Treatment of Mammary Paget Disease: A systematic review and meta-analysis of real-world data

Background: Because the lesions of mammary Paget disease (MPD) are often limited to the nipple-areolar com-plex, the extension of optimal tumor excision is inconclusive. Moreover, the risk of potential tumor upstaging is unknown; therefore, the application of sentinel lymph node biopsy (SLNB) is required for analysis. We sys-tematically reviewed the real-world data to evaluate the optimal treatment and potential predictors of poorer prognosis for MPD.Methods: The PubMed, Embase, and Cochrane Library databases were searched for relevant studies. Clinical studies were included if they evaluated the outcome of positive rates of SLNB, prognostic risk factors of MPD, and survival outcomes of treatments of interest for MPD, including mastectomy, breast-conserving surgery (BCS) with radiotherapy, and BCS alone.Results: A total of 38 studies with 24,062 patients were retrieved. Compared with BCS alone (21.2%), mastectomy (5.9%; P < 0.001) and BCS with radiotherapy (8; P = 0.001) had significantly lower local recurrence rates. Patients with palpable tumors (30.2%) had significantly worse prognoses than those with impalpable (3.4%) tumors in metastasis (P < 0.001), and significantly higher local recurrence rates were observed in patients with underlying invasive carcinoma (6.7%) than those with noninvasive carcinoma (4.5%; P = 0.032). The positive rate of SLNB was 17% (95% CI: 0.115-0.226).Conclusion: Except for MPD alone, BCS alone is not recommended for treating MPD with invasive ductal carci-noma and MPD with ductal carcinoma in situ. Moreover, a palpable mass, underlying invasive carcinoma, and positive lymph node status may lead to a poorer prognosis, which may be taken into consideration for the application of SLNB.