EOD Primary Tumor

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For Prostate cancer, clinical and pathological evaluation of the primary tumor are done and collected in two separate fields. This is different from any other schema.

Clinical evaluation of the primary tumor is collected in EOD Primary Tumor, while the pathological evaluation is collected in EOD Prostate Pathologic Extension [NAACCR Data Item #3919].

Prior to 1995, primary tumor extension was collected as the “best” information. When studies were done comparing survival and other outcomes based on age, it was found that the younger men had worse prognosis then the older men. The reason behind this was that younger men were getting prostatectomies, which led to a greater T value many times, while older men were not getting prostatectomies. This led to collecting both the clinical and pathological primary tumor.

Note, prostate is the only schema where you will collect the clinical extension (EOD Primary Tumor) and the pathological extension (EOD Prostate Path).

EOD Primary Tumor (Clinical Primary Tumor)

Clinical evaluation of the prostate is based on three main factors.

  • Prostate Specific Antigen (PSA): If a patient has an elevated PSA and the prostate is determined to be free of any nodules or masses, the PSA is used to determine the clinical stage (per AJCC).
  • Digital rectal exam [DRE]: The DRE is used to palpate the prostate to see if there are any nodules, or masses that can be felt.
    • The DRE was the gold standard for over 20 years, but is slowly being replaced by more sophisticated imaging. The MRI imaging is normally used to determine if the patient has prostate cancer.
    • For staging purposes, the DRE is still used to determine the AJCC stage; however, EOD does not require a DRE. Per Note 1 for EOD Primary Tumor.
      • For this schema, the EOD Primary Tumor field captures a clinical extent of disease only.
      • The guidelines for assigning Clinical Extension for AJCC and EOD are different.
        • Per AJCC, a digital rectal exam (DRE) is required to assign a clinical T (cT).
        • For EOD, a code can be assigned if there is no DRE information.
    • For registrars assigning both AJCC and EOD, it is imperative that you understand that the rules are different. Do not apply the stricter rules from AJCC to EOD.
  • Imaging: Advances in technology now allow physicians to diagnose and stage a patient (Not AJCC) based on an MRI; however, findings from any imaging may NOT be used to determine clinical stage. (See Note 3 in EOD Primary Tumor).
    • These rules are based on how AJCC collects clinical stage.
    • In the future, AJCC may update their criteria for clinical staging, at which time EOD (and Summary Stage) will also be updated. For now, the “gold standard” is the DRE.

Findings from a Simple Prostatectomy and Prostatectomy, NOS are coded in EOD Primary Tumor, NOT EOD Prostate Pathologic Extension. These are not Radical Prostatectomies. See Surgery of Primary Site for more information.

Record extension from prostate biopsies, simple prostatectomies, or any other clinical workup in this data item. Do NOT record findings from a Radical Prostatectomy (see EOD Prostate Path Extension).

For localized prostate cancers, the biggest criteria is inapparent (non-palpable) vs apparent (palpable) tumors. Inapparent vs apparent tumors have historically been determined by the digital rectal exam (DRE). Clinical medicine has evolved so that they are being diagnosed increasingly via imaging; however, per AJCC (and subsequently EOD/SS), imaging cannot be used to determine primary tumor extension.

  • This rule does not apply to regional nodes and mets.
  • Apparent (palpable) tumors include a statement of a nodule, mass, positive DRE.
  • Non-apparent (non-palpable): statement of a negative DRE.
Extension Comment
In situ Noninvasive, intraepithelial.
Note: In situ prostate cancer is very rare.
Incidental findings
Clinically inapparent (non-palpable) tumor		 TURPs are a common treatment for benign prostatic hypertrophy (BPH). During some of those TURP’s, cancer is diagnosed. These are inapparent tumors
  • This is an incidental finding of prostate cancer, and there are specific codes in EOD Primary Tumor for these. The codes are based on the percentage of tissue resected, <5%, 5% and more, or unknown.
Elevated PSA,
Clinically inapparent (non-palpable) tumor		 If a patient has a clinically inapparent tumor (confirmed by physician) with an elevated PSA, this is a tumor identified by needle core biopsy.
  • This does not apply to apparent tumors (see next row).
  • If there is an elevated PSA and apparency is unknown (DRE not done or unknown if done), see localized tumor, apparency unknown.
Apparent (palpable) tumors Clinically apparent tumors can be classified several different ways (cannot use the findings from a biopsy to code).
  • ½ of one side or less
  • > then one-half of one side but not both sides
  • Involves both lobes/sides
  • Confined to prostate, lobe involvement unknown
Localized tumor, apparency unknown This is a localized tumor and is used for the following
  • No DRE information
  • Elevated PSA and unknown if inapparent or apparent tumor
  • Physician are using imaging information (MRI) to clinically stage. (Reminder that registrars cannot use the imaging information to code this data item)
  • Biopsy only, no other information available
    • NOTE: This instruction is for Prostate ONLY. Do NOT apply this instruction to any other primary site or schema.
As a reminder, AJCC and EOD DIFFER when it comes to the DRE. To code AJCC Clinical Stage, you MUST have a DRE (Contact AJCC for more information regarding clinical stage). A DRE is NOT required for EOD or Summary Stage.
Invasion of the seminal vesicle If the seminal vesicles are palpable during rectal examination, assume they are involved by tumor extension from the prostate.
Extraprostatic invasion Also known as extracapsular penetration.
  • The following factors are predictive of capsular penetration: seminal vesicle invasion, regional lymph node involvement, Invasion of the bladder, or other regional structures.

EOD Prostate Pathologic Extension

Note: This data item is based on findings from a radical prostatectomy ONLY. Findings from a TURP, simple prostatectomy, or prostatectomy, NOS are coded in EOD Primary Tumor. See Surgery of Primary Site for more information.

  • Code 900 is used for cases where a radical prostatectomy is not done (includes biopsy only, TURP only, or simple prostatectomy only.)
  • Code 950 is used when a patient initially chooses active surveillance, and then later chooses to have a radical prostatectomy due to progression or patient changed their mind. The radical prostatectomy performed in this situation would not be first course of treatment.
Extension Comment
In situ Noninvasive, intraepithelial.
Note: In situ prostate cancer is very rare.
Tumor confined to the prostate These are localized tumors, no extension beyond the prostate This also applies to cases where a radical prostatectomy is done and there is no residual disease, meaning that the biopsy removed all the tumor.
Extraprostatic extension This is invasion of cancer cells beyond the prostate’s fibromuscular pseudocapsule into adjacent periprostatic tissue AND there is no extension to adjacent structures.
Invasion of other adjacent structures Adjacent structures include, but not limited to bladder, external sphincter, levator muscles, penis, sigmoid colon, also includes a fixed or frozen pelvis.

See SEER*RSA, Prostate, for the current version of EOD and complete coding instructions for the Prostate schema.

Updated: June 15, 2026

Suggested Citation

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