The side effects from radiation revolve around the breast. Towards the end of treatment the breast most likely will become pink and in a small percentage of patients there could be peeling of some of the skin. This happens most commonly were the breast tissue is moist; underneath the breast and in the armpit. The patient will not be ill from the treatment and can drive her car because there is no nausea, vomiting, diarrhea, or other major effect from the treatment on a daily basis.
There are some potential long-term side effects from treatment. The appearance of the breast may be slightly different after surgery and radiation. There can be volume loss and firmness of the breast years after radiation. However, the cosmetic outcome is good in the vast majority of patients. Some patients will have weakness of the ribs. This occurs in about 1/100 women and is related to the fact that small blood vessels feeding the ribs are at some time affected by the radiation treatment. Rib fractures may occur more frequently in these people if there is excessive stress put on the chest wall, i.e., severe coughing with the flu or pneumonia. These ribs will heal, but they will heal a little more slowly than normal.
The patient also may experience a mild reaction weeks to months after radiation. On rare occasions, a patient may have cough and fever associated with an inflammatory reaction in the lung caused by the radiation. This usually disappears in about two weeks, but an occasional patient may require the use of steroids and antibiotics to help alleviate some of the symptoms. This occurs in less than 5% of patients.
When the left breast is treated, the tip of the heart will be in the radiation beam. Older radiation techniques have shown a slight risk of pericarditis or coronary disease after breast radiation. The modern radiation techniques lower the radiation received to the heart and the risk of developing side effects of the heart is thought to be much lower. Finally, radiation not only cures cancer; it can also cause cancer. The chance of a radiation-induced cancer is very rare, on the order of approximately 1/500. A radiation induced cancer typically happens years to decades after treatment and is a completely different cancer than the original breast cancer. Most often they are soft tissue sarcomas