In patients with clinically localized (stage I or stage II) prostate cancer, Gleason pathologic grade and enzymatic serum prostatic acid phosphatase values (even within normal range) predict the likelihood of capsular penetration, seminal vesicle invasion, or regional lymph node involvement. Analysis of a series of 166 patients with clinical stage I or stage II prostate cancer undergoing radical prostatectomy revealed an association between Gleason biopsy score and the risk of lymph node metastasis found at surgery. The risks of nodal metastasis for patients grouped according to their Gleason biopsy score was 2%, 13%, and 23% for Gleason scores of 5, 6, and 8, respectively.
Whether to subject all patients to a PLND is debatable, but in patients undergoing a radical retropubic prostatectomy, nodal status is usually ascertained as a matter of course. In patients who are undergoing a radical perineal prostatectomy in whom the PSA value is less than 20 ng/ml and the Gleason sum is low, however, evidence is mounting that a PLND is probably unnecessary, especially in patients whose malignancy was not palpable but detected on ultrasound.[7,9]
Transrectal or transperineal biopsy
The most common means to establish a diagnosis and determine the Gleason score in cases of suspected prostate cancer is by needle biopsy. Most urologists now perform a transrectal biopsy using a bioptic gun with ultrasound guidance. Over the years, there has been a trend toward taking eight to ten or more biopsy samples at the same time. Less frequently, a transperineal, ultrasound-guided approach can be used for those patients who may be at increased risk of complications from a transrectal approach.
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.