Fundamentals of Cancer Diagnosis and Assessment

Abstract

The symptoms caused by a cancer typically depend on and are referable to its site of origin. Nevertheless, they are rarely specific to cancer. Therefore, the first step in the clinical work-up of a cancer patient is verifying that they actually do have cancer. The patient’s age, personal medical history, family history, and any known exposures to carcinogens help to define their risk for cancer. A physical examination or imaging study may be needed to identify a mass. Almost without exception, however, the diagnosis of cancer requires the examination of cells or tissues from an identified mass or the blood, if it is a leukemia. With cytology or biopsy material, the presence of cancer can be confirmed, and its histopathological type, grade, and other relevant predictive or prognostic features, either morphologic or molecular, can be determined. Radiological imaging studies are then required to determine the extent and distribution of disease in the body, codified as the anatomical stage of the tumor. The cancer stage is not only a very strong prognostic factor; it is the key determinant in treatment planning. Cancer that is localized to its site of origin on diagnosis (stage I or II) is primarily treated with local therapy such as surgery and/or radiation. Tumor that has spread to regional lymph nodes only (stage III) may be treated with surgery but also may require systemic treatment such as chemotherapy. Cancer that has spread to any distant body site(s) (stage IV), however, requires either systemic therapy or palliative therapy but will not be improved by surgical treatment. This chapter discusses the steps in the diagnosis and clinical assessment of a new cancer patient and explains how the findings on work-up impact prognosis and treatment planning.