A new first-line chemotherapy treatment for metastatic HER2- breast cancer

The authors aimed to assess the value and safety of eribulin mesylate (Halaven, a chemotherapy drug) when used to treat women with recurrent (the cancer has returned) or metastatic (the cancer has spread) breast cancer.

Human epidermal growth factor 2 negative (HER2-, not dependent on HER2 for growth) breast cancer is more common and generally more positively associated with survival than HER2+ breast cancer. However, differences in hormone receptors (whether or not the cancer is dependent on the hormones estrogen or progesterone for growth) may affect a woman's survival.

Currently, eribulin mesylate chemotherapy is used in patients who have already undergone two other chemotherapy treatments. It is thought that women with recurrent or metastatic breast cancer may benefit from eribulin mesylate as a first line of chemotherapy.

The aim of this study was to determine whether eribulin mesylate could be used as a first-line treatment in women with HER2- metastatic breast cancer.

56 women with HER2-, metatstatic breast cancer were included in this study. eptor-2 (HER2-). 73% of these women had estrogen-receptor positive (ER+; dependent on estrogen for growth) breast cancer. 21% had triple negative breast cancer (not dependent on either hormones or HER2 for growth). Patients recieved an average of 7 cycles of eribulin.

28.6% of patients showed a response to treatment (such as tumor shrinkage). 34.1% of women with ER+ breast cancer showed an improved response, compared to 16.7% of those with triple negative breast cancer.

Average progression-free surivial (time from treatment until disease progression) was 6.8 monhts. 52% of patients showed a response to treatment that lasted at least 6 months.

Neutropenia (a reduction in neutrophils, a type of white blood cells) occured in 50% of patients. Nerve damage in the arms and legs occured in 21% of patients, and leukopenia (reduction in white blood cells) occured in 21%. While neutropenia was the most common severe side-effect, it did not disrupt treatment.

The authors concluded that eribulin mesylate was a valuable first-line chemotherapy treatment with minimal side-effects and toxicites.