Frequently Asked Questions for Healthcare Providers: Ontario’s Lung Cancer Screening Pilot for People at High Risk

Lung cancer is the leading cause of cancer death for people in Ontario. In 2018, approximately 7,400 people were expected to die from lung cancer in Ontario. That is more than the number of people who were expected to die of breast, colon and prostate cancers combined.^[1]Reference 1 Close reference Cancer Care Ontario. Ontario Cancer Statistics [Internet]. 2018 [cited 2018 Nov 2]. Available from: https://www.cancercareontario.ca/sites/ccocancercare/files/assets/OCS2018_1.pdfOpenClose

Survival for people in Ontario who have been diagnosed with lung cancer has improved, rising from 16.9% (1999 to 2003) to 21.7% (2009 to 2013).^[2]Reference 2 Close reference Cancer Quality Council of Ontario. Cancer in Ontario [Internet]. 2018. [cited 2018 Nov 2]. Available from: https://www.csqi.on.ca/2019/highlights/lung-cancer-ontarioOpenClose However, lung cancer survival continues to be much lower than survival for breast (87.9%), colon (67.9%) and prostate (94.1%) cancers.^[2]Reference 2 Close reference Cancer Quality Council of Ontario. Cancer in Ontario [Internet]. 2018. [cited 2018 Nov 2]. Available from: https://www.csqi.on.ca/2019/highlights/lung-cancer-ontarioOpenClose

The reason so many people die from lung cancer is that by the time it is usually diagnosed, the cancer has spread to other parts of the body or is too big. When the cancer has spread or is too big, treatment has less of a chance of working.

Now we have an effective and evidence-based way to screen people so that we can find some lung cancers early, when treatment has a better chance of working.

People who are at high risk of getting lung cancer and are eligible to get screened will be offered a special type of computed tomography (CT) scan that uses a small amount of radiation. This test is called a “low-dose CT scan.”

During an LDCT scan, the screening participant lies on an open table that passes through a large donut-shaped machine called a “scanner.” The scanner uses a small amount of radiation to take detailed pictures of the lungs. The test only takes a few minutes and is not painful. There are no medications or needles given during the test.

Cancer Care Ontario recommends using LDCT through an organized cancer screening program to screen people at high risk of getting lung cancer.^[3]Reference 3 Close reference Roberts H, Walker-Dilks C, Sivjee K, Ung Y, Yasufuku K, Hey A, et al. Screening High-Risk Populations for Lung Cancer: Guideline Recommendations. J Thorac Oncol [Internet]. 2013 Oct;8(10):1232–7. Available from: https://www.sciencedirect.com/science/article/pii/S1556086415330148?via%3DihubOpenClose We based this recommendation on evidence from the National Institute of Health’s National Lung Screening Trial, a randomized controlled trial with over 50,000 participants.^[4]Reference 4 Close reference Aberle D, Adams A, Berg C, Black W, Clapp J, Fagerstrom R, et al. Reduced lung-cancer mortality with low-dose computed tomographic screening. N Engl J Med. 2011 Aug;365(5):395–409.OpenClose The trial showed that people at high risk of getting lung cancer who got screened with 1 LDCT scan annually over approximately 2 years (1 scan shortly after randomization and 2 follow-up scans) had a 20% relative reduction in lung cancer mortality over 6 years, compared with people who got screened the same number of times at the same interval with chest X-ray.^[4]Reference 4 Close reference Aberle D, Adams A, Berg C, Black W, Clapp J, Fagerstrom R, et al. Reduced lung-cancer mortality with low-dose computed tomographic screening. N Engl J Med. 2011 Aug;365(5):395–409.OpenClose Because of its randomized controlled trial design, this study provides strong evidence for the efficacy of screening.

