Endocrine therapy and targeted therapy are safe for patients over 65 with HR+/HER2- advanced breast cancer

This study aimed to evaluate the effectiveness and safety of endocrine therapy, with or without targeted therapy, for patients with advanced metastatic breast cancer. This study concluded that the use of endocrine therapy and targeted therapy is safe for use in patients over 65. 

There are several treatment options for hormone positive, HER-2 negative advanced breast cancer (dependent on hormones such as estrogen for growth). Endocrine therapies (ET, such as letrozole) are commonly used. These act by decreasing the hormone estrogen. However, other treatments are also being developed.

Palbociclib (Ibrance), ribociclib (Kisqali), and abemaciclib (Verzenio) are treatments that inhibit the proteins CDK4 and CDK6. They are important in regulating the cell cycle and cell growth. Blocking these proteins has shown to slow the growth of hormone positive breast cancer. 

Everolimus (Afinitor) and temsirolimus (Torisel) are treatments that interact with a protein called mTOR, which regulates the cell cycle. This treatment has been shown to slow the growth of tumor cells. 

The role of ET, with or without targeted therapy, is unclear in the setting of metastatic (spread) breast cancer in an older population. 

This study examined 10 clinical trials. Between 24.1% and 46.1% of the patients in these trials were 65 years or older. 

The effectiveness of ET and targeted therapies were similar for all ages. Risk of disease progression was reduced with the use of targeted therapies like palbociclib, ribociclib, and everolimus with ET as compared to ET alone. In older patients, the average time to disease progression with first-line treatment of ET and palbociclib was 26.2 months. It was 18.8 months in younger patients. Average time to disease progression with ET and temsirolimus was 8.5 months for older patients and 8.5 months for younger.

Combination treatment was associated with a higher rate of side effects. Depending on the trial, older patients were more likely to experience decreased appetite, low white blood cells, low red blood cells, and fatigue. Decreases in medication dose and stopped treatment were similar between the two age groups. 

This study found that the combination of targeted therapies with endocrine therapy was safe and effective in older patients. 

This study only looked at Stage 2 clinical trials, which are not the best measure of effectiveness. 

Discuss these treatments with your doctor.