Paget's disease of the breast: the experience of the European Institute of Oncology and review of the literature.

BACKGROUND: Paget's disease of the breast is an uncommon presentation of breast malignancy, accounting for 1-3% of all the breast tumors and presents in different histopathologic patterns: in association with an underlying invasive or non invasive carcinoma, or without any underlying neoplasia. In the literature, different methods are used for the treatment. Mastectomy with or without axillary dissection has been considered as the standard treatment procedure for many years. Several studies have already shown that breast conservation with radiation therapy is an oncologically safe option. Regarding the axillary approach, several studies have documented the presence of positive sentinel lymph node even in Paget's disease alone. The objective of this study was to retrospectively analyze outcome of patients affected by Paget's breast disease and to define our institutional experience. PATIENTS AND METHODS: Between May 1996 and February 2003, 114 patients with confirmed Paget's disease of the breast were retrieved and underwent surgery at the European Institute of Oncology of Milan, Italy. The median age of the patients was 54 years at the time of the diagnosis. In our study, the histopathological examination of the operated specimen revealed one hundred seven patients with Paget's disease associated with an underlying invasive or non invasive carcinoma, and seven patients without underlying carcinoma. Patients underwent either conservative breast surgery or mastectomy, with or without sentinel lymph node biopsy and/or axillary surgery. Each patient was evaluated after surgery at a multidisciplinary meeting to selecting systemic therapy.
RESULTS: Seven patients had "pure" Paget's disease of the breast and one hundred seven had the disease associated with an underlying carcinoma. As surgical techniques 71 mastectomies and 43 breast conserving surgeries have been performed. Complete axillary dissection was done in patients with clinically positive lymph node and/or sentinel lymph node biopsy positive. Sentinel lymph node biopsy was performed in nineteen patients with invasive component and five were positive and underwent axillary dissection. Eleven sentinel lymph node biopsies were done in patients with non invasive component and none of them was positive. Adjuvant systemic therapies were based on the final tumor, node and metastasis stage: thirty patients received adjuvant chemotherapy alone, fourteen received endocrine treatment alone, twenty-six patients were evaluated to receive both chemo and endocrine therapy. The median duration of follow up was 73 months and was updated in the last 6 months. Five patients developed local recurrence, one had regional recurrence, another two had loco-regional recurrences and fourteen had distant metastasis as a first event. Malignancy-related deaths were censored in the statistical analyses cancer for and due to another tumor in eleven patients. Additionally, deaths were not related to malignancy totally in thirteen patients.
CONCLUSIONS: Screening examination and imaging techniques are fundamental. Breast conserving surgery combined with breast irradiation for patients with invasive and non invasive breast carcinoma has become the treatment of first choice. All surgical conservative approaches should include the complete nipple-areolar complex and margins of resected specimen free of tumor. Thanks to the evolution of the conservative approach, good cosmetic result can be obtained. To be informed about the axillary lymph node status and to avoid the patient to have a second surgical approach, sentinel lymph node biopsy should be performed.