In a nutshell
This paper studied whether palbociclib (Ibrance) used in combination with letrozole (Femara) benefits breast cancer patients who are estrogen receptor positive (presence of receptor on cells) and human epidermal growth factor receptor 2 negative (absence of receptor on cells).
Some background
Estrogen receptor and human epidermal growth factor receptor 2 (HER2) can be found on cancer cells. Drugs can specifically target these receptors and prevent cancer from growing. Palbociclib is a newly approved drug that inhibits proteins that regulate cell growth. It is suggested that it can be used together with drugs that target the estrogen receptor. Letrozole is one such a drug.
Methods & findings
Post-menopausal women with estrogen receptor-positive, HER2 negative, advanced breast cancer were studied. 84 women were randomly assigned to receive palbociclib plus letrozole. 164 women were randomly assigned to receive letrozole alone.
The average progression-free survival (time without disease worsening) was 20.2 months for patients taking combination treatment and 10.2 months for patients taking letrozole alone. A greater proportion of patients taking combination treatment had a decrease in tumor size compared to patients taking letrozole only. The average overall survival was 37.5 months among patients taking combination treatment and 33.3 months among patients taking letrozole alone.
All patients who received combination treatment and 84% of patients who received letrozole alone had at least one adverse event. Patients who received combination treatment most commonly had low white blood cell levels and fatigue. Serious adverse events only occurred among patients taking combination treatment. 3 of these patients had blocked arteries of the lungs. 2 patients had back pain and 2 patients had diarrhoea. 13% of patients receiving combination treatment and 2% of patients receiving letrozole had to stop treatment due to adverse events.
The bottom line
The authors concluded that adding palbociclib to letrozole benefits women with estrogen receptor positive and HER2-negative breast cancer.
What’s next?
Talk to your doctor about receiving palbociclib together with letrozole.
Published By :
The Lancet. Oncology
Date :
Jan 01, 2015
