The role of sentinel lymph node biopsy in extramammary paget disease: a systematic review

Sentinel lymph node biopsy is increasingly used to detect subclinical nodal metastases in extramammary Paget disease. We performed a comprehensive systematic review of the literature to further explore the role of sentinel lymph node biopsy in extramammary Paget disease. Five databases were searched for relevant terms. Articles were included if they were in English and presented primary data on at least one patient with extramammary Paget disease who underwent sentinel lymph node biopsy in the absence of lymphadenopathy or known metastatic disease. Twenty-eight articles were included, with 366 subjects. Seventy-seven sentinel node biopsies (21.2%) were positive, including 12 in which the primary tumor had microinvasion (15.6%) and 56 with deep invasion (72.7%). Of the positive cases, 11 (14.3%) had no further treatment, 54 (70.1%) underwent nodal dissection, 4 (5.2%) were treated with systemic agents, and 1 (1.3%) had radiation. After a mean follow up of 24 months, 9 subjects with a positive lymph node biopsy experienced nodal recurrence (11.7%), 15 had distant metastases (19.5%), and 13 died of the disease (16.9%). In conclusion, invasive extramammary Paget disease is strongly associated with poor outcomes including nodal metastasis, distant metastasis, and disease specific death. Sentinel lymph node biopsy is a useful tool to screen for subclinical nodal metastases in invasive disease, and can be used to help guide clinical management.