Prostate Cancer - TNM Staging

View the Prostate Cancer Slideshow Pictures
Doctor's Responses Archive

Viewer Question:
We have been diagnosed as having prostate cancer, which is in the B1 stage. These stages are A, B, C, and D. Now there is a new stage system and we are classified as T2A. We would like to obtain the entire new stage classification. Also, our Primary Care Physician will obtain from us a PFT and a CXR. We would like to know what these abbreviations mean before we go to our appointment in order to have a better understanding of what is going on because our doctors always seem to be in a rush. We have tried accessing Medical Dictionaries, the AMA Encyclopedia of Medicine and a nursing manual all to no avail. No doubt it is there but one needs to know the meaning of the abbreviation before it can be found.
Doctor's Response:
CXR stands for chest x-ray. PFT stands for pulmonary function testing.

The TNM staging system refers to Tumor, Nodes, Metastasis. The full explanation is below. A T2a tumor indicates that it involves half of the prostate or less. At the stage of the workup you describe, the lymph node status or possibility of metastatic disease would not be known.

For more information please visit the Prostate Cancer Center in the Diseases and Conditions section of

TX     Primary tumor cannot be assessed
T0     No evidence of primary tumor
T1     Clinically inapparent tumor not palpable or visible by imaging
T1a     Tumor incidental histologic finding in 5% or less of tissue resected
T1b     Tumor incidental histologic finding in more than 5% of tissue resected
T1c     Tumor identified by needle biopsy (e.g. because of elevated PSA)
T2     Palpable tumor confined within prostate *
T2a     Tumor involves half of a lobe or less
T2b     Tumor involves more than half of a lobe, but not both lobes
T2c     Tumor involves both lobes
T3     Tumor extends through the prostatic capsule
T3a     Unilateral extracapsular extension
T3b     Bilateral extracapsular extension
T3c     Tumor invades seminal vesicle(s)
T4     Tumor is fixed or invades adjacent structures other than seminal vesicles
T4a     Tumor invades external sphincter and/or bladder neck and/or rectum
T4b     Tumor invades levator muscles and/or is fixed to pelvic wall*

* Note: Tumor found in one or both lobes by needle biopsy, but not palpable or visible by imaging, is classified as T1 c.
* Note: Invasion into the prostatic apex or into (but not beyond) the prostatic capsule is not classified as T3, but as T2.

NX     Regional lymph nodes cannot be assessed
NO     No regional lymph node metastasis
N1     Metastasis in a single lymph node, 2 cm or less in greatest dimension
N2     Metastasis in a single lymph node, more than 2cm but not more than 5 cm ingreatest dimension, or multiple lymph nodes, none more than 5 cm in greatest dimension N3 Metastasis in a lymph node more than 5 cm in greatest dimension

MX     Presence of distant metastasis cannot be assessed
MO     No distant metastasis
M1     Distant metastasis
M1a     Non­ regional lymph nodes
M1b     Bone
M1c     Other.sites.

Thank you for your question.

Last Editorial Review: 4/4/2001

Subscribe to MedicineNet's Cancer Report Newsletter

By clicking Submit, I agree to the MedicineNet's Terms & Conditions & Privacy Policy and understand that I may opt out of MedicineNet's subscriptions at any time.

Health Solutions From Our Sponsors