Early Detection of Lung Cancer with LDCT Scans

At least 80% of all lung cancer cases are attributed to smoking or extensive exposure to secondhand smoke. According to the American Cancer Society estimates, there will be at least 238,340 new cases in 2023.

If you are a current smoker or stopped smoking within the past 15 years, there is something you can do to protect yourself and stay healthy: have a low-dose CT lung cancer screening exam. Similar to breast cancer screening, annual lung cancer screening provides the reassurance that you are cancer-free or identifies cancer at its earliest stages when curative treatment is most effective.

Most people don’t know when they develop lung cancer because it starts without symptoms. Only in its more advanced stages, when the cancer has started to spread to other parts of the body, do symptoms appear. These may initially include unexpected weight loss, bone or joint pain, headaches, and/or dizziness. Symptoms that may follow include a persistent dry cough, coughing up blood, unexpected exhaustion and fatigue, shortness of breath or having trouble breathing, and/or hoarseness or wheezing.

You don’t need to wait for symptoms to get checked for lung cancer. A simple exam, called low-dose CT lung cancer screening, can detect lung cancer at its earliest stages. Taking just a few minutes to perform, this highly detailed, low radiation dose imaging exam shows very fine details in the lungs with 3D clarity, pinpointing the location of suspicious lesions, and facilitating their diagnosis.

This exam can be free or nearly free-of-charge for most people who meet the high-risk profile criteria. Because of its proven effectiveness in saving lives, this exam is paid for by Medicare and by many health insurance companies.

Who is at high risk For Lung Cancer?

In 2021, the U.S. Preventive Services Task Force (USPSTF) considerably expanded its definition guidelines defining people who are at high risk of developing lung cancer.

You are now considered to be at high risk if you are 50-80 years old and have a smoking history of 20 pack years. (A pack year is equal to smoking 1 pack of cigarettes per day for 1 year, 2 packs per day for 6 months, or 1/2 pack per day for 2 years, etc.).

Race also may be a factor with respect to lung cancer susceptibility. This is only now being clinically studied, but a multi-institutional study of diagnosed lung cancer participants in the nearly 59,000-person Black Women’s Health Study published in JAMA Oncology revealed that only 34% would have met the 2021 USPSTF high-risk guidelines for lung cancer screening. So it is very important to talk with your doctor or a health cancer screening referral program healthcare staff member about your own personal history.

The proven value of annual low-dose CT lung cancer screening

When cancer is detected at an early stage, it can be treated successfully for many patients. More than 75% survive for at least five years. An LDCT screening exam is the gold standard for detecting early-stage cancers and is significantly better than a chest X-ray or a sputum cytology lab test.

The landmark clinical trial that first proved this was the National Lung Screening Trial (NLST) which was conducted from 2002 to 2010. The trial involved 53,454 high-risk individuals, current or former heavy smokers aged 55-74.

The NLST compellingly demonstrated the life-saving potential of early lung cancer screening. Participants were assigned to undergo either a Low-Dose Computed Tomography (LDCT) scan or a chest X-ray over an extended time period. The findings, published in 2011 in the New England Journal of Medicine, revealed a 20% reduction in participant mortality who underwent LDCT scans in the NLST trial.

Numerous subsequent clinical trials have proven the effectiveness of LDCT lung cancer screening. In November 2022, the findings of the longest-running lung cancer clinical trial, International Early Lung Cancer Action Program (I-ELCAP), concluded with over 87,000 participants. Of the 1,285 lung participants who had been diagnosed with early-stage lung cancers during this trial, 80% were alive after 20 years.

Should everyone have a LDCT lung cancer screening?

No. According to the USPSTF, screenings are recommended for individuals between the ages of 50 and 80 with a smoking history of at least 20 pack-years, who are currently smoking or have ceased smoking within the last 15 years.

According to a study of 5835 LCS CTs published in 2020, only about 2% of LDCT scans of high-risk individuals identify suspicious lesions. That is why high-risk profiles have been created and a lung cancer screening referral protocol established by health care providers.

Similar to a breast cancer screening, the percentage of total patients screened who have a suspicious lesion is very low. Low to begin with, this rate drops dramatically with subsequent annual scans, but it can lead to additional testing.

Much research is taking place on a worldwide basis to reduce the false-positive rate, especially with respect to the use of biomarkers and artificial intelligence (AI) software. Commercial software is being developed to assist radiologists with their diagnoses and to help identify malignant lesions from benign ones. Advances in the next few years will undoubtedly significantly reduce the false positive rate of LDCT lung scans.

If you qualify as a high-risk individual based on USPSTF guidelines, or if you think you may be at high risk for developing lung cancer, don’t wait for symptoms to appear.

Here at Radiology Associates, our subspecialized expert radiologists will interpret your thoracic CT and make recommendations to your doctor. Consult with your doctor on whether or not you should start an annual lung cancer screening. A few minutes of your time in one of our imaging centers may make all the difference.

REFERENCES

  1. https://www.lung.org/lung-health-diseases/lung-disease-lookup/lung-cancer/screening-resources/what-to-expect-from-lung-cancer-screening

  2. https://www.nejm.org/doi/full/10.1056/NEJMoa1102873

  3. https://pubmed.ncbi.nlm.nih.gov/32893112/

  4. https://press.rsna.org/timssnet/media/pressreleases