New Study Examines Long-Term Benefits of Prostate-Specific Antigen (PSA) Screening for Prostate Cancer

Genitourinary cancer specialists from Seattle Cancer Care Alliance, University of Washington School of Medicine, Fred Hutchinson Cancer Research Center, and Weill Cornell Medicine have published an article, “Reconsidering the Trade-offs of Prostate Cancer Screening,” in the New England Journal of Medicine on the long-term benefits of prostate-specific antigen (PSA) screening for prostate cancer in men. In the article, investigators concluded that the advantages of widespread screening – including reduced mortality and the potential to avoid metastases – are likely greater than estimates cited in current guidelines.

Antigen A foreign substance, such as bacteria, that causes the body’s immune system to respond by making antibodies. Antibodies defend the body against antigens. Screening Checking for disease when there are no symptoms. Because screening may find diseases at an early stage, there may be a better chance of curing the disease Checking for disease when there are no symptoms. Because screening may find diseases at an early stage, there may be a better chance of curing the disease. Examples of cancer screening tests are the mammogram (for breast cancer), colonoscopy (for colon cancer) and Pap and HPV tests (for cervical cancer). Screening can also include a genetic test to check for a person’s risk of developing an inherited disease.

Seattle, Washington (June 17, 2020) – “Currently, much of the medical community considers PSA testing as an example of a screening tool that is ineffective largely based on short-term data from two trials,” said Yaw Nyame, MD, MBA, MS, study co-lead author and investigator and clinical fellow in the Department of Urology at the University of Washington School of Medicine and Seattle Cancer Care Alliance, and a post-doctoral fellow at the Fred Hutchinson Cancer Research Center. “Using data from the more reliable of the two trials and conservative assumptions, our team created a microsimulation model to extrapolate the mortality reduction due to screening from 16 years of follow-up to 25 years of follow-up. Our results show that continued accrual of benefit over time creates a significantly more favorable picture of the value of screening.”

Routine prostate cancer screening relies on measurements of the level of prostate-specific antigen (PSA), produced by the prostate gland, in a man's blood. Men with prostate cancer often have elevated PSA levels.  The trade-off with PSA screening is a balance between the potential benefit (i.e., preventing a man from dying of prostate cancer) with possible drawbacks, such as overdiagnosis and overtreatment of prostate cancer. Overdiagnosis is the diagnosis of cancer by screening that would not have been diagnosed without screening in the patient’s remaining lifetime. Overtreatment—the treatment of an overdiagnosed cancer—can cause substantial harms, including urinary incontinence and erectile dysfunction. 

“Prostate cancer screening can lead to overdiagnosis, but screening trials did not provide a correct perception of the harms relative to benefits and underestimated the lives that could be saved over the long term. This manuscript leverages a simulation model that was developed by our group to overcome these limitations,” explained Dr. Ruth Etzioni, faculty member of the Public Health Science Division at the Fred Hutchinson Cancer Research Center. 

Perceptions of PSA testing as ineffective, combined with overstated harms, have led agencies such as the U.S. Preventive Services Task Force (USPSTF) and organizations including the American Academy of Family Physicians to shy away from recommending routine screening for men. In 2018, the USPSTF provided a grade C recommendation for PSA screening, recommending instead “shared decision making” between patients and their healthcare providers.  

These recommendations are rooted on short-term data that suggests that screening prevents one death from prostate cancer per 1,000 men screened at the expense of diagnosing 100 cancers. “Our model, however, shows that we would have to diagnose 11 extra cases of prostate cancer to prevent 1 prostate cancer death at 25-years of follow-up,” states Dr. Nyame.  “These recommendations also fail to acknowledge the marked changes occurring in the field that are improving our detection of clinically significant cancer, and changes in our management of low-risk cancers (i.e., active surveillance) that is markedly reducing the harms of overtreatment. The time has come to rethink the use of PSA testing, particularly in high-risk populations, so that we do not miss the opportunity to improve our ability to diagnosis prostate cancer earlier, enhance our ability to treat it effectively, and save more men from serious illness and death.”

