Some immune-boosting cancer drugs may pose rare heart risks

By The Associated Press

Doctors have found a downside to some powerful new drugs that harness the immune system to fight cancer. In rare cases, they may cause potentially fatal heart damage, especially when used together.

The drugs are called checkpoint inhibitors. In less than one percent of patients, the immune system seems to attack not only the tumor but the heart and other muscles.

Doctors stress that this does not negate the huge benefits

of these drugs.