Stage Information for Prostate Cancer
Transrectal ultrasound (TRUS)
TRUS may facilitate diagnosis by directing needle biopsy; however, ultrasound is operator dependent and does not assess lymph node size.
A prospective multi-institutional study of preoperative TRUS in men with clinically localized prostate cancer eligible for radical prostatectomy showed that TRUS was no better than digital rectal examination in predicting extracapsular tumor extension or seminal vesicle involvement.
Computed tomography (CT) scans
CT scans can detect grossly enlarged lymph nodes but poorly define intraprostatic features; therefore, it is not reliable for the staging of pelvic node disease when compared with surgical staging.
Historically, two systems have been in common use for the staging of prostate cancer.
- In 1975, the Jewett system (stage A through stage D) was described and has since been modified. This staging system is no longer in common use, but older studies and publications may refer to it.
- In 1997, the American Joint Committee on Cancer (AJCC) and the International Union Against Cancer adopted a revised tumor, nodes, metastasis (TNM) system, which used the same broad T-stage categories as the Jewett system but included subcategories of T stage, such as a stage to describe patients diagnosed through PSA screening. This revised TNM system more precisely stratifies newly diagnosed patients. In 2010, the AJCC updated the TNM classification for prostate cancer.
AJCC Stage Groupings and TNM Definitions
The AJCC has designated staging by TNM classification.
Staging of prostate cancer.
Table 1. Definitions of TNM Stage I
|T = Primary tumor; N = Regional lymph nodes; M = Distant metastasis; G = Histopathologic grade.
|Reprinted with permission fromAJCC: Prostate. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 457-68.
|The explanation for superscript a is at the end ofTable 4.
||T1a, N0, M0, G1
||T1a = Tumor incidental histologic finding in ≤5% of tissue resected.
|N0 = No regional lymph node metastasis.
|M0 = No distant metastasis.a
|G1 = Well differentiated (slight anaplasia) (Gleason score of 2–4).