Table 1 The Finnish Cancer Registry classification system and its relation to UICC TNM^a staging (8th edition)

0) Unknown

The extent of cancer cannot be assessed

TX

NX

MX

1) Localised

Tumour in situ or tumour invades submucosa or muscularis propria

Tis, T1, T2

N0

M0

0–I

2) Nonlocalised with only regional lymph node metastases

Metastasis to the local lymph node(s). Primary tumour can be localised or locally advanced, but no distant metastases are found

Any T

N1–2

M0

III

3) Metastasised further than to regional lymph nodes or invasion to adjacent tissues

More detailed information on tumour spread has not been reported to FCR. This class was used when marked on an old paper clinical form and no more specific information was available

II–IV

4) Nonlocalised with no information on extent

Metastasis to the local lymph node(s), but distant metastasis cannot be assessed

Any T

N1–2

MX

III–IV

5) Locally advanced with the tumour invading adjacent tissues

Tumour invades through the muscularis propria into the subserosa or pericolorectal tissues; penetrates to the surface of the visceral peritoneum; or directly invades or is adherent to other tissues. No local lymph node metastasis or distant metastasis detected

T3–4

N0

M0

II

6) Nonlocalised with distant lymph node metastases as well

Distant metastasis

Any T

Any N

M1

IV