Screening with LDCT can find lung cancer at an early stage, when treatment has a better chance of working. The amount of radiation someone is exposed to through an LDCT for lung cancer screening is:

• several times that of a chest X-ray
• much less than that of a diagnostic chest computed tomography (CT) scan^[5]Reference 5 Close reference Radiological Society of North America I (RSNA). Radiation Dose in X-Ray and CT Exams [Internet]. 2015 [cited 2018 Nov 2]. Available from: http://www.radiologyinfo.org/en/info.cfm?pg=safety-xrayOpenClose
• approximately the same as 1 year of natural background radiation (radiation from the sky and the ground, and through breathing, eating and drinking)^[6]Reference 6 Close reference Canadian Nuclear Safety Commission. Natural background radiation [Internet]. 2013 [cited 2018 Nov]. Available from: http://nuclearsafety.gc.ca/eng/resources/fact-sheets/natural-background-radiation.cfmOpenClose

Therefore, LDCT minimizes the potential harms of screening for people who are otherwise healthy.

People who participate in screening may have many scans over time, so it is important to keep their radiation dose as low as possible. Although the lower dose of radiation in an LDCT scan produces less detailed images than a diagnostic CT, LDCT is good at finding small lung nodules. However, a diagnostic quality CT and/or other tests are needed to accurately diagnose and stage lung cancer.

The benefit of screening with LDCT is that it reduces the chance of dying from lung cancer because it can find lung cancer at an early stage when treatment has better chance of working.

The potential risks of screening with LDCT include:

• false-positive results (i.e., when someone has an abnormal LDCT screening result, even though they do not have cancer)
• over-diagnosis (i.e., identifying a cancer that would not have caused someone harm if they had not been screened)
• harms from radiation exposure and other procedures that may be needed

Organized cancer screening has important benefits, such as

• screening appropriate people at the recommended interval
• appropriate and timely follow-up of abnormal findings
• ongoing quality monitoring, reporting and performance management

The Lung Cancer Screening Pilot for People at High Risk also ensures that a screening navigator is in place to help participants through the screening process, from risk assessment to diagnostic evaluation.

Organized cancer screening programs reinforce the benefits of screening and ensure greater protection against the potential harms of screening, such as over-screening and unnecessary follow-up testing. An organized lung cancer screening program ensures that screening computed tomography scans:

• use the appropriate low dose of radiation
• are done without intravenous contrast
• are interpreted by radiologists who have been trained to read screening LDCTs

With guidance from a multidisciplinary expert panel, Cancer Care Ontario led the development of a radiology quality assurance program, which outlines the requirements for all pilot site hospitals. This program requires pilot site hospitals to ensure that all screening LDCT scans are reported using a standardized radiology template based on the American College of Radiology’s Lung-RADS^TM classification system.^[7]Reference 7 Close reference American College of Radiology. Lung-RADS Version 1.1 Assessment Categories. [Internet] 2019 [cited 2019 Jul]. Available from: https://www.acr.org/-/media/ACR/Files/RADS/Lung-RADS/LungRADSAssessmentCategoriesv1-1.pdf?la=enOpenClose

The Lung-RADS^TM classification system is a quality assurance tool designed to:

• standardize lung cancer screening computed tomography (CT) reporting and management recommendations
• reduce confusion in lung cancer screening CT interpretations
• facilitate monitoring of participant outcomes^[8]Reference 8 Close reference American College of Radiology. Lung CT Screening Reporting and Data System (Lung-RADS^TM) [Internet]. [cited 2019 Jul]. Available from: https://www.acr.org/Clinical-Resources/Reporting-and-Data-Systems/Lung-RadsOpenClose

Lung-RADS^TM minimizes the risks of potentially harmful and possibly unnecessary follow-up scans or invasive diagnostic testing.

The main purpose of the Lung Cancer Screening Pilot for People at High Risk (the pilot) is to assess how to best implement organized lung cancer screening for people at high risk across Ontario.

This pilot is not a research study. The National Lung Screening Trial already demonstrated the efficacy of low-dose computed tomography in reducing lung cancer mortality.^[4]Reference 4 Close reference Aberle D, Adams A, Berg C, Black W, Clapp J, Fagerstrom R, et al. Reduced lung-cancer mortality with low-dose computed tomographic screening. N Engl J Med. 2011 Aug;365(5):395–409.OpenClose

On March 31, 2016, Cancer Care Ontario issued a Request for Proposals to hospitals interested in piloting lung cancer screening for people at high risk. The hospitals had to have a level 1 thoracic surgery centre with an organized program on-site for lung diagnostic assessment.

An evaluation committee made up of Cancer Care Ontario senior leaders and clinical experts from across Canada assessed the proposals.

