According to a new US study, after the tumor has been removed from the breast, chemotherapy would only be needed in 20% of cases for patients suffering of breast cancer.
Being able to avoid chemotherapy would be a blessing for thousands of women with breast cancer. A new US study, TAILORx, has shown that up to 70% of these women could avoid this painful treatment, which has multiple side effects. The results were presented at the annual cancer conference (ASCO) held in Chicago.
Only hormone therapy would suffice
Usually, after the removal of the tumor, many women undergo chemotherapy combined with hormonal treatment to prevent any return of the cancer. But the TAILORx study, conducted on more than 6,500 women, concluded that the level justifying this combination could be safely elevated. Indeed, a genetic test can be done at the time of the operation to predict the risk of recurrence. This test, called Oncotype Dx, gives a score between 0 and 100.
Until now, chemotherapy was highly recommended with a result greater than 25, and below 10 it was not. But what to do when the result is between 10 and 25 remained unclear.
This is where the study comes in. Women were separated into 2 groups, one receiving only hormone therapy, the other receiving chemotherapy and hormone therapy. The researchers found that 83.3% of women on hormone therapy and 84.3% of classically treated women had not seen the disease progress. In both groups 89% of women had survived the disease.
A “recalibration” of the genetic test
More specifically, in women over 50 years (whose risk of recurrence is lower), chemotherapy is useless for a score between 0 and 25. The results are similar for women under 50 with a score between 0 and 15. By contrast, when it is greater than 15, chemotherapy is necessary. Following this “recalibration” of the genetic test, the researchers estimated that chemotherapy was not justified in 70% of cases of breast cancer.