Most current and former heavy smokers do not receive screening that could help detect lung cancer early, when it is easier to treat, according to a study to be presented at the American Society of Clinical Oncology (ASCO) annual meeting next month.

Out of more than 7.6 million current and former smokers considered eligible for screening, only 1.9 percent have received the imaging tests recommended by ASCO and the United States Preventive Services Task Force (USPSTF).

“This is a call to action on everyone’s part to increase much needed screening for the Number 1 cancer killer in America,” Danh Pham, MD, of the James Graham Brown Cancer Center at the University of Louisville in Kentucky said at an ASCO advance media briefing last week.

About 234,000 people in the United States will be diagnosed with lung cancer and about 154,000 will die from it this year, according to the American Cancer Society. Lung cancer is often detected late, when it is difficult to treat, and it is the leading cause of cancer-related death for U.S. men and women.

Since 2013, the USPSTF has recommended annual lung cancer screening using low-dose computed tomography (CT) scans for people ages 55 to 80 with a cumulative smoking history of at least 30 pack-years who either still smoke or have quit within the past 15 years. This is equivalent to smoking one pack of cigarettes a day for 30 years, two packs a day for 15 years or a half pack a day for 60 years.

The large National Lung Screening Trial, which enrolled more than 53,000 current and former heavy smokers, found that participants who received annual low-dose CT scans had a 20 percent lower risk of lung cancer death than those who received chest X-rays, although the majority of positive results in both groups turned out to be false positives.

Pham and colleagues conducted a study to determine the number of lung screening scans performed across the United States. Using 2016 data from the American College of Radiology’s Lung Cancer Screening Registry, they compiled the total number of scans performed at nearly 1,800 accredited radiographic screening sites across the country. They used data from the 2015 National Health Interview Survey to compare the number of scans to the estimated number of people eligible for screening according to the USPSTF criteria.

The study found that nationwide, only 141,260 of the 7,612,975 eligible current and former smokers were screened in 2016, Pham reported. But rates varied considerably by region. Screening rates were 3.5 percent in the Northeast, 1.9 percent in the Midwest, 1.6 percent in the South and just 1.0 percent in the West. In comparison, around 65 percent of women age 40 or older received a mammogram in 2015, according to an ASCO press release.

The largest proportion of eligible smokers and ex-smokers—more than 3 million—live in the South, and this region also had the most accredited screening sites, at 663. The West had the fewest screening sites, 232 for nearly 1.4 million eligible people. The Northeast had 404 sites for more than 1.1 million people, while the Midwest had 497 sites for more than 2 million people. Preliminary data for 2017 show a small increase across all regions.

Approximately 85 percent of the screened current smokers were offered smoking cessation assistance; this did not differ by region. 

“Annual low-dose CT screening remains inadequate following USPSTF recommendations despite the time since implementation and potential to prevent thousands of lung cancer deaths each year,” the researchers concluded. “It remains unclear why the lung cancer screening rate is dramatically lower than other cancer screening modalities such as mammography and colonoscopy.”

Pham told reporters that stigma and shame might play a role in limiting lung cancer screening, which he estimated could prevent around 12,000 lung cancer deaths annually.

“It is unclear if the screening deficit is due to low provider referral or perhaps patient psychological barriers from fear of diagnosis,” he said. “Lung cancer is unique in that there may be stigma associated with screening, as some smokers think that if cancer is detected, it would confirm they’ve made a bad lifestyle choice.”

Asked what steps could be taken to increase the screening rate, Pham suggested awareness efforts and making lung cancer screening a mandated national quality health measure like breast cancer and colon cancer screening.

“This study makes a strong case that our country needs an effective public service campaign about encouraging lung cancer screening,” said ASCO president Bruce Johnson, MD, of the Dana-Farber Cancer Institute. “Public service campaigns from the 1990s encouraged women to get mammograms, saving many lives in subsequent years. We need something similar to encourage current and former heavy smokers to get screened for lung cancer.”

One such effort, the American Lung Association’s Saved by the Scan campaign, provides a listing of screening facilities and information about insurance coverage. Most employer-sponsored insurance plans, Affordable Care Act plans and Medicare should cover screening at no cost for people who meet the USPSTF criteria; Medicaid coverage varies by state.

ASCO chief medical officer Richard Schilsky, MD, noted that cancer screening of healthy people—and people who have cancer but don’t yet know it—is typically done by primary care providers, not oncologists, and it is important to make sure these providers are aware of the data and know about screening resources in their communities.

Click here to read the ASCO study abstract.

Click here to read an ASCO press release about the study.