Pilot site hospitals were chosen from the highest ranked proposals to ensure diversity based on geography, hospital type (academic versus community) and service delivery model (single site versus hub and spoke).

The Ottawa Hospital uses a hub and spoke model that supports pilot operations out of 2 local hospitals (Renfrew Victoria Hospital and Cornwall Community Hospital) in addition to its own hospital site. The advantage of this model is that administrative functions can remain efficient and centralized at The Ottawa Hospital, while people in smaller communities near the spoke hospitals have better access to screening.

Determining eligibility for the pilot is a 2-step process. Only people who meet the criteria in steps 1 and 2 will be eligible to get screened for lung cancer through the pilot.

• Step 1: Physicians refer current and former smokers ages 55 to 74 who have smoked cigarettes daily for at least 20 years (not necessarily 20 years in a row, which means there could be times when they did not smoke) to a pilot site hospital. People can also self-present (contact the pilot site hospital on their own) to a pilot site hospital to have their age and smoking history criteria assessed.
• Step 2: A pilot site hospital screening navigator conducts a risk assessment with anyone who meets the age and cigarette smoking history criteria in step 1. The results of the risk assessment in step 2 determine whether someone is eligible to get screened for lung cancer through the pilot.

When physicians refer their patients to a pilot site hospital in step 1, they must complete the pilot referral form to authorize the use of low-dose computed tomography in case their patient is found to be eligible for the pilot in step 2.

People who self-present to a pilot site hospital and are found to be eligible in step 2 will still need a referral from a physician to participate in lung cancer screening in the pilot.

Find the referral form at Lung Cancer Screening Pilot for People at High Risk – Referral Form & Criteria

The risk assessment conducted by the screening navigator is done using a risk calculator, which is based on a statistical risk prediction model that gives an estimate of someone’s risk (as a percentage) of developing lung cancer in the next 6 years.^[9]Reference 9 Close reference Tammemagi MC, Katki HA, Hocking WG, Church TR, Caporaso N, Kvale PA, et al. Selection criteria for lung-cancer screening. N Engl J Med. 2013 Feb;368(8):728–36.OpenClose The risk assessment considers factors such as^[9]Reference 9Close referenceTammemagi MC, Katki HA, Hocking WG, Church TR, Caporaso N, Kvale PA, et al. Selection criteria for lung-cancer screening. N Engl J Med. 2013 Feb;368(8):728–36.OpenClose:

• age
• cigarette smoking history
• body mass index
• education
• personal history of cancer and chronic obstructive pulmonary disease
• family history of lung cancer

People with a 2% or greater risk of developing lung cancer over the next 6 years are considered eligible to participate in the pilot.

Someone is not eligible to participate in the pilot if they:

• have been diagnosed with lung cancer
• are under surveillance for lung nodules
• have had hemoptysis of unknown cause or unexplained weight loss of more than 5 kilograms in the past year
• are currently undergoing diagnostic assessment, treatment or surveillance for life-threatening conditions (such as a cancer with a poor prognosis) as assessed by the referring physician

The risk assessment to determine eligibility for the pilot is done using a risk calculator, which is based on a statistical risk prediction model that gives an estimate of someone’s risk (as a percentage) of developing lung cancer in the next 6 years.^[9]Reference 9 Close reference Tammemagi MC, Katki HA, Hocking WG, Church TR, Caporaso N, Kvale PA, et al. Selection criteria for lung-cancer screening. N Engl J Med. 2013 Feb;368(8):728–36.OpenClose

The risk calculator is used to determine eligibility for lung cancer screening in the pilot because its risk prediction model has been demonstrated to be more sensitive and have a higher positive predictive value than the criteria used to determine eligibility in the NLST, which was based on age, pack-years (number of packs of cigarettes someone smoked per day multiplied by the number of years they smoked) and the time since someone stopped smoking.^[9]Reference 9 Close reference Tammemagi MC, Katki HA, Hocking WG, Church TR, Caporaso N, Kvale PA, et al. Selection criteria for lung-cancer screening. N Engl J Med. 2013 Feb;368(8):728–36.OpenClose By using a more sensitive risk prediction model to choose participants, the pilot identifies people who are most likely to develop lung cancer and who are therefore most likely to benefit from lung cancer screening.^[9]Reference 9 Close reference Tammemagi MC, Katki HA, Hocking WG, Church TR, Caporaso N, Kvale PA, et al. Selection criteria for lung-cancer screening. N Engl J Med. 2013 Feb;368(8):728–36.OpenClose

People can enter the pilot through a physician referral or by contacting the pilot site hospitals directly.

