Signs and symptoms of prostate cancer
Early prostate cancer usually causes no symptoms and is most often found by a PSA test and/or DRE. Some advanced prostate cancers can slow or weaken your urinary stream or make you need to urinate more often. In some cases kidney blockage can occur. But non-cancerous diseases of the prostate, such as BPH (benign prostatic hyperplasia) cause these symptoms more often.
If the prostate cancer is advanced, you might have blood in your urine (hematuria) or trouble getting an erection (impotence). Advanced prostate cancer commonly spreads to the bones, which can cause pain in the hips, back (spine), chest (ribs), or other areas. Cancer that has spread to the spine can also press on the spinal nerves, which can result in weakness or numbness in the legs or feet, or even loss of bladder or bowel control.
Other diseases can also cause many of these same symptoms. It is important to tell your doctor if you have any of these problems so that the cause can be found and treated.
Medical history and physical exam
If your doctor suspects prostate cancer, he or she will perform a physical exam, including a digital rectal exam (DRE). The DRE can sometimes tell whether the cancer is only on one side of the prostate, whether it is present on both sides, or whether it is likely to have spread beyond the prostate gland to nearby tissues. The DRE is also sometimes used together with the PSA blood test to detect prostate cancer early and is discussed in the section, "Can prostate cancer be found early?" Your doctor may also examine other areas of your body to see if the cancer has spread.
Your doctor will also ask you about symptoms such as urinary problems or bone pain, which could suggest that the cancer may have spread to your bones.
If certain symptoms or the results of early detection tests -- the prostate-specific antigen (PSA) blood test and/or digital rectal exam (DRE) -- suggest that you might have prostate cancer, your doctor will do a prostate biopsy to find out if the disease is present. Imaging tests may be ordered if it is likely that the cancer is advanced.
The prostate biopsy
A biopsy is a procedure in which a sample of body tissue is removed and then looked at under a microscope. A core needle biopsy is the main method used to diagnose prostate cancer. It is usually done by an urologist, a surgeon who treats cancers of the genital and urinary tract, which includes the prostate gland. Using transrectal ultrasound (described in the section, "Can prostate cancer be found early?") to "see" the prostate gland, the doctor quickly inserts a needle through the wall of the rectum into the prostate gland. When the needle is pulled out it removes a small cylinder (core) of tissue, usually about 1/2-inch long and 1/16-inch across. This is repeated from 8 to18 times, but most urologists will take about 12 samples. These are sent to the lab to see if cancer is present.
Though the procedure sounds painful, it may only cause a very brief, uncomfortable sensation because it is done with a special spring-loaded biopsy instrument. The device inserts and removes the needles in a fraction of a second. Most doctors who do the biopsy will numb the area first by injecting a local anesthetic alongside the prostate. You might want to ask your doctor if he or she plans to do this.
Some doctors will do the biopsy through the perineum, the skin between the rectum and the scrotum. The doctor will place his or her finger in your rectum to feel the prostate and then insert the biopsy needle through a small incision (cut) in the skin of the perineum. The doctor will also use a local anesthetic to numb the area.
The biopsy itself takes about 10 minutes and is usually done in the doctor's office. You will likely be given antibiotics to take before the biopsy and for a day or 2 after to reduce the risk of infection.
For a few days after the procedure, you may feel some soreness in the area and will likely notice blood in your urine. You may also have some light bleeding from your rectum, especially if you have hemorrhoids. Many men also see some blood in their semen or have rust colored semen, which can last for several weeks after the biopsy, depending on how frequently you ejaculate.
Your biopsy samples will be sent to a pathology lab. There, a pathologist (a doctor who specializes in diagnosing disease in tissue samples) will see if there are cancer cells in your biopsy by looking at the samples under the microscope. If cancer is present, the pathologist will also assign it a grade (see below). Getting the results usually takes at least 1 to 3 days, but it can take longer.
