Objective To explore whether Paget's disease (PD) has an effect on outcome in patients with breast cancer.
Design Retrospective analysis of comprehensive pathology database, medical records, and slides of samples showing pathologic features.
Setting UMass Memorial Health Care.
Patients All patients with breast cancer and PD with records in a prospectively maintained database between January 1, 1990, and December 31, 2008, were identified. Each participant was matched (criteria: age within 5 years, year of treatment, and stage of breast cancer) with 2 controls (1:2 ratio).
Main Outcome Measures Overall and disease-free survival were analyzed using Kaplan-Meier statistics and Cox proportional hazards modeling, accounting for matching in the latter analyses by using robust standard error estimates.
Results Mean (SD) follow-up was 47 (33) months. Treatment involved mastectomy in 29 (91%) PD vs 16 (25%) non-PD patients (P < .001), radiotherapy in 14 (44%) PD vs 53 (83%) non-PD patients (P < .001), and hormonal therapy in 14 (44%) PD vs 33 (52%) non-PD patients (P = .004). Biological markers were not significantly different except for ERBB2 (formerly HER2 or HER2/neu) overexpression in 14 (44%) PD vs 16 (25%) non-PD patients (P = .008). The PD group had an overall 5-year survival of 81.2% vs 93.8% of the non-PD group (Kaplan-Meier log-rank, P = .03). The unadjusted hazard ratio for the PD vs non-PD group was 5.31 (95% CI, 1.74-16.27; P = .003). The corresponding hazard ratio after adjusting for local and systemic treatment was 2.26 (95% CI, 0.46-11.06; P = .32).
Conclusions These exploratory data show that PD may have a negative effect on breast cancer survival. This finding needs to be substantiated in larger data sets.