In a revision of a ten-year-old lung cancer screening guideline that initially recommended low-dose CT (LDCT) screening for people ages 55 to 80 with a 30 pack-year smoking history, researchers from the University of North Carolina suggest updated changes. The guidelines published ten years ago were put forth originally by the United States Preventive Services Task Force following an analysis of results from the National Lung Screening Trial that suggested LDCT screenings could reduce lung cancer deaths.
The recently suggested changes have updated the guidelines to lower the screening age to 50 and reduce pack-year eligibility from 30 to 20. The researchers say that such changes advocate for health equity, given that African Americans at are a higher risk of lung cancer despite less exposure to smoking. Yet, say the investigators, the new guidelines consider not only the benefits of lung cancer screening but also the potential harms.
"Two large studies have now confirmed that screening can lower the chance of dying of lung cancer in high-risk people. However, people considering screening should know that a relatively small number of people who are screened benefit, and that screening can also lead to real harms," said Daniel Reuland, MD, MPH.
What harms, you may be asking? While those at high-risk do benefit from screening, lower-risk people may often receive false positives from screening results, due to the difficult-to-decipher images on scans. Such false positives may lead to unnecessary additional scans, and in some cases even surgery or other procedures. This process surely causes emotional distress to patients as they consider the consequences of a possible cancer diagnosis.
"Applying screening tests to a population without symptoms of disease can certainly benefit some people but also has the potential for some harms," said lead author Daniel Jonas, MD, MPH. "In the case of lung cancer screening, we now have more certainty that some individuals will benefit, with some lung cancer deaths prevented, and we also know others will be harmed. The USPSTF has weighed the overall benefits and harms, and on balance, based on our review and from modeling studies, has determined that screening with LDCT has an overall net benefit for high-risk people ages 50 to 80."
Nevertheless, the researchers say that these guidelines, as with the original ones, may be modified as we gain more insight into lung cancer risk factors. "Different trials have used different screening approaches, and we still do not know how often screening should be done or which approach to categorizing lesions is best for reducing the harms, costs, and burdens of screening while retaining the benefits," said Reuland. "I would prioritize this as an important area of future research, as it could likely be addressed by implementing less expensive studies or using approaches other than those used in the large trials we just reviewed."