Prostate cancer is the second leading cause of cancer death in men. There are 240,000 new prostate cancer cases diagnosed annually, and it accounts for 30,000 deaths per year. However, unlike many other cancers, prostate cancer is often not a fatal disease and may never need to be treated.
Patients with slow-growing, early stage prostate cancer as well as older men with other health issues may be put on active surveillance, also known as watchful waiting, as opposed to traditional treatment with surgery or radiation.
The problem is that not all prostate cancer cases are slow-growing and early stage. The challenge is predicting the future behavior of the cancer so it can be treated appropriately – offering cure to those with aggressive cancer, but sparing the side effects of treatment in those who have non-aggressive cancer.
What is active surveillance?
About 1 in 6 men will be diagnosed with prostate cancer during his lifetime, yet only 1 in 40 men will die from it. These statistics point out that many men with prostate cancer have a slow growing cancer. Because of this fact, an alternative strategy to aggressive management of prostate cancer is active surveillance, which includes careful follow-up with strict monitoring and immediate intervention should signs of progression develop.
The goal of active surveillance is to allow men with low risk prostate cancer to avoid radical treatment with its associated morbidity and/or delay definitive treatment until signs of progression occur. This involves two things:
- Vigilant monitoring
- A compliant patient who is compulsive about follow-up
Which patients are good candidates for active surveillance?
Being a candidate for this approach is based upon the results of the PSA blood test, findings on the digital rectal exam, and the details of the prostate biopsy. General eligibility criteria for active surveillance include all of the following:
- PSA (Prostate Specific Antigen) less or equal to 10 (PSA is the blood test that when elevated or accelerated indicates the possibility of a problem with the prostate and is often followed by a prostate ultrasound/biopsy)
- Gleason score 6 or less (possible score 2-10, more about this below)
- Stage T1c-T2a (T1c = picked up by PSA with normal prostate on rectal exam; T2a = picked up by abnormal prostate on rectal exam, involving only one side of the prostate)
- Less than 3 of 12 biopsy cores involved with cancer
- Less than 50% of any one core involved with cancer
Note that these are basic guidelines and need to be modified in accordance with patient age and general health— certainly if one has a life expectancy of less than 10 years, he would be a good candidate for active surveillance, regardless of the above.
How is prostate cancer grade determined?
Prostate cancer grade is often the most reliable indicator of the potential for growth and spread. The Gleason Score provides one of the best guides to the prognosis and treatment of prostate cancer and is based on a pathologist’s microscopic examination of prostate tissue. This score can predict the aggressiveness and behavior of the cancer.
To determine a Gleason Score, a pathologist assigns a separate numerical grade to the two most predominant architectural patterns of the cancer cells. The numbers range from 1 (the cells look nearly normal) to 5 (the cells have the most cancerous appearance). The sum of the two grades is the Gleason Score. The lowest possible score is 2, which rarely occurs; the highest is 10. High scores tend to suggest a worse prognosis than lower scores because the more deranged and mutated cells usually grow faster than more normal-appearing ones.
Prostate cancers can be “triaged” into one of three groupings based upon Gleason Score. Scores of 2-4 are considered low grade; 5-7, intermediate grade; 8-10, high grade.
What is involved in active surveillance?
The active surveillance monitoring schedule is typically:
- PSA and DRE every 3-6 months for several years, then annually
- Prostate biopsies: once a year after initial diagnosis, then periodically until age 80 (this depends on the patient)
As long as the cancer remains low-risk, active surveillance may be continued, sparing the patient the potential side effects of surgery or radiation.
Approximately half of men on active surveillance remain free of progression at ten years, and definitive treatment is most often effective in those with progression. The absence of cancer on repeated prostate biopsies (because the cancer is of such low volume) identifies men who are unlikely to have progressive prostate cancer.