Diagnosis of Prostate Cancer
By prostate Doc at 15 September, 2008, 8:34 am
Diagnosis of prostate cancer is most often made by needle biopsy of the prostate, following suspicion of its presence by digital rectal examination and PSA testing. Digi- tal rectal examination may strongly suggest the diagnosis; however, tissue confirma- tion is needed and may proceed by transrectal or transperineal biopsy of the prostate under a local anesthetic or transurethral resection of the prostate.
Since most cancers present in the peripheral zone of the prostate, transurethral resection is less likely to find cancer since it samples the central and transition zones of the prostate. Histologic examination of the biopsy material is categorized by the Gleason method with a possible total score of 10 based on the major histological pattern combined with the minor histologic pattern. Gleason scores of 2, 3, and 4 are con- sidered well-differentiated, 5 and 6 moderately differentiated, and 7, 8, 9, and 10 aggressive tumors with worse prognosis. An overall assessment of patient prognosis can be established by the level of PSA test, the Gleason score at presentation, and the volume of tumor estimated in the gland, as well as the clinical stage. “Parten” tables are nomograms for predicting the probability of organ confined disease, capsular penetration of the prostate by tumor, seminal vesicle involvement and lymph node involvement based on levels of PSA and Gleason score, and can be useful in evaluating for patients for the type of treatment. Imaging studies may include a radionucleotide bone scan if the PSA test is more than 20, and can also include MRI scanning of the prostate and pelvic CT scanning for assessment of the extent of disease. Staging systems for prostate cancer have historically been based on the Whitmore-Jewett system of A, B, C, and D; however, in recent years conformity to the tumor node metastases, TNM (tumor, nodes, metastasis) system has pre- vailed and been adopted by the American Joint Committee for Cancer Staging. The systems are compatible
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