Second harmonic generation for collagen I characterization in rectal cancer patients with and without preoperative radiotherapy
Journal article, 2017

Rectal cancer is treated with preoperative radiotherapy (RT) to downstage the tumor, reduce local recurrence, and improve patient survival. Still, the treatment outcome varies significantly and new biomarkers are desired. Collagen I (Col-I) is a potential biomarker, which can be visualized label-free by second harmonic generation (SHG). Here, we used SHG to identify Col-I changes induced by RT in surgical tissue, with the aim to evaluate the clinical significance of RT-induced Col-I changes. First, we established a procedure for quantitative evaluation of Col-I by SHG in CDX2-stained tissue sections. Next, we evaluated Col-I properties in material from 31 non-RT and 29 RT rectal cancer patients. We discovered that the Col-I intensity and anisotropy were higher in the tumor invasive margin than in the inner tumor and normal mucosa, and RT increased and decreased the intensity in inner tumor and normal mucosa, respectively. Furthermore, higher Col-I intensity in the inner tumor was related to increased distant recurrence in the non-RT group but to longer survival in the RT group. In conclusion, we present a new application of SHG for quantitative analysis of Col-I in surgical material, and the first data suggest Col-I intensity as a putative prognostic biomarker in rectal cancer.

collagen I

rectal cancer



second harmonic generation


Stephanie Blockhuys

Chalmers, Biology and Biological Engineering, Chemical Biology

Nisha Rani Agarwal

Chalmers, Biology and Biological Engineering, Chemical Biology

C. Hildesjo

Linköping University

Linköping University Hospital

I. Jarlsfelt

County Hospital Ryhov

Pernilla Wittung Stafshede

Chalmers, Biology and Biological Engineering, Chemical Biology

X. F. Sun

Linköping University

Journal of Biomedical Optics

1083-3668 (ISSN) 15602281 (eISSN)

Vol. 22 10 106006

Subject Categories

Biochemistry and Molecular Biology



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