Published online May 28, 2023. doi: 10.3748/wjg.v29.i20.3145
Peer-review started: December 12, 2022
First decision: March 9, 2023
Revised: April 10, 2023
Accepted: April 27, 2023
Article in press: April 27, 2023
Published online: May 28, 2023
Processing time: 164 Days and 20.8 Hours
Cancer detection is a global research focus, and novel, rapid, and label-free techniques are being developed for routine clinical practice. This has led to the development of new tools and techniques from the bench side to routine clinical practice. In this study, we present a method that uses Raman spectroscopy (RS) to detect cancer in unstained formalin-fixed, resected specimens of the esophagus and stomach. Our method can record a clear Raman-scattered light spectrum in these specimens, confirming that the Raman-scattered light spectrum changes because of the histological differences in the mucosal tissue.
To evaluate the use of Raman-scattered light spectrum for detecting endoscop-ically resected specimens of esophageal squamous cell carcinoma (SCC) and gastric adenocarcinoma (AC).
We created a Raman device that is suitable for observing living tissues, and attempted to acquire Raman-scattered light spectra in endoscopically resected specimens of six esophageal tissues and 12 gastric tissues. We evaluated formalin-fixed tissues using this technique and captured shifts at multiple locations based on feasibility, ranging from six to 19 locations 200 microns apart in the vertical and horizontal directions. Furthermore, a correlation between the obtained Raman scattered light spectra and histopathological diagnosis was performed.
We successfully obtained Raman scattered light spectra from all six esophageal and 12 gastric specimens. After data capture, the tissue specimens were sent for histopathological analysis for further processing because RS is a label-free methodology that does not cause tissue destruction or alterations. Based on data analysis of molecular-level substrates, we established cut-off values for the diagnosis of esophageal SCC and gastric AC. By analyzing specific Raman shifts, we developed an algorithm to identify the range of esophageal SCC and gastric AC with an accuracy close to that of histopathological diagnoses.
Our technique provides qualitative information for real-time morphological diagnosis. However, further in vivo evaluations require an excitation light source with low human toxicity and large amounts of data for validation.
Core Tip: Cancer diagnosis is a critical step in patient management, and involves a combination of diagnostic modalities or a single investigation. Diagnostic techniques that provide comprehensive data on the disease process can be particularly valuable, and Raman spectroscopy (RS) is one such modality that offers detailed molecular-level information. In this study, we utilized RS to rapidly detect cancer in resected esophageal and stomach specimens, providing information beyond morphology. By providing detailed molecular-level data, RS can provide a more comprehensive understanding of disease processes and aid in accurate diagnosis.