Published in:
01-06-2021 | Colorectal Cancer | Original Article—Alimentary Tract
Histopathological characteristics and artificial intelligence for predicting tumor mutational burden-high colorectal cancer
Authors:
Yoshifumi Shimada, Shujiro Okuda, Yu Watanabe, Yosuke Tajima, Masayuki Nagahashi, Hiroshi Ichikawa, Masato Nakano, Jun Sakata, Yasumasa Takii, Takashi Kawasaki, Kei-ichi Homma, Tomohiro Kamori, Eiji Oki, Yiwei Ling, Shiho Takeuchi, Toshifumi Wakai
Published in:
Journal of Gastroenterology
|
Issue 6/2021
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Abstract
Background
Tumor mutational burden-high (TMB-H), which is detected with gene panel testing, is a promising biomarker for immune checkpoint inhibitors (ICIs) in colorectal cancer (CRC). However, in clinical practice, not every patient is tested for TMB-H using gene panel testing. We aimed to identify the histopathological characteristics of TMB-H CRC for efficient selection of patients who should undergo gene panel testing. Moreover, we attempted to develop a convolutional neural network (CNN)-based algorithm to predict TMB-H CRC directly from hematoxylin and eosin (H&E) slides.
Methods
We used two CRC cohorts tested for TMB-H, and whole-slide H&E digital images were obtained from the cohorts. The Japanese CRC (JP-CRC) cohort (N = 201) was evaluated to detect the histopathological characteristics of TMB-H using H&E slides. The JP-CRC cohort and The Cancer Genome Atlas (TCGA) CRC cohort (N = 77) were used to develop a CNN-based TMB-H prediction model from the H&E digital images.
Results
Tumor-infiltrating lymphocytes (TILs) were significantly associated with TMB-H CRC (P < 0.001). The area under the curve (AUC) for predicting TMB-H CRC was 0.910. We developed a CNN-based TMB-H prediction model. Validation tests were conducted 10 times using randomly selected slides, and the average AUC for predicting TMB-H slides was 0.934.
Conclusions
TILs, a histopathological characteristic detected with H&E slides, are associated with TMB-H CRC. Our CNN-based model has the potential to predict TMB-H CRC directly from H&E slides, thereby reducing the burden on pathologists. These approaches will provide clinicians with important information about the applications of ICIs at low cost.