Highly accurate colorectal cancer prediction model based on Raman spectroscopy using patient serum

BACKGROUND Colorectal cancer (CRC) is an important disease worldwide, accounting for the second highest number of cancer-related deaths and the third highest number of new cancer cases. The blood test is a simple and minimally invasive diagnostic test. However, there is currently no blood test that can accurately diagnose CRC. AIM To develop a comprehensive, spontaneous, minimally invasive, label-free, bloodbased CRC screening technique based on Raman spectroscopy. METHODS We used Raman spectra recorded using 184 serum samples obtained from patients undergoing colonoscopies. Patients with malignant tumor histories as well as those with cancers in organs other than the large intestine were excluded. Consequently, the specific diseases of 184 patients were CRC (12), rectal neuroendocrine tumor (2), colorectal adenoma (68), colorectal hyperplastic polyp (18), and others (84). We used the 1064-nm wavelength laser for excitation. The power of the laser was set to 200 mW. RESULTS Use of the recorded Raman spectra as training data allowed the construction of a boosted tree CRC prediction model based on machine learning. Therefore, the generalized R-2 values for CRC, adenomas, hyperplastic polyps, and neuroendocrine tumors were 0.9982, 0.9630, 0.9962, and 0.9986, respectively. CONCLUSION For machine learning using Raman spectral data, a highly accurate CRC prediction model with a high R-2 value was constructed. We are currently planning studies to demonstrate the accuracy of this model with a large amount of additional data.