The purpose of the current study was to assess the outcome of breast-conserving therapy by means of a cone excision and radiotherapy in patients with Paget disease of the nipple without associated invasive breast carcinoma.

Between 1987 and 1998, 61 eligible patients were registered in the European Organization for Research and Treatment of Cancer Study 10873. The majority of patients (97%) presented without an associated palpable mass. At histologic examination, the majority (93%%) of patients had an underlying ductal carcinoma in situ (DCIS); in the remaining 7%, only Paget disease was found. Treatment was comprised of a complete excision of the nipple-areolar complex including the underlying breast tissue with tumor free margins, followed by external irradiation to the whole breast (50 gray in 25 fractions). The primary endpoint was local recurrence.

At a median follow-up of 6.4 years, 4 of the 61 patients developed a recurrence in the treated breast (1 patient with DCIS and 3 patients with invasive disease). One patient with an invasive local recurrence died of disseminated breast carcinoma. The 5-year local recurrence rate was 5.2% (95% confidence interval, 1.8-14.1%).

Breast-conserving therapy is a feasible alternative for patients with Paget disease and a limited extent of underlying DCIS. To achieve good local control, treatment should be comprised of a complete excision of the nipple-areolar complex including the underlying disease, followed by irradiation to the whole breast.