Adenoid cystic breast carcinoma: is axillary staging necessary in all cases? Results from the California Cancer Registry.

Adenoid cystic carcinoma (ACC) is an uncommon type of breast cancer. There are limited data about its epidemiology, tumor characteristics, and outcomes. Using a large, population-based data base, this study aimed to identify specific characteristics of patients with adenoid cystic breast cancer, investigate its natural history, and determine its long-term prognosis. The California Cancer Registry, a population-based registry, was reviewed from the years 1988 to 2006. The data were analyzed with relation to patient age, tumor size and stage, and overall survival. Relative cumulative actuarial survival was determined using the Berkson-Gage life table method. A total of 244 cases of invasive adenoid cystic cancer were identified in women during this time period. The patients' median age was 61.9 years. Most cases were diagnosed in non-Hispanic White women (82%, n = 200), followed by African American (6%, n = 15), Asian/Pacific-Islander (5.7%, n = 14) and Hispanic women (4.4%, n = 12). The remainder of the patients was of unknown or other ethnicity. Tumors were between 1 and 140 mm in size. At the time of diagnosis, 92% (n = 225) of patients had localized disease, 5% (n = 12) of patients had regional disease, and even fewer (n = 7) had either distant or unknown staged disease. Lymph node involvement was not present in any tumors smaller than 1.4 cm. The relative cumulative survival of patients with adenoid cystic breast carcinoma was 95.6% at 5 years and 94.9% at 10 years. ACC of the breast is a rare disease with an overall good prognosis. Knowing that this cancer usually presents as localized disease, with lymph node involvement seen only with larger tumors, can help clinicians plan the operative management of these tumors.