Angiosarcoma of the breast is a type of cancer that develops from abnormal cells in the walls of blood vessels or lymphatic vessels.

It is very rare. Less than 1 in 10,000 women are affected, whereas 1 in 9 women will develop one of the more common types of breast cancer in their lifetime.

There are two types of angiosarcoma of the breast, primary and secondary:

• Primary angiosarcoma tends to affect younger women in their 30s or 40s. It may cause a painless lump within the breast or the whole breast may be swollen. Sometimes it causes reddish or purplish patches of colour on the skin of the breast. It's not known what causes this type of angiosarcoma.

• Secondary angiosarcoma of the breast tends to affect women in their 60s or 70s. The cancer appears on the skin of the breast or in the scar from previous breast surgery and may cause generalised redness or patches of red, blue or purple on the skin.

It can be a late complication of treatment for breast cancer, particularly radiotherapy. Rarely it's a complication of long-term swelling of the arm and breast tissues (lymphoedema).

Angiosarcoma after breast cancer treatment is rare. Less than 1 in every 7000 women who have breast radiotherapy develop the condition. When it does occur it tends to be about 7 or 8 years after radiotherapy (although intervals of anywhere from 2 to 15 years have been reported).

Because so few women get either type of angiosarcoma of the breast no clinical trials have been possible, and there have been no studies based on large numbers of patients. So there are no agreed guidelines for how it should be treated.

Surgery is the preferred treatment when possible, for both types of the cancer. This usually involves a mastectomy. It's rare for angiosarcoma of the breast to spread to lymph nodes, so surgery to the lymph nodes isn’t usually necessary. Chemotherapy may also be given.

Women with primary angiosarcoma of the breast are sometimes given radiotherapy to reduce the risk of cancer returning after surgery. Occasionally immunotherapy drugs such as interferon may be used.

Angiosarcomas can spread to other parts of the body, most often to the lungs, and this means they cannot always be cured.

References

• Vorburger SA et al. Angiosarcoma of the breast. Cancer, 2005; 104: 2682-2688.
• Weiss SW, Goldblum JR Soft Tissue Tumors. 4th edition pp933-936.