Adenoid cystic carcinomas of the breast are rare. They make up less than 1 in every 1000 breast cancers. They usually occur in women, but men can also be affected. The tumour may found at any age from 30 onwards, the average age at the time of diagnosis is about 50.

The condition begins as a lump in the breast, which is usually very slow growing. Unlike other breast cancers, adenoid cystic carcinomas are often painful.

The cancer usually grows slowly within the breast and rarely spreads to the nearby lymph nodes under the arm (the axillary lymph nodes). If these tumours spread it is usually through the bloodstream, to the lungs, but this is uncommon and is only likely in tumours that have been present for some years before they are treated.

Because they are so slow growing, surgery usually leads to a cure. If a lumpectomy is performed, removing the cancer with a margin of normal breast tissue, there is a high risk the cancer will return in the future.   Because of this risk a mastectomy is normally recommended. It is very unusual for an adenoid cystic cancer to contain oestrogen receptors (to be ER+) and so hormonal treatment is seldom of any value in these tumours.

As most of these cancers are cured by surgery there is little information on the use of chemotherapy in their treatment.

Reference

• Nicholson BP et al. Adenoid cystic carcinoma of the breast. In, Raghaven D et al eds. Textbook of uncommon cancer, 2nd edition. John Wiley, 1998