Even with many samples, biopsies can still sometimes miss a cancer if none of the biopsy needles pass through it. This is known as a "false negative" result. If your doctor still strongly suspects prostate cancer (due to a very high PSA level, for example) a repeat biopsy may be needed to help be sure.
Grading the prostate cancer
Almost all pathologists grade prostate cancers according to the Gleason system. This system assigns a Gleason grade, using numbers from 1 to 5 based on how much the cells in the cancerous tissue look like normal prostate tissue.
- If the cancerous tissue looks much like normal prostate tissue, a grade of 1 is assigned.
- If the cancer lacks these normal features and its cells seem to be spread haphazardly through the prostate, it is called a grade 5 tumor.
- Grades 2 through 4 have features in between these extremes.
Today, most biopsies are grades of 3 or higher, and the other grades are not often used.
Since prostate cancers often have areas with different grades, a grade is assigned to the 2 areas that make up most of the cancer. These 2 grades are added together to yield the Gleason score (also called the Gleason sum) between 2 and 10. There are some exceptions to this rule. If the highest grade takes up most (95% or higher) of the biopsy, the grade for that area is counted twice in the Gleason score. Also, if 3 grades are present in a biopsy core, the highest grade is always included in the Gleason score, even if most of the core is taken up by areas of cancer with lower grades.
- Cancers with Gleason scores of 6 or less are called low-grade or well-differentiated
- Cancers with Gleason scores of 7 may be called moderately-differentiated or intermediate-grade.
- Cancers with Gleason scores of 8 to 10 may be called poorly-differentiated or high-grade.
The higher your Gleason score, the more likely it is that your cancer will grow and spread quickly.
Other elements of a biopsy report
The pathologist's report contains the grade of the cancer (if it is present) but it also often contains other pieces of information that may give a better idea of the scope of the cancer. These can include:
- The number of biopsy core samples that contain cancer (for example, "7 out of 12")
- The percentage of cancer in each of the cores
- Whether the cancer is on one side (left or right) of the prostate or both sides (bilateral)
Suspicious results
Sometimes when the pathologist looks at the prostate cells under the microscope, they don't look cancerous, but they're not quite normal, either. These results are often reported as suspicious. They generally fall into 2 categories -- either prostatic intraepithelial neoplasia (PIN) or atypical small acinar proliferation (ASAP).
In PIN, there are changes in how the prostate cells look under the microscope, but the abnormal cells don't look like they've grown into other parts of the prostate (like cancer cells would). PIN is often divided into low-grade and-high grade. Many men begin to develop low-grade PIN at an early age but do not necessarily develop prostate cancer. The importance of low-grade PIN in relation to prostate cancer is still unclear.
If high-grade PIN is found on a biopsy, there is about a 20% to 30% chance that cancer may already be present somewhere else in the prostate gland. This is why doctors often watch men with high-grade PIN carefully and may advise a repeat prostate biopsy, especially if the original biopsy did not take samples from all parts of the prostate.
Another finding that is sometimes reported on a prostate biopsy is atypical small acinar proliferation (ASAP), which is sometimes just called atypia. In ASAP, the cells look like they might be cancerous when viewed under the microscope, but there are too few of them to be sure. If ASAP is found, there's a high chance that cancer is also present in the prostate, which is why many doctors recommend getting a repeat biopsy within a few months.
Imaging tests to look for prostate cancer spread
Your doctor will use your digital rectal exam (DRE) results, prostate-specific antigen (PSA) level, and Gleason score to figure out how likely it is that your cancer has spread outside of the prostate. This information is used to decide which other tests (if any) need to be done before deciding on a treatment. Men with a normal DRE result, a low PSA, and a low Gleason score may not need imaging or other tests because the chance that the cancer has spread is so low. The imaging tests used most often include:
Radionuclide bone scan
When prostate cancer spreads to distant sites, it often goes to the bones first. (Even when prostate cancer spreads to the bone, it is still called prostate cancer, not bone cancer.) A bone scan can help show whether cancer has reached the bones.
