Imagine if a Boeing 777 jet crashed and killed all on board. And then imagine such a crash occurring every day for a year. That is how many Americans die of lung cancer, a disease that is not only preventable (if you don’t smoke) and curable (if found early). More people die of lung cancer than die of colon cancer, breast cancer, and prostate cancer combined.
This year, 235,760 Americans will be diagnosed with lung cancer which accounts for 12.4% of all cancer diagnoses. The 5-year survival rate is only 21.7% and an estimated 131,880 Americans will die of their lung cancer this year. The problem with lung cancer is that it is usually found late, after it has already spread and no longer surgically curable. As a consequence, the 5-year survival of lung cancer is much lower than any other common type of cancer. However, lung cancer screening programs can identify lung cancer at an early stage, when it can still be surgically cured.
Screening for colon cancer and breast cancer is relatively straight forward: at a certain age, everyone starts getting a colonoscopy every 10 years and all women start getting a mammogram every year. Screening for lung cancer is more complicated for two reasons. First, because the criteria for who should or should not undergo screening is more complex and second, because there has to be a process in place for managing all of the abnormalities that are identified on screening tests (most of which are not lung cancer).
It has long been known that screening with regular chest x-rays does not work; x-rays just do not identify lung cancers at an early enough stage. A landmark study in 2011 showed that low-dose chest CT scans not only identify more lung cancers than chest x-rays, but patients who got chest CT scans were 20% less likely to die of lung cancer in the subsequent 6.5 years than those who only got screening chest x-rays:
A more recent study from last year showed that patients who got lung cancer screening chest CTs had a 25% lower risk of dying of lung cancer in the subsequent 10 years:
Clearly we need to be screening patients for lung cancer but only 2-4% of eligible smokers are currently getting screened. So, why aren’t we screening more? The two major barriers are patients and healthcare providers. Patients are often unaware of screening programs, fear a cancer diagnosis, worried about the costs, or simply do not have access to screening. Physicians are often unfamiliar with the screening guidelines, unsure of insurance coverage, lack the time in the office to counsel patients about screening, don’t know what to do about abnormalities found on CT, are skeptical about the efficacy of screening, or are worried about the risks of false positive findings. In February 2015, CMS approved lung cancer screening for Medicare recipients if they met a group of specific criteria. In March 2021, the US Preventive Services Task Force revised the guidelines for screening to now include:
- Adults age 50 – 80 years old
- At least a 20 pack-year smoking history
- Currently smoking or quit within the past 15 years
People who meet all three of these criteria are recommended to undergo an annual low-dose chest CT scan. Screening should continue until the person has quit smoking > 15 years earlier, is no longer willing to undergo curative surgery if a cancer is found, or develops another medical condition that substantially reduces life expectancy. For Medicare coverage, the patient must additionally have no signs/symptoms of lung cancer and screening must include smoking cessation counseling.
One of the issues raised by lung cancer screening is that chest CT scans can pick up a lot of benign abnormalities. In fact, 97% of all abnormalities found on screening chest CTs are not cancer. For this reason, there has to be a process for managing these abnormalities – both for choosing the best way to biopsy those patients who have abnormalities that are more likely to be cancer and for arranging follow up testing for those patients who have abnormalities that are less likely to be cancer. This is where a carefully designed lung cancer screening program can be effective and efficient.
Components of a lung cancer screening program
To be successful, a lung cancer screening program should include a CT scan capable of low-dose chest imaging, a radiologist available to interpret that CT, a clinical provider, and a pulmonologist. Ideally, the screening should be able to be completed within an hour and a half with the patient going to just one location. The entire screening visit should be able to be ordered by the patient’s primary care provider using a single order set. The screening visit should consist of:
- An initial review of the patient for inclusion criteria
- An encounter with a clinical provider with experience in pulmonary nodule management and smoking cessation counseling
- The chest CT scan with radiologist interpretation
- A second encounter with the clinical provider after radiologist’s CT interpretation is available
- Ordering of appropriate follow-up testing
Let’s look at each of these steps in detail:
Initial review of patient for inclusion criteria. The US Preventive Services Task Force lung cancer screening criteria have not yet been adopted by all insurance companies. As a result, different insurance companies will have different requirements for screening eligibility. After the primary care provider places an order for lung cancer screening, the order should initially go to a nurse who can check the patient’s insurance and verify that the patient meets the age and smoking history requirements for that specific insurance company. Most insurance plans additionally require that the patient has not had a chest CT for any purpose within the past year. Once the patient’s eligibility is confirmed, then the order can be routed to the screening clinic for scheduling.
