For some women, surviving breast cancer may no longer need to involve chemotherapy. Doctors have long known that many early-stage breast cancer patients who undergo chemotherapy don’t actually need it to prevent recurrence of the disease after surgery. But they haven’t known exactly which patients might safely skip the toxic treatment.
A new study published in the New England Journal of Medicine says based on the gene activity of tumor. The so-called genomic test measures the activity of genes that control the growth and spread of cancer, and can identify women with a low risk of recurrence and therefore little to gain from chemotherapy.
The MINDACT trial analyzed whether a different genomic test – the 70-gene MammaPrint test — could also determine which women needed chemotherapy with early stage breast cancer. The researchers estimated that their findings would apply to 35,000 to 40,000 women a year in the United States, and 60,000 to 70,000 in Europe. They are patients with early disease who because of tumor size, cancerous lymph nodes and other factors would normally be prescribed chemotherapy. The biggest benefit to patients, using this genomic test, is the ability to avoid the toxicities of chemotherapy (potentially including permanent nerve damage, heart failure and leukemia).
The results of the study will be of most use for cases that have fallen into a gray zone, when the disease is in an early stage but has some anatomical features that suggest it may be aggressive. But the genomic test says it is low risk.
Dr. Fatima Cardoso, an author of the study and a breast oncologist at Champalimaud Clinical Center in Lisbon, said that traditionally, women with early cancer, but a high clinical risk were usually given chemotherapy. She said that doctors knew that not all would benefit from it, but gave it to all anyway to err on the side of caution, because they could not identify which women did not really need it.
The main goal of the study was to find out whether women with a high clinical risk but a low genomic risk could safely forgo chemotherapy. The researchers said that it was safe for women with early disease and high clinical risk, but low genomic risk, to skip chemotherapy. The findings mean that 46 percent of women with early-stage disease who are thought to be at high clinical risk may be able to skip chemotherapy.
The genomic test is expensive, but the price pales in comparison to the cost of chemotherapy. By allowing patients to avoid toxic and costly unnecessary chemotherapy treatments, this particular test demonstrates the value of advanced diagnostic testing which leads to better decision-making for women with breast cancer.
Bottom line: Genomic testing and other advanced diagnostic tools are re-shaping the way we treat breast cancer and improving decision making. The end result is better for patient care and improves clinical outcomes.
About the author: Raja P. Reddy, MD is a board certified diagnostic radiologist specializing in breast imaging. He is also a contributing editor for Women’s Imaging Specialists, a leading provider of outpatient women’s imaging services in the greater Atlanta, GA area.