Radiation Therapy^1,2

Radiation therapy is treatment with high-energy rays (such as x-rays) or particles to kill cancer cells. Radiation therapy may be used to kill cancer cells remaining in the breast, chest wall, or underarm area after surgery or, less often, to shrink a tumor before surgery. Radiation to the breast is often needed after breast-conserving surgery. Radiation may also be recommended after mastectomy in patients either with a cancer larger than 5 cm, or when cancer is found in the lymph nodes.It is usually given after any chemotherapy. Radiation is also used to treat cancer that has spread to other areas, for example to the bones or brain.

Chemotherapy^1,2

Chemotherapy (chemo) is the use of cancer-killing drugs. These drugs can be put into a vein, given as a shot, or taken as a pill or liquid. They enter the bloodstream and reach most parts of the body, making this treatment useful for cancers that have spread to distant organs. While these drugs kill cancer cells, they also damage some normal cells, which can lead to side effects.

Chemo can be used either before or after surgery for early-stage breast cancer. This is to kill any cancer cells that may have spread but are too small to be seen by exam or tests.

• When chemo is given after surgery to patients who have no signs of cancer spread it is called adjuvant chemo. This lowers the chance of the cancer coming back later.
• When chemo is given before surgery to cure the cancer it is called neoadjuvant chemo. This can shrink large cancers so that they are small enough to be removed with breast-conserving surgery instead of mastectomy. It also works as well as adjuvant chemo in lowering the chance that the cancer will come back later.

Chemo can also be used as the main treatment for women with cancer that has spread to distant sites (outside the breast and the nearby lymph nodes).

Hormone therapy: (ESMO guidelines) ^1,2

• Premenopausal patients: Tamoxifen 20 mg/day for 5–10 years.
• In patients becoming postmenopausal during the first 5 years of tamoxifen, a switch to letrozole, an aromatase inhibitor (AI), seems to be particularly beneficial.
• Postmenopausal patients: Aromatase inhibitors.

Targeted therapy^1,2

Most of the targeted drugs used to treat breast cancer target HER2/neu. In some patients, their breast cancer cells have too much of this protein. Certain drugs target this protein, stopping it from causing breast cancer cell growth. These are trastuzumab, pertuzumab, ado Trastuzumab emtansine and lapatinib.