For this test, a small amount of low-level radioactive material is injected into a vein (intravenously, or IV). The substance settles in damaged bone tissue throughout the entire skeleton over the course of a couple of hours. You then lie on a table for about 30 minutes while a special camera detects the radioactivity and creates a picture of your skeleton.
Areas of bone damage appear as "hot spots" on your skeleton -- that is, they attract the radioactivity. Hot spots may suggest the presence of metastatic cancer, but arthritis or other bone diseases can also cause the same pattern. To tell the difference between these conditions, your cancer care team may use other imaging tests such as simple x-rays or CT or MRI scans to get a better look at the areas that light up, or they may even take biopsy samples of the bone.
The injection is the only uncomfortable part of the scanning procedure. The radioactive material is passed out of the body in the urine over the next few days. The amount of radioactivity used is very low, so it carries very little risk to you or others. But you still may want to ask your doctor if you should take any special precautions after having this test.
Computed tomography (CT)
The CT scan (also known as a CAT scan) is a special kind of x-ray that gives detailed, cross-sectional images of your body. Instead of taking one picture, like a standard x-ray, a CT scanner takes many pictures of the part of your body being studied as it rotates around you. A computer then combines these pictures into images of slices of the part of your body being studied.
For some scans, you may be asked to drink 1 or 2 pints of oral contrast before the first set of pictures is taken. This helps outline the intestine so that it looks different from any tumors. This is rarely needed in scans done for prostate cancer. You may receive an IV (intravenous) line through which a different kind of contrast is injected. This helps better outline structures in your body. You will also need to drink enough liquid to have a full bladder. This will keep the bowel away from the area of the prostate gland.
The IV contrast can cause your body to feel flushed (a feeling of warmth with some redness of the skin). A few people are allergic and get hives. Rarely, more serious reactions, like trouble breathing or low blood pressure, can occur. Medication can be given to prevent and treat allergic reactions, so be sure to tell your doctor if you have ever had a reaction to any contrast material used for x-rays. It is also important to let your doctor know about any other allergies.
CT scans take longer than regular x-rays. You need to lie still on a table while they are being done. During the test, the table moves in and out of the scanner, a ring-shaped machine that completely surrounds the table. You might feel a bit confined by the ring you have to lie in while the pictures are being taken.
This test can help tell whether prostate cancer has spread into nearby lymph nodes. If your prostate cancer has come back after treatment, the CT scan can often tell whether it is growing into other organs or structures in your pelvis. On the other hand, CT scans rarely provide useful information about newly diagnosed prostate cancers that are likely to be confined to the prostate based on other findings (DRE result, PSA level, and Gleason score). CT scans are not as useful as magnetic resonance imaging (MRI) for looking at the prostate gland itself.
Magnetic resonance imaging (MRI)
MRI scans use radio waves and strong magnets instead of x-rays. The energy from the radio waves is absorbed by the body and then released in a pattern formed by the type of body tissue and by certain diseases. A computer translates the pattern into a very detailed image of parts of the body. This produces cross-sectional slices of the body like a CT scanner, but it can also show slices (views) from several angles. Like a CT scan, a contrast material might be injected, but this is done less often. Because the scanners use magnets, people with pacemakers, certain heart valves, or other medical implants may not be able to get an MRI.
MRI scans can be helpful in looking at prostate cancer. They can produce a very clear picture of the prostate and show whether the cancer has spread outside the prostate into the seminal vesicles or the bladder. This information can be very important for your doctors in planning your treatment. But like CT scans, they may not provide useful information about newly diagnosed prostate cancers that are likely to be localized (confined to the prostate) based on other factors.
MRI scans take longer than CT scans -- often up to an hour. During the scan, you need to lie still inside a narrow tube, which is confining and can upset people who don't like enclosed spaces. The machine also makes clicking and buzzing noises. Some places provide headphones with music to block this out. To improve the accuracy of the MRI, many doctors will place a probe, called an endorectal coil, inside your rectum. This must stay in place for 30 to 45 minutes and can be uncomfortable.
