be a new and important risk factor for women,” Dr. Mosca said.

But she and other experts also warned that the results needed to be verified because the study was not a controlled experiment, but was based on an analysis of records and estimates of radiation exposure to the heart.

Dr. Javid Moslehi, co-director of the cardio-oncology program at the Dana-Farber Cancer Institute in Boston and the author of an editorial accompanying the study, said the research was the first to provide risk estimates correlated with doses in breast cancer treatment, over a long time period.

“This is a huge paper, both in terms of how many women it impacts, and how it opens the door for new studies that need to be done,” Dr. Moslehi said.

He said the study reflected the fact that many people with cancer are now living long enough to encounter long-term effects of both radiation and chemotherapy.

They have given rise to a new and fast-growing field in medicine, cardio-oncology.

About three million women in the United States have been treated for breast cancer, and the majority have had radiation.

Although doctors try to spare the heart, it still gets some of the dose, especially when the left breast is treated. Radiation can damage the linings of blood vessels and scar the heart muscle.

Dr. Darby’s study is based on the records of 2,168 women who had radiation for breast cancer from 1958 to 2001 in Sweden and Denmark; 963 of the women had “major cardiac events” sometime after their cancer treatment, meaning a heart attack or clogged coronary arteries that needed treatment or caused death.

From the treatment records, the researchers estimated the radiation dose to the women’s hearts. They found that the risk began to increase within a few years after exposure, and that it continued for at least 20 years. The higher the dose, the higher the risk, and there was some increase in risk at even the lowest level of exposure.

“It was certainly a surprise to us that the risk started within the first few years after exposure, as radiation-related heart disease has traditionally been thought of as usually occurring several decades after exposure,” Dr. Darby said.

Radiation is measured in units called Grays, and the researchers found that for each Gray to which the heart was exposed, the odds of heart attack or another coronary events rose by 7.4 percent. The average dose to the heart over an entire course of radiation treatment was 5 Gray, they said. For an individual woman, the net effect would depend on her baseline initial risk of heart disease and the total radiation dose to her heart.

Women who already had risk factors, especially those who had had heart attacks in the past, would have seen the largest absolute risk from radiation.

Some radiation oncologists say that nowadays, the dose to the heart is lower than 5 Gray.

Dr. Louis S. Constine, vice chairman of radiation oncology at the University of Rochester Medical Center, said that 2 Gray was more common and that doctors could now put shields in front of the heart and “curve radiation around the chest wall instead of shooting it through the heart and lungs.”

Dr. Formenti thinks that for most patients, the best way to protect the heart is to treat them while they are lying on their stomachs, instead of the usual way, lying on their backs. Women lie on a table or a mattress with openings that let the breasts drop away from the chest.

Anatomy differs, but in most women this prone position helps keep the radiation beams as far as possible from the heart and lungs. The heart still receives some radiation, but significantly less than when women lie on their backs, especially when the left breast is being treated.

“If you can keep it below 1 Gray, which is what we are doing, you are probably O.K. with the majority of patients,” Dr. Formenti said.

During the past 15 years, she said, she has treated several thousand patients this way.

Dr. Formenti and her colleagues also teach the technique to other doctors. But, she said, it is taking a long time to catch on.

Experimental Breast Cancer Treatment Proving Beneficial

story first appeared on usatoday.com

Vickie Baker did not have time for breast cancer.

The 49-year-old Hazard resident knew she needed radiation therapy, but she couldn't imagine how she could get to University Hospital in Louisville for treatments five days a week. Not when she lives more than three hours away and babysits eight grandchildren.

But a University of Louisville study allowed her to receive radiation treatment just once a week in March and April, after a lumpectomy in January.

Baker, who is doing well today, said the experimental treatment for people with early stage breast cancer made her life easier and offered hope for the future.

Dr. Anthony Dragun, a radiation oncologist at the University of Louisville's James Graham Brown Cancer Center who is overseeing the study, hopes it will make radiation treatment more accessible to women facing such obstacles as distance, transportation problems and time constraints — while also cutting treatment costs by more than half.

Research subjects get higher doses of radiation once weekly than they would receive during each daily treatment, but less radiation during the overall five-week course of treatment. Traditional daily radiation schedules are also usually five weeks, but in some cases may be six or seven weeks.

Some areas of the country have better access to this type of treatment. A Cancer Specialist Detroit procedure might be available in areas less rural than in Appalachia.

Dragun led a study two years ago showing that about a third of Kentucky women with early stage breast cancer didn't get recommended radiation treatments after lumpectomy surgeries.

Among those least likely to get radiation were the elderly, African Americans and women in rural areas, including the Appalachian region of the state.

Women who did not get recommended radiation were 60% more likely to die during the time they were studied.

Dragun said that many times studies like these are published but never followed through to the next step, but made sure that wasn't the case here.

He said he's hopeful about the new regimen. In his study and previous European studies, women getting weekly radiation report similar levels of side effects as those getting radiation five days a week.

Some outside experts say the approach seems promising, but one pointed to research that found drawbacks in terms of breast appearance after once-a-week treatments.

Baker, who is scheduled for a follow-up doctor visit later this month, said she's glad to play a part in advancing the science.

Less trips, money

Dragun's study targets women with breast cancer in Stages 0-II who have undergone lumpectomies and who may be getting chemotherapy or hormonal therapy.

He said the experimental regimen not only improves access to care, but also significantly reduces treatment costs as measured by Medicare reimbursement. Five weekly treatments total $2,901, compared with $6,884 for 25 daily treatments over five weeks.

