Hume, Celyne Bueno

Abstract Background: Adenoid cystic carcinoma of the breast is a rare type of breast cancer accounting for approximately 0.1% of all breast cancer and less than 200 cases are reported in the literature. Hence, data for treatment and outcome are limited. This retrospective review reports the Mayo Clinic's experience.Methods: We identified 30 patients between 1971 and 2009 who were diagnosed with adenoid cystic breast cancer at Mayo Clinic Rochester, Arizona or Florida. Median follow-up was 62 months with a range of 1 to 424 months. Data regarding demographics (age, gender, and race), tumor characteristics (size, grade, and margin status), biological features (Estrogen receptor (ER), Progesterone receptor (PR) status, HER2 status) and clinical course (recurrence, secondary treatment) were collected. Disease free survival was calculated using Kaplan Meier estimates.Results: The median age of all patients was 58 (range, 22 – 78 years). All were female. Median tumor size was 1.3 cm (range, 0.6 – 8.5cm). Axillary lymph node sampling (sentinel or complete dissection) was performed in 15 patients. No patient had lymph node positive disease on presentation. The majority of patients had hormone receptor negative disease. Only 3 patients (10%) had weak hormone receptor (1-10%) positivity. No tumors were HER2 positive. Only two patients had high grade disease. Initial surgical data only available in twenty one patients: fifteen (50%) were treated with lumpectomy and adjuvant radiation, and 6 (20%) were treated with mastectomy. There were no local recurrences. Only one patient was treated with adjuvant chemotherapy (with cyclophosphamide, methotrexate and fluorouracil (CMF) followed by tamoxifen) but still suffered a distant recurrence within 5 years. There were a total of five patients that recurred. The 5-year disease free survival (DFS) rate for the entire cohort was 90%, and 10 year DFS was 83%. Median time to recurrence was 47.5 months (Range, 23-77 months). Recurrence occurred almost exclusively in patients with ≥ T2 disease. The primary site of metastases was lung (80%) and bone (20%) but subsequent liver and brain metastases were also seen. Treatments at relapse included surgical resection, radiosurgery and chemotherapy.Conclusion: Adenoid cystic carcinomas of the breast are rare but have overall good prognosis. This review confirms that the majority of these patients present with node negative disease, low to intermediate histologic grade and endocrine unresponsive tumors. Primary treatment is surgery (mastectomy or lumpectomy plus radiation) and there seems to be no role of any adjuvant therapy at the present time. In general, recurrences (80%) occurred with tumors larger than 2 cm and adjuvant chemotherapy and/or targeted therapy could be explored for selected patients in the context of a clinical trial. Overall mortality after recurrence was 50% but median overall survival was variable in years (1-14 years). Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2055.

Abstract Disparities in clinical outcomes of breast cancer have been described among different racial and ethnic groups in the U.S. Convincing data exist showing that Latina women have a lower incidence of breast cancer but a higher breast cancer–related mortality rate compared with white women. Noticeable differences in breast cancer incidence are present even within different Latina subsets with a higher incidence in second- and third-generation women compared with foreign born. An increasing amount of data exists pointing to significant differences in the genetics and biology of breast cancer in Latinas as a significant contributor to the higher mortality, including a higher incidence of triple-negative breast cancers (which do not overexpress HER-2 protein and are negative for estrogen receptors and progesterone receptors). Other social and environmental factors are likely to play a significant role as well, including a lower rate of screening mammography, variable access to medical care, among others. Recent data are inconclusive regarding differences among racial/ethnic groups in the response to chemotherapy. Data on racial/ethnic variations in the pharmacogenomics of chemotherapy, endocrine treatments, and toxicity are more limited, with some data suggesting differences in frequencies of polymorphisms of genes involved in the metabolism of some of these agents. Further studies are needed on this subject.