Progress in Cancer Treatment
Progress in cancer treatment – Her2 positive breast cancer is a highly curable disease
A distinct type of Breast cancer called Her2 positive breast cancer forms 15 to 20% of all breast tumors. In the 1990s when this type of breast cancer was first described, the outcome of these patients was very poor. If left untreated, Her2 positive breast cancer patients had very aggressive cancers that spread very fast and often also went to the brain. The lifespan of these patients was less than one year.
The last 2 decades have seen a revolution in the treatment of Her2 positive breast cancer. We have over 8 good drugs to treat this disease, each is targeted against the Her2 gene drives the growth and spread of this subtype of Breast cancer.
The first reports for the successful treatment of Her2 positive Breast cancer came in 2000. Women treated with Trastuzumab, an anti Her2 antibody along with chemotherapy lived 6 months longer than with chemotherapy alone, and that too in stage 4 or advanced disease. Later Trastuzumab was moved forward and given to women with early breast cancer and succeeded in cutting down the relapse rates by half. Thus many women were cured of this disease.
The second drug that became available for the treatment of Her2 positive Breast cancer was an oral drug called Lapatinib. It is useful in patients where Trastuzumab has stopped working and is used mainly in stage 4 disease. After Lapatinib, came a drug called Pertuzumab. The combination of Trastuzumab and Pertuzumab with chemotherapy has improved the survival of stage 4 Her2 positive breast cancer patients from 3 ½ years to over 5 years. So women with disease spread to the liver, lung, and bones can now live with a good quality of life for at least 5 years if they respond to the treatment.
Another new drug in the armamentarium against Her2 positive Breast cancer is TDM1. This is a superb technology where the chemotherapy drug is embedded inside the antibody. When given to the patient, the drug is then directly delivered inside the tumor cell. This is truly a targeted approach. As can be imagined, the side effects of these anti Her2 therapies are minimal and women tolerate these treatments very well, often leading a near-normal life.
All these drugs are available in India. Although they are expensive, drug companies have come up with innovative schemes to make them affordable. If there is one type of Breast cancer worth spending on, for cure or prolongation of life, it is the subtype of Her2 positive disease.
There is another approach that is being adopted throughout the world and in India as well. For Breast tumors, more than 2 cm in size oncologists prefers to give anti Her2 therapy along with chemotherapy before the surgery. This not only shrinks the tumor and allows for better surgery, but also tells us if there is disease remaining behind at the time of tumor removal. Should there be any disease remaining then we can add another treatment like TDM1 to help the patient get cured. This is commonly referred to as a risk-adapted approach.
If one uses just Trastuzumab with chemotherapy, in 30% of women there is no disease found at the time of surgery. However, if one uses Trastuzumab and Pertuzumab with chemotherapy, no disease is found in 60 to 70% of patients. Women with no disease found at the time of surgery do especially well and have a very high chance of cure. This is useful information to have and reassuring for the patient as well.
There are many more drugs available abroad for Her2 positive breast cancer and we hope these will be available in India soon. To name a few – TDxD and Tucatinib which again have proven extremely useful in stage 4 disease and even in patients where the disease has spread to the brain.
In conclusion, Her2 positive breast cancer was considered incurable 20 years ago. With the advent of a plethora of targeted therapies against the Her2 gene – we are curing many women with Breast cancer. In the years to come, this group of patients will have the best prognosis. They will also have chemotherapy-free treatments and receive only anti Her2 antibodies, be it in early or late-stage disease. The treatment of Her2 positive breast cancer has truly been a breakthrough in cancer medicine.