And that doesn't count such costs as increased medical staff time for the more frequent treatments, and wear-and-tear on the linear accelerator that provides the radiation.

Dragun said it is less costly for the health care system, and added that it also saves patients money on transportation and potential expenses such as overnight stays near cancer centers.

But Dragun said the biggest benefit is improving access to care — which can potentially save lives, while also giving patients more time with their families and less time off of work.

Baker said distance was a big obstacle for her after doctors found a lump in her right breast on a mammogram in 2011 and her family physician referred her to University.

After the lumpectomy in January, she didn't hesitate to join Dragun's research.

Baker said she and family members drove to Louisville each week, returning to Hazard the same day. Noting that she frequently takes care of her grandchildren, she predicted that, if the only option were daily radiation treatments, she would simply have skipped some.

Baker is one of 90 patients who have joined the study, which opened in January 2011 and aims to enroll 250 patients.

An article on the results among the first 42 patients has been accepted for publication in the International Journal of Radiation Oncology, and it concludes that women's tolerance of the weekly radiation compares well with recent reports of daily schedules, and the new regimen appears feasible and cost-effective.

Dr. Bruce Haffty, associate director of the Cancer Institute of New Jersey and president-elect of the American Society for Radiation Oncology, said he's aware of Dragun's research, which is one of several alternatives to daily, five-week radiation regimens being studied right now.

Haffty said radiation technology has grown more sophisticated, and such pared-down treatment schedules may someday help patients with long distances to travel.

Unequal treatment

If weekly regimens do become common, Dragun said they could be particularly helpful in such places as Kentucky, a largely rural state beset by doctor shortages, high levels of poverty and cancer disparities.

In his previous study, he and his colleagues analyzed the radiation rates for 11,914 women who underwent lumpectomies for early breast cancer, and found the percentages who didn't get radiation were 47.5% for women 70 or older, compared with 28.9% for those under 50; 43.8% for Appalachian women, compared with 30.4 for non-Appalachian women, and 35.4% for black women, compared with 33.6% for white women.

The study found that women without private health insurance fared worse. Among uninsured women, 34.4% didn't get radiation, compared with 27.8% for those with insurance, 34.5% for those with Medicaid and 42.1% for those with Medicare.

Dr. LaQuandra Nesbitt, director of the Louisville Metro Department of Public Health and Wellness, said some people believe that breast-cancer disparities could be eliminated simply by making screenings more available.

But she said the problem is much more complicated, considering big issues with access to care, timeliness of care and quality of treatment for cancer.

She said even the issue of transportation isn't as simple as it seems. In rural areas, public transportation is often scarce.

Nesbitt said new treatment schedules such as the one Dragun is studying could help — not only by reducing the number of commutes but also by improving women's quality of life.

Dragun said if his results hold up, the new treatment regimen eventually could help all early stage breast cancer patients who need radiation because less frequent treatments would be a boon to any woman juggling work and child-rearing.

Heart Tests add to U.S. Radiation Dose Concerns

Reuters

Heart imaging procedures can deliver a significant amount of radiation to patients, U.S. researchers said on Wednesday, urging patients and doctors to weigh the risks against the benefits.

They said nearly one in 10 adults under the age of 64 had a heart procedure involving radiation over a three-year period in five major healthcare markets.

"For many patients in the United States, there is a substantial cumulative radiation exposure from cardiac procedures," said Dr. Jersey Chen of Yale University School of Medicine, whose study appears in the Journal of the American College of Cardiology.

An advanced type of heart stress test called myocardial perfusion imaging, in which doctors inject a radioactive tracer in patients to test blood flow, accounted for 74 percent of radiation exposure from heart scans.

Heart catheterization and stenting -- procedures in which thin tubes are fished through blood vessels to open blocked arteries -- were the second biggest contributor to radiation exposure, Chen said.

More than half of the heart procedures using radiation were done in the doctor's own office, the team found.

"Policymakers have been concerned that there is a rise in physician office imaging and a rise in total use of imaging," Chen said in a telephone interview.

"I think there is legitimate concern that easy availability -- convenience -- makes the threshold for testing lower. Whether it is inappropriate or not, our study can't say."

While doctors disagree over how much, most agree that radiation can cause cancer, and researchers are growing concerned that an explosion in the use of medical imaging is making it more likely that patients may develop cancer.

A report last year by the National Council on Radiation Protection and Measurement found that Americans receive seven times more radiation from diagnostic scans than in 1980.

Chen's team, looking specifically at radiation exposure from heart imaging procedures in Indiana, studied medical claims records from nearly 1 million patients aged 18 to 64 insured by United Healthcare.

They calculated the annual radiation dose based on three exposure ranges: less than 3 millisieverts a year, the average exposure level for people from the sun and environment; between 3 and 20 millisieverts a year and more than 20 millisieverts a year, the upper safety limit for workers exposed to radiation.

Of those who got Indianapolis heart procedures using radiation, most fell into the middle range but more than 3,000 patients got more than 20 millisieverts a year over the three-year period and 75 people got more than 50 millisieverts a year.

"The average patient who gets a nuclear stress test is going to get 16 millisieverts each time. It's going to increase their risk on a statistical basis," Chen said.

Dr. Pamela Douglas of Duke University in North Carolina and a former president of the American College of Cardiology said doctors need to pay attention to radiation but she said the benefits of these heart tests and procedures should be weighed against the risk that a cancer might develop down the road.

"Let's not get hysterical," she said in a telephone interview.

"Overall, patients with heart disease are doing way better. The procedures are helping people. If we can change them or tweak them to help reduce radiation exposure even more, that would be wonderful."