Towards an Early Lung Cancer

Detection and Screening Protocol

for the Ridge Meadows Area Grand Rounds December 2015

Frank Ervin, MD, FRCPC, FCCP

Lung Cancer

• High case fatality ratio

• Leading cause of cancer death

• Improved survival with earlier stage disease

• High risk population identifiable

• Goals of screening programs

• Sources of bias in studies of screening programs

• Benefits and risks of Low dose CT scans for lung

cancer screening

• Current recommendations for CT screening

programs

• CT screening in BC

• Who should be referred for screening and how?

Screening: Rationale

• Screening individuals at risk for a disease before

they have signs or symptoms of the disease

• Treat the disease when found on screening aiming

to improve outcomes, lower morbidity and

mortality

• Achieve a reduction in disease related mortality

• Balance benefit with harms (pseudodisease,

morbidity and cost)

Overestimation of survival duration among screen-detected cases (relative to those detected by signs and symptoms) when survival is measured from diagnosis. This simply reflects earlier diagnosis because the overall survival time of the patient is unchanged.

Lead-time bias

http://www.vaoutcomes.org/downloads/Lead_Time_Bias.pdf

Patz EF Jr et al. N Engl J Med 2000;343:1627-1633.

Overdiagnosis bias

Overestimation of survival duration among screen-detected cases caused by inclusion of pseudo- disease—subclinical disease that would not become overt before the patient dies of other causes.

www.vaoutcomes.org/downloads/Lead_Time_Bias.pdf

Patz EF Jr et al. N Engl J Med 2000;343:1627-1633.

Length bias Overestimation of survival duration among

screening-detected cases caused by the relative excess of slowly progressing cases. These cases are disproportionately identified by screening because the probability of detection is directly proportional to the length of time during which they are detectable and thereby inversely proportional to the rate of progression

www.vaoutcomes.org/downloads/Lead_Time_Bias.pdf

Patz EF Jr et al. N Engl J Med 2000;343:1627-1633.

Risks of Screening for Lung

Cancer with LDCT

• Radiation induced cancers

• Anxiety

• Cost

• Overdiagnosis of indolent cancers

Screening with CXR

• Several studies from 1960 through 2011 studied

CXR +/- sputum cytology

• PLCO study negative

• Lung cancer incidence/ 10,000 pt-yrs varied by

smoking history: 3.1, 23 and 83 in never, ex and

current smokers

The National Lung Screening Trial Research Team . N Engl J Med 2011;365:395-409.

The National Lung Screening Trial Research Team . N Engl J Med 2011;365:395-409.

The National Lung Screening Trial Research Team . N Engl J Med 2011;365:395-409.

The National Lung Screening Trial Research Team . N Engl J Med 2011;365:395-409.

Video

N Engl J Med 2013; 369:910-919

Probability of cancer in nodules detected on screening

http://www.nejm.org/doi/full/10.1056/NEJMoa1214726

McWilliams A et al. N Engl J Med 2013;369:910-919.

McWilliams A et al. N Engl J Med 2013;369:910-919.

Radiation Risks

• Current low dose algorithms: 1.5 mSv

• Average annual background radiation: 3-4 mSv

• Repeat screening to follow small nodules often

needed

• Average NSLT dose over three years 8 mSv,

maximum 20-22 mSv over 4 years

Radiation Risks

• “Risks of medical imaging at effective doses

below 50 mSv for single procedures or 100 mSv

for multiple procedures over short time periods

are too low to be detectable, and may be

nonexistent”

• Estimate risk of radiation induced cancer in

NSLT is one cancer death in 2,500 screened

participants

Risks of Screening

• Small increase in risk of death in screened

patients in the NSLT

• Death or major complications/10,000

participants:

• 4.1 and 4.5 in LDCT arm

• 1.1 and 1.5 in CXR arm

Recommendations

ACCP May 2013

• Smokers and former smokers

• 30 pack years or more

• Not quit for 15 years

• Annual screening with LDCT should be offered

US Preventive Services Task Force

Recommendation Statement

March 2014

• Asymptomatic adults aged 55-80 years

• 30 pack year smoking history

• Current and former smokers < 15 years quit

Caveats

• Persons screened should be relatively healthy

and be willing and able to undergo curative

treatment for any cancers found

• The screening program should include smoking

cessation counselling

• The program should model that of the NLST in

terms of quality of scan interpretation, follow up

of nodules, patient selection, etc.

Who benefits most from

screening?

• In the NLST persons in the highest 60% of risk

accounted for 88% of all deaths preventable by

screening

Screening programs in BC

• No formal screening program exists

• VGH Lung Health Study

• Interested respirologists/radiologists

Suggestions for Screening Your Patients

or…

“It is easier to get into something than to get

out of it.” - Donald H. Rumsfeld • Identify patients who meet either the NLST or USPSTF criteria

• Do not suggest screening for patients who are too ill to be treated

for lung cancer or unwilling to be followed

• Explain the benefits and risks of screening

• Ensure that the CT requested is “Low Dose CT Chest for Screening”

and include the number of pack years, quit times, asbestos

exposure, etc

• Ensure that the CT report is reviewed and that follow up CT Scans

are ordered per the radiologist’s recommendation

• Promptly refer patients for further assessment as needed.

Practical Issues for Maple

Ridge • Should we be offering screening to the general

public, advertise in local papers, etc.?

• Who orders the repeat CT scans: GP,

Respirologist, Radiologist?

• Should we maintain a registry of screened

patients?

• Where is the funding for this? Consult and visit

fees? Counselling?

Towards an Early Lung Cancer

Detection and Screening Protocol

for the Ridge Meadows Area Grand Rounds December 2015

Frank Ervin, MD, FRCPC, FCCP