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SEER Training Modules

General Rules

Coding Tumor Extension

  1. Record the farthest documented extension of the primary tumor.
  2. Do not include discontinuous metastases to distant sites except for ovary and corpus uteri.
  3. Distant metastasis must be coded in the CS Mets at Dx field.
  4. Record extension information in the following order:
    1. Record extension from the pathology report, when no neoadjuvant radiation or systemic therapy is given.
    2. If neoadjuvant therapy is given, code farthest extension whether prior to or following treatment.
    3. Imaging/radiographic information can be used when no pathology or operative report information is available and takes priority over physical exam information.
    4. Physical examination information may be used when no path, operative or imaging information is available.
    5. Microscopic residual disease or positive tumor margins does not increase extension code.
    6. If an involved organ is not listed, approximate the location and code with similar tissues.
    7. Refer to the ambiguous terminology list for terms that constitute involvement or extension.
    8. If information in the medical record is ambiguous or incomplete regarding the extent of tumor spread, this may be inferred from the T category stated by the physician. If only indication for extension is the physician's statement of T category, record the numerically lowest equivalent extension code for that T category.
    9. If there is nodal or metastatic involvement, extension can not be "in situ." Use the code for "Localized, NOS" if there is no better information.