A long-time family doctor in Colorado, Calonge presided over the U.S. Preventive Services Task Force, an influential government-backed panel of health experts, when it said that most women under 50 could skip their regular mammograms.

The recommendation two years ago challenged the conviction of many breast cancer patients that they survived precisely because they were screened early. It unleashed a public fury that has weighed on the panel's deliberations ever since.

"We blew the message," said Calonge, now president and CEO of the Colorado Trust foundation. "The nuance was completely gone."

Two men phoned in death threats to Calonge. Protesters showed up by the offices of the government agency that supports the panel, tucked away in a Maryland suburb. The furor slowed down work on a decision to limit prostate cancer screenings as President Barack Obama fought to pass his signature healthcare law and his Democratic party faced a mid-term election challenge in 2010.

"There was a lot of pressure from above to be more careful politically and orchestrate things better," said Dr. Kenneth Lin, who at the time was an officer at the Agency for Healthcare Research and Quality (AHRQ), a Department of Health and Human Services entity that supports the panel. "Everything with the word 'cancer' got shoved back."

Calonge rotated off the panel this past March after eight years, while Lin quit AHRQ late last year in protest over the delay to prostate cancer screening guidelines that were only released in October. A White House official noted that Calonge has attributed the delay in a final decision on prostate cancer screenings to scheduling conflicts.

Their experience shows just how difficult it will be to curb spiraling costs in the world's most expensive healthcare system by determining what screenings work, based on a rigorous study of clinical evidence, and what can lead to unnecessary and risky procedures.

"More screening is not always better," said Dr. Christine Laine, a general internist and editor of the Annals of Internal Medicine who is not part of the panel. "That message is lost in healthcare in general."

The U.S. Preventive Services Task Force is right on the firing line. For much of its 27-year history, it helped convince millions of Americans to get screened early for disease.

Now the panel of primary care doctors, nurses and academics has reviewed a growing body of research that shows some early screening harms more people than it helps. But it has struggled to convince patients and doctors.

In the wake of the mammogram guidelines, the rate of such screenings for women aged 40 to 69 was barely changed in 2010 compared with 2009, according to the National Committee for Quality Assurance.

"We have a public health measure that we know is effective. Why is it continually being questioned?" said Dr. Carol Lee, breast imaging commission chairwoman at the American College of Radiology.

Graphic on mammograms: link.reuters.com/zuc25s

Graphic on U.S. cancer rates: link.reuters.com/byc25s

BROACHING THE NEGATIVES

The public at large is no less skeptical. A recent Gallup poll showed that nearly 60 percent of Americans believed that standard cancer screenings - including mammograms and prostate specific antigen (PSA) blood tests - were performed often enough. Thirty-one percent thought they should be conducted more frequently. Only 7 percent said they were done too often.

"It's extraordinarily hard to give up the notion that there's a way to protect yourself from dying from cancer... Our goal here is to make it a matter of evidence, not a matter of opinion," said Virginia Moyer, a pediatrician from Baylor College of Medicine, who now chairs the 16-member panel.

"Our successes are measured in positives," she said of the public's growing awareness of screening in the last three decades. "We are just beginning to approach the negatives."

Burned by the experience with mammograms, the task force is looking for a better way to deliver the message, consulting with powerful consumer interest groups, hiring public relations professionals and reworking some of the language tied to its system of letter-based recommendations.

"We're spending more time paying attention to how we say things to make sure it's understood well," said long-time panel member and current co-vice chair Dr. Michael LeFevre, a professor of family medicine at the University of Missouri School of Medicine. "We have no interest in being some wizard behind the curtain."

The panel now issues its recommendations in draft form first and solicits public comment before making them final. In about a year, the public may have a chance to chime in early on the evaluation process, including posing questions for researchers and reviewing the evidence report draft used by the panel.

Task force officials concede that the comments are unlikely to change the recommended letter grade, unless they introduce crucial new evidence. But they can point to misunderstandings and help the panel better craft its message.

In late October, the panel met with consumer interest groups, including retired persons lobby AARP and the Consumers Union, to get input on how to frame recommendations that was once reserved for patient advocates.

The public's participation has been unprecedented. The panel is now finalizing its PSA prostate cancer recommendation and public comments on the subject have reached into the thousands, LeFevre said.

