Update on guidelines for the use of preoperative systemic therapy in breast cancer

This report summarized important updates that have been made to the National Comprehensive Cancer Network’s guidelines for the use of systemic therapy in the treatment of breast cancer. 

The National Comprehensive Cancer Network (NCCN) is a group of 26 of the world's leading cancer centers that work together to develop treatment guidelines for cancer. This includes guidelines on the use of systemic therapy. Systemic therapies are drugs that travel through the blood to affect cells all around the body. They include chemotherapy, hormonal therapy, targeted drugs, and immunotherapy. The systemic therapy options for patients with breast cancer are complex and varied. Therapy can depend on menopausal status, the size of the tumor and whether the tumor is HER2 or hormone receptor (HR) positive (dependent on HER2 or the hormones estrogen or progesterone for growth).  These guidelines are in place to help doctors and patients make decisions on therapy.

These recommendations for the use of systemic therapy prior to surgery have been made by a panel of medical experts and are based on the evidence from clinical trials.  

It was recommended that among patients with inoper­able breast tumors, systemic therapy could be given to reduce tumor size to allow for surgery in certain patients subgroups. In patients with operable breast cancer, pre-operative systemic therapy may be given to decrease tumor size to allow for surgery that removes the tumor but conserves the breast. However if the cancer progresses while the patient is undergoing preoperative systemic therapy, then they should be taken to surgery.

Patients with HR positive cancers can be treated with therapies that block the activity of those hormones, such as tamoxifen (Nolvadex). Postmenopausal women can be treated with aromatase inhibitors (such as Femara).

A combination of palbociclib (Ibrance) and fulvestrant (Faslodex) is recommended for postmenopausal women. They are also recommended premenopausal women with HR positive and HER2-negative metastatic (spread to other areas of the body) breast cancer that has progressed despite hormonal therapy and ovarian suppression.

In patients with HER2-positive breast cancers, chemotherapy combined with an HER2 blocker, such as trastuzumab (Herceptin) is recommended. Combining trastuzumab with another HER2 blocker, pertuzumab (Perjeta) improved treatment response by 16.8%.

Based on new clinical trial evidence, the HER2 blocker ado-trastuzumab emtansine (Kadcyla) has been included as one of the first-line options for the treatment of patients with HER2-positive metastatic breast can­cer. However, a combination of trastuzumab, pertuzumab, and chemotherapy is still the preferred option.

The report concluded that ultimately, the doctor and the patient together should explore and select the most appropriate treatment option from among the available alternatives.

Not all of the recommendations are based on high-level evidence. Some recommendations are based upon lower-level evidence but with uniform NCCN agreement that the treatment is appropriate.