Treatment guidelines for early breast cancer

This article provides an overview of the new treatment guidelines for early invasive breast cancer as set by the 2013 St. Gallen Consensus.

The St. Gallen Consensus of 2011 offered the current guidelines for the treatment of early-stage breast cancers. Recently, an expert panel of 51 physicians and scientists convened to examine the latest advances in the treatment of breast cancer and update the current guidelines. The current article summarizes their recommendations for early breast cancer treatment.

Overall, the panel recommends less extensive procedures whenever possible and safe. For instance, breast conserving surgery (surgical removal of only the tumor while sparing the entire breast) has been shown to be as effective as a mastectomy (removal of the entire breast), without additional risk of cancer recurrence or mortality. However, a short course of radiation therapy is recommended for all patients undergoing breast conserving surgery. In addition, breast conserving surgery is not recommended for any patient with genetic risk factors, such as the BRCA gene mutation.

In the case of limited lymph nodes involvement (when only a very small amount of cancer cells are found in the sentinel lymph node which was removed), complete dissection of the regional lymph nodes is no longer recommended, particularly if the patient will be undergoing radiation therapy as well.

One of the major changes to the guidelines is the added recommendation of genetic testing to all breast cancer patients. Tests such as the 21-gene recurrence score (RS) measure the activity of genes that play a role in breast cancer. The level of activity in each gene can help to identify the molecular subtype of the disease, which can aid in determining the optimal treatment. For example, patients with Luminal A breast cancer (a subtype of estrogen receptor-positive breast cancer, which depends on the hormone estrogen for growth) have been shown to exhibit a limited response to chemotherapy, while patients with Luminal B breast cancer have been shown to respond well to chemotherapy treatments.

The current expert opinion now recommends additional chemotherapy treatments for patients with high levels of Ki-67 (a protein which indicates an aggressive tumor type), for patients with involvement of more than three lymph nodes and for patients with triple negative breast cancer (not dependent on HER2, progesterone or estrogen for growth).

The treatment length of hormonal and targeted therapies was also addressed in this consensus report. For patients with HER2-positive breast cancer, trastuzumab (Herceptin) should be used for at least one year. For patients with estrogen receptor-positive cancer, it is now recommended that tamoxifen treatment be extended for an additional 5 year period, for a total of 10 years following diagnosis.