Summary Stage 2018

See Summary Stage 2018 for the current version of the Summary Stage 2018 Manual and complete coding instructions for the Prostate chapter. This is a condensed version.

See Summary Stage 2018 (SS2018) | SEER Training website for general information on Summary Stage.

Summary Stage is the most basic way of categorizing how far a cancer has spread from its point of origin. It is used by the National Cancer Institute’s (NCI) Surveillance, Epidemiology and End Results (SEER) program and the Centers for Disease Control and Prevention’s (CDC) National Program of Cancer Registrars (NPCR).

For Summary Stage, there is one general rule, “code what you know.” For example, if you know there is lymph node involvement, and no metastatic disease, yet you have no information on the extension, code to 3 for regional lymph node involvement.

For Summary Stage, if there is no information on lymph node involvement or metastatic disease, assume there is no involvement and code Summary Stage based on the extension/size of the tumor.

Note: If you are assigning AJCC and your AJCC stage is unknown, do not assume that Summary Stage will also be unknown. Summary Stage is not based on tumor size (only whether it’s a localized or regional tumor), nor the number of lymph nodes or where they are located (only whether regional lymph nodes are involved), and for Prostate, neither the DRE or PSA are used.

General Guidelines and Codes for Coding Summary Stage 2018 for Prostate Cancer
Summary Stage Code Staging Details
Code 0: In situ (IS) Behavior must be /2 (in situ) AND NO lymph node or metastatic involvement.

Exception: A primary tumor that is in situ WITH regional lymph node involvement is code 3: Regional Lymph Node involvement or WITH metastatic disease is code 7: Distant metastasis.
  • Both of these would be behavior /3 (malignant).
  • See Summary Stage 2018 Manual, General Instructions, #5, bullet point iv.
Note: In situ cancer of the prostate is very rare.
Code 1: Localized (L) Tumor confined to the prostate
  • Clinically apparent or inapparent tumor
  • Invasion into (but not beyond) prostate capsule
  • No extraprostatic extension
Code 2: Regional extension (RE) Tumor extends to connective tissue or adjacent organs.
(See Summary Stage manual for complete list)

Note 1: See Summary Stage 7 for extension or fixation to pelvic wall, frozen pelvis, penis, sigmoid colon.
Code 3: Regional Lymph Nodes (RN) Tumor confined to prostate
  • Regional lymph node involvement
  • No metastatic involvement
Code 4: Regional extension and Regional Lymph Nodes (RE+RN) Tumor extends to connective tissue or adjacent organs
  • Regional lymph node involvement
  • No metastatic involvement
Code 7: Distant metastasis Metastatic involvement
  • Including distant lymph node, organs, bone, etc.
Note 1: Tumors with extension to the pelvic wall (or fixation to the pelvic wall), frozen pelvis, penis, sigmoid colon are Summary Stage Distant.
Code 9: Unknown This code is used for the following
  • Historical cases
  • Cases with limited information
  • Death certificate only cases (Central Registries only)

Updated: June 15, 2026

Suggested Citation

SEER Training Modules: Summary Stage 2018. U.S. National Institutes of Health, National Cancer Institute. Cited 17 June 2026. Available from: https://training.seer.cancer.gov.