Assessment of Tumor Invasion Depth in Colorectal Carcinoma Using Multiphoton Microscopy

Assessment of tumor invasion depth prior to making therapeutic decisions in colorectal carcinoma is crucial for both the patient and the physician. In this paper, multiphoton microscopy (MPM) was used to simultaneously label freely image loose areolar connective tissue in the submucosa and intramuscular septa in the muscularis propria to perform assessment of colorectal carcinoma invasion depth. The results indicated that MPM can accurately exhibit whether colorectal carcinoma invades into the submucosa or the muscularis propria. Collagen content alteration and the presence of dirty necrosis can be extracted to serve as quantitatively intrinsic biomarkers for reflecting collagen degradation, the occurrence of desmoplastic reaction, and breakdown of cancer cells, which are tightly related to the prognosis of colorectal carcinoma. With the development and clinical applications of the multiphoton endoscope, in vivo histological-like diagnosis of tumor invasion depth may become its main application in the field of colorectal carcinoma and lead to faster and improved therapeutic decision making in the clinics.