Derivation of a subtype-specific biochemical signature of endometrial carcinoma using synchrotron-based Fourier-transform infrared microspectroscopy Jemma G. Kelly a , Maneesh N. Singh a,b , Helen F. Stringfellow b , Michael J. Walsh a , James M. Nicholson c , Fariba Bahrami c , Katherine M. Ashton b , Mark A. Pitt b , Pierre L. Martin-Hirsch a,b , Francis L. Martin a, * a Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LAI 4YQ, UK b Lancashire Teaching Hospitals NHS Trust, Fulwood, Preston, UK c Science and Technology Facilities Council, Daresbury Laboratory, Daresbury Science and Innovation Campus, Warrington, Cheshire, UK article info Article history: Received 19 July 2008 Received in revised form 19 July 2008 Accepted 10 September 2008 Available online xxxx Keywords: Endometrial carcinoma FTIR microspectroscopy Principal component analysis Synchrotron-based radiation Tamoxifen m s PO 2  abstract Endometrial carcinoma consists of endometrioid (type I) and serous papillary (SP; type II) subtypes; a rarer form is malignant mixed müllerian tumours (MMMT; type II/mixed). We set out to determine whether one might be able to biochemically signature these subtypes using Fourier-transform infrared (FTIR) microspectroscopy and distinguish non-tamoxifen associated from tamoxifen-associated cases. Paraffin-embedded blocks were obtained from non-tamoxifen associated cases reported as endometrioid (n = 7), SP (n = 4) or MMMT (n = 4). From tamoxifen-associated cases, endometrioid (n = 1), SP (n = 3) and MMMT (n = 4) blocks were retrieved; benign tissues (n = 3) were also analysed. Exploiting synchro- tron-based radiation, sections (10-lm thick) on BaF 2 windows were interrogated through a 10 lm  10 lm aperture. Point spectra were derived from P10 locations in each of six glandular elements per tissue; a further 20 stromal spectra were obtained. Following nor- malisation to Amide I, average spectra (1800–900 cm 1 ) per gland or stroma were analysed for variance using principal component analysis (PCA) and linear discriminant analysis (LDA). In scores plots, segregation of spectra from different subtypes or benign tissues was noted and it proved possible to distinguish tamoxifen-associated cases. In the PCA- LDA loadings plots, the wavenumbers that highlighted variance for benign or endometrioid carcinoma tissues were in the protein region (1800–1480 cm 1 ) whereas those contribut- ing most to SP or MMMT segregation were primarily in the DNA/RNA region (1425– 900 cm 1 ) of the vibrational spectrum. Our results suggest that the application of FTIR mic- rospectroscopy is a powerful new approach in disease diagnosis and characterisation. Ó 2008 Elsevier Ireland Ltd. All rights reserved. 1. Introduction Endometrial carcinoma is a commonly occurring cancer in both pre- and post-menopausal women, primarily the latter [1,2]. There are two main types of disease: type I, which has a similar histology to the normal endometrium and accounts for the majority (80%) of diagnosed uterine cancers [3] and, type II (serous papillary; SP) which tends to be more aggressive with a histology far removed from the normal endometrium [1]. The 5-y survival of type I 0304-3835/$ - see front matter Ó 2008 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.canlet.2008.09.018 * Corresponding author. Tel.: +44 1524 594505; fax: +44 1524 593192. E-mail address: f.martin@lancaster.ac.uk (F.L. Martin). Abbreviations: m as PO 2  , asymmetric phosphate; BSAT, 0.2% bovine serum albumin in Tris-buffered saline (pH 7.4); DAB, 3,3 0 -diaminobenzi- dine; ER, oestrogen receptor; FTIR, Fourier-transform infrared; FIGO, international federation of gynaecology and obstetrics; IR, infrared; LDA, linear discriminant analysis; LHS, left-hand side; MMMT, malignant mixed müllerian tumour; PC, principal component; PCA, principal component analysis; RHS, right-hand side; SP, serous papillary; SNR, signal-to-noise ratio; SRS, synchrotron-based radiation; m s PO 2  , symmet- ric phosphate. Cancer Letters xxx (2008) xxx–xxx Contents lists available at ScienceDirect Cancer Letters journal homepage: www.elsevier.com/locate/canlet ARTICLE IN PRESS Please cite this article in press as: J.G. Kelly et al., Derivation of a subtype-specific biochemical signature of endometrial ..., Cancer Lett. (2008), doi:10.1016/j.canlet.2008.09.018