Cancer Staging

A cancer diagnosis answers what the disease is; staging answers how far it has extended. A biopsy establishes the tumour type, while staging combines the primary tumour's extent, regional lymph-node involvement, and distant spread to describe the anatomic burden of disease. Stage therefore helps the team estimate prognosis and select treatment, but it is not the same as tumour grade, symptom severity, or an exact prediction of one patient's outcome. The AJCC/UICC Tumor–Node–Metastasis (TNM) classification is Canada's standard framework for staging. The categories and stage groups are tumour-site specific, so a Stage III label does not carry identical criteria across every cancer. TNM is used mainly for solid tumours; some haematologic malignancies use disease-specific staging systems instead. The staging system documented for that patient's cancer must take priority over a generic stage table. The prefix also tells you when the assessment was made. Clinical stage, or cTNM, is assigned before definitive treatment from examination, imaging, and biopsy findings. Pathological stage, or pTNM, is assigned after surgical resection, when the tumour and any sampled nodes can be examined directly. When neoadjuvant...