Invasive breast cancer: a review

This review outlined the recommended treatment options for invasive breast cancer. 

Breast cancer is the most commonly diagnosed cancer in the world and it is the leading cause of cancer-related death in women. Breast cancer often begins in the milk ducts and lobules. In invasive breast cancer, the cancer moves beyond the milk ducts to invade breast tissue.

The National Comprehensive Cancer Network brought together a panel of experts to outline the preferred treatment options for invasive breast cancer.

The general treatment course for localized invasive breast cancer includes surgery, radiation, and systemic therapies such as chemotherapy, hormone therapy, or biological therapies. The combination of treatments used should depend on the specifics of the patient. All breast cancers should be tested for hormone receptor status (whether it depends on hormones such as estrogen for growth), HER2 status (whether it depends on HER2 for growth) and spread of cancer to the lymph nodes.

Prior to treatment, women who have not gone through menopause should be counselled on methods for preserving fertility. Embryo cryopreservation (freezing of eggs) is one option for women who want to continue to become pregnant.

Surgery is the basis of treatment for localized invasive breast cancer. Results from several studies indicate that breast-conserving therapy (lumpectomy, or removal of just the tumor, followed by radiation) is as effective as mastectomy (removal of one or both breasts). This is only true, however, if the margins around the removed tumor do not contain any cancer cells (negative margins). Positive margins are an indication for further surgery. While removing both breasts (compared to only the breast containing the cancer) generally leads to only small improvements in survival, it is recommended for younger patients (under age 35) or those with a BRCA mutation.

The lymph nodes closest to the tumor (sentinel lymph nodes) should be checked for cancer cells. Patients with positive sentinel lymph nodes should have further nodes tested.

Radiation is another cornerstone of treatment. Whole breast radiation has been shown to improve survival. This is recommended following lumpectomy, as one analysis found it decreased the risk of 10-year recurrence by 48%. Lymph nodes should also receive radiation if they were found to be positive for cancer cells. Whole breast radiation, however, is not always indicated for women over the age of 70.

Chest wall radiation is generally recommended for patients following mastectomy. It may not be necessary in patients with smaller tumors and no lymph node involvement.

Breast reconstruction is an option for women receiving surgical treatment. This can involve implants or the transplantation of tissue from other areas of the body. However, reconstruction should be carefully timed, as radiation can affect the cosmetic outcome of the breast. 

This article reviewed a variety of options and recommendations for the treatment of invasive breast cancer.