Extraordinary news from the U.S. on a study conducted by doctors from a number of cancer centers including Memorial Sloan Kettering, Dana-Farber, Vanderbilt University and University of Michigan. The Study is published in the New England Journal of Medicine.
The leading cancer center in this study, Montefiore Medical Center in New York has found that there are thousands of breast cancer patients that are receiving chemotherapy unnecessarily.
A test is conducted that looks at 21 genes within the tumor. The score from this test predicts whether chemotherapy is a benefit to the patient or not.
The low scores mean no need for chemo and the high scores mean chemo is recommended.
But what happens with all the patients with mid range scores. That’s what this study looked at – women who’s scores fell in the mid range, between low and high.
This study registered over 10 000 women between 2006 and 2010 and completed research up to 96 months post treatment. These patients had a specific type of cancer – hormone receptor positive, axillary node negative, which accounts for approximately half the cases of breast cancer in the U.S.
Patients with mid range scores were randomly placed into two groups:
- endocrine therapy only (such as tamoxifen or tamoxifen & aromatase inhibitor)
- chemotherapy and endocrine therapy
There were a number of findings that were reviewed over the years of the study to determine the percentage of woman who survived, had invasive disease, recurrence of disease etc.
From the study:
“The estimated 9-year rates of invasive disease–free survival in the as-treated population were 83.1% for patients who received endocrine therapy alone and 84.7% for those who received chemoendocrine therapy.”
The study concludes that many patients are no longer going to have chemotherapy recommended as treatment when endocrine therapy provides essentially the same results.
A word of caution to women less than 50 years old with this type of cancer: the study found that chemotherapy still provided some benefit in this age category.
You can see the whole study here:
New England Journal of Medicine Article
and the NY Times article here:
NY Times article on breast cancer study
Chemotherapy Side Effects
Aside from the side effects during treatment, there are many long term side effects.
These can include problems with many of the body’s systems including:
changes to the endocrine system
Take a look at the blog post about Cardiotoxicity.
Here’s the link:
Chemotherapy Side Effects: Cardiotoxicity