Table 1.

Histological scoring criteria

Score	Histological criteria
0	The epithelial layer structure is intact, with no obvious damage
1	The epithelial layer structure is disorganized, accompanied by slight deformation of epithelial cells.
2	The structure of the superficial lamina propria is disorganized or 1/3 of the glandular structure is missing.
3	The structure of the intermediate lamina propria is disorganized or 2/3 of the glandular structure is missing.
4	The lower lamina propria is eroded or more than 2/3 of the glandular structure is missing.