Adenoid Cystic Carcinoma of the Breast: Profile of Cases Between 2000 and 2010 at National Cancer Institute of Brazil – INCA

INTRODUCTION: Adenoid cystic carcinoma of the breast (ACCB) is rare, accounting for less than 0, 1% of the mammary carcinomas. It is an unusual variant of adenocarcinoma that usually occurs in the salivary glands. In contrast of the aggressiveness of this tumor at other sites, ACCB has a favorable prognosis. Its rarity has made them difficult to study systematically. The objective of this study was to characterize the clinical features of patients with ACCB at our institution. METHODS: A search in the database of the department of pathology of the National Cancer Institute of Brazil (INCa) from 2000 to 2010 was performed and the cases of ACCB were identified. Its clinical features where reviewed from each clinical records and analysed. RESULTS: Six patients with ACCB were identified from database. The age of diagnosis ranged between 46 and 67 years (an average of 56, 5 years). We found six patients: five women and one man. All initial presentations were as palpable breast masses, ranging from 1, 0 cm to 15 cm. Surgical treatment was performed to all of the patients: 3 had mastectomy with sentinel lymph node biopsy (SLNB), 2 had lumpectomy with SLNB and 1 had mastectomy with axillary lymphadenectomy. All axillary nodes studied were negative. The patients with breast conservative surgery had adjuvant radiotherapy. One patient had positive estrogen recptor (ER) and progesterone receptor (PR) and had used tamoxifen. Another patient had positive ER and negative PR and didn’t had hormone therapy. The other four cases had negative hormone receptors. C-ERB-B2 was quantified only in 3 cases, with negative results. Adjuvant chemotherapy was used in only one patient. Average follow up was 60 months, with a range of 24 to 96 months. All patients are alive, without evidence of disease activity, in annual follow-up. DISCUSSION: ACCB is described as a rare type, low growing rate, and with a good prognosis. The incidence of lymph node metastasis is lower and distant metastases are uncommon. This tumor occurs predominantly in women aged between 50 and 64 years. The most frequent presenting symptom is a well demarcated movable mass which may be discomfort on palpation if there is growth in the perineural spaces. The imaging features of this tumor have rarely been described. Primary treatment of ACCB of the breast is surgical and may be treated with breast conservation therapy with negative margins; mastectomy can be offered. Radiation following breast conservative surgery is used to reduce local recurrence rates. The role of adjuvant chemotherapy is completely unknown. CONCLUSION: ACCB is a rare, indolent evolution, unusual metastasis and good prognosis type of breast cancer. There is no consensus related to better treatment or whether it should be treated differently than ductal carcinoma. The cases treated in our hospital had evolution according to descriptions available in the literature.