Method for diagnosing neoplastic lesions by quantitative fluorescence value

Ayaka Kosugi,Taisuke Mori,Masataka Kasahara,Aki Nakamura-Takahashi,Takahiko Shibahara,Longqiang Yang

doi:10.1038/s41598-019-44287-z

Ayaka Kosugi, Taisuke Mori + Show 4 more

Open Access

https://doi.org/10.1038/s41598-019-44287-z

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Journal: Scientific Reports	Publication Date: May 24, 2019
Citations: 12	License type: open-access

Affiliation: Tokyo Dental College, Tokyo National Hospital

Abstract

Fluorescence visualization devices (FVs) are useful for detecting malignant lesions because of their simple and noninvasive application. However, their quantitative application has been challenging. This study aimed to quantitatively and statistically evaluate the change in fluorescence intensity (FI) during the progression from normal epithelium to squamous cell carcinoma using a reproducible animal tongue carcinogenesis model. To establish this model, rats were treated with 50 ppm 4-Nitroquinoline 1-oxide (4NQO) in their drinking water for 10, 15, and 20 weeks. After 4NQO administration, each rat tongue was evaluated by gross observation, histology, and FI measurements. Fluorescence images were captured by FV, and ImageJ was used to measure FI, which was analyzed quantitatively and statistically. The establishment of a reproducible tumor progression model was confirmed, showing precancerous lesions (low-grade dysplasia [LGD]), early cancers (high-grade dysplasia/carcinoma in situ [HGD/CIS]), and advanced cancers (Cancer). This carcinogenesis model was quantitatively evaluated by FI. The FI of LGD stage was 54.6, which was highest intensity of all groups. Subsequently, the HGD/CIS and Cancer stages showed decreased FI (HGD/CIS: 46.1, Cancer: 49.1) and manifested as dark spots. This result indicates that FI had more variation and a wider range with increasing tumor progression. We demonstrated that FI migration and an uneven distribution are consistent with tumor progression. Since each step of tumor progression occurs reproducibly in this animal model, statistical evaluation was possible. In addition, tumor progression can be monitored by this new FI analysis method in humans.

Highlights

The morbidity of oral cancer has increased over the past few decades
We examined the transition of disease from normal tissue to low grade dysplasia (LGD), high grade dysplasia (HGD), carcinoma in situ (CIS), and squamous cell carcinoma (Cancer)[18], using a reproducible 4-nitroquinoline 1-oxide (4NQO)-induced rat cancer model[19,20]
The HGD/CIS surface plot showed more roughness than that of LGD, and the fluorescence image showed an increase in the dark fluorescent area (Fig. 2C)

Summary

Introduction

The morbidity of oral cancer has increased over the past few decades. While treatment methods are improving, survival rates remain low, largely because it is hard to distinguish oral mucosal lesions, such as oral potentially malignant disorders (OPMDs), from early stage cancer. Normal oral mucosa has a fluorescence spectral range of approximately 375 nm to 440 nm Under this light, normal mucosa emits pale green fluorescence while abnormal areas absorb the fluorescent light, resulting in dark patches with fluorescence visualization loss (FVL)[12,13]. Other reports have demonstrated that FV can be used as a diagnostic tool of for oral malignant disorders, but such observations have not been evaluated quantitatively[15] This lack of quantification may be a result of human oral cancer being caused by many factors, including smoking, alcohol consumption, and viral infection. The aim of this study was to quantitatively evaluate the early stages of cancer by a new, noninvasive FV-based analysis method We demonstrate this evaluation system for accurately digitized observations by using a reproducible cancer model under consistent conditions (Fig. 1)

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