New Study Can Prevent Heart Damage in Patients Cured of Cancer

Researchers have now identified which patients would suffer chemo-induced cardiac side effects.

Cancer patients who receive a particular type of chemotherapy, called doxorubicin, run a risk of sustaining severe, lasting heart damage. But until now, there was no way of knowing who would experience this serious side effect. It was also not known exactly how the drug damages heart muscle. But now, a team of researchers has shown that heart muscle cells made from the skin cells of breast cancer patients who suffered cardiac side effects after receiving doxorubicin respond more adversely to the drug than cells made from patients who did not.

Doxorubicin is a chemotherapy drug used to treat many cancers, but it causes serious heart damage in some patients. Heart muscle cells made from the skin cells of breast cancer patients were used to study this phenomenon. These cells provided researchers with a sorely needed platform to study the effects of doxorubicin exposure on human heart muscle cells. The study can also identify the patients who should avoid the drug.

Study Findings

For this study, the researchers collected skin cells from 12 women, eight of whom had been treated at Stanford for breast cancer. Out of the study group

• 4 had experienced heart damage in response to the drug
• 4 had no heart damage in relation to the drug, and
• 4 served as healthy control subjects

“We found that cells from the patients who had experienced doxorubicin toxicity responded more negatively to the presence of the drug,” said Paul Burridge, PhD, an assistant professor of pharmacology at Northwestern University. “They beat more irregularly in response to increased levels of doxorubicin, and we saw a significant increase in cell death after 72 hours of exposure to the drug when we compared those cells to cells from healthy controls or patients who didn’t have heart damage.”

The researchers found that the doxorubicin-sensitive cells experienced higher levels of DNA damage and of reactive oxygen species in the presence of doxorubicin. These cells were also significantly more likely than cells from healthy controls or from patients who didn’t sustain heart damage to initiate a program of cellular suicide, which can be triggered by damage to the mitochondrial membrane. But the researchers made another telling discovery.

Heart Damage in Cancer Patients: Avoidable

Nearly 8% of cancer patients treated with doxorubicin will experience heart damage. Sometimes the damage is so severe that patients would need a heart transplant. The failing heart function is due to the death of the cells in the organ’s muscle tissue. This situation is a huge medical dilemma for patients who are relieved to be cured of cancer but then later end up suffering a heart disease because of the same chemotherapy that cured them.

If health practitioners can predict and identify the patients that are susceptible to doxorubicin’s heart damage, it would greatly benefit cancer patients.