Chemotherapy: Testing Helps, But It's Still a Tough Decision

Patient Expert

When a woman is diagnosed with early stage breast cancer, whether or not to undergo chemotherapy can be a very difficult decision.

Genomic testing (mapping the activity of genes in a cancer tumor) can help make the decision-process easier by revealing whether a woman’s risk of recurrence is high or low — but it’s not foolproof. How do you ultimately decide whether or not to have chemo?

A recent article in the New England Journal of Medicine details a randomized phase 3 study that assessed the accuracy of the MammaPrint test, one of several genomic tests available to oncologists. The test surveyed 70 different genes in more than 6,600 women with early stage breast cancer, then used that information to predict how likely the cancer was to recur for each woman.

A subset of the entire group was classified as being at low risk according to the test, but high risk according to standard measures of assessment (size of tumor, grade, spread to lymph nodes, etc.) Women in this group were randomized for treatment: some received chemotherapy, and some didn’t.

By the end of the study, data showed that those who didn’t receive chemo were just 1.5 percent more likely to have a recurrence than those who did — and this despite every outward indication showing that chemo would offer a significant benefit.

Why is this important? It indicates that many women who currently receive chemo based on traditional methods of assessment would remain cancer free even without that devastating treatment.

The genomic test most widely used in the U.S. is the Oncotype DX test, which assigns women a score of 0-100 based on a tissue sample of their tumor. A low score indicates low risk of recurrence; a high score, high risk. Women with low recurrence risk can more confidently consider skipping chemo than those at high risk.

Still, all the tests in the world can’t guarantee the result you hope for. You might be in the small group of low-risk women who have a breast cancer recurrence; or the high-risk group who stays cancer-free.

So how do you decide whether or not to have chemo?

See More Helpful Articles:

Chemo: Yes or No? New Research Validates Oncotype DX

Will My Cancer Come Back? New Tool Predicts Risk

Chemotherapy’s Hidden Side Effect: It’s Devastating

Chemotherapy: Dealing With Side Effects

Making Hard Decisions Regarding Cancer Treatment and Care

Breast cancer survivor and award-winning author PJ Hamel_, a long-time contributor to the HealthCentral community, counsels women with breast cancer through the volunteer program at her local hospital. She founded and manages a large and active online survivor support network. _