According to a new study standard radiation therapy for some breast cancer patients may not be medically required and may, therefore, be causing unnecessary serious side effects.
The study suggests some breast cancer patients facing radiation after a mastectomy may be over-treated and suffering serious side effects such as lymphedema and pulmonary problems without good reason.
The research which was conducted at Fox Chase Cancer Center involved women who had a mastectomy, but whose lymph nodes were negative and the researchers say when a woman has a tumour greater than 5 centimeters and negative lymph nodes, a mastectomy followed by radiation is recommended.
Dr. Penny Anderson, from the radiation oncology department at Fox Chase, says usually the chest wall is irradiated because it has been shown to improve survival.
Dr. Anderson says as a precaution, many radiation oncologists also treat the surrounding lymph nodes, but there is little evidence that this improves the outcome.
The researchers say irradiation of the lymph nodes under arm and above the collarbone can lead to lymphedema, a swelling of the extremities caused by fluid build up because the nodes which allow the fluids to drain have been damaged by the radiation.
They say there are also pulmonary radiation risks including pneumonitis, inflammation, scarring and fibrosis.
For the study, Anderson and her colleagues evaluated the need for irradiating these lymph nodes in women whose axillary nodal status following surgery was negative which involved 64 patients with node-negative breast cancer.
The women were treated by mastectomy and radiation from 1985-2006 - fifty-three patients received radiation therapy to the chest wall only and 11 patients received radiation to the regional lymph nodes in addition to the chest wall.