Summary staging is the most basic way of categorizing how far a cancer has spread from its point of origin. Summary staging has also been called General Staging, California Staging, and SEER Staging.

Summary staging uses all information available in the medical record; in other words, it is a combination of the most precise clinical and pathological documentation of the extent of disease.

Summary staging is a required data item for facilities and central registries participating in the National Program of Cancer Registries (NPCR) of the Centers for Disease Control and Prevention (CDC). Many cancer registries report their data using summary stage because the staging categories are broad enough to measure the success of cancer control efforts and other epidemiologic efforts. However, even though summary staging is used frequently in cancer registries, it is not always understood by physicians. Rather physicians are more likely to understand AJCC TNM staging.

Summary staging is based on the theory of cancer growth. Intraepithelial, noninvasive, or non-infiltrating cancer is described as in "situ." In situ tumors fulfill all microscopic criteria for malignancy except invasion of the basement membrane of the organ. A "localized" tumor is confined to the organ of origin without extension beyond the primary organ. "Regional extension" of tumor can be by direct extension to adjacent organs or structures or by spread to regional lymph nodes. If the cancer has spread to parts of the body remote from the primary tumor, it is recorded as "distant" stage. Sometimes there is insufficient information to assign a stage, such as in cases without thorough diagnostic workups or cases in which there is ambiguous or contradictory information.