Screening Gets Personal
Conflicting and changing cancer screening guidelines have led to uncertainty and controversy. Can screening recommendations tailored for groups or individuals enhance benefits and reduce harms?
By Kate Yandell
Thomas Farrington’s father and both of his grandfathers died of prostate cancer, but for many years, Farrington wasn’t concerned about his own risk. Then, in 2000, he was diagnosed with moderately aggressive stage I prostate cancer at age 57. An elevated score on a routine prostate-specific antigen (PSA) test led to the diagnosis for Farrington, who lives in Quincy, Massachusetts, and worked for many years in the information technology industry.
During his diagnosis and treatment, Farrington was surprised to learn that, as an African-American man, he was part of a group at increased risk of prostate cancer. As of 2016, African-American men are 1.7 times more likely than white men to get prostate cancer and 2.4 times more likely to die of it.
In 2003, Farrington founded the Prostate Health Education Network (PHEN), a nonprofit organization dedicated to education and to reducing disparities in prostate cancer incidence and mortality affecting African-American men. Likely due in part to increased awareness of prostate cancer risk in African-American men, PSA testing rates have risen in this group since the 1990s. In 2012, African-American men 45 to 60 years old in the U.S. reported higher rates of screening than white men, according to one study, although older African-American men were still screened at slightly lower rates than white men.
Also in 2012, the U.S. Preventive Services Task Force (USPSTF), a panel of volunteer experts that rates screening and preventive health services, issued new prostate cancer screening guidelines. The USPSTF gave PSA testing its lowest grade: D. Physicians are advised to discourage patients from using D-rated screening tests. Prior to the new guidelines, the USPSTF had said there was insufficient evidence to determine if risks of PSA testing outweighed harms for men under age 75. The D score alarmed patient advocates.
“We worked hard to get the level of PSA testing for black men at the same level it was for white men,” says Farrington. “We worked years to make that happen, and we achieved that goal.” After all the hard work, the USPSTF was saying the test should not be offered routinely to any men.
A cancer screening test is successful when it finds an early-stage cancer that can be treated effectively, when a later-stage diagnosis would have been fatal. At one time, the notion that early detection of cancer must save lives was often embraced uncritically. But recently, researchers have taken a more nuanced look by considering screening’s possible harms, such as false-positive results and early-stage diagnoses that can sometimes lead to unneeded treatments.
The “catch-it-early” screening strategy works better for some cancers than for others. For example, colorectal cancer usually grows slowly and is highly treatable early on. Colonoscopy, one method of colorectal cancer screening, even allows for the removal of precancerous polyps. Many experts agree that the risks of colorectal screening, such as injury during a colonoscopy, are worth taking for the relatively large potential benefit. “Colon cancer is the perfect cancer for screening,” says gastroenterologist Philip Schoenfeld of the John D. Dingell VA Medical Center in Detroit. Cervical cancer screening also can catch lesions before they become cancerous, making its benefits potentially quite large. While recommendations on the frequency and method of cervical cancer screening have shifted over the years, U.S. guidelines are now largely in harmony.
The same cannot be said for screening for the two most common cancers in U.S. women and men, respectively: breast cancer and prostate cancer.
In 2009, the USPSTF updated its guidelines on breast cancer screening to say that every-other-year mammograms should be given routinely to women starting at age 50. From 2002 to 2009, the task force had recommended that women begin mammography routinely at age 40. The changing guideline prompted major backlash from some members of the breast cancer community. After all, breast cancer deaths in the U.S. had declined by approximately one-third since their peak around 1990. Why was the USPSTF weakening its recommendations for mammograms, which grew in popularity in the 1980s and 1990s, in the face of such seemingly positive statistics?
In making the change to mammograms starting at age 50, the USPSTF cited a relatively low number of lives lengthened in women aged 40 to 49, amid high rates of false-positives. Women in their 50s benefit more from mammograms than those in their 40s, and women in their 60s benefit the most, according to the USPSTF, which reaffirmed its 2009 mammography recommendations in 2016. The task force gave mammography for women in their 40s a C grade, meaning doctors and patients should decide whether to start screening on a case-by-case basis.
Besides guiding primary care doctors’ recommendations, USPSTF guidelines help determine preventive care that insurance companies must make available at no cost to patients under the 2010 Affordable Care Act, with services rated A and B making the cut. This link has made the task force’s C recommendations particularly controversial—so much so that Congress has twice mandated that mammograms be provided by private insurers at no cost to women in their 40s, in keeping with the 2002 USPSTF guidelines rather than the current ones.