This monograph is the result of an effort by the International Union Against Cancer (UICC) to study prognostic factors related to cancer. It is an extension of the long-term work on the TNM classification and the strongest prognostic tool for most cancers. The monograph aims to compile information on prognostic factors for most tumour sites and selected tumour types. Each site- or tumour-specific chapter provides a general overview of the relevant literature on prognostic factors. Where possible, the authors have attempted to assess these factors in terms of their clinical relevance and of their strength and independence in influencing prognosis.