Explanatory Notes—General

Two classifications are described for each site, namely: a) Clinical classification (Pretreatment clinical classification), designated TNM (or cTNM). This is based on evidence acquired before treatment. Such evidence arises from physical examination, imaging, endoscopy, biopsy, surgical exploration and other relevant examinations. b) Pathological classification (Postsurgical histopathological classification), designated pTNM. This is based on the evidence acquired before treatment, supplemented or modified by the additional evidence acquired from surgery and from pathological examination. The pathological assessment of the primary tumour (pT) entails a resection of the primary tumour or biopsy adequate to evaluate the highest pT category. The pathological assessment of the regional lymph nodes (pN) entails removal of nodes adequate to validate the absence of regional lymph node metastasis (pN0) and sufficient to evaluate the highest pN category. The pathological assessment of distant metastasis (pM) entails microscopic examination.