Physicians can refer people who meet the referral inclusion criteria to the nearest pilot site hospital to do a risk assessment with the screening navigator to determine whether they are eligible to participate in the pilot. Find the referral form at Lung Cancer Screening Pilot for People at High Risk – Referral Form & Criteria.

Someone can also self-present to a pilot site hospital for a risk assessment to determine whether they are eligible for screening. If they are found to be eligible through the risk assessment, they still need a referral from a physician to participate in screening. The pilot site hospital will contact their family physician to get a referral. If an eligible person does not have a family physician, the pilot site hospital will find them one.

Physicians must complete the pilot referral form to authorize the use of low-dose computed tomography (LDCT) for screening. Currently, authorization of LDCT is not within the scope of practice for nurse practitioners or other non-physician clinicians who deliver primary care. However, all healthcare professionals are encouraged to identify people who may be eligible for lung cancer screening and facilitate physician referrals for them.

If a physician feels that a patient needs a computed tomography scan because their risk of developing lung cancer is high, it is important to consider whether the benefits would outweigh the potential harms of a scan. Primary care providers should use their discretion and consider a patient’s individual circumstances when making a decision about their care.

Physicians referring individuals who live outside of pilot recruitment catchment areas must confirm the pilot site hospitals have received the referrals and work with the pilot site hospitals to make sure appropriate diagnostic follow-up is organized.

We encourage all physicians to discuss smoking cessation with their patients. People who stop smoking greatly reduce their risk of disease and early death. Smoking cessation services can help reduce the morbidity and mortality for lung cancer, other cancers and chronic diseases associated with smoking, such as stroke and coronary heart disease.

Primary care providers and organizations can refer people to Telehealth Ontario for smoking cessation support by faxing referrals to 1-888-857-6555 or 519-434-9028. People can also contact the following services directly for support:

• Telehealth Ontario: 1-866-797-0000
• Smokers’ Helpline: SmokersHelpline.ca

For patient resources, please visit:

• One Step at a Time (Canadian Cancer Society)
  • For Smokers Who Want to Quit
  • For Smokers Who Don’t Want to Quit
  • Help a Smoker Quit
• Journey 2 Quit (Lung Health Foundation)
• On the Road to Quitting (Health Canada)
• Indigenous Tobacco Program (Cancer Care Ontario)
• Be Tobacco-Wise - First Nations
• Be Tobacco-Wise - Inuit

These are the key considerations for radiologists who get a requisition for a computed tomography (CT) scan for lung cancer screening:

• Whether the benefits would outweigh the potential harms of the scan
• Cancer Care Ontario recommends using low-dose computed tomography to screen people at high risk of getting lung cancer through an organized cancer screening program.
• Screening people at an official pilot site hospital provides several benefits of an organized cancer screening program, such as:
  • screening appropriate people at the recommended interval
  • appropriate and timely follow-up of abnormal findings
  • ongoing quality monitoring, reporting and performance management
• Screening is not appropriate for people with suspected lung cancer. If someone has lung cancer symptoms, follow the Program in Evidence-Based Care’s guidelines for referral of suspected lung cancer and Cancer Care Ontario’s lung cancer diagnosis pathway

If someone has already had a CT scan for screening outside of the pilot, their physician may follow the recommendation provided by the radiologist on the radiology report.

The radiologist’s recommendation for follow-up should be based on an established system for managing nodules. For screening, lung nodules should be classified and managed according to the American College of Radiology’s Lung-RADS^TM. The Fleischner Society’s Guidelines for Management of Incidental Pulmonary Nodules Detected on CT Images (2017) should be used to manage nodules found incidentally (i.e., not through screening).

If there is no clear recommendation on the radiology report, the physician should contact the reporting radiologist to determine appropriate follow-up.

For lung cancer screening resources, including those for radiologists, please see Lung Cancer Screening Pilot for People at High Risk.