If you are — or were — a long-time smoker, you may be wondering if lung cancer screening is right for you. Lung cancer is the leading cause of cancer death, largely because patients usually don’t find out they have cancer until it’s at an advanced stage.
Cancer screening looks for signs of cancer in someone who has no symptoms. However, until the last decade, there really was no good way to screen for lung cancer. In 2002, the National Cancer Institute initiated the National Lung Screening Trial, a large study that compared low-dose helical computed tomography with a standard chest X-ray to screen for lung cancer. The trial enrolled more than 53,000 heavy smokers (current and former) between the ages 55 and 74.
[See: 7 Things You Didn’t Know About Lung Cancer.]
The NLST found that patients who received the CT scan had a 15 to 20 percent lower risk of dying from lung cancer over the seven years of the trial than those who received a chest X-ray. This equates to about three fewer deaths per 1,000 people screened with CT scan (17.6 deaths per 1,000 versus 20.7 with a chest X-ray).
A CT scan creates an image of the entire chest so doctors can look for nodules, which may indicate lung cancer. On a scan, a nodule appears like a shadow, says Dr. Vamsidhar Velcheti, staff physician in the department of hematology and oncology and associate director of the Center for Immuno-Oncology Research at Cleveland Clinic. Finding something in the lung does not necessarily mean you have cancer. In fact, more than 95 percent of lung nodules are not cancer, but scar tissue or inflammation, for example.
Based on the size and shape of the finding, oncologists must determine what’s next. If it’s not terribly suspicious looking, your doctor may recommend a repeat scan a few months later to see if the nodule has changed shape or size. Or if it’s worrisome, your doctor may recommend a PET (positron emission tomography) scan or additional testing, such as a biopsy or lung endoscopy (viewing the airways through a scope) to learn more.
Current Screening Recommendations
The U.S. Preventive Services Task Force, an independent panel of experts, recommends lung cancer screening with low-dose CT scans for adults 55 to 80 who have a 30 pack-year smoking history and either currently smoke or quit smoking within the past 15 years. Pack years is the number of packs of cigarettes you smoked daily multiplied by the number of years you smoked.
Qualified candidates should undergo screening annually until they’ve been a non-smoker for 15 years or until they have a health problem that limits their life expectancy or ability to undergo lung surgery. Medicare and most insurance plans cover CT screening for lung cancer in eligible patients (check your individual plan for specific coverage).
[See: What Not to Say to Someone With Lung Cancer.]
Benefits of Screening
For most cancers, treatment is most effective when you find the cancer early, Velcheti says. “If you find lung cancer in an early stage — stage 1 or stage 2 — you can potentially do surgery to remove it and potentially cure [the patient].” In later stages, treatment was traditionally palliative (to relieve symptoms) or to help prolong life. However, newer lung cancer treatments are helping some advanced stage cancer patients live much longer.
The Downsides of Screening
The technology is very good at finding things in the lungs. In fact, CT scans are so sensitive that about 30 percent of patients will have a finding that’s not cancerous but worrisome enough to warrant follow up, says Dr. Abraham Chachoua, associate director of cancer services at Perlmutter Cancer Center at NYU Langone Medical Center.
These false positives (a finding that is not cancer) are significant and can lead to additional medical interventions, which all have potential risks and downsides. According to the USPSTF, if you screen 1 million people for lung cancer, about one quarter will have a false positive. Most of these false positives will be resolved with additional imaging. However, based on the results from the NLST, about 8,000 will need an invasive procedure to prove the finding is not cancer.
Velcheti says scientists are researching new techniques to help oncologists more accurately determine if scan findings are cancer or something benign, so lung cancer screening will likely become more sophisticated over time. Despite the risks and the need for further research, Chachoua says CT screening is an important first step for people with a heavy smoking history.
[See: 7 Innovations in Cancer Therapy.]
“Screening for lung cancer does save lives,” Velcheti says, “and primary care physicians should definitely refer patients for screening.”
Of course, the best way to ensure you don’t develop lung cancer is by not smoking — or quitting if you currently smoke. Smoking is the single biggest risk factor for lung cancer.
More from U.S. News
7 Things You Didn’t Know About Lung Cancer
What Not to Say to Someone With Lung Cancer
7 Innovations in Cancer Therapy
Screening for Lung Cancer originally appeared on usnews.com
