10 Sep Prostate Cancer Work Up
Well since it is September and it is Prostate Cancer Awareness Month, I figured it would be a good idea to describe what the typical work up would be for a patient that is thought to have prostate cancer.
The very first thing to do is to determine the PSA level. Age-related PSA levels can be assessed, as can clinical evidence of prostatitis. If the physician believes the PSA level might be elevated secondary to infection, 4-6 weeks of antibiotics are provided, and then the PSA level is rechecked.
Next would be to perform a DRE. This is examiner dependent, and serial examinations, over time, are best. View nodules or changes in the texture or the level of asymmetry with a high index of suspicion. Physical examination findings alone cannot reliably differentiate a cyst or calculus from cancer foci; therefore, a biopsy is warranted in these circumstances.
If there is an elevated PSA and there is suspicion of an abnormal DRE, the next thing would be to perform a biopsy. Performing a biopsy will aid in making the diagnosis, and determine the Gleason score. For a typical biopsy, antibiotics are administered, and, often, an enema is provided before the procedure, followed by a short course of antibiotics after the biopsy. Patients are typically told to stop aspirin and nonsteroidal anti-inflammatory drugs 10 days prior to the biopsy. Many physicians use lidocaine (to numb the area) prior to the biopsy, while others do not. Much debate exists on the subject of how many biopsies should be performed. Sextant (6) versus 12- versus 18-core biopsy protocols are published in the literature. The 12- or 18-core protocols yield more specimens from the lateral regions and usually sample the transition zone. Several studies have demonstrated an increase in the cancer detection rate, while others have not. The more core specimens one gets, the better chance to have a better picture of the extent of the prostate cancer.
When patients have a persistently elevated PSA and negative biopsy results, the literature supports repeating the biopsy 1 or 2 times. Of cancer cases, 31% were detected on repeat biopsy and 39% were detected if the PSA value was greater than 20 ng/mL. If all the biopsy results are negative, then a repeat round of biopsies has been suggested when the PSA increases by 25% from the level at which the last biopsies were performed.
Further workup depends on the clinical staging. A higher clinical stage of cancer, determined by DRE findings, PSA level, and Gleason score (as determined by biopsy), correlates with an increased risk of extraprostatic spread, and these tests are considered key factors in determining the staging workup and predicting patient prognosis.
Men with PSA levels less than 10 ng/mL and low- or moderate-grade histology (Gleason score <7) with no findings or minimal findings upon physical examination may proceed to surgery or brachytherapy without further studies. Men with PSA levels greater than 10 ng/mL, high-grade histology (Gleason score >7), or physical findings suggesting stage T3 disease should probably undergo a staging CT scan and bone scan. The CT scan is the one modality with evidence-based guidelines. The CT scan can evaluate extension into the bladder and lymph nodes to help stage the patient’s cancer or to consider lymph node sampling prior to treatment. TRUS is no better than DRE, and positron emission tomography scans are not proven effective.
MRI is superior to bone scan in evaluating bone metastasis, but it is impractical for routine total body surveys. Instead, it is used to determine the etiology of questionable lesions found on bone scans. MRI is promising for local staging, but it is not readily accessible and no published guidelines are available.
Neither CT scan nor MRI can be used to determine if lymph nodes are reactive or contain malignant deposits unless the nodes are significantly enlarged and a percutaneous biopsy can be undertaken.
There are some more recent studies and research being done on the use of CT/PET in the work up of prostate cancer as well. It is a very sensitive tool for detecting cancer that is confined to the prostate as well as cancer that may have spread outside of the prostate as well to distant areas of the body. For most cancer types, FDG is used to detect cancers with PET/CT. However with prostate cancer, the research is shown that it may be more effective to use acetate or choline to detect prostate cancer specifically with PET. It is not currently widely used as a diagnostic or prognastic factor for prostate cancer, but is yet another tool that may be used depending on your physician and the nature of your diagnosis.
Another effective tool that your physician can use is a nomogram. A nomogram is a calculation tool that can be used to take into consideration a patients PSA score, Gleason Score, and clinical stage. It crunches all of these numbers and then will compute what the chances and percentages are for each patient. This will help the patient and the physician to determine the risk for cancer being limited to the prostate, or if it has spread to other areas of the body. All of this information can then be used to help determine the best possible choice for treatment options as well.
If you have any further questions or concerns, please feel free to contact me directly at the following email: CANCERGEEK@GMAIL.COM