Diagnosis of prostate cancer
In the diagnosis of prostate cancer, a doctor will examine the patient by way of a general look at the physical condition of the patient and then, more specifically, examine for bladder enlargement and any change in the prostate outline. The prostate shape can be examined only by a rectal assessment. After the examination, if the doctor feels that there may be a problem with the prostate, he will carry out blood tests. These will measure levels of PSA (prostate specific antigen) within the blood stream.
If the symptoms are significant and his clinical suspicion is of prostate cancer, a referral will be made to a hospital doctor. The current waiting time recommendation for receipt of an appointment is 2 weeks, that is, a hospital consultant is required to review the patient with suspected prostate cancer in Outpatients within two weeks of receipt of the letter of referral from the GP.
For the symptomatic patient or those with suspicious PSA (PCA-3) results and perhaps an abnormal pelvic MRI scan – the optimal imaging modality for diagnosis (and detection of capsules breach by tumour), a biopsy (or more advisedly multiple 4-12 biopsies are taken for microscopic / histological confirmation of diagnosis and Gleason Grading (vide supra).
Transrectal ultrasound examination of the prostate with biopsies
Hospital tests should include a transrectal ultrasound examination of the prostate. In this test, a small cylindrical tube about the size of a finger is inserted into the anus. This is an ultrasound probe which emits high-frequency sound waves. These waves bounce back from internal structures and are computed. The computations allow an image to be produced on a screen. This image gives the radiologist an idea as to the outline of the prostate and the look of the internal structure of the gland.
The doctor may also ask for biopsies to be carried out. These biopsies are performed through small needles inserted into the ultrasound probe and then into the prostate. The whole procedure should take between 10 and 20 minutes to complete.
The specimens that are taken from the prostate are processed in the pathology department of the hospital.
The doctor will review the PSA levels and the biopsy results and try to give a view on to the next step in the patient’s journey to treatment. Overall, in England and Wales about 60% of patients will have a cancer that has spread.
If the results of the PSA levels are over 100 ng/l then it is likely that there will be spread of the disease to bones or lymph nodes. Levels between 20 and 100 are associated with spread beyond the prostate but not necessarily to bones or lymph nodes.
The next investigations should include an X-ray of the chest and pelvis. The doctor will also book a bone scan and possibly a CT scan or MR scan of the abdomen and pelvis.
The bone scan tests involve the injection of a radioactive tracer into a vein. The tracer will help to show whether or not there is spread to bone, which is where prostate cancer prefers to travel. 2 – 4 hours after the injection of the tracer, images are taken of the body. This involves the patient lying on a bed in the radiology department. A Gamma camera, which is like a large X-ray machine in appearance, is used to collect images of the emissions from the radioactive tracer.
CT and MR scanning
The patient undergoing a CT scan will lie on an X-ray table and have a series of X-rays taken of the internal contents of his abdomen and pelvis. This process takes approximately quarter of an hour. The films are then reviewed by a radiologist and assessments made on the possibility of spread of the cancer. Prostate cancer may spread to lymph nodes which are the internal glands within the abdomen and pelvis.
The whole point of these investigations that have been carried out are to define the degree of spread of a tumour. Defining the degree of spread allows the doctor to make a judgement as to treatment which can then be discussed with the patient.