ProstaScintTM scan
Like the bone scan, the ProstaScint scan uses an injection of low-level radioactive material to find cancer that has spread beyond the prostate. Both tests look for areas of the body where the radioactive material collects, but they work in different ways.
While the radioactive material used for the bone scan is attracted to bone, the material for the ProstaScint scan is attracted to prostate cells in the body. It is attached to a monoclonal antibody, a type of man-made protein that recognizes and sticks to a particular substance. In this case, the antibody sticks to prostate-specific membrane antigen (PSMA), a substance found at high levels in normal and cancerous prostate cells.
After the material is injected, you will be asked to lie on a table while a special camera creates an image of the body. This is usually done about half an hour after the injection and again 3 to 5 days later.
The advantage of this test is that it can find prostate cancer cells in lymph nodes and other soft (non-bone) organs. Because the antibody only sticks to prostate cancer cells, other cancers or benign problems should not cause abnormal results. But the test is not always accurate, and the results can sometimes be confusing.
Most doctors do not recommend this test for men who have just been diagnosed with prostate cancer. But it may be useful after treatment if your blood PSA level begins to rise and other tests are not able to find the exact location of your cancer. Doctors may not order this test if they believe it will not be helpful for a given patient.
Lymph node biopsy
In a lymph node biopsy, one or more lymph nodes are removed to see if they contain cancer cells. These procedures, known as lymph node dissection, lymphadenectomy, or lymph node biopsy, are sometimes done to find out whether the cancer has spread from the prostate to nearby lymph nodes. If cancer cells are found in a lymph node, surgery is not likely to cure the cancer, so other treatment options are considered. Lymph node biopsies are rarely done unless your doctor is concerned that the cancer has spread. There are several ways to biopsy lymph nodes.
Surgical biopsy
The surgeon may remove lymph nodes through an incision in the lower part of your abdomen. This is often done in the same operation as the radical prostatectomy. (See the section, "How is prostate cancer treated?" for information about radical prostatectomy.)
If the surgeon has a reason to suspect that the cancer may have spread (such as a PSA level over 20 or a Gleason score over 7), he or she may remove some lymph nodes before attempting to remove the prostate gland. A pathologist then looks at the nodes while you are still under anesthesia to help the surgeon decide whether to continue with the radical prostatectomy. This is called a frozen section exam because the tissue sample is frozen before thin slices are taken to check under a microscope. If the nodes contain cancer, the operation may be stopped (leaving the prostate in place). This would happen if the surgeon felt that removing the prostate would be unlikely to cure the cancer, but would still result in serious complications or side effects.
More often now, the prostate is removed even if the lymph nodes contain cancer. In that case, surgeons do not often request a frozen section exam and instead the lymph nodes are sent to be looked at along with the removed prostate gland. The test results are usually available 3 to 7 days after surgery.
Laparoscopic biopsy
A laparoscope is a long, slender tube with a small video camera on the end that is inserted into the abdomen to let the surgeon see making a cut about the size of width of a finger. Other small incisions are made to insert long instruments to remove the lymph nodes. The surgeon removes all of the lymph nodes around the prostate gland and sends them to the pathologist. Because there are no large incisions, most people recover fully in only 1 or 2 days, and the operation leaves very small scars. This procedure is not common, but it is sometimes used when it's important to know the lymph node status and radical prostatectomy is not planned (such as for certain men who choose treatment with radiation therapy).
Fine needle aspiration (FNA)
If your lymph nodes appear enlarged on an imaging study (CT or MRI) a specially trained radiologist may take a sample of cells from an enlarged lymph node by using a technique called fine needle aspiration (FNA). To do this, the doctor uses the CT scan image to guide a long, thin needle through the skin in the lower abdomen and into an enlarged lymph node. A syringe attached to the needle allows the doctor to take a small tissue sample from the node. Before the needle is placed, your skin will be numbed with local anesthesia. You will be able to return home a few hours after the procedure.
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