A decades-old debate rears its head again: Is earlier breast cancer screening better?

A decades-old scientific debate over cancer screening has been reignited.

Earlier this year, the U.S. Preventive Services Task Force released new mammogram recommendations that advise doctors to begin screening women every other year for breast cancer starting at 40 years old, 10 years earlier than was previously recommended.

The new guidelines have divided physicians into two groups: those who believe this screening will help drive down mortality rates and those who believe younger patients don’t benefit enough from early screening to warrant the risks.

An editorial written by Duke Health’s Dr. Shelly Hwang is the latest to stir up controversy in this debate. Last week, she and other researchers argued in the New England Journal of Medicine that this recommendation would subject women to costly and stressful procedures with only marginal benefits.

Hwang pointed to data from the National Cancer Institute, which shows that for women in their 40s, mammograms reduce the 10-year risk of dying from breast cancer from about 0.3% to about 0.2%.

Hwang said this potential benefit is small in comparison to the high risk of false positives.

USPST modeling estimated that more than a third of women who are screened every other year in their 40s receive a false positive, which may require a biopsy or other costly testing to disprove.

A small percentage of these women will undergo treatment for breast cancer that wouldn’t have otherwise caused harm, the model also found.

Rather than making a blanket recommendation for all women, Hwang said doctors should make decisions with their patients based on their individual risk of developing breast cancer.

“It’s hard to put that in a bite-sized message,” she said. “It’s much easier to say mammograms save lives.”

The perspective has been controversial, even within Hwang’s own institution. Dr. Jay Baker, a Duke breast radiologist, said while he agrees with most of the statistics presented in the editorial, he has a completely different interpretation of what they mean for screening recommendations.

“There are facts that we all agree on and yet it’s a little bit like an optical illusion,” he said. “If you look at it one way, it’s a vase. If you look at it another way, it’s a lady.”

For example, while he agrees that mammograms decrease a woman’s risk of dying in their 40s by about .1%, he disagrees that this is a small effect. That percentage is roughly equivalent to 100,000 lives saved over the period of a decade, he said.

Baker acknowledges that screening comes with risks (though he argues in the editorial that the risk is overblown), he said they are outweighed by the potentially life-saving benefits. He presented his own statistic: one study found that half of all fatal breast cancers are diagnosed before age 50.

“All of these are real issues — but they’re dwarfed by dying of breast cancer,” he said.

Ultimately, Baker agrees that women should be able to weigh the costs and benefits of screening in their 40s and make a decision with their doctor. But he said USPST recommendations are key to keeping those options open — insurance companies base their screening coverage on these guidelines.

“I don’t understand why anyone would argue against fewer women dying, more years of life to live, and less invasive treatment,” Baker said.

Teddy Rosenbluth covers science and health care for The News & Observer in a position funded by Duke Health and the Burroughs Wellcome Fund. The N&O maintains full editorial control of the work.