title: Using global gene expression to discriminate thin melanomas with poor outcomes.
abstract: Most melanomas present as thin lesions (≤1.0 mm) with a good prognosis; however, a small percentage of patients with thin lesions experience recurrence or metastasis. The aim of our study was to identify a distinct pattern of gene expression within thin melanomas known to have eventually metastasized to regional lymph nodes or distant sites compared with those that followed the typical course with good response to wide local excision alone. Patients who were disease-free for a minimum of 10 y served as controls (n = 10) to the experimental group who developed metastasis (n = 9). Laser capture microdissection was used to specifically isolate cancer cells from formalin-fixed paraffin-embedded tissue with subsequent gene expression analysis on Affymetrix Human Transcriptome Array 2.0 Arrays. Although gene expression differences were observed between the patients with thin melanoma with poor clinical outcome and those with good clinical outcome, neither the number of genes nor the magnitude of the fold difference was very substantial or significant. Cluster analysis with this subset of genes could definitively separate a subset of the poor responders from the good responders, but there remained a mixed group of tumors that could not be predicted from gene expression alone. Pathway analysis identified cellular processes that were regulated based on the response, including categories commonly associated with melanoma progression. Ultimately, we concluded that there were very few differences between these groups. Future research will be required and investigation of the mutational landscape may be another strategy to uncover genomic changes that drive recurrence and metastasis in thin melanoma.
authors.affiliation: Department of Surgery, William Beaumont Hospital , Royal Oak, MI, USA.
authors.forename: Zachary
authors.initials: Z
authors.lastname: Hothem
authors.affiliation: Department of Surgery, William Beaumont Hospital , Royal Oak, MI, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Bayci
authors.affiliation: Beaumont BioBank, William Beaumont Hospital , Royal Oak, MI, USA.
authors.forename: Bryan J
authors.initials: BJ
authors.lastname: Thibodeau
authors.affiliation: Beaumont BioBank, William Beaumont Hospital , Royal Oak, MI, USA.
authors.forename: Billie E
authors.initials: BE
authors.lastname: Ketelsen
authors.affiliation: Beaumont BioBank, William Beaumont Hospital , Royal Oak, MI, USA.
authors.forename: Laura E
authors.initials: LE
authors.lastname: Fortier
authors.affiliation: Department of Anatomic Pathology, William Beaumont Hospital , Royal Oak, MI, USA.
authors.forename: Alison F
authors.initials: AF
authors.lastname: Uzieblo
authors.affiliation: Department of Anatomic Pathology, William Beaumont Hospital , Royal Oak, MI, USA.
authors.forename: Diane
authors.initials: D
authors.lastname: Cosner
authors.affiliation: Oakland University William Beaumont School of Medicine , Rochester, MI, USA.
authors.forename: Kristin
authors.initials: K
authors.lastname: Totoraitis
authors.affiliation: Department of Surgery, William Beaumont Hospital , Royal Oak, MI, USA.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Keidan
authors.affiliation: Beaumont BioBank, William Beaumont Hospital , Royal Oak, MI, USA.
authors.forename: George D
authors.initials: GD
authors.lastname: Wilson
keywords: Gene expression; melanoma; microarray; surgical response; thin melanoma