Abstract 5312: Near-infrared multichannel Raman spectroscopy with a 1064-nm excitation wavelength for ex vivo diagnosis of gastric cancer

Abstract

Abstract Background: Gastric cancer is one of the major causes of death in Japan. Endoscopic submucosal dissection (ESD) has been developed for the treatment of early cancers. ESD needs accurate diagnosis of the demarcation line, pathological type and depth of cancer lesions. We have previously reported, using biopsy specimens, the usefulness of the 1064-nm near-infrared multichannel Raman spectroscopy (RAS) system as a novel diagnostic modality for gastric cancer (J Gastroenterol.43(4), 2008). However, our study might not have reflected in vivo use of RAS due to a lack of tissue other than the mucosal layer in the biopsy specimens. Here, we used the 1064-nm near-infrared multichannel RAS ex vivo for optical diagnosis of gastric cancer in surgically resected stomach. Methods: A total of 213 Raman spectra were obtained from 12 cancer lesions and their corresponding non-neoplastic areas in 10 stomachs following resection for gastric cancer. Without any pretreatment, the fresh specimens were measured with a near-infared multichannel Raman spectroscopic system with an excitation wavelength of 1064nm, and Raman spectra specific for the specimens were obtained. To develop optical diagnostic systems for gastric cancer, principal component analysis (PCA) of all the Raman spectra was performed. Results: The averaged Raman spectra of the cancer lesions could be distinguished from those of the non-neoplastic regions. Discrimination analysis of cancer from non-neoplastic regions with 10 principal components revealed that sensitivity, specificity and accuracy of cancer diagnosis was 73%, 73% and 72%, respectively. RAS discriminated between differentiated and undifferentiated cancers, early and advanced cancers, as well as T1a (M) and T1b (SM) cancers with high accuracy (98%, 93% and 98%, respectively). Conclusions: The 1064-nm near-infrared multichannel RAS system is useful not only for gastric cancer detection, but also for discrimination between differentiated and undifferentiated, as well as early and advanced cancers. RAS could help establish indications for endoscopic treatment by eliminating cancer lesions with an undifferentiated component or submucosal invasion. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5312. doi:10.1158/1538-7445.AM2011-5312