All men undergoing curative treatment for prostate cancer hope for a successful outcome. After surgery or radiation, they want their PSA levels to remain low and stable, and, most of all, they want to have seen the last of cancer. So hearing that the cancer is back can be even more disheartening for them than being diagnosed in the first place. This is not surprising.

However, once over the initial shock and disappointment, these men and their families and friends realize that there are still treatments available. And many discover that it is possible to live long and well with cancer.

What is recurrence?
A recurrence means that the prostate cancer has returned after initial treatment. Other terms you may hear to describe this situation are

• biochemical recurrence, biochemical failure, or PSA recurrence;
• local recurrence; and
• distant recurrence or metastatic cancer.

The first group of terms (i.e., biochemical recurrence) refers to the way a recurrence is usually detected---by means of a blood test that measures concentrations of prostate-specific antigen (PSA). After successful surgery or radiation to treat localized prostate cancer, PSA levels should become almost undetectable (dropping to zero or nearly zero after surgery and usually, over time, to below 1.0 ng/mL after radiation). And a man’s PSA level should remain low and stable. Rising PSA levels can signal that prostate cancer has returned. A recurrence detected through rising PSA levels is called a biochemical or PSA recurrence. (A word of caution: many things can contribute to an elevated PSA level, so it usually takes at least two consecutive increases; a marked rise, say of 2 points or more; or a quick PSA doubling time before doctors confirm a recurrence.)

Once a biochemical recurrence is suspected or diagnosed, physicians do tests to determine whether that recurrence is local or distant.

A local recurrence means that the cancer has returned in the prostate, if it wasn’t surgically removed, or in the area immediately surrounding the prostate. Some sites of local recurrence include the seminal vesicles (which are next to the prostate and store semen), the lymph nodes in the pelvis, or the tissues near the prostate bed, for example, the muscles of the rectum or the wall of the pelvis.

A distant recurrence means that the cancer has spread beyond the area of the prostate, often to bones or to lymph nodes at a distance from the prostate bed. Distant recurrence means that the cancer is metastatic. In other words, the cancer has metastasized---spread from one part of the body to another non-adjacent part through the bloodstream or the lymphatic system. (Metastasis comes from a Greek word meaning “removal from one place to another.)

What is my risk for recurrence?
Some researchers estimate that as many as 30 per cent of the men treated for prostate cancer will experience a biochemical recurrence. According to statistics provided by the American Cancer Society, however, nearly 100 per cent of men diagnosed with prostate cancer survive 5 years after diagnosis. The 10-year survival rate is 91 per cent, and the 15-year survival rate is 76 per cent. (Keep in mind that the treatments available to men diagnosed over 15 years ago were much less advanced than they are now, and even this last statistic is fairly comforting.)

Another important point is that, of those who experience biochemical recurrence, many live with prostate cancer and eventually die of something other than this disease. Researchers out of Yale found that almost 90 per cent of those who failed initial treatment (surgery or radiation), had not died from prostate cancer 5 years later; at 10 and 15 years, the prostate cancer mortality rate among those who failed initial treatment was 20 per cent and 42 per cent, respectively, meaning that, even at 15 years, over half of those who experienced biochemical recurrence had not died of the disease. Dr. E. M. Uchio, lead author of this study, concluded that the phrase “most men die with prostate cancer not of it” applies even to those who have experienced a biochemical recurrence. (Read this study.)

Some men, though, are more at risk of a recurrence than others. When you are first diagnosed and deciding among treatment options, your medical team will more than likely advise you regarding your risk of recurrence after various therapies. But here are some of the factors they consider.

• Tumour size: In general, the larger the tumour the greater the chance of recurrence.
• Grade: If your cancer is described as low grade, your chance of experiencing a recurrence is also lower. The higher the grade, the greater the likelihood of recurrence. Remember that prostate cancer is graded using the Gleason score.
• Stage: Again, the more advanced the stage, the greater the risk of recurrence. Locally advanced prostate cancer (or clinical stage T3) carries the largest risk. (Learn more about TNM staging.)

Various methods are used to determine risk for recurrence, but one useful categorization comes from the Prostate Cancer Charity of the United Kingdom. This organization defines the risk of recurrence as low if PSA level at diagnosis was less than 10 ng/mL, Gleason score was less than 7, and the cancer was localized (clinical stage T2 or less). A medium or moderate risk profile is defined as a PSA level between 10 to 20 ng/mL or a Gleason score of 7 and no spread of cancer outside of the prostate (clinical stage T2). A high risk is any of the following: PSA level at diagnosis over 20 ng/mL, Gleason score over 7, or the cancer is locally advanced or at clinical stage T3 (i.e., spread outside the capsule of the prostate gland or into the seminal vesicles).

What can be done now?
There are various treatments for recurrent prostate cancer. These are often called “salvage” or “second-line” treatments because they come after your initial or “primary” treatment has failed. The treatment options available to you depend on a number of factors, including your age and general health, where your cancer has come back, and what your “primary” treatment was.

• How healthy am I outside of my cancer diagnosis, and, given my age and general health, what is my life expectancy? These blunt questions are very difficult for anyone to face. However, men with recurrent prostate cancer and their doctors do need to base decisions and recommendations concerning treatment on likely answers. Why? Consider this scenario. A robust and healthy 65-year-old man is diagnosed with prostate cancer. Fifteen years later, when he is 80, he has a biochemical recurrence. This time, certain treatments for prostate cancer may be dangerous or, on the whole, unbeneficial because of their effects on his quality of life.
• Where is the cancer?  Your doctor will most often order various imaging tests to determine where your prostate cancer has returned. A bone scan is commonly done because the bone is frequently the site of prostate cancer metastases. A CT scan is also often used to check for enlarged lymph nodes, and an MRI (magnetic resonance imaging), which produces no radiation and is useful for scanning the abdomen and pelvis, might be ordered too.
• What are my “second-line” treatment options? The most common treatment is hormone therapy. But treatment options vary depending upon your initial treatment.

Local treatment options are sometimes available for recurrent prostate cancer after surgery, radiotherapy, and brachytherapy. But very different approaches are necessary if hormone therapy, a system-wide treatment, can no longer control prostate cancer because it has become “hormone resistant” (often called hormone refractory prostate cancer or castration resistant prostate cancer).

References:

American Cancer Society, 2011, Survival Rates: Prostate Cancer.

Edward M. Uchio and colleagues, 2010, Impact of Biochemical Recurrence in Prostate Cancer Among US Veterans, Archives of Internal Medicine 170(15): 1390-1395.

Dr. Fred Saad & Dr. Michael McCormack, 2008, Understanding Prostate Cancer (Montreal, PQ: Rogers Media).

The Prostate Cancer Charity, 2009, Recurrent Prostate Cancer (London, UK: The Prostate Cancer Charity).