Treatment After Surgery

Treatment after surgery for breast cancer can include radiation therapy, chemotherapy, and/or hormone therapy.

Radiation Therapy
Radiation therapy, also known as radiotherapy, uses high-energy x-rays to kill cancer cells or keep them from growing. Often patients who have had breast-conservation therapy such as partial mastectomy (lumpectomy, excision, or quadrantectomy) will be treated with a combination of surgery and radiation therapy for five to six weeks to keep the cancer from returning.

The 2 types of radiation therapy are external radiation therapy, which is delivered outside the body by a machine that sends radiation to the cancer site, and internal radiation therapy, which involves placing a radioactive substance in a needle, seed, wire, or catheter directly into or near the tumor or cancer site. The type and stage of the cancer will determine the way your radiation therapy will be delivered.

Chemotherapy
Chemotherapy includes either systemic or regional chemotherapy. Patients treated with systemic chemotherapy are given an oral or injected medication that attacks cancer cells throughout the body. Regional chemotherapy is delivered directly to the spine, an organ, or body cavity to attack the cancer cells in that area. In both cases, chemotherapy kills cancer cells or stops them from dividing. Like radiation therapy, the type and stage of the cancer will determine how chemotherapy will be delivered.

Hormone Therapy
To be clear, hormone replacement therapy (HRT) and hormone therapy for breast cancer are different. Whereas HRT is used to replace hormones in postmenopausal women, hormone therapy for breast cancer is used to reduce or remove hormones such as estrogen to stop them from making certain cancer cells grow. Estrogen will send signals to hormone receptors to encourage this growth. With less estrogen in the body, hormone receptors receive fewer growth signals and cancer growth can be slowed or stopped. Most estrogen is produced by the ovaries before menopause; however, after menopause, most of the estrogen is made from another hormone known as androgen. Aromatase inhibitors inhibit the aromatase enzyme from turning androgen into estrogen, which lowers the amount of estrogen produced outside of the ovaries. With less estrogen in the bloodstream, there will be less estrogen to reach the estrogen receptors—a process that can slow or stop the growth of cancer cells.

Your doctor can determine whether the cancer cells in your breast have places (receptors) where hormones can attach. Receptor-positive, or hormone-dependent, breast cancer refers to cancer cells that are affected by hormones, and receptor-negative breast cancer refers to cancer cells that are not affected by hormones. If you have receptor-positive breast cancer, your doctor will prescribe treatment to reduce or block hormone production in your body.

Some patients with early stage breast cancer or breast cancer that has spread to other body areas (metastatic breast cancer) are often treated with a combination of hormone therapy and tamoxifen. An oral medication, tamoxifen binds to the estrogen receptors on tumors to reduce the risk of breast cancer in patients at high risk for breast cancer or who have noninvasive (ductal carcinoma in situ) or invasive receptor-positive breast cancer. Tamoxifen can be given for up to five years in women before or after menopause. Women with advanced (metastatic) cancer can continue taking tamoxifen as long as it's working.

Because hormone therapy with tamoxifen or estrogens can increase the risk of endometrial cancer and other serious adverse events, women treated with this approach should immediately report vaginal bleeding that is not related to menstruation and have a pelvic examination each year to check for cancer.

Femara^® (letrozole tablets) is approved for the adjuvant (following surgery) treatment of postmenopausal women with hormone receptor-positive  early stage breast cancer. The benefits of Femara in clinical trials are based on 24 months of treatment. Further follow-up will be needed to determine long-term results, safety and efficacy.