Purpose and principles
Distinguish anatomical stage, pathological grade and functional performance status, establish each with the correct evidence, and use them with biology and patient priorities rather than as interchangeable labels.
Staging provides a common language for disease extent, prognosis, treatment selection and audit. TNM describes the primary tumour, regional nodal disease and distant metastasis, but definitions are site- and edition-specific. Some cancers use dedicated systems or clinically important risk groups. Clinical stage is assigned from pre-treatment information; pathological stage follows adequate surgery and histology. Treatment can change appearances, so post-treatment assessment should not erase the original burden.
Grade is a pathology construct based on differentiation, architecture, mitoses, necrosis or defined molecular features depending on tumour type. It estimates behaviour within that disease but cannot be compared casually across cancers. Performance status is separate again: ECOG or WHO categories reflect activity and self-care. It contributes to treatment safety and trial eligibility but may improve when reversible cancer complications are treated.
The correct workflow defines the tumour type, consults the current staging manual and dataset, selects site-specific imaging, obtains tissue, then discusses stage, grade, biomarkers, comorbidity, organ reserve and preferences in the MDT. The resulting plan should specify curative, disease-control or symptom-focused intent and note any stage uncertainty that further testing could resolve.