Dear Doctor: A friend of mine was recently diagnosed with breast cancer and is terrified of the chemotherapy her doctor is recommending. I read that some women can skip it. Is this true?
Dear Reader: Your friend's fear of chemotherapy is understandable. Its harsh side effects and its risk of toxicity to the body's organs are well-known. However, survival rates significantly improve with chemotherapy. This too is well-known -- and has been shown even in women with breast cancer that hasn't spread to the lymph nodes.
A recent study in The New England Journal of Medicine, however, has called into question the need for chemotherapy in some women who have breast cancer without lymph node metastasis. The trial looked at 9,719 women, ages 18 to 75, with cancer that was hormone receptor-positive and HER2-negative. The authors gauged the need for chemotherapy based on a genetic tool called the 21-gene breast cancer assay, which evaluates the risk of recurrence based on 16 cancer-related genes and five other genes.
In this study, women with a 21-gene score of 26 or greater received chemotherapy and endocrine therapy (medications that block the estrogen receptor in breast cancer). Those with scores of 11 to 25 received either chemotherapy with endocrine therapy (chemoendocrine therapy) or endocrine therapy alone. Those with a score of 10 or less received only endocrine therapy. The majority of women in the trial (6,711) had scores between 11 and 25.
In the group with scores of 11 to 25, no statistically relevant difference was found between those who received chemoendocrine therapy and those who received endocrine therapy alone. There was no difference in survival rates between those who received chemotherapy and those who didn't.