Local and Systemic Therapy

Local therapies such as surgery and radiation are used to treat the main or primary breast tumour. Systemic therapies such as chemotherapy and hormonal therapy are given through the bloodstream to reach cancer cells that may have spread beyond the breast.

Treatment of Breast Cancer by Stage

Staging is the process of finding out how far the cancer has spread. Your treatment and the outlook for your recovery depend on the stage of your cancer. Treatment choices for breast cancer depend not only on the stage of the disease, but also on other factors, such as your health and personal preferences.

In general, the lower the number, the less the cancer has spread. A higher number, such as stage IV (4), means a more serious cancer.

Stage 0: There are two types of stage 0 cancer, ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS). Most women with LCIS do not need treatment but close follow-up is important. This condition increases the risk of later developing cancer in either breast.

Treatment for DCIS includes:

• lumpectomy, usually with radiation therapy
• mastectomy, depending on mammography and biopsy results

Stage I: One option is lumpectomy with removal of lymph nodes under the arm followed by radiation therapy. Another option is modified radical mastectomy. Additional therapy may follow the surgery depending on the size and other features of the tumour.

Stage II: Surgery and radiation therapy options for stage I and stage II tumours are similar, except that in stage II, radiation therapy may be considered after mastectomy if the tumour is large or has spread to many lymph nodes. Adjuvant therapy may include chemotherapy, hormone therapy or both.

Stage III: Some combination of surgery (lumpectomy or a modified radical mastectomy), chemotherapy, radiation and hormone therapy is often used. Sometimes chemotherapy (with or without hormonal therapy) is given both before and after the surgery.

Stage IV: Systemic therapy is the primary treatment, using chemotherapy, hormonal therapy or both. Radiation and/or surgery may also be used to provide relief of certain symptoms.

Chemotherapy

Chemotherapy refers to the use of anticancer drugs to kill cancer cells, which may have spread to other parts of the body. It is given by injection or in pills. Chemotherapy can also be used as a treatment for cancer which has become widespread or if the origin of the cancer is unknown.

Chemotherapy may also be given after surgery. This is called adjuvant therapy. It can reduce the chance of breast cancer's return. It may also be given before surgery (neoadjuvant chemotherapy) to shrink the tumour and make it easier to remove.

Side effects depend on the dosage of the drugs, the length of treatment and the individual. They may include:

• nausea and vomiting
• loss of appetite
• hair loss
• mouth sores
• changes in menstrual cycle including menopause
• a higher risk of infection caused by a shortage of white blood cells
• fatigue
• rarely, more severe side effects such as leukemia or heart failure

Chemotherapy is given in cycles, with each period of treatment followed by a recovery period. The total course lasts three to six months. It is often more effective to use several drugs, rather than a single drug alone.

Radiation Therapy

• can be combined with a lumpectomy
• can be used in treating cancer that has spread to distant sites
• uses high-energy rays to destroy cancer cells remaining in the breast, chest wall or underarm area after surgery
• sometimes used to reduce the size of a tumour before surgery

Radiation destroys cancer cells, but it also destroys normal cells in the surrounding area. 
Temporary side effects may include:

• swelling and heaviness in the breast sunburn-like
• changes in the treated area
• fatigue

Patients are usually treated five days a week on an outpatient basis for four to five weeks.

Hormonal Therapy

In some women, estrogen has been found to increase the growth of breast cancer cells.

Tumour growth may be suppressed by reducing the level of the female hormone estrogen. Drugs such as tamoxifen, which blocks the effect of estrogen, are given to counter this growth. Tamoxifen is taken in pill form, usually for five years.

Other drugs called aromatase inhibitors, block the production of estrogen. Drugs in this group include anastrozole and letrozole. These drugs are sometimes used instead of tamoxifen or if tamoxifen has not worked.