Factors Associated With Metastasis of Eccrine Porocarcinoma: A Retrospective Cohort Analysis of National Cancer...

Eccrine porocarcinoma is a rare cutaneous adnexal malignancy. Factors associated with metastasis of porocarcinoma and evidence for the utility of sentinel lymph node biopsy are incomplete within the literature.

Determine prognostic factors that may guide the decision to pursue sentinel lymph node biopsy in patients with porocarcinoma.

Retrospective analysis of the National Cancer Database and the Survival, Epidemiology, and End Results databases for cases of porocarcinoma. Multivariable logistic regression was performed examining tumor size and lymphovascular invasion for association with metastasis of porocarcinoma. The cumulative probability of sentinel node metastasis was calculated as a function of tumor size.

A total of 1,351 patients were identified; 75 (5.6%) had a positive lymph node on pathology and 15 (1.1%) had distant metastatic disease. Patients with tumors greater than 17 mm in size had a 6.8% risk of occult lymph node metastasis identified by sentinel lymph node biopsy. In the subset of tumors analyzed for lymphovascular invasion, 40% (14 of 47) had metastasized at diagnosis.

Tumor size and lymphovascular invasion affect metastasis of porocarcinoma. Tumors greater than 17 mm in size or with lymphovascular invasion warrant consideration of sentinel lymph node biopsy.