Analysis of Melanocytes (Pigment Cells) in Sun-Exposed Skin
The purpose of this study is to estimate and define the mean number, degree of confluence, and depth of penetration of melanocytes in chronically sun exposed skin of the head and neck using Mart-1 immunostains on frozen sections. The study was conducted to confirm whether similar results were found using permanent sections. The present study used hematoxaline and eosin (H&E) staining as well as Mart-1 staining, and included patients from both Mayo Clinic Jacksonville and Rochester.
Carcinoma, Basal Cell
Carcinoma, Squamous Cell
|Study Design:||Observational Model: Case-Only
Time Perspective: Prospective
|Official Title:||Immunohistochemical Analysis of Melanocytes in Sun-Exposed Skin|
- The mean number of melanocytes per high power field for Mart-1 was 12.7 in FL and 11.2 in MN. Using H&E, the means were 10.3 and 8.3 for FL and MN respectively. [ Time Frame: one year ] [ Designated as safety issue: No ]
- Evidence of higher means in FL than in MN after adjusting for age and gender (p<0.001 for H&E, p=0.08 for Mart-1) and strong evidence of an increase in observed numbers of melanocytes with use of the Mart-1 stain compared to the H&E stain (p<0.001) [ Time Frame: one year ] [ Designated as safety issue: No ]
Biospecimen Retention: Samples Without DNA
The proposed dog-ears excised, that were to be discarded during reconstruction, were evaluated for the presence of any visible lesions (i.e. ephelid, lentigo, seborrheic keratosis, nevi). Dog-ears with any skin lesions were excluded. The specimens were inked by the surgeon on the side to be cut by the histotechnician. The specimens were placed in formalin bottles and submitted to the pathology department at Mayo Clinic Rochester for processing. The tissue was cut (4 microns) along its long access and stained with routine H& E and Mart-1 (MelanA) immunostains.
|Study Start Date:||September 2007|
|Study Completion Date:||December 2007|
|Primary Completion Date:||December 2007 (Final data collection date for primary outcome measure)|
For each study participant we recorded their age, sex, state they lived in, tumor type, tumor location, recent sun exposure (during the two weeks prior to the surgery), whether or not a follicle was present on the slide, and if so the follicular extension (mm) from the granular layer, presence of atypia, nesting, pagetoid spread. Two slides were obtained; one stained with Mart-1; the other with H&E. For both, melanocyte counts per high power field (400 X HPF magnification) were obtained in three locations of the slide. The mean of the 3 counts was used for analysis, though the individual counts were considered in some data summaries (see below). Classification of photo-aging according to the Glogau scale was noted by the surgeon as type1: "no wrinkles"; type II "wrinkles in motion"; type III "wrinkles at rest" and type IV "only wrinkles." Confluence was categorized by the number of adjacent melanocytes as none, mild (2 side-by-side), moderate (3-6), or severe (7 or more).
Please refer to this study by its ClinicalTrials.gov identifier: NCT00875381
|Principal Investigator:||Lawrence E Gibson, MD||Mayo Clinic|