Assessed for the tumor as a whole according to the WHO classification of tumors:
- Good: exhibits glandular structures in >95% of the tumor
- Moderate: exhibits glandular structures in 50-95% of the tumor
- Poor or undifferentiated: exhibits glandular structures in <50%

Assessed according to the method as proposed by Haggitt et al:
- Level 1: invasion of the submucosa but limited to the head of the polyp
- Level 2: invasion extending into the neck of polyp
- Level 3: invasion into any part of the stalk
- Level 4: invasion beyond the stalk but above the muscularis propria
In polypectomy specimens, Haggitt level 3 invasion with positive resection margins was considered Haggitt level 4 invasion.

Cancer cell nest consisting of 1-4 cells that infiltrates the interstitium at the invasive margin. After selecting one field where budding was the most intensive, the number of buddings was counted in a field measuring 0.785 mm2 observed through a 209 objective lens (WHK 109 ocular lens). The grade was defined as follows:
- Grade 1: 0-4 buds
- Grade 2: 5-9 buds
- Grade 3: 10 or more buds

Cancer clusters in the stroma composed of ≥5 cancer cells and lacking a gland-like structure. After selecting one field where PDC was the most intensive, the number of PDCs was counted in a field measuring 0.785 mm2 observed through a 209 objective lens (WHK 109 ocular lens). The grade was defined as follows:
- Grade 1: 0-4 PDCs
- Grade 2: 5-9 PDCs
- Grade 3: 10 or more PDCs

The presence of cancer cells within endothelial-lined channels. Distinction between lymphatic-invasion and blood vessel-invasion was not made.

The status of the muscularis mucosa was classified as:
- Type A: shattered but aligned muscularis mucosa
- Type B: incompletely or completely disrupted muscularis mucosa