Late Effects with External Beam Radiation
There are very real long-term side effects from external beam radiation. Fortunately, most are mild. Serious side effects are rare. Some possible long-term side effects reported by patients and doctors are discussed below.
- Slight thickening of the skin of the treated breast is common. There is also some mild increased firmness of the breast, which can be permanent. In some patients the breast may sit slightly higher on the chest than the other (untreated) breast. This is called retraction and is the result of slight scarring in the breast that occurs under the skin. Surgery and radiation both contribute to this retraction.
- The surgery and radiation may often lead to the treated breast looking different than the other breast. This is called asymmetry and this is an uncommon side effect. Often the treated breast is slightly smaller than the untreated breast, and has a small visible scar from the lumpectomy surgery. Depending on the location of the cancer, the scar that remains after the patient has healed from the lumpectomy may or may not be easily visible, and may or may not contribute to breast retraction. Scars in the very lower part of the breast are more obvious. Scars that are curved around the nipple area (called circum-areolar meaning around the nipple area) are less obvious and may even be invisible after a few months of healing. The location of the scar depends on the location of the cancer and the technique used by the surgeon.
- Tenderness in parts of the treated breast is common. This is usually very mild, and patients note it only during a breast exam or mammogram. Sometimes this tenderness is permanent, but it is usually mild. The tenderness is usually located around the lumpectomy area.
- Arm-swelling (edema) is rare with modern lymph node surgery and radiation therapy. Lymph node surgery alone will cause arm swelling in less than 10% of patients. Most of this swelling is mild, and severe swelling - that is, serious enough to affect a woman's quality of life - occurs in less than 4%. Most arm-swelling occurs in patients who have had a full axillary dissection (which removes more lymph nodes and causes more scarring) combined with external beam radiation. Arm swelling can be permanent. Sentinel node surgery has reduced arm swelling rates even more because this procedure removes less tissue from the armpit and causes less scarring. Arm swelling occurs in about 1% of patients who have sentinel node surgery and radiation.
- Nerve or muscle damage from external beam radiation is very rare. This is much less common than arm edema. In fact, most radiation doctors will never see a case of this even if they practice for many years. We only include this side effect on this list because many patients ask about this during their consultation. Most cases of serious nerve problems in breast cancer patients are actually due to cancer growth, not the treatment. And most cases of radiation-caused nerve and muscle damage occur in patients who receive unusually high doses of radiation to the axilla (armpit area), after a full axillary dissection. We think that all the scarring that occurs after such surgery and high dose radiation damages the nerves over many months or years. Such surgery and high radiation doses are essentially never used for patients with early stage breast cancer.
- Rib fractures from external radiation are rare, occurring in about 1% of patients. They occur several months after the radiation treatment and may cause a side ache for a few months. All such fractures heal themselves and no specific treatment is needed.
We have over 30 years of experience with external beam radiation. External beam radiation for breast cancer is very successful. As discussed above, with this treatment recurrence of cancer in the breast is very uncommon and side effects are usually very mild.