Do all breast cancer patients need chemotherapy?

August 29, 2016 Providence Health Team

Not every woman with early-stage breast cancer need submit to a grueling regimen of chemotherapy. Many would survive five years without a recurrence of the cancer at almost the same rate as women who undergo chemotherapy.

That’s the conclusion reached by researchers who explored the genetic risks of breast cancer patients and published their results in the New England Journal of Medicine.

The European researchers reported the results of a five-year study of almost 6,700 women with early-stage breast cancer. They assessed the women’s genomic risk for recurrence of cancer as well as their clinical risk – that is, an assessment of how quickly the cancer would advance based on such factors as the woman’s age and the size of the tumor.

They concluded that women with low genomic risk but high clinical risk who received no chemotherapy survived at nearly the same rate as women who did receive chemotherapy.

Avoiding chemotherapy

In other words, getting chemotherapy did little to increase the survival rate of women in that group. This is a powerful finding considering the often-debilitating effects of chemotherapy, which can cause pain, nausea, fatigue, weakness and other problems.

“We found that chemotherapy with its attendant toxic effects could be avoided in these patients at high clinical risk but low genomic risk,” the authors wrote.

Of the women in the study with low genomic risk but high clinical risk who didn’t get chemotherapy, 94.7 percent went five years with no recurrence of their cancer. Women in the same group who underwent chemotherapy had a no-recurrence rate that was 1.5 percentage points higher.

In an editorial accompanying the results, editors of the New England Journal of Medicine said “these results could allow some doctors and patients to choose to avoid chemotherapy if they have carefully considered their own tolerance for toxicity, risk, and uncertainty.”

But they also called for more studies.

Methods for the study

The authors were interested in finding out if a genetic assessment of women with breast cancer could help inform treatment decisions, especially for those women who would normally be considered high-risk patients based on their age, the size of the tumor and other factors.

They enrolled patients at 112 institutions in nine European countries over a five-year period. The women, ages 18 to 70, had been diagnosed with early-stage invasive breast cancer.

The researchers then ran a genomic assessment that sought the signatures of 70 genes. The results allowed them to sort the patients into groups with high- and low-genomic risk.

“In conclusion,” the authors wrote, “in a large group of patients at high clinical risk for breast-cancer recurrence, the addition of the 70-gene signature to the traditional clinical and pathological factors provided valuable information for considering which patients might benefit from … chemotherapy.”

To read more

The study, “70-Gene Signature as an Aid to Treatment Decisions in Early-Stage Breast Cancer,” is available at the New England Journal of Medicine website. So is the accompanying editorial, “Increasing Precision in Adjuvant Therapy for Breast Cancer.”

The U.S. Centers for Disease Control and Prevention offers an extensive set of breast cancer resources, including statistics, risk factors and information about screening.

Providence is focused on women’s health and has resources to help you learn about—and be treated for—breast cancer.

Talk to your provider about breast cancer screening and, if you’ve been diagnosed, about options for treatment. To find a Providence provider, please check our multistate directory.

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