Group I: Localised disease, completely resected:

A. Confined to organ or muscle of origin;

B. Infiltration outside organ or muscle origin; regional nodes not involved;

Group II: Compromised or original resections of three types including:

A. Grossly resected tumours with microscopic residual;

B. Regional disease, completely resected, in which nodes may be involved and/or extension of tumour into an adjacent organ present;

C. Regional disease with involved nodes, grossly resected, but with evidence of microscopic residual;

Group III: Incomplete resection or biopsy with gross residual disease;

Group IV: Distant metastasis, present at onset.