Longtime heavy smokers should be offered annual lung cancer screening using low-dose CT scans instead of chest X-rays, a group of prevention experts recommended on Monday.
A CT scan is better at finding tumors early, when they are most treatable, and the benefits outweigh the risks for people ages 55 to 79 who smoked the equivalent of a pack a day for 30 years and continue to smoke or quit fewer than 15 years ago, according to the US Preventive Services Task Force. The group is an independent panel of primary care experts created by Congress.
Using CT scans trumped chest X-rays, which are currently recommended for screening this group of 7 million Americans, in reducing lung cancer deaths, the panel said.
The new recommendation could prevent some of the 160,000 lung cancer deaths that occur in the United States every year because 85 percent of these deaths occur in those with a strong smoking history. It also means that insurance companies will be required to cover the $300 to $400 screening, under a mandate in the federal health law.
“It’s a fantastic move,” said Dr. Christopher Lathan, an oncologist who treats lung cancer at Dana-Farber Cancer Institute. “Lung cancer is the number one cancer killer; but there hasn’t been a reliable, safe way to screen high-risk people until now.”
But some preventive health experts argued that patients also need to be informed of the potential harms of screening, including overdiagnosis, excess radiation exposure, and lung biopsies for growths that turn out not to be cancer.
While the American Cancer Society adopted very similar recommendations in January, the organization put a “high emphasis ... on informed decision making about the benefits and harms associated with screening for lung cancer,” Dr. Otis W. Brawley, the society’s chief medical officer, said in a statement responding to the Task Force guidelines.
In particular, he added, those at increased lung cancer risk should be told by their doctors about the high rate of false findings on the ultra-sensitive screening test. Such findings usually result in a full-dose followup CT scan, which delivers 10 times more radiation than a low-dose screening scan.
The Task Force calculated that screening 287,000 high-risk individuals would prevent 521 lung cancer deaths but cause an additional 24 cancer deaths from excess radiation exposure.
“I think the group that they’re recommending to be screened is too broad,” said Dr. Kenny Lin, a primary care physician at Georgetown University Medical Center who used to evaluate screening research to provide to the Task Force.
Some patient advocacy groups, on the other hand, say the recommendations should be broader, applying to those who smoke less but have other risk factors such as a family history of lung cancer or exposure to a lung carcinogen such as asbestos, expanded criteria that one cancer research organization recommends.
The task force based its draft recommendation, which will be finalized later this year after a public comment period, on a clinical trial of 50,000 current and former smokers with a history of smoking a pack a day for decades. That trial showed a reduction in lung cancer deaths of 16 percent compared with an annual chest X-ray after nearly seven years of followup.
“It’s hard to find the sweet spot, but we think the population we proposed has a pretty good balance,” said Dr. Michael LeFevre, co-vice chair of the task force. He said the group considered the issue of CT scans detecting and leading to treatment of very-early-stage lung cancers that would never have become life threatening. Researchers have raised similar concerns for breast and prostate cancer screening tests.
“We calculated this occurs in about 3 to 4 percent of lung cancers diagnosed through screening, which is a pretty low rate as far as cancers go,” LeFevre said. At least 10 percent of breast cancers detected via mammograms are considered to be non-threatening cancers, and the percentage is even greater for prostate cancer screening.
With a current lack of insurance coverage, low-dose CT screening is offered only in a handful of hospitals in the Boston area. Brigham and Women’s Hospital offers it to those willing to pay $350 a scan. Lahey Hospital and Medical Center in Burlington began offering free screenings in January 2012, with the hospital picking up the tab.
“We’ve screened over 1,300 patients and we’ve gone from diagnosing 70 percent of lung cancers in an advanced stage to finding 70 percent in the early stage when they’re most likely to be cured,” said Dr. Andrea McKee, chair of radiation oncology at Lahey. Screening patients before and after regular business hours has helped defray some of the costs, McKee said, and so has the revenue generated by an increase in patients being treated for lung cancer found by the scans.