Tag: CT lung screening

Lung Screening’s Long-Term Benefits

Posted on by Brian Casey

CT lung cancer screening produced lung cancer-specific survival over 80% in the most recent data from the landmark I-ELCAP study, a remarkable testament to the effectiveness of screening. 

The findings were published this week in Radiology from I-ELCAP, one of the first large-scale CT lung screening trials, and are the latest in a series of studies pointing to lung screening’s benefits. The findings were originally presented at RSNA 2022. 

The I-ELCAP study is ongoing and has enrolled 89k participants at over 80 sites worldwide from 1992-2022 who have been exposed to tobacco smoke and who received annual low-dose CT (≤ 3mGy) scans. Periodic I-ELCAP follow-up studies have documented the survival rates of those whose cancers were detected with LDCT, and the new numbers offer a 20-year follow-up, finding: 

  • Primary lung cancers were detected on LDCT in 1,257 individuals who had lung cancer-specific survival of 81%, matching the 10-year survival rate of 81%
  • 1,017 patients with clinical stage I lung cancer underwent surgical resection and saw a lung cancer-specific survival rate of 87%
  • The I-ELCAP survival rate is much higher than another landmark screening study, NLST, in which it was 73% for stage I cancer at 10 years
  • Lung cancer-specific survival hit a plateau after 10 years of follow-up, at a cure rate of about 80%

I-ELCAP is unique for a variety of reasons, one of which is that it continues to screen people beyond a baseline scan and 2-3 annual follow-up rounds – perhaps the reason for its higher survival rate relative to NLST. 

  • It also has included people who were exposed to tobacco smoke but who weren’t necessarily smokers – an important distinction in the debate over how broad to expand lung screening criteria.  

The findings come as CT lung cancer screening is generating growing momentum. Studies this year from Germany, Taiwan, and Hungary have demonstrated screening’s value, and several countries are ramping up national population-based screening programs. 

The Takeaway

The 20-year I-ELCAP data show that CT lung cancer screening works if you can get people to do it. But achieving survival rates over 80% also requires work on the part of healthcare providers, in terms of defined protocols for working up findings, data management for screening programs, and patient outreach to ensure adherence to annual screening. Fortunately, I-ELCAP offers a model for how it’s done.

CT Detects Early Lung Cancer

Posted on by Brian Casey

A massive CT lung cancer screening program launched in Taiwan has been effective in detecting early lung cancer. Research presented at this week’s World Conference on Lung Cancer (WCLC) in Singapore offers more support for lung screening, which has seen the lowest uptake of the major population-based screening programs. 

Previous randomized clinical trials like the National Lung Screening Trial and the NELSON study have shown that LDCT lung cancer screening can reduce lung cancer mortality by at least 20%. But screening adherence rates remain low, ranging from the upper single digits to as high as 21% in a recent US study. 

Meanwhile, lung cancer remains the leading cause of cancer death worldwide. To reduce this burden, Taiwan in July 2022 launched the Lung Cancer Early Detection Program, which offers biennial screening nationwide to people at high risk of lung cancer.

The Taiwan program differs from screening programs in the US and South Korea by including family history of lung cancer in the eligibility criteria, rather than just focusing on people who smoke. 

Researchers at WCLC 2023 presented the first preliminary results from the program, covering almost 50k individuals screened from July 2022 to June 2023; 29k had a family history of lung cancer and 19k were people who smoked heavily. Researchers found …

  • 4.4k individuals receive a positive screening result for a positive rate of 9.2%
  • 531 people were diagnosed with lung cancer for a detection rate of 1.1%
  • 85% of cancers were diagnosed at an early stage, either stage 0 or stage 1

This last finding is perhaps the most significant, as part of the reason for lung cancer’s high mortality rate is that it’s often discovered at a late stage, when it’s far more difficult to treat. As such, lung cancer’s five-year survival rate is about 25% – far lower than breast cancer at 91%.

The Takeaway

Taiwan is setting an example to other countries for how to conduct a nationwide LDCT lung cancer screening program, even as some critics take aim at population-based screening. Taiwan’s approach is broader and more proactive than that of the US, for example, which has erected screening barriers like shared decision-making.

Although it’s still early days for the Taiwan program, future results will be examined closely to determine screening’s impact on lung cancer mortality – and respond to screening’s critics.

Screening Foes Strike Back

Posted on by Brian Casey

Opponents of population-based cancer screening aren’t going away anytime soon. Just weeks after publication of a landmark study claiming that cancer screening has saved $7T over 25 years, screening foes published a counterattack in JAMA Internal Medicine casting doubt on whether screening has any value at all. 

