LOPRESTI

Dr. Leigh LoPresti

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Ounce of Prevention is a weekly column which presents recommendations for preventative services derived from The United States Preventive Services Task Force (USPSTF). Each column begins with the name of the condition, the grade provided by the USPSTF as well as the official recommendation, the type of prevention, and more. Each will have a date of publication for the recommendation, referencing the date of the most recent update, not the original publication.

Name of the Condition/Recommendation: Prostate cancer, screening

Grade: C

Official recommendation:

Grade C: For men aged 55 to 69 years, the decision to undergo periodic prostate-specific antigen (PSA)-based screening for prostate cancer should be an individual one. Before deciding whether to be screened, men should have an opportunity to discuss the potential benefits and harms of screening with their clinician and to incorporate their values and preferences in the decision. Screening offers a small potential benefit of reducing the chance of death from prostate cancer in some men. However, many men will experience potential harms of screening, including false-positive results that require additional testing and possible prostate biopsy; overdiagnosis and overtreatment; and treatment complications, such as incontinence and erectile dysfunction. In determining whether this service is appropriate in individual cases, patients and clinicians should consider the balance of benefits and harms on the basis of family history, race/ethnicity, comorbid medical conditions, patient values about the benefits and harms of screening and treatment-specific outcomes, and other health needs. Clinicians should not screen men who do not express a preference for screening.

Type of Prevention: Secondary

Month/Year of Publication: May, 2018 (topic is under revision)

The most important risk factors for prostate cancer are older age (2/3 of all men dying of prostate cancer are older than 75 years; for men who die of other causes, 33% of those in their 70s also had prostate cancer, African-American heritage (close to double the risk of white men; they are also more likely to have it at younger ages, and to have more advanced disease at detection), and a family history of prostate cancer.

The PSA test that is used for screening can increase with inflammations of the prostate (prostatitis) and age-related enlargements (benign prostatic hypertrophy), so a rise in PSA does not equal cancer. Using PSA screening tests in long trials (13 years of screening) reduce the death rate from prostate cancer by 0.1% (1.3 prevented deaths for every 1000 men screened; number needed to screen=781) and is thought to prevent metastatic disease in 0.3% of screened men (NNS=324). The death rate reduction, as minor as it is, disappears in the research studies after the age of 70, hence the limitation of the recommendation to men under 70 years.

Screening, because of the other causes of elevated PSAs has a significant false positive rate (15% to 67% in quoted studies), and can result in biopsies and other procedures that can result in complications. Indeed, 1% of men in the studies who had a prostate biopsy ended up being hospitalized for complications of the procedure. Another major harm is known as overdiagnosis, where cancer is diagnosed in men who would never have been symptomatic (at any level) with their prostate cancer). This is in the range of 20-50% of the men diagnosed with prostate cancer in a screening program. It increases with age. Of all men with prostate cancer treated with removal of the prostate (prostatectomy) 20% will have persistent urinary leakage post-operatively, and 2/3 will lose the ability to get an erection. Any adverse effects matter a lot more, of course, in any men that are over diagnosed. Just to be sure you have heard this, the rectal exam for prostate cancer screening is no longer considered useful, and shouldn’t be done.

The harms of treatment are listed above. Many current recommendations for treatment start with a surveillance phase, because most prostate cancers progress only slowly. In a 10 year study of “active surveillance” (frequent tests and sometimes biopsies; if the cancer changes, they are then treated) the survival rate of that group was 99%.

Few African-American heritage patients were included in the trials of prostate cancer screening, so there is no separate recommendation for screening them, though the shared decision making must note their higher risk. The same analysis can be applied to men with a family history of prostate cancer—again no studies contained a significant number of these men, but they are clearly at higher risk, especially if a prostate cancer caused a relative’s death, or if they have multiple affected family members. It also clear that a number of genetic mutations which may be present in a man’s family can raise the risk of prostate cancer. This includes both BRCA1 and BRCA2, the five Lynch syndrome genes, CHEK2, PALB2, and ATM. Men with a family history of one of those mutations in a first degree relative (parent, sibling, or child) should see a genetic counselor to consider testing for themselves. (Hopefully, the revision of this topic will address these serious gaps in our knowledge).

The final summary is that prostate cancer is common, but screening has limited benefits, some significant risks, and we know little about the change in that benefit-to-risk ratio in those likely to be at higher risk (African-American heritage, family history or known genetic mutation).

Dr. Leigh LoPresti is a physician, educator, and owner of Manchester Direct Family Practice. Opinions expressed by columnists do not necessarily reflect the views of Vermont News & Media.


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