PCa is diagnosed primarily through a combination of two widely used diagnostic tests-Prostate Specific Antigen (PSA) and the Digital Rectal Exam (DRE). A PSA of 4.0 ng/mL or less is less suggestive of PCa; however, the cutoff value may be dependent on your age. A higher PSA level by itself does not necessarily mean that you have PCa, and a lower PSA level does not necessarily mean that you don't have PCa. The DRE enables your doctor to feel the size, shape, and texture of your prostate to determine if you have a clinically important prostate. However, you can have PCa without having a palpable tumor, and palpable nodules or abnormalities are not always PCa.
Other diagnostic tests which your doctor may perform on a blood or tissue sample include the PSA II or Free PSA, which should rule out prostatitis and/or BPH. The Reverse Transcriptase-polymerase chain reaction test (RT-PCR)test, which can determine the presence of small numbers of PCa cells; the serum acid phosphate test, and the alkaline phosphatase test (Alk Phos); the prostatic acid phosphatase (PAP); or the ProstaScint, which involves injecting a radioisotope into the blood-stream which attaches itself to the cancer, then using a gamma-ray camera to locate the PCa, if any, in your body. None of these tests or procedures are 100% accurate.
Even though much of the testing is controversial, most survivors prefer that newcomers be diagnosed early in the hope that early diagnosis will give greater choice of treatment and cure with fewer side or after effects.
High PSA's may also be the result of BPH, or a urinary infection, and although the FDA has approved a number of PSA assays for monitoring (already treated) men, the Hybritech Tandem PSA (Code: 140236) is the only assay which has had long- time FDA approval for use as a diagnostic tool. It's thought of by most professionals as the most accurate, reproducible PSA assay available. Know that NO PSA assay is perfect!
The results of one or more of these tests, including a suspicious DRE are good cause for a biopsy, however, a "clean" pathology report of the prostatic tissue is no guarantee that PCa doesn't exist. (E-mail me and I'll reply with a copy of a very fine presentation by Dr. D'Amico which explains, simply and clearly, how a negative biopsy doesn't prove anything), If PCa is found in the tissue removed at biopsy, a Gleason Score will be assigned. It will be someplace between 2 and 10, the higher number indicating a more aggressive PCa. The Gleason score has two components, the GRADE and the SUM. The grade is based on how the individual cells look under the microscope. The grades range from 1 to 5, with 1 being the closest to normal and 5 being bad. There are both general and specific guidelines for each grade, but the experience of the pathologist is key - which is why a second opinion on the biopsied tissue is often a good approach.
When the pathologist reads a specimen, s/he looks at it to determine the most common grade of tumor seen: that is the first number of the Sum Score. Then the pathologist determines the next most common tumor area and assigns a Gleason Grade to it. This is the second number. The two numbers together give the sum. Close reading of the pathology report, will often indicate both the grade and the percentage of each grade, which may make you feel better or worse than knowing the GSS (Gleason Sum Score) - but the GSS is what is reported in most of the medical literature and used for comparisons. So a 3+4 means more grade 3 than grade 4 and a 4+3 is just the opposite. Also a 5+2 means more 5 than 2, etc. A few pathologists feel that if the scores are not adjacent (like 5 and 2) there is something wrong with either the sample or the reading and will often ask for an independent second opinion. A final note; reviewing specimens after hormone therapy is even more difficult, and, should be sent to a specialist who sees a lot of this tissue.