Initial encounter with clinical provider. This provider can be a physician or an advance care provider. Given the nature of this encounter, a nurse practitioner or physician assistant is an ideal choice. During this encounter, the screening process is discussed, the patient’s eligibility is confirmed, smoking cessation counseling is given (if the patient is an active smoker), and the CT scan is ordered. There should be “shared decision making” between the provider and the patient so that the patient understands that non-cancerous abnormalities are common but may require additional testing. It should also be confirmed that the patient is willing to undergo biopsy and/or surgery if warranted by the CT findings. Typically, 8-10 patients can be scheduled during a 4-hour clinic time.
The chest CT scan. Ideally, this should be done immediately following and at the same location as the encounter with the clinical provider. The CT machine should be capable of low-dose chest CT protocols. The procedure time for this type of CT scan is less than a minute. The radiation dose of a standard chest CT scan is 7.0 mSv whereas the low-dose chest CT is only 1.5 mSv. To put this in perspective, a chest x-ray is 0.1 mSv and a mammogram is 0.4 mSv. A normal person gets 3.0 mSv in background radiation every year. Ideally, the CT should be interpreted by the radiologist immediately with the results available to the clinical provider.
Second encounter with clinical provider. If the CT scan results are immediately available, then the patient should go directly from the CT scan back to see the clinical provider. If the results are not immediately available, then this second encounter can be done by telephone or telemedicine later that day or the following day. Because most electronic medical records are configured to release radiology reports the same day as the CT scan is performed, there is the potential for patients to see the results before the clinical provider if the second encounter does not happen immediately after the CT scan is performed. This can result in a great deal of anxiety if the patient does not understand the significance of abnormalities noted in the radiology report. For this reason, it is optimal for the clinical provider to be able to discuss and explain the findings as soon as possible following the CT scan. Depending on the radiologist’s report, the clinical provider has several options:
- If the CT scan is normal, a follow up lung cancer screening visit in 1 year can be ordered.
- If the radiologist identifies a nodule or other abnormality and the patient has had a previous chest CT elsewhere in the past, the provider can request those images and arrange a follow-up appointment to compare the findings and determine if they meet radiographic stability criteria.
- If the radiologist identifies a nodule or other abnormality and the patient has NOT had a previous chest CT, then the clinical provider can order a follow-up chest CT scan and office visit based on the 2017 Fleischner Society guidelines. These guidelines provide recommendations for how soon to perform follow-up CT scans based on whether nodules are solid or subsolid, whether nodules are solitary or multiple, the size of the nodule, and whether the patient has lung cancer risk factors.
- If a finding suspicious for lung cancer is identified, then the provider should have access to a pulmonologist to determine the most appropriate next step. Because a PET scan is most commonly performed prior to biopsy or surgery, this will often entail the clinical provider ordering a PET scan to be followed by consultation with a pulmonologist. Sometimes, the pulmonologist may be able to advise the clinical provider regarding next steps via a telephone consultation. These next steps could include:
- PET scan
- Bronchoscopic biopsy
- CT-guided needle biopsy
- Surgical biopsy/resection
- If the patient desires more extensive smoking cessation assistance, then the clinical provider can refer the patient to a formal smoking cessation clinic.
Lung cancer screening is more than just ordering a chest CT
Lung cancer screening is a lot more complex than screening for other cancers. To be successful, lung cancer screening requires interdisciplinary coordination, incorporation of smoking cessation, and ability to order follow-up testing. Although some primary care physicians may be able to orchestrate all of these elements themselves, it is far more efficient for hospitals to develop a comprehensive lung cancer screening program with standardized management protocols.
September 30, 2021