Treatment of HER-2 positive breast cancer: Current knowledge.

This study wanted to analyse the various treatment plans for HER2-positive breast cancers. The study concluded that while treatment has developed significantly, ongoing work is needed to find ways to minimise any harmful side effects.

HER-2 positive breast cancer is a type of cancer where the cells have a receptor on them for the human epidermal growth factor 2 (HER-2). This receptor is on the cells in 15-20% of breast cancers. Cancers that are HER-2 positive are often hard to treat and result in a bad outcome for the patients. However, this receptor allows scientists to find medications that only work on the cells which have that receptor. A medication which targets the HER-2 positive cells is called trastuzmab (Herceptin). This medication has really helped in treating HER-2 positive breast cancers. Patients who use this medication have better outcomes in terms of how long they survive without the cancer coming back, and how long they survive overall. However, 15-24% of patients who use this medication still have problems with the cancer coming back.

This study looked at trastuzmab and compared it with other treatments being developed. First of all, the study found that adding trastuzmab to other chemotherapies is effective, but does have a small risk of having heart problems associated with it. Current guidelines say that treatment with trastuzmab should last for one year. Other studies have been done to see if extending the time of treatment to two years helps, and they found no added benefit to extended treatment. Using trastuzmab in addition to surgery to remove the tumor was also found to be a good method for treatment. Patients who had surgery and also had treatment with trastuzmab were more likely to have no traces of cancer left in their system compared to those who only had surgery.

Another cancer drug called pertuzumab (Perjeta) has been developed. It was tested alongside trastuzmab, and it was found that using both these drugs increased survival by almost 16 months, compared to just using trastuzmab. This is currently being confirmed.

The drug lapatinib (Tyverb or Tykerb) was found to not work as well as trastuzmab, and it had more side effects. Using the drugs together did not work better than just using trastuzmab alone.

The drug neratinib (Nerlynx) is another mediciation targeted for HER-2 postive breast cancers. It has been found to work well, however it is related to many side effects. It is considered a second choice compared to trastuzmab.

Finally, a new way of delivering trastuzmab is being developed, called ado- trastuzmab emtansine or T-DM1. T-DM1 works very well on patients who have cancer which has spread, or very high risk cancer. Studies are still going on to see how well this medication works.

The study concluded that trastuzmab used alongside chemotherapy has significantly improved survival in patients with early stage HER-2 positive breast cancer. Additional benefits may be seen if trastuzmab is combined with other treatments, espeically pertuzumab. 

This is a review of all the information currently available on treating HER-2 positive breast cancer.