 

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About Us

Seattle Cancer Care Alliance brings together the leading research teams and cancer specialists from Fred Hutch, Seattle Children’s and UW Medicine — one extraordinary group whose sole purpose is the pursuit of better, longer, richer lives for our patients. Based in Seattle’s South Lake Union neighborhood, Seattle Cancer Care Alliance has nine clinical care sites in the region, including a medical oncology clinic at EvergreenHealth in Kirkland; hematology/medical oncology and infusion services at Overlake Medical Center in Bellevue, medical and radiation oncology clinics at UW Medical Center - Northwest Seattle and medical oncology services at SCCA Issaquah, as well as Network affiliations with hospitals in five states. For more information about SCCA, visit seattlecca.org.

 

About University of Washington Medicine

UW Medicine is one of the top-rated academic medical systems in the world. With a mission to improve the health of the public, UW Medicine educates the next generation of physicians and scientists, leads one of the world’s largest and most comprehensive biomedical research programs, and provides outstanding care to patients from across the globe. The School of Medicine faculty is second in the nation in federal research grants and contracts. In all, UW Medicine represents nearly 30,000 caring professionals who come together to improve the health of the public. Our family of providers, researchers, faculty and staff include: Airlift Northwest, Harborview Medical Center, UW Medical Center – Northwest, UW Medical Center-Montlake, UW Neighborhood Clinics, UW School of Medicine, UW Physicians, Valley Medical Center.

For details about UW Medicine, please visit http://uwmedicine.org/about.

 

Contacts

Karina San Juan-Guyton, ksanjuangu@seattlecca.org or (206) 606-1926

Heather Platisha, hplatisha@seattlecca.org or (415) 676-8030

Barbara Clements, bac60@uw.edu or (253) 740-5043
 

Antigen A foreign substance, such as bacteria, that causes the body’s immune system to respond by making antibodies. Antibodies defend the body against antigens. Grade In cancer, a grade is a description of a tumor based on how abnormal the cancer cells and tissue look under a microscope and how quickly the cancer cells are likely to grow and spread. In cancer, a grade is a description of a tumor based on how abnormal the cancer cells and tissue look under a microscope and how quickly the cancer cells are likely to grow and spread. Low-grade cancer cells look more like normal cells and tend to grow and spread more slowly than high-grade cancer cells. Grading systems are different for each type of cancer. They are used to help plan treatment and determine prognosis. Also called histologic grade and tumor grade. Infusion An injection of medications or fluids into a vein over a period of time. Screening Checking for disease when there are no symptoms. Because screening may find diseases at an early stage, there may be a better chance of curing the disease Checking for disease when there are no symptoms. Because screening may find diseases at an early stage, there may be a better chance of curing the disease. Examples of cancer screening tests are the mammogram (for breast cancer), colonoscopy (for colon cancer) and Pap and HPV tests (for cervical cancer). Screening can also include a genetic test to check for a person’s risk of developing an inherited disease. Surveillance Closely watching a patient’s condition but not treating it unless there are changes in test results. Surveillance is also used to find early signs that a disease has come back. In medicine, surveillance means closely watching a patient’s condition but not treating it unless there are changes in test results. Surveillance is also used to find early signs that a disease has come back. It may also be used for a person who has an increased risk of a disease, such as cancer. During surveillance, certain exams and tests are done on a regular schedule. In public health, surveillance may also refer to the ongoing collection of information about a disease, such as cancer, in a certain group of people. The information collected may include where the disease occurs in a population and whether it affects people of a certain gender, age or ethnic group. Prostate-specific antigen A protein made by the prostate gland and found in the blood. Prostate-specific antigen blood levels may be higher than normal in men who have certain prostate diseases or conditions.

A protein made by the prostate gland and found in the blood. Prostate-specific antigen blood levels may be higher than normal in men who have prostate cancer, benign prostatic hyperplasia (BPH), or infection or inflammation of the prostate gland.