Can Breast Radiation Therapy Cause Sarcoma?

Can radiation therapy for breast cancer cause cancer; more specifically, can it cause a soft tissue cancer known as a sarcoma? The answer is clearly yes.


Angiosarcoma is a type of rare, rapidly proliferating, soft tissue sarcoma (STS) derived from anaplastic endothelial cells lining the blood vessel walls. They make up 4.1% of soft tissue sarcomas, which comprise 1% of all malignant tumors. Angiosarcomas are becoming recognized as a complication following radiation therapy in women receiving conservative therapy for breast cancer treatment, as well as lymphedema following axillary node dissection.

Rare (0.9 per 1,000 treated)

As the incidence of breast cancer in the western world rises, so is the incidence of radiation induced angiosarcoma of the breast (RIASB), with a cumulative 15-year incidence of 0.9/1,000 breast cancer patients receiving radiation as a means of conservative therapy, with an average age of onset of 68 years. Overall survival for post-irradiation breast sarcomas are poor, with a mean 5-year survival of 27–35%.

How it Presents

RIASB typically presents with non-specific clinical findings, such as skin thickening and discoloration, scarring, a series of little red dots, and nodularity. Under the microscope findings include a poorly defined bleeding mass, and there may be connecting blood vessel channels within the breast tissue that are lined by cancerous cells containing small and pale nuclei. Treatment generally consists of surgical resection with mastectomy, and chemotherapy to reduce the risk of recurrence.

But Radiation Has Been Recommended

For selected patients with breast cancer, the omission of radiation therapy has not only been associated by a much higher risk of local (chest wall after mastectomy, or breast after lumpectomy) and regional (lymph nodes) recurrence, but a lower survival as well (by up to 10 percent). So, on balance, the vast majority of patients who are recommended to receive radiation therapy, particularly for invasive disease, should commit to radiation therapy.

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I received an undergraduate degree from Harvard, a medical degree from Yale, and completed a residency in radiation oncology at the University of Pennsylvania. I have been blessed to be named a “top doctor” in Seattle Magazine, US News & World Report, Seattle Metropolitan Magazine, 425 Magazine, and WA magazine. Readers of the Kirkland Advertiser have voted me the top doctor (in any field) in the region. I help individuals with cancer at Evergreen Hospital, outside Seattle.

Any information provided herein is not to serve as a substitute for the good judgment of your valued health care provider.