Ask the Care Team
If I have an early breast cancer removed and my lymph nodes are negative, will having chemotherapy lower my risk of a recurrence?
Many women today are diagnosed with early breast cancer that has not spread to the underarm lymph nodes or other parts of the body. After surgery to remove the cancer, most women will have some kind of whole-body, or systemic, treatment to help prevent the cancer from reappearing in the breast or elsewhere. These systemic treatments can include chemotherapy and/or hormonal therapy, such as tamoxifen or an aromatase inhibitor. Women at lower risk of recurrence may receive no treatment or a hormonal therapy alone; women at higher risk may get chemotherapy alone or in combination with hormonal treatment.
Until recently, doctors could estimate a woman's risk only in averages for her age and tumor type. Today, a new genetic test can offer some women a more individualized assessment of their recurrence risk. Oncotype DX, a test that uses microarray analysis (see "Chipping away at cancer,"), measures the activity of 21 genes in a sample of the tumor that was removed during surgery.
This test is only useful for women with Stage 1 or Stage 2 breast cancer that is estrogen receptor-positive and lymph node-negative. It costs about $3,500, is still relatively new, and not all insurers covers it.
The results of an Oncotype DX test are given in the form of a "recurrence score" indicating how high the risk of breast cancer recurrence would be if the patient were treated with tamoxifen alone. Scores, which do not reflect risk percentage, were classified as follows:
- Less than 18: a low risk of recurrence outside the breast (51 percent of the women in a large trial were in this group),
- 18 to 30: a medium risk of distant recurrence (22 percent of the women were in this group),
- 31 or higher: a high risk of distant recurrence (27 percent of the women were in this group).
Post-surgical chemotherapy would be strongly considered for women with scores over 30, while those with scores under 18 may not benefit from it. The test also may help determine which patients respond best to chemotherapy and which are likely to do best with hormonal therapy.
"The decision on whether to use chemotherapy can be made based on conventional criteria for most women with early breast cancer," says Ian Krop, MD, of the Breast Oncology Center at Dana-Farber. "But there are circumstances in which a gene-based test such as Oncotype DX can provide additional, useful information. It is not a test that can be used alone to make a decision; other factors must be considered.
"Oncotype DX is just the first of a new generation of tests," Dr. Krop adds. "And current research into the molecular characteristics of breast cancer will lead to more powerful prognostic tools that will allow us to precisely tailor therapy to the individual woman."
