Women who are at high risk for developing a common type of breast cancer may not need chemotherapy if they undergo a genetic test to assess the nature of their tumor, a new, large study has shown. The study results, presented at the annual meeting of the American Society of Clinical Oncology, in Chicago, could save thousands of patients from unindicated treatment, while also improving their quality of life.
Why chemotherapy decisions can be challenging?
A major dilemma in the treatment of breast cancer for years has been the question of when and whether it is necessary for certain patients to receive chemotherapy. Chemotherapy saves lives, but also comes with serious side effects such as loss of hair, nausea, tiredness, high risk of infections, heart or nerve damage after a while and fertility problems.
How the Prosigna genetic test works?
Its new approach is a genetic test identified as Prosigna, which looks for the level of activity of certain genes associated with cancer within the tumor. The test examines whether genes are turned on or off as a way of evaluating the tumor to make a diagnosis rather than by relying on traditional indicators like the size of the tumor or whether cancer has spread to nearby lymph nodes. It then creates a score that helps to predict the aggressiveness of the cancer and the likelihood of the cancer returning.
A low score implies the cancer is not as intense and can be adequately treated with surgery, radiotherapy and hormone therapy. For these patients, chemotherapy might not be very useful. Higher however suggests even more risk of reoccurrence and also chemotherapy will be more efficient.
The results, as well as being drawn from one of the largest trials of its kind, come from a trial known as Optima Trial. The research team led by University College London managed a trial that involved over 4,400 patients, aged at least 40, with the most common type of cancer, HER2-negative, hormone-sensitive early breast cancer.
There were two groups of participants. The chemotherapy recommendation for one group of patients was made using traditional clinical factors, and for the other group, the recommendation was made using Prosigna. Patients were followed for several years after treatment and compared to other patients.
Key findings from the study
Findings indicated that over two-thirds of women that would typically be considered for chemotherapy according to their standard risk assessment, actually scored low in Prosigna and could safely forego chemotherapy. Importantly, those treated compared poorly over time to those who were conventionally treated.
Survival rates with and without chemotherapy
When comparing those who did and did not undergo chemotherapy, 5-year survival rates were 94.7% and 94.9% respectively. Based on this small difference, researchers found that the potentially lower side effects and complications from treatment outweighed this difference.
The study doesn’t mean, however, that chemotherapy is not needed anymore. About one-third of the patients scored as high risk, which suggests that chemotherapy continues to be a vital treatment of theirs. The absence of this test sometimes leaves us without the ability to choose and direct specific treatment to those who might most benefit and so give the sensitive person key choices to avoid.
Disclaimer: This article is for informational and educational purposes only and is not intended to replace professional medical advice, diagnosis, or treatment. Patients should consult their oncologist or healthcare provider.
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