Advanced breast cancer patients who are treated with a combination of drugs that target specific cancer molecules are at increased risk of suffering side effects.
Researchers examined data from 16 randomized clinical trials that included more than 8,500 patients with advanced hormone receptor-positive breast cancer. The team analyzed hormonal therapies given in combination with targeted drugs such as CDK4/6 inhibitors, mTOR inhibitors and anti-HER2 agents.
The results, presented at the Advanced Breast Cancer Fourth International Consensus Conference, revealed that combining targeted drugs with hormone therapy significantly increased the risk of severe or life-threatening adverse events such as fatigue, rash, nausea, diarrhea and liver enzyme elevation.
CDK4/6 inhibitors were associated with low white blood cell counts; mTOR inhibitors were associated with sore and inflamed mouth; PI3K inhibitors were linked to hyperglycemia (high blood sugar levels); and anti-HER2 agents caused diarrhea.