If you've been diagnosed with recurrent breast cancer (cancer that has come back) that is metastatic (cancer that has spread beyond the breast area and surrounding lymph nodes), you may want to discuss the results of a new study with your doctor. In some cases, certain "personality" factors of recurrent metastatic breast cancer -- hormone-receptor status and HER2 status -- can be different from the original breast cancer. If the hormone-receptor status or HER2 status of the recurrent metastatic cancer has changed, it can affect the treatment plan you and your doctor develop.
The researchers looked at biopsies of cancers from 29 women. The women were thought to have metastatic disease that was a recurrence of previously diagnosed early-stage breast cancer. For each woman, the biopsy of the metastatic cancer was compared to the biopsy of the original cancer.
The biopsies showed that:
- 3 areas that were thought to be metastatic disease weren't cancer at all
- 1 lesion that was thought to be metastatic breast cancer was lymphoma, a different type of cancer
- 10 of the metastatic breast cancers had a different hormone receptor status than the original cancer; 3 cancers were no longer estrogen-receptor-positive and 7 cancers were no longer progesterone-receptor-positive
- 2 metastatic cancers were HER2-positive, but the original cancer was HER2-negative
A breast cancer's hormone-receptor status helps doctors figure out if hormonal therapy medicine would help treat the cancer. Hormonal therapy can be an effective way to treat hormone-receptor-positive breast cancer. Hormonal therapy medicines work by blocking estrogen's effects on the receptors, or by lowering the amount of estrogen produced by the body. Hormonal therapy medicines used to treat metastatic breast cancer include:
- the aromatase inhibitors: Arimidex (chemical name: anastrozole), Aromasin (chemical name: exemestane), and Femara (chemical name: letrozole)
- Faslodex (chemical name: fulvestrant)
Hormonal therapy medicines don't work on hormone-receptor-negative breast cancers.
A breast cancer's HER2 status helps doctors figure out if the targeted therapies Herceptin (chemical name: trastuzumab) or Tykerb (chemical name: lapatinib) will help treat the cancer. Herceptin and Tykerb can be effective treatments for HER2-positive breast cancers. HER2-positive breast cancers make too many copies of the HER2 gene or have too many HER2 receptors. Herceptin and Tykerb don't work on HER2-negative cancers.
Assuming that metastatic recurrent breast cancer has the same hormone-receptor status and HER2 status as the original cancer may seem logical. Still, this study suggests that these "personality" factors can sometimes change when the cancer comes back as metastatic disease. So assuming that a metastatic breast cancer's hormone-receptor status and HER2 status have stayed the same may cause a woman to get treatment that isn't the best for her situation. This study also suggests that assuming an abnormal area is definitely metastatic breast cancer without a doing biopsy also may not be correct.
If you've been diagnosed with recurrent metastatic breast cancer, you may want to ask your doctor about the hormone-receptor status and HER2 status of the recurrent cancer and how these two factors were determined. Is your treatment plan based on the hormone-receptor status and HER2 status of the original cancer? You also may want to ask whether a biopsy of the recurrent metastatic cancer should be done. Based on this study, a new biopsy might show changes in the cancer's personality that may affect treatment decisions. When you have the best and most accurate information, you and your doctor can decide on a treatment plan that's best for your unique situation.