Primary Squamous Cell Carcinoma (SqCC) of the Breast

Abstract

Primary squamous cell carcinoma (SqCC) of the breast is a rare tumor that presents a unique biologic behavior. Thus, it challenges the justification for routine axillary dissection and adjuvant therapy. A MEDLINE search of all reported cases of primary SqCC of the breast was performed. Data on lymph node status, estrogen receptor (ER) and progesterone receptor (PR) status, and surgical and adjuvant treatment modalities were collected. We add three cases from our own experience. SqCC has several unique biologic characteristics; it is associated with a lower rate of lymph node metastasis at presentation (22% vs. 40-60% for infiltrating ductal carcinoma [IDC]) and a significant rate of distant metastasis without lymph node involvement. ER and PR receptor levels are usually very low. Because lymph node involvement plays a lesser prognostic and therapeutic role in this disease, we propose a more selective approach (i.e., sentinel node biopsy). The issue of adjuvant treatment remains unresolved, owing to lack of data. Surgical and medical treatment of SqCC of the breast should be tailored to fit its distinct biologic characteristics. The 5-fluorouracil-doxorubicin-cisplatin combination may be warranted in lieu of the combinations used for IDC.

Pure Primary Squamous Cell Carcinomas of the Breast: A Report of Eight Cases

“…Metastases to axillary nodes in all patients with PPSCC have been reported to range from 10% to 30% [1,4,5]. This is lower than the reported rates of 40-60% in usual ductal adenocarcinomas.…”

“…These tumors are also associated with a significantly lower rate of axillary lymph node metastasis compared to usual ductal adenocarcinoma of the breast [1,5]. Metastases to axillary nodes in all patients with PPSCC have been reported to range from 10% to 30% [1,4,5].…”

“…Most patients present with a well circumscribed palpable mass, with a median size of 3 -4 cm. In some reports more than half of these tumors measure over 5cm, with some massive lesions (> 20cm) which may displace the nipple and ulcerate through the skin [1][2][3][4][5][6][7][8][9][10]. Like our patients, the tumor occurs very rarely as breast abscess.…”

“…In our experience, it accounts for more than 0.5% of all invasive breast cancer and 68% of all metaplastic carcinoma. In PPSCC, all or the majority of the cells, are squamous type with keratinization, and the presence of some glandular features should make us disregard this diagnosis [1][2][3][4][5][6][7][8][9]. These criteria are critical to distinguish true squamous breast cancers from the common ductal carcinoma not otherwise specified with squamous metaplasia.…”

“…Prognosis of this breast cancer is poor and the disease is associated with frequent locoregional and distant metastasis [1,4]. There is no scientific evidence of the usefulness of adjuvant treatments and more studies are needed [5].…”