Treatment time with trastuzumab in HER-2 positive breast cancer

This study wanted to find out if shortening treatment for HER2-positive breast cancer with trastuzumab (Herceptin) from 1 year to 9 weeks would make the treatment less effective. The study found that treatment for nine weeks was not less effective than treatment for 1 year.

HER-2 positive breast cancer is a type of cancer that has a receptor on the tumor cells called HER-2. It is possible to target these types of cancer with medication like trastuzmab. Usually, treatment with trastuzumab is combined with chemotherapy. The standard length of treatment is 1 year. This long treatment time can result in issues with heart functions. It is not known if decreasing the treatment time will result in less effective treatment.

This study consisted of 1254 patients. Each patient had HER-2 positive breast cancer. The patients were randomly assigned into two groups. One group received treatment with chemotherapy and trastuzumab for one year. The other group received the same treatment, but for nine weeks only. All the patients were followed after treatment for an average of six years.

In the patients who were treated for one year, 88% of them survived without the disease for five years.  In the patients who were treated for nine weeks, 85% of them survived without the disease for five years.  After 5 years, 95.2% of the patients who were treated for one year were still alive. After 5 years, 95.0% of the patients who were treated for nine weeks were still alive.

The study concluded that decreasing treatment time of HER-2 positive breast cancer from one year to nine weeks did not significantly impact on the effectiveness of the treatment.

This is a medium sized study. It did not prove that nine weeks of treatment was better than one year. It only proved that nine weeks is not worse than one year of treatment. More study should be done into the effects of reducing the treatment time.  

Talk to your doctor about the right treatment for you.