Evaluation of the Extent of Disease

Once the diagnosis of cancer is made, evaluation of the extent of spread of the cancer, using the various diagnostic procedures noted in the previous chapter, is essential before therapeutic decisions (discussed in the next chapter) are made. Radical treatment designed for cure (particularly surgical treatment) is usually not indicated if there is spread of the cancer beyond the limits of the proposed treatment field. Even when using chemotherapy, radiotherapy, or multimodal therapy, there must be reason to believe there is a chance for cure (or major benefit) before radical treatment is proposed for what may be extensive disease. For most cancers, treatment will vary depending on the extent of disease. Therefore accurate assessment of spread is essential. This assessment is called “staging” and an increasingly elaborate set of rules has been developed over the years to make staging more accurate and meaningful.