A large part of practicing primary care consists of providing reassurance to healthy persons. The patient who asks me to look at the mole on her back to make sure it isn't melanoma. The patient who recently recovered from a cold but is still coughing and wants to know that it isn't a sign of something more serious. The patient whose friend's doctor found a lump on his thyroid gland and wants to have his neck checked too.
The last time the U.S. Preventive Services Task Force recommended against screening for thyroid cancer was in 1996. That it took more than 20 years to release an updated recommendation statement (still a "D," or don't do) speaks to how non-controversial the Task Force judged this topic to be. Unfortunately, in the interim many clinicians and patients ignored this advice. In South Korea, a national cancer screening program that began in 1999 encouraged general practitioners to routinely perform thyroid ultrasound scans, resulting in an "epidemic" of new thyroid cancers but no change in thyroid cancer deaths. In the United States, papillary thyroid cancer diagnoses have quadrupled since 1995, again with no change in mortality. In both countries and around the world, physicians are finding and treating thousands of pseudo-cancers that would not have otherwise been found and don't need to be treated. Overdiagnosis begets more overdiagnosis: patients who are "successfully" diagnosed and treated tell friends and relatives to have their necks palpated or scanned for thyroid tumors. And if that feedback cycle wasn't enough, advocacy groups such as the Light of Life Foundation initiated fear-mongering awareness campaigns, as Dr. Gilbert Welch described in an editorial accompanying the USPSTF recommendation:
About a decade ago, public service announcements began to appear encouraging people to have their physicians “check your neck.” The Light of Life Foundation campaign featured actual testimonials of patients describing their positive health behaviors on the day before they were diagnosed with thyroid cancer. The ads used compelling language: “Thyroid cancer doesn’t care how healthy you are. It can happen to anyone. Including you. That’s why it is the fastest growing cancer in the US. Ask your doctor to check your neck. It could save your life.” The campaign’s title—and its main slogan—was “Confidence Kills.” That’s a great public health message: if you feel good, you are about to die.
Fear-mongering isn't limited to thyroid cancer, of course. From the 1980s-era American Cancer Society print advertisement that lectured women, "If you haven't had a mammogram, you need more than your breasts examined," promoters of breast cancer screening long used fear to motivate women to undergo screening mammography. In 2015, several advocacy organizations successfully persuaded the U.S. Congress to override the U.S. Preventive Services Task Force's "C" grade (small net benefit) on screening mammography for women aged 40-49 with a "Stop the Guidelines" campaign that included full-page advertisements in major newspapers asking the rhetorical question "Which of our wives, mothers, daughters, and sisters would be be OK to lose?"
The major difference between screening for thyroid and breast cancer is that the latter actually reduces cancer deaths. But women under 50 are less likely to benefit because there is less lethal breast cancer to be found in younger women, and consequently much higher false positive rates that affect more than half of all women receiving annual mammograms from age 40 to 50. And the USPSTF didn't tell clinicians don't screen - more accurately, they said don't screen reflexively, and the message to younger women is not to avoid mammograms, but to talk about the pros and cons with your doctor.
That hasn't stopped a new alliance of radiologists and breast cancer surgeons from targeting the Task Force with a 40not50 campaign which encourages women in their 40s to turn off their brains, eschew shared decision-making, and demand that their doctors start screening them at age 40 because mammograms save lives, and a government-appointed panel (whose 16 members include 7 women) wants to prevent women from seeing their 50th birthdays. Notwithstanding the ulterior motives behind this absurd campaign, it is insulting to women. It says that they can't be trusted to consider the medical evidence, have conversations with their primary care physicians, and make decisions about their healthcare that are right for them.