Investigator: Adam S. Feldman, MD, MPH–Assistant Professor of Surgery, Massachusetts General Hospital, Harvard School of Medicine
Active Surveillance: Identifying When to Treat and When Not to Treat
In 2010 nearly 218,000 men will be diagnosed with prostate cancer in the United States. However, ~50% of those men will have low risk prostate cancer. Recent epidemiology studies have shown that many patients are being over treated. Therefore, the National Comprehensive Cancer Network, a not-for-profit alliance of leading cancer hospitals, recently published a set of guidelines to identify prostate cancer patients with low risk cancer who should consider Active Surveillance. Active surveillance is the decision made between a physician and patient with very early stage prostate cancer to forgo local treatment such as surgery or radiation. Instead these individuals are closely monitored on a protocol every 6 months including repeat biopsy, PSA testing, and physical examination.
Dr. Feldman’s research goal is to optimize the guidelines for Active Surveillance by defining biomarkers that distinguish indolent disease from aggressive disease and by determining which clinical events during Active Surveillance should trigger treatment intervention.
To accomplish this he and his colleagues at MGH have initiated a retrospective study of ~220 men who were on Active Surveillance between 1991 and 2005. Ninety-five percent had a Gleason score of 6 or less. These men had a median follow up time of ~6 years. Overall survival at 5 and 10 years was ~95% and ~80%, respectively. Four of the men developed distant metastases. Dr. Feldman found that only PSA doubling time and cancer volume were significant predictors for Active Surveillance patients that left the program for surgical or radiation therapy.
Dr. Feldman continues to build their retrospective and prospective database of patients on active surveillance. During his third year he plans to assess the quality of life reported by these men, who were not treated, compared to men in active treatment groups. Additionally, he will analyze tissue specimens and urine collected from these men to test candidate biomarkers of disease progression. Dr. Feldman’s research highlights the general success of Active Surveillance protocols that allow patients to avoid local therapy for very early stage prostate cancer. However, since there were patients whose cancer progressed during Active Surveillance, further investigations to select appropriate patients for this strategy are warranted. The overarching objective is that the discovery of predictive biomarkers will better select individuals for which Active Surveillance is appropriate so that no man will undergo unnecessary treatment or experience life-threatening disease progression during Active Surveillance.
Terms to know from this article:
Active surveillance is an option offered to patients with very low-risk prostate cancer (low grade, low stage, localized disease). Patients are monitored carefully over time for signs of disease progression. A PSA blood test and digital rectal exam (DRE) and prostate biopsy are performed at physician-specified intervals. Signs of disease progression will trigger immediate active treatment.
The removal of cells or tissues for examination under a microscope. When only a sample of tissue is removed, the procedure is called an incisional biopsy or core biopsy. When an entire lump or suspicious area is removed, the procedure is called an excisional biopsy. When a sample of tissue or fluid is removed with a needle, the procedure is called a needle biopsy or fine-needle aspiration.
Gleason Score (GS) - Gleason Grade: A system of grading prostate cancer cells based on how they look under a microscope. Gleason scores range from 2 to 10 and indicate how likely it is that a tumor will spread. A low Gleason score means the cancer cells are similar to normal prostate cells and are less likely to spread; a high Gleason score means the cancer cells are very different from normal and are more likely to spread.
Increase in the size of a tumor or spread of cancer in the body.
prostate-specific antigen (PSA): A substance produced by the prostate that may be found in an increased amount in the blood of men who have prostate cancer, benign prostatic hyperplasia, or infection or inflammation of the prostate.