Breast Cancer: Treatment...

The mainstay of breast cancer treatment is surgery when the tumor is localized, with possible additional hormonal therapy (with tamoxifen or an aromatase inhibitor), chemotherapy, and/or radiotherapy.

Breast Cancer Treatment

At present, the treatment recommendations after surgery (adjuvant therapy) follow a pattern. This pattern is subject to change as every two years a worldwide conference takes place in St. Gallen, Switzerland to discuss the actual results of worldwide multi-center studies. Depending on clinical criteria (age, type of cancer, size, metastasis) patients are roughly divided to high risk and low risk cases which follow different rules for therapy. Treatment possibilities include Radiation Therapy, Chemotherapy, Hormone Therapy, and Immune Therapy.

Breast Cancer Surgery

Depending on the staging and type of the tumor, just a lumpectomy (removal of the lump only) may be all that is necessary or removal of larger amounts of breast tissue may be necessary. Surgical removal of the entire breast is called mastectomy.

While there has been an increasing utilization of lumpectomy techniques for breast-conservation cancer surgery, mastectomy may be the preferred treatment in certain instances:

• Two or more tumors exist in different areas of the breast (a "multifocal" cancer).
• The breast has previously received radiation (XRT) treatment.
• The tumor is large relative to the size of the breast.
• The patient has had scleroderma or another disease of the connective tissue, which can complicate XRT treatment.
• The patient lives in an area where XRT is inaccessible.
• The patient is apprehensive about their risk of local recurrence after lumpectomy.

Standard practice requires the surgeon to establish that the tissue removed in the operation has margins clear of cancer, indicating that the cancer has been completely excised. If the tissue removed does not have clear margins, then further operations to remove more tissue may be necessary. This may sometimes require removal of part of the pectoralis major muscle which is the main muscle of the anterior chest wall.

During the operation, the lymph nodes in the axilla are also considered for removal.

Breast Cancer Radiation therapy

Radiation therapy consists of the use of high powered X-rays or gamma rays (XRT) that precisely target the area that is being treated. These X-rays or gamma rays are very effective in destroying the cancer cells that might recur where the tumor was removed. These X-rays are delivered by a machine called a linear Accelerator or LINAC. Alternatively, the use of implanted radioactive catheters (brachytherapy), similar to those used in prostate cancer treatment, is being evaluated. The use of radiation therapy for breast cancer is usually given after surgery has been performed and is an essential component of breast conserving therapy. The purpose of radiation is to reduce the chance that the cancer will recur.

Radiation therapy works for breast cancer by eliminating the microscopic cancer cells that may remain near the area where the tumor was removed during surgery. Since by the nature of radiation and its effects on normal cells and cancer cells alike the dose that is given is to ensure that the cancer cells are eliminated. However, the dose cannot be given in one sitting. Radiation causes some damage to the normal tissue around where the tumor was but normal healthy tissue can repair itself. The treatments are given typically over a period of five to seven weeks, performed five days a week. Each treatment session takes about fifteen minutes per day. Breaking the treatments up over this extended period of time gives the healthy normal tissue a chance to repair itself. Cancer cells do not repair themselves as well as normal cells, which explains the efficacy of radiation therapy.

Although radiation therapy can reduce the chance that breast cancer will recur in the breast, it is much less effective in prolonging patient survival.

Indications for radiation

Indications for radiation treatment are constantly evolving. Patients treated in Europe have been more likely in the past to be recommended radiation after breast cancer surgery.

Radiation therapy is usually recommended for all patients who had a lumpectomy or quadrant-resection. Radiation therapy is usually not indicated in patients with advanced (stage IV disease) except for relief of symptoms like bone pain.

In general recommendations would include:

• As part of breast conserving therapy of breast cancer when the whole breast is not removed (lumpectomy or wide local excision)
• After mastectomy: Patients with higher chances of cancer recurring such as : large primary tumor and involvement of 4 or more lymph nodes.

Types of radiotherapy

Radiotherapy can be delivered in many ways. Most commonly this is done using radiation from linear accelerators. Since this is delivered from outside, one needs to restrict the amount of dose that can be given at one time so that normal tissues are not harmed. So the course usually lasts for several days, typically every day for 5 to 6 weeks.

Side effects of radiation therapy

The side effects of radiation have decreased considerably over the past decades. Aside from general fatigue caused by the healthy tissue repairing itself, there will probably be no side effects at all. Some patients develop a suntan-like change in skin color in the exact area being treated. As with a suntan, this darkening of the skin will fade with time. Other side effects experienced with radiation include the fact that radiation therapy can and often does cause permanent changes in the color and texture of skin, in addition to:

• reddening of the skin
• muscle stiffness
• mild swelling
• tenderness in the area
• long-term shrinking of the irradiated breast

Systemic therapy

Systemic therapy uses medications to treat cancer cells throughout the body. Any combination of systemic treatments may be used to treat breast cancer. Systemic treatments include chemotherapy, immune therapy, and hormonal therapy.
Chemotherapy
Chemotherapy (drug treatment for cancer) may used before surgery, after surgery, or instead of surgery in those patients who are unsuitable for surgery.

Hormonal treatment
Patients with estrogen receptor positive tumors will typically receive hormonal therapy after chemotherapy is completed. Typical hormonal treatments include:

• Tamoxifen is typically given to premenopausal women to inhibit the estrogen receptors
• Aromatase inhibitors are typically given to postmenopausal women to lower the amount of estrogen in their systems
• GnRH-analogues
• ovarian ablation or suppression is used in premenopausal women

Targeted therapy
In patients whose cancer expresses an over-abundance of the HER2 protein, a monoclonal antibody known as trastuzumab (Herceptin®) is used to block the activity of the HER2 protein in breast cancer cells, slowing their growth. This drug was originally used only in the treatment of patients with metastatic disease, however in the summer of 2005 two large clinical trials published results suggesting that patients with early-stage disease also benefit significantly from Herceptin. The drug was approved by the FDA in 1998 for the treatment of metastatic breast cancer, though oncologists have also been using it since 2005 for postoperative patients with localized, Her-2/neu positive disease.