Population-based cancer screening has been controversial since the first programs were launched decades ago. 

  • A vocal minority of skeptics continues to raise concerns about screening, despite the fact that mortality rates have dropped and survival rates have increased for the four cancers targeted by population screening.

This week’s JAMA Internal Medicine featured a series of articles that cast doubt on screening. In the main study, researchers performed a meta-analysis of 18 randomized clinical trials (RCTs) covering 2.1M people for six major screening tests, including mammography, CT lung cancer screening, and colon and PSA tests. 

  • The authors, led by Norwegian gastroenterologist Michael Bretthauer, MD, PhD, concluded that only flexible sigmoidoscopy for colon cancer produced a gain in lifetimes. They conclude that RCTs to date haven’t included enough patients who were followed over enough years to show screening has an effect on all-cause mortality.

But a deeper dive into the study produces interesting revelations. For CT lung cancer screening, Bretthauer et al didn’t include the landmark National Lung Screening Trial, an RCT that showed a 20% mortality reduction from screening.

  • With respect to breast imaging, the researchers only included three studies, even though there have been eight major mammography RCTs performed. And one of the three included was the controversial Canadian National Breast Screening Study, originally conducted in the 1980s.

When it comes to colon screening, Bretthauer included his own controversial 2022 NordICC study in his meta-analysis. 

  • The NordICC study found that if a person is invited to colon screening but doesn’t follow through, they don’t experience a mortality benefit. But those who actually got colon screening saw a 50% mortality reduction.  

Other articles in this week’s JAMA Internal Medicine series were penned by researchers well known for their opposition to population-based screening, including Gilbert Welch, MD, and Rita Redberg, MD.

The Takeaway

There’s an old saying in statistics: “If you torture the data long enough, it will confess to anything.” Among major academic journals, JAMA Internal Medicine – which Redberg guided for 14 years as editor until she stepped down in June – has consistently been the most hostile toward screening and new medical technology.

In the end, the arguments being made by screening’s foes would carry more weight if they were coming from researchers and journals that haven’t already demonstrated a longstanding, ingrained bias against population-based cancer screening.

Is There Hope for CT Lung Screening?

Posted on by Brian Casey

New data on CT lung cancer screening rates offer a good news/bad news story. The bad news is that only 21.2% of eligible individuals in four US states got screened, far lower than other exams like breast or colon screening.

The good news is that, as low as the rate was relative to other tests, 21.2% is still much higher than previous estimates. And the study itself found that the rate of CT lung screening has risen over 8 percentage points in 3 years. 

Compliance has lagged with CT lung screening ever since Medicare approved payments for the exam in 2015. A recent JACR study found that screening rates were low for eligible people for both Medicare and commercial insurance (3.4% and 1.8%).

Why is screening compliance so low? Explanations have ranged from fatalism among people who smoke to reimbursement requirements for “shared decision-making,” which unlike other screening exams require patients and providers to discuss CT lung screening before an exam can be ordered.

In this new study in JAMA Network Open, researchers examined screening rates in four states – Maine, Michigan, New Jersey, and Rhode Island – from January 2021 to January 2022. The study drew data from the National Health Interview Survey and weighted it to reflect the population of the US of individuals eligible for CT lung screening, based on the criteria of ages 55-79, 30-pack-year smoking history, and having smoked or quit within the past 15 years. Major findings included: 

  • The rate for CT lung cancer screening was 21.2%, up from 12.8% in 2019
  • People with a primary health professional (PHP) were nearly 6 times more likely to get screened (OR=5.62)
  • The age sweet spot for screening was 65-77, with lower odds for those 55-64 (OR=0.43) and 78-79 (OR=0.17)
  • Rates varied between states, with Rhode Island having the highest rate (30.3%) and New Jersey the lowest (17.5%).
  • Of those who got screened, 27.7% were in poor health and 4.5% had no health insurance

The Takeaway

The findings offer some hope for CT lung screening, as the compliance rate is among the highest we’ve seen among recent research studies. On the other hand, many of those screened were in such poor health they might not benefit from treatment. The high rate of compliance in people with PHPs indicates that promoting screening with these providers could pay off, especially given the requirement for shared decision-making. 

Get every issue of The Imaging Wire, delivered right to your inbox.

You might also like..

Select All

You're signed up!

It's great to have you as a reader. Check your inbox for a welcome email.

-- The Imaging Wire team

You're all set!