SEER Training Modules

Review: Summary Staging

In Summary Staging, we focused on Summary Staging, one of the most fundamental staging systems. Summary staging is the most basic way of categorizing how far a cancer has spread from its point of origin. This staging system is also called General Staging, California Staging, or SEER Staging. Since this staging system uses all information available in the medical record, it is a combination of the most precise clinical and pathological documentation of the extent of disease.

The five main categories in summary staging are also discussed in detail in this unit. They are: in situ, localized, regional, distant, and unknown.

  1. In Situ
    The term in situ is defined as the "presence of malignant cells within the cell group from which they arose." There is no penetration of the basement membrane of the tissue and no stromal invasion. An in situ diagnosis can only be made microscopically, because a pathologist must identify that the basement membrane has not been invaded.
  2. Localized
    A localized cancer is a malignancy limited to the organ of origin; it has spread no farther than the organ in which it started. There is infiltration past the basement membrane of the epithelium into the functional part of the organ, but there is no spread beyond the boundaries of the organ.
  3. Regional
    Regional stage refers to tumor extension beyond the limits of the organ of origin. Although the boundary between localized and regional tumor extension is usually well-identified, the boundary between regional and distant spread is not always clear. So, regional stage is perhaps the broadest category as well as the most difficult to properly identify.
  4. Distant
    Distant stage is also called remote, diffuse, disseminated, metastatic, or secondary disease. Distant metastases are tumor cells that have broken away from the primary tumor, have traveled to other parts of the body, and have begun to grow at the new location. Cancer cells can travel from the primary site in any of four ways: extension from primary organ beyond adjacent tissue into next organ; travel in lymph channels beyond the first drainage area; hematogenous or blood-borne metastases; and spread through fluids in a body cavity.
  5. Unknown

In addition to some general guidelines for using the SEER Summary Staging Manual-2000, answers are provided in this unit to four basic questions, which will determine the correct code for summary stage.


Go to the quiz if you want to test yourself on the material you learned in this section. The quiz is a self-assessment tool and no records are kept. The feedback will let you know if you have answered the questions correctly. You can take the quiz as many times as you want.

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