WEIGHING THE EVIDENCE

The 2009 mammogram guidance from the task force was based on the panel's assessment of new research that showed most women over 40 face a 3 percent risk of dying from breast cancer if they have not been screened. Beginning mammogram screening at age 50 and following up every other year reduced that risk to 2.3 percent, compared with 2.2 percent risk starting at age 40.

An extra decade of screening could invite harms such as unnecessary biopsies and tests, the possible treatment of non-deadly cancers and radiation. Women in their forties are also more likely to receive false positive results.

Another view of the data showed that starting screening at age 40 led to 5,000 more mammograms, 500 false positive results and 33 biopsies for every breast cancer death prevented, according to LeFevre.

"If it was just how many deaths do you cause versus how many deaths you prevent, that would be too easy, that would be simple math," LeFevre said. "We start with somebody who feels well, and we risk making them feel worse."

The panel voted on a "C" recommendation, which calls for patients to decide on the screening with their doctor. But when the recommendation came out in November 2009, it started with a sentence saying the panel "recommends against" routine mammograms for most women under 50, and that language triggered the controversy.

Under pressure, the task force dropped the phrase "recommends against" a month later. Its rating on mammograms remains a "C."

The American Cancer Society questioned the evidence, saying the panel focused on gold-standard clinical trials but weeded out newer observational studies that showed better results.

"Screening is not perfect and it's not error-free, but the question is... do you take protective measures against the unlikely probability that you develop cancer... or do you take your chances?" said Robert Smith, director of cancer screening at the ACS.

That calculation still appears to be guiding doctors, either out of concern of missing an early sign of disease or fear of lawsuits, health experts said.

"Shared decision-making (between doctors and patients) sounds nice, but in practice usually you just end up doing the test," said Dr. Roger Chou, an internist and researcher at the Oregon Evidence-Based Practice Center. Chou authored the report on prostate cancer behind this year's task force recommendation.

POLITICAL RUMBLINGS

The heat over mammograms weighed on deliberations over prostate cancer screening. In 2008, the task force gave an "I" recommendation on the PSA test in healthy men under 75, which meant it had insufficient evidence to make a call.

The panel usually updates its recommendations every five years, but new research published in 2009 warranted an earlier evaluation. One U.S. study showed a slightly higher risk of death for men with no symptoms of illness who received a PSA test, while European research showed a slightly lower risk of death.

Although the PSA blood test itself is innocuous, data reviewed by the task force also showed that 90 percent of American men who tested positive got treated, even if they may have been able to forego it, LeFevre said. Out of 1,000 men treated, five would die, 70 would have serious complications and 200 to 300 would be impotent or incontinent.

Given the possibility of false positives in the screening and the fact that prostate cancer can take many years to progress and show symptoms, the question is whether those risks are greater than the risk of doing nothing.

"It looks like your chance of being alive and well is greater if you don't get screened than if you do get screened," LeFevre said.

In November 2009, task force members voted on a stronger "D" rating on PSA tests, meaning they recommended against the prostate cancer screening in men under 75.

But the timing was poor as Obama struggled to win over a majority of lawmakers for his healthcare overhaul and Congressional elections loomed large. Once the law was passed in March 2010, it brought more attention to the task force by mandating insurance coverage of services it does recommend.

Republicans opposed to the bill used the mammogram example to show how government could intrude on life or death decisions. The task force's "C" and "D" recommendations don't dictate insurance coverage, but Congress quickly turned around legislation to make sure insurers covered mammograms for women in their forties.

"The thought that my work was being use as a fulcrum by one party to kill the most substantial part of healthcare legislation since I've been in practice? I've got to tell you, that's something to lose sleep over," Calonge said.

Officials working with the panel heard that more controversy could threaten the task force budget, up for Congressional approval. In 2010, Health Department funding for the panel was $4.3 million. This year, the agency overseeing the panel spent about $11 million on work related to the task force.

Calonge says the panel wanted more evidence of how the tests could harm healthy patients, and ordered further research. He canceled a new vote on PSA screenings in November 2010, citing scheduling problems, a decision that was widely criticized.

"In my heart of hearts I'd really like to believe that we'd delay it anyway," without the surrounding politics, Calonge said. "We were trying to make the recommendations solid."

That was too much for Lin, who believed the evidence was already enough to show the public was at risk. After talking with his pastor and his wife, he quit AHRQ.

"Even delaying it for a few months, much less a year, it was really relegating the men to the harms they were exposed to," Lin said.

(Editing by Michele Gershberg, Ed Tobin and Claudia Parsons)

• A Permanent Economic Emergency