Endoscopic non-ablative fractional laser therapy in an orthotopic colon tumour model

Su Woong Yoo,Gyungseok Oh,Kyung-Hwa Lee,Euiheon Chung,Abdul Mohaimen Safi,Young L Kim,Young-Seok Seo,Soonjoo Hwang

doi:10.1038/s41598-018-19792-2

Abstract

Colorectal cancer is one of the leading causes of cancer-related deaths. Although several therapeutic management strategies are available at the early colon cancer stages, such as endoscopic mucosal or submucosal dissection, associated complications often include bleeding or bowel perforations. As an alternative approach, we investigated endoscopic non-ablative fractional laser (eNAFL) irradiation as a minimally invasive therapeutic modality for the treatment of early-stage colorectal cancer. By implanting SL4-DsRed colon cancer cells into the colons of the C57BL/6 mice, we developed an orthotopic colon tumour mouse model and demonstrated the early-stage tumour growth delay following the eNAFL irradiation. Additionally, we evaluated the temperature changes in the eNAFL-irradiated area using numerical simulations, and induced inflammation using histological analysis. Our results indicate a minimal thermal damage confined to the irradiated spot, sparing the adjacent tissue and alteration in the tumour microenvironment. eNAFL irradiation may be clinically useful as a minimally invasive therapeutic intervention at the early stage of tumourigenesis. In future, an optimal eNAFL therapeutic dose should be determined, in order to increase the efficacy of this approach.

Highlights

Colorectal cancer is the second most frequent cause of cancer-related deaths in the US1, and colonoscopy is firmly established as the mainstay of cancer prevention
We recently reported the therapeutic efficacy of non-ablative fractional laser (NAFL) irradiation in a subcutaneous tumour model[20]
We developed an endoscopic NAFL irradiation system to determine its therapeutic effects on the early-stage tumours

Summary

Introduction

Colorectal cancer is the second most frequent cause of cancer-related deaths in the US1, and colonoscopy is firmly established as the mainstay of cancer prevention. Several therapeutic options for the early-stage colorectal cancer therapy using the endoscopy are available, such as snare polypectomy[3], endoscopic mucosal resection[4], and endoscopic submucosal dissection[5] These treatment strategies are associated with complications such as bleeding or bowel perforations[6,7,8]. Other therapeutic options include radiation therapy, chemotherapy, immunotherapy, and targeted therapy, and a combination of these treatments may lead to the improvement in the progression-free or overall survival rates[10,11,12] These approaches are primarily used for the treatment of the advance-stage colon cancer rather than the early-stage colon cancer[13]. The non-ablative laser treatment is less invasive, it was shown to have a limited therapeutic efficacy[16], and fractional laser was developed www.nature.com/scientificreports/

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Conclusion