Using Radiation to Treat Breast Cancer

About 25% of mastectomy patents are considered to be at high risk of a breast cancer recurrence following surgery. Radiation following surgery can reduce the risk of breast cancer recurrence by about 70%. Studies have shown that even women with very small cancers (less than half an inch) benefit from having radiation following surgery.

Radiation, also called radiotherapy, targets any malignant cells left over after cancer surgery. Individual cells missed during surgery can continue to replicate and grow form a new tumor. In the case of breast cancer, radiation may also be delivered to the nearby lymph nodes under the arm.

Radiation treatment is used to treat all forms of breast cancer, from stage 0 to stage IV cancers, following either a lumpectomy (surgical removal of the lump) or a mastectomy (removal of the entire breast). 

The combination of radiation and a lumpectomy is often called breast-preservation surgery. A number of studies have established that a lumpectomy followed by radiation is as effective a breast cancer treatment as a complete mastectomy and radiation for non-invasive cancer.

The type of radiation used to treat breast cancer is not to be confused with the radiation from bombs or nuclear reactors. Highly focused and controllable, it is delivered in a special, invisible high-energy beam. Radiation therapy is painless, although some people feel a slight warmth or tingling.

Radiation is normally well-tolerated, with any side effects limited to the treated area. Unlike chemotherapy, radiation does not cause your hair to fall out.

However, radiation is not safe during pregnancy. People with connective tissue diseases such as scleroderma or vasculitis are extra sensitive to the side effects of radiation, and are not candidates for the treatment.

Radiation treatment is supervised by a radiation oncologist. There are two different ways of delivering radiation:

1. A machine called a linear excelerator.
2. Radiation emitting pellets or seeds that are implanted in the body.

The radiation works by damaging a cell's DNA, which is necessary for cells to divide and multiply. The radiation impacts both cancerous and healthy cells, but has a larger impact on cancer cells, which can't repair the damage done by radiation as well as healthy cells can.

Breast cancer radiation oncologist and www.breastcancer.org founder Dr. Marisa Weiss is says, “Cancer cell growth is unwieldy and uncontrolled - these cells just don't have their act together like normal cells do. When normal cells are damaged by radiation, they are like a big city with a fire and police department and trained emergency squads to come and 'put out the fire.' Damaged cancer cells are more like a disorganized mob with a bucket.”

A new technique (not yet available everywhere) is to expose the calls to hyperthermia prior to radiation. Hyperthermia (also called thermal therapy or thermotherapy) uses energy from an ultrasound or microwave to heat the cancer cells to a high temperature (up to 113 degrees). Some studies show that heating cells prior to radiation makes them more sensitive to radiation's effect.

The timing of radiation treatment differs according to the patient's individual treatment plan. Often radiation begins immediately after surgery, but if she is also receiving chemotherapy, the order is usually surgery, then chemo, then radiation. On occasion, chemo and targeted or hormone therapy will be given before surgery in an attempt to shrink the tumor. If the cancer is hormone receptor positive, radiation will be followed by hormone therapy (oral breast cancer drugs such as aromatase inhibitors).

There are three types of radiation:

External – the most common. A linear accelerator directs a beam of radiation at the area where the tumor was. It is usually delivered 5 days a week for 5 to 7 weeks, as an outpatient treatment. Most people continue with their normal activities.

Internal – a newer treatment still being studied for use after a lumpectomy. Small "seeds" of radioactive material are implanted in the area where the tumor was. These seeds emit radiation directly into the surrounding tissue. Internal radiation has the advantage of reducing the amount of radiation to surrounding tissue, and is less time consuming. The treatment can be conducted with either low dose (an inpatient procedure) or high dose seeds (an outpatient procedure). The course of treatment varies with the dose, but it's usually a maximum or five days. Sometimes, internal radiation is used as a "booster" at the end of external radiation.

Intraoperative – a newer type of radiation that is given during surgery directly after a lumpectomy, before the patient is stitched up.

The most common and complained about side effect of radiation is a sunburn-like reaction to the skin - redness, itching, burning, tenderness and sometimes peeling. Other side effects are less common, but some patients experience pain in the underarm area, fatigue, lowered white blood cell counts, chest pain and heart and lung problems. Any side effects typically disappear in a few weeks following treatment, although the fatigue may linger for a few months.

Because healthy cells are exposed to the maximum tolerable dose of radiation during radiotherapy, patients can't have a full dose of radiation again in the same area should the cancer recur, to prevent causing damage to normal cells.