September 12, 2010
In Europe, around 10 percent of breast cancer diagnoses are given to women under the age of 40. Those who are given chemotherapy in addition to surgery and radiotherapy may not be benefiting from it. This is especially true if their cancer is hormone dependent and the tumors respond to the hormone estrogen. Two thirds of breast cancers are known as estrogen receptor positive (ER+) and they contain cells that have high levels of estrogen receptors. Another type of tumor is estrogen receptor negative (ER -). These grow more aggressively than positive ones but are not dependent on estrogen.
The research team looked at women from four trials to study the affect of chemotherapy and found that women with the less aggressive ER+ did not survive in greater numbers than the ER – group.
The difference in survival rates of the two groups was just 5 percent and the higher survival rate was in the ER – group, indicating that chemotherapy had no effect on the ER+ patients. In fact, over 25 percent had died seven years after the treatment.
Chemotherapy itself has numerous side-effects and can even cause death in some patients.
“Developing breast cancer at a young age is very worrying in terms of survival,” explained lead researcher Dr J van der Hage. “But some young women may be undergoing not only unpleasant but also unnecessary chemotherapy, which can be avoided. Adjuvant chemotherapy is a well established, but ineffective treatment in ER+ breast cancer patients aged 40 years or less. Hormone responsiveness is the key to tailoring therapy in the future fight against this disease for young women.”