Prostate Cancer Diagnosis and Prostate Biopsies
Cancer is an emotive word and anxiety about prostate cancer is understandable, particularly when one hears so much about it. Prostate cancer is slow growing unlike many other cancers. Most men will have evidence of prostate cancer by the time reach their 80's; however that is no reason to be complacent, because prostate cancers diagnosed later in life are more likely to be locally advanced or metastatic. Treatments at this stage aim to control rather than cure the disease. Prostate cancer when identified early at a localised stage is curable. The critical thing to determine is the aggressive potential for the disease in an individual.
A man may be suspected to be at risk for a prostate cancer diagnosis following either a routine health screen, which has shown an abnormally elevated PSA blood test. This may have been combined with a digital rectal examination (DRE) which indicated an abnormal feeling prostate. Alternatively, an abnormal PSA or prostate examination may have been discovered during the routine investigation of lower urinary tract symptoms or erectile dysfunction. An abnormal PSA test or DRE does not necessarily mean a diagnosis of prostate cancer in all cases, the tests are prostate specific, they are not prostate cancer specific. Prostate cancer can only be diagnosed following pathological examination of a section of the prostate. The removal of cores of tissue from the prostate uses a technique known as prostate biopsy.
Indications for Prostatic Biopsy
There are a number of reasons why it may be recommended that prostatic biopsies should be carried out:-
There is an elevated standard age related PSA level
40 - 49 years > 2.5 ng/ml 50 - 59 years > 3.5 ng/ml
60 - 69 years > 4.5 ng/ml 70 - 79 years > 6.5 ng/ml
A prostate MRI scan suggests the presence of a focal abnormality within the prostate considered suspicious for prostate cancer.
There is a significant increase in the standard PSA level over time (PSA velocity). An increase of more than 20% per annum would be suspicious.
There is a standard PSA level of between 2.5 and 10 ng/ml and a low free/total PSA ratio (an F/T ratio of over 23% is unlikely to be associated with prostate cancer but an F/T ratio under 12% is much more suspicious).
The prostate feels suspicious on digital rectal examination (DRE) irrespective of the PSA value
A prostate biopsy is indicated if at least one of the above applies.
What is a prostatic biopsy ?
Prostatic biopsies are most often carried out under ultrasound guidance. A lubricated sheathed transrectal ultrasound probe is passed into the back passage and the prostate gland examined to identify any obvious abnormalities within the peripheral zone of the prostate. The ultrasound machine can detect differences in the sonographic echoes observed within different parts of the prostate. The prostate gland is comprised of three distinct glandular zones:
The peripheral zone encompasses the postero-lateral and anterior aspects of the prostate from the base to the apex. It is the area where over 90% of prostate cancers develop.
The central zone comprises the tissue immediately surrounding the ejaculatory ducts towards the base of the gland. It is indistinguishable from the peripheral zone of the prostate.
The transition zone surrounds the urethra and is the site where benign prostatic enlargement occurs. It is this tissue that is removed during prostate rebore surgery (TURP). It rarely contains cancerous tissue.
A prostate biopsy should systematically target the areas most likely to contain cancer, this is predominantly the peripheral zone and the central zone towards the base of the gland.
Transrectal Prostate Biopsy
Local anaesthetic transrectal prostate biopsies after an elevated PSA (Prostate Specific Antigen) blood test have been the mainstay for prostate cancer diagnosis but have proven too unreliable as a screening tool. The PSA blood test is NOT prostate cancer specific and standard transrectal prostate biopsies miss cancer in 30% of men. The main reason for this is that the TRUS biopsy under samples the peripheral zone, particularly the anterior peripheral zone where at least 20% of prostate cancers exist. This leads to both missed diagnosis or under diagnosis of prostate cancer in over 30% of patients. At London Bridge Urology we routinely offer a more comprehensive biopsy approach, a systematic MRI - US Fusion Targeted & Transperineal Sector Mapping Biopsy.
MRI - US Fusion Targeted Biopsy and Transperineal Sector Mapping Biopsy
The increasing use of pre biopsy MRI scanning and modern software developments have led to more effective and accurate biopsy protocols. In simple terms the MRI scan can identify the presence of a suspicious abnormality within the outer peripheral zone of the prostate. These lesions can be as small as 0.5mm in diameter and can be targeted accurately using a technique which fuses the MRI images with the abnormal area outlined directly with the live ultrasound images. It is these fused images which are used to target the prostate in the biopsy procedure. Although the MRI scan will identify abnormal areas within the prostate and the biopsies will confirm the presence of cancer in over 70% of these, the MRI may not identify all the cancerous changes and nor does a normal MRI completely exclude cancer. For that reason we combine the targeted biopsies with a systematic transperineal sector mapping biopsy to comprehensively sample the gland. The morbidity and side effects for the procedure are very low with minimal risk of infection and significant bleeding or swelling of the prostate occurring in less than 5% of patients. The procedure is done as a day case with a 5 hour hospital stay and the results are available within 24 hours.
Dealing with the diagnosis
The diagnosis of prostate cancer can be terribly emotive and have a major impact upon relationships and family. An element of depression and stress is a common feature of the normal response to the diagnosis and it is absolutely crucial that you take time to reflect upon your treatment options as explained to you. Decisions should not be taken too quickly and a focused, reasoned, and calm attitude will be an asset in dealing with the pressures you will face.
Remember - if a particular treatment doesn't feel right for you, then it probably isn't suitable for you. If a treatment feels right, then it probably is. Keep asking questions until you are satisfied. After studying all your options, spoken to the appropriate specialists, use the knowledge gained and trust your instincts.
Be realistic - If a man is not generally in good health, surgery may not be the best option. Surgery of any kind is hard, and recovery is easiest when a person is in good shape. If a man has bowel or bladder problems already, radiation of any kind may make them worse. Fortunately, there are a number of other options, including various forms of radiation therapy and hormone therapy, or a combination of treatments, which may still result in a successful outcome.
The ideal treatment - for early prostate cancer would both provide an excellent chance of cure (over 90% of the time) and minimal side effects with regard to urinary continence (leakage) and potency (erectile function). Unfortunately the ideal treatment does not exist (if it did then there would be no question about the benefit of prostate cancer screening), they all have significant side effects and an individual’s options are very dependant upon a number of interrelated factors:
The PSA level at diagnosis
The Clinical Stage local extent of disease based on DRE and imaging.
The Gleason score the pathological grade of the tumour.
The age and physical well being of the patient (co morbidity).
The presence or absence of significant lower urinary tract symptoms.
The current quality of erectile function (potency).
An individual’s preference for a particular treatment.
The most appropriate treatment for an individual can often be determined by the careful assessment and appraisal of these factors in conjunction with the advice of your urologist.