By Sarah Webb
Taking It to Heart
Hodgkin’s survivors face a long-term heart attack risk
By Sarah Webb
One consequence of surviving Hodgkin’s lymphoma is coping with the long-term effects of lifesaving therapies. The five-year survival rate for the disease is now 85 percent, compared with just 29 percent in 1950, before Hodgkin’s was treated with radiation and chemotherapy. But due to such therapies, survivors may be facing two and a half times the risk of dying of a heart attack compared with the general population, for at least 25 years after treatment, according to a study in the Feb. 7 Journal of the National Cancer Institute.
“It is a consequence of the success of treatment that we are finding these things,” says Anthony Swerdlow, an epidemiologist at the Institute of Cancer Research in Sutton, in the United Kingdom, and the study’s senior author. “Forty, 50 years ago this wouldn’t have happened because the patients wouldn’t have survived.”
Swerdlow and his colleagues analyzed data from more than 7,000 British patients who had been diagnosed with Hodgkin’s lymphoma between 1967 and 2000 and whose follow-up was tracked through September 2000. Of those patients, 166 died of heart attacks. Patients who had been treated with wide fields of radiation, such as total nodal irradiation, had death rates from heart attack that were nine times those of the general population.
Current treatments typically focus radiation therapy more precisely at cancerous tissue. Patients treated with mantle radiotherapy, which is focused on the neck, chest and lymph nodes in the armpits, showed a rate of lethal heart attacks three times that of the general population.
The researchers found that a survivor’s risk, compared with the risk of a similar person who hadn’t been treated for cancer, spiked in the first year after treatment and peaked again 15 to 19 years later. Hodgkin’s survivors aged 55 to 64 showed the greatest extra risk of dying of a heart attack. Researchers could not evaluate the effects of different doses of radiation or the influence of other risk factors for heart disease, such as smoking or high blood pressure.
Chemotherapy regimens that included anthracyclines or vincristine were also linked to higher death rates by heart attack, the researchers found. Previous studies have shown that these drugs can be toxic to the heart.
The study supports what doctors have known for a long time: High doses of radiation and drugs like anthracyclines can cause serious heart damage, says John D. Boice Jr., an epidemiologist at the International Epidemiology Institute in Rockville, Md., and at the Vanderbilt-Ingram Cancer Center in Nashville, Tenn.
Because the study looked at deaths from heart attacks, “it may just be the tip of the iceberg,” Boice says. “There may be much larger numbers of survivors who have heart disease that does not result in death.”
Cancer patients need to be aware of the risk factors associated with their treatments, such as heart attacks or secondary cancers, says Hildy Dillon, the vice president of patient services disease programs at the Leukemia & Lymphoma Society in White Plains, N.Y. As patients prepare for and complete treatment for Hodgkin’s lymphoma, they should keep complete medical records and work out clear long-term care plans with their oncologists.
The normal recommendations for cardiovascular health—such as not smoking, eating a healthy diet, exercising, and monitoring cholesterol and blood pressure levels—are particularly important for Hodgkin’s survivors, Boice adds, “because it’s possible that the patients are starting out with some heart damage.”