Shaofeng Yan
Dartmouth Hitchcock Medical Center
USA
Title: Prognostic significance of isolated immunohistochemical positive cells in sentinel lymph nodes and metastatic tumor burden in sentinel lymph nodes from melanoma patients
Biography
Biography: Shaofeng Yan
Abstract
Histological and immunohistochemical (IHC) studies have been used to evaluate metastatic melanoma in sentinel lymph nodes (SLN). Occasionally, isolated IHC positive (IHC+) cells have been identified in SLN without atypical cells seen on H&E stained sections. We previously reported isolated IHC+ cells in lymph nodes from patients without melanoma. The aim of this study is to evaluate the prognostic significance of these IHC+ cells in SLN from melanoma patients, compared to patients with negative SLN and patients with SLN positive for metastatic melanoma. 826 melanoma patients who received a sentinel lymph node biopsy between 2000 and 2012 were identified from a tertiary medical center. Among them, 125 had metastatic disease in SLN, 639 had negative SLN and 60 had rare IHC+ cells in SLN without atypical cells seen on H&E sections. Within the SLN+ group, 51 had metastatic deposits <0.2 mm, 44 had deposits >2 mm and 30 had deposits between 0.2 and 2 mm. A control group was created by selecting 125 patients from the 639 negative SLN group to match the positive SLN group, based on age and sex. With a mean follow-up time of 58.8 months, the disease specific survival of patients with rare IHC+ cells in SLN was similar to patients with negative SLN and patients with tumor deposits less than 0.2 mm (P=0.19), but was significantly different from those with metastatic deposits between 0.2 mm and 2 mm and those with deposits >2 mm (P<0.0001). Further studies with longer follow up are needed.