C L I N I C A L A N D L A B O R A T O R Y I N V E S T I G A T I O N S Noninvasive genomic detection of melanoma W. Wachsman,* V. Morhenn, § T. Palmer,– L. Walls,* S. Mraz,§§ K. Gross,–– H. Rabinovitz,*** D. Polsky T. Hata, J. Zalla,** R. Scheinberg, and S. Chang– H. Sofen, *Research Service, VA San Diego Healthcare System, San Diego, CA 92161, U.S.A. Division of Hematology–Oncology and Moores Cancer Center, Department of Medicine, University of California San Diego, La Jolla, CA, U.S.A. Division of Dermatology, Department of Medicine, University of California San Diego, La Jolla, CA, U.S.A. §Therapeutics Clinical Research, San Diego, CA, U.S.A. –DermTech International, Inc., La Jolla, CA, U.S.A. **Dermatology Associates, Florence, KY, U.S.A. Dermatologist Medical Group of North County, Oceanside, CA, U.S.A. Dermatology Research Associates, Los Angeles, CA, U.S.A. §§Solano Dermatology Associates, Vallejo, CA, U.S.A. ––Skin Surgery Medical Group, San Diego, CA, U.S.A. ***Skin and Cancer Associates, Plantation, FL, U.S.A. Departments of Dermatology and Pathology, New York University School of Medicine, New York, NY, U.S.A. BJD British Journal of Dermatology Correspondence William Wachsman. E-mail: wwachsman@ucsd.edu Accepted for publication 21 January 2011 Funding sources Support for this investigation was provided by DermTech International, Inc. (La Jolla, CA, U.S.A.), who also provided the tape strip packets used for sample collection. Conﬂicts of interest W.W. was a recipient of research support from a UC Discovery award, co-sponsored by the University of California and DermTech International, and is an uncompensated member of the DermTech scientiﬁc advisory board; T.P. and S.C. are employees of DermTech and have DermTech stock options; J.Z. owns stock in DermTech; H.R. was an uncompensated member of DermTech’s melanoma advisory board, is a member of the scientiﬁc advisory board of Mela Sciences, and receives research support from Mela Sciences, Lucid, Spectral Image, Inc. and SciBase AB; D.P. is a member of DermTech’s melanoma advisory board; V.M. is a consultant to DermTech. DOI 10.1111/j.1365-2133.2011.10239.x Re-use of this article is permitted in accordance with the Terms and Conditions set out at http:// wileyonlinelibrary.com/onlineopen#OnlineOpen_ Terms Summary Background Early detection and treatment of melanoma is important for optimal clinical outcome, leading to biopsy of pigmented lesions deemed suspicious for the disease. The vast majority of such lesions are benign. Thus, a more objective and accurate means for detection of melanoma is needed to identify lesions for excision. Objectives To provide proof-of-principle that epidermal genetic information retrie- val (EGIR ; DermTech International, La Jolla, CA, U.S.A.), a method that non- invasively samples cells from stratum corneum by means of adhesive tape stripping, can be used to discern melanomas from naevi. Methods Skin overlying pigmented lesions clinically suspicious for melanoma was harvested using EGIR. RNA isolated from the tapes was ampliﬁed and gene expression proﬁled. All lesions were removed for histopathological evaluation. Results Supervised analysis of the microarray data identiﬁed 312 genes differen- tially expressed between melanomas, naevi and normal skin specimens (P < 0Æ001, false discovery rate q < 0Æ05). Surprisingly, many of these genes are known to have a role in melanocyte development and physiology, melanoma, cancer, and cell growth control. Subsequent class prediction modelling of a train- ing dataset, consisting of 37 melanomas and 37 naevi, discovered a 17-gene classiﬁer that discriminates these skin lesions. Upon testing with an independent dataset, this classiﬁer discerned in situ and invasive melanomas from naevi with 100% sensitivity and 88% speciﬁcity, with an area under the curve for the recei- ver operating characteristic of 0Æ955. Conclusions These results demonstrate that EGIR-harvested specimens can be used to detect melanoma accurately by means of a 17-gene genomic biomarker. BJD 2011 The Authors 2011 British Association of Dermatologists 2011 164, pp797–806 797