Chemotherapy Is Not Needed In The Treatment of Most Early Breast Cancers: TAILORx Trial Results

Overtreatment of medical conditions has become the most talked about topic in medicine.  Every medical speciality is looking at overtreatment and how to minimise it. 
 
There are two main reasons why this is happening.  First, if a patient is not going to benefit from treatment, then we as doctors are placing these patients under unnecessary risks of complications from the treatment.  Secondly, we are wasting the resources that should be used for other treatments that patients would benefit from.
 
One part of overtreatment in breast cancer is looking at who might and who might not benefit from chemotherapy in the treatment of breast cancer.  One such trial is TAILORx (Trial Assigning IndividuaLised Options for Treatment) which has shown that chemotherapy is not necessary for a majority of women with early breast cancer. 
 
This trial included over 10,000 women who had hormone-positive (oestrogen and/or progesterone positive), HER2 negative and lymph node-negative breast cancer.  Their cancer tissue was tested with Oncotype DX genetic test.  This test does not screen for inherited predisposition to cancer.  It checks for accumulated genetic mutations profile of the woman's individual cancer.   
 
Despite the diagnosis of early breast cancer, up to 30% of these women will develop recurrences within 10 years.  Chemotherapy is recommended to reduce the risk of this relapse, but the overall benefit is minimal (3-5%) of all women.  All these women receive endocrine treatment consisting of Tamoxifen or Aromatise Inhibitor tablets.
 
Oncotype Dx test is used to predict the risk of recurrences.  Women with a low score (0-10), have a low risk of recurrence (2%) and these women will not benefit from chemotherapy.  Women with a high score (26 or higher), are at higher risk of recurrence and would benefit from having chemotherapy. 
 
TAILORx has conclusively shown that women with the intermediate score (11-25) would not benefit from receiving chemotherapy. 
 
This study allows us to make individualised treatment recommendations based on each woman's breast cancer profile.
 
Unfortunately, Oncotype Dx is not funded in New Zealand.  It costs almost $5000.00 to have this test performed.  I believe that individualised cancer treatment (based on the genetic profile of cancer) will be the standard of care in the next 5-10 years. 
 
I hope that New Zealand will soon have this, or a similar test funded.