Invasive Breast Cancer^*

If you are diagnosed with early-stage breast cancer (invasive disease), your doctor will likely recommend surgery to remove the tumor and any other cancerous tissue surrounding it. One of the reasons breast cancer is challenging to treat, however, is the possibility that it can come back, or recur, after initial treatment. This is why surgery is often followed by additional treatment, such as chemotherapy, hormone therapy, and/or radiation therapy.

To determine breast cancer treatment options for you, you and your doctors should consider the specific implications of various treatments. For example, you should discuss a treatment's ability to reduce the likelihood that your breast cancer will return, and contrast this with likely side effects from that particular treatment.

You may already know that chemotherapy can treat breast cancer effectively, but it does have side effects. Also, chemotherapy does not benefit all women equally. In fact, studies have shown that, on average, less than 10% of patients with early-stage estrogen receptor-positive ( ER+ ), lymph node-negative breast cancer who are treated with hormone therapy derive a benefit from chemotherapy in addition to hormone therapy.

Before deciding whether chemotherapy is right for you (in addition to hormone therapy), you and your doctor should consider how likely your breast cancer is to return and how much benefit you are likely to get from additional treatment, such as chemotherapy. The individual likelihood of your breast cancer returning can provide you and your healthcare team with insight into appropriate treatment options for your breast cancer.

Non-Invasive / Ductal Carcinoma In-Situ (DCIS) Breast Cancer

DCIS is an early or pre-invasive form of breast cancer that poses challenging decisions for patients and physicians in determining how to best treat the disease. Unlike invasive breast cancer, the tumor cells in DCIS are confined to the milk ducts within the breast. Breast-conserving surgery (usually lumpectomy), rather than mastectomy, has become the most common surgical procedure for DCIS. For DCIS patients after breast conserving surgery alone, local recurrences of DCIS or a new invasive breast cancer occur, on average, in 20-25 percent of patients at 10 years. However, the vast majority (65-70 percent) of DCIS patients go on to receive radiation. While the addition of radiation therapy for DCIS has been shown in clinical trials to reduce local recurrence risk, it has not been shown to prolong survival in DCIS patients (unlike invasive breast cancer, where the addition of radiation significantly reduces the rates of distant metastases and improves survival between treated and untreated patients).¹ Similar to chemotherapy, radiation has significant side effects and to date, there have been no clinically validated molecular markers that clearly identify which patients might be low-risk and avoid radiation and which patients might be high-risk, for whom the side effects of radiation might be worth obtaining a reduction in local recurrence risk.

Please note: This Web site contains a number of medical terms related to breast cancer that are highlighted. When you click on these terms, you will be taken to a Glossary that contains their definitions.