Lung Cancer Screening Computed Tomography Screening in Pa6ents at Risk for Lung Cancer

Transcription

1 Lung Cancer Screening Computed Tomography Screening in Pa6ents at Risk for Lung Cancer Doug Arenberg, M.D. University of Michigan

2 Disclosures

3 Objec6ve Define patients who will benefit from screening for lung cancer

4 According to USPSTF guidelines, which of the following persons SHOULD NOT be offered LDCT lung cancer screening A. A 65 year old former smoker, quit 6 years ago, and smoked 40 pack- years B. A 79 year old current smoker with COPD, res6ng hypoxemia on oxygen, chronic kidney failure and coronary artery disease C. A 55 year old woman with COPD and a family history of lung cancer, smoked for 25 years, 1.5 ppd, quit 10 years ago D. A 75 year old man with a 55 pack year tobacco history, who quit 5 years ago.

5 NLST study design Study design 50,000 healthy current or former (15 yrs), heavy (30 pk- yr) smokers, age Exclusion criteria included a CT of the chest within 18 months and inability to tolerate lung cancer treatment Yearly CXR or CT at 0, 1, and 2 yrs y

6 Where we are now USPSTF recommends annual screening for lung cancer with lowdose computed tomography (LDCT) in persons at high risk for lung cancer based on age (55-80) and smoking history (>30 pk-yrs, within 15 yrs) Ann Intern Med. 2014;160(5): doi: /m

7 According to USPSTF guidelines, which of the following persons SHOULD NOT be offered LDCT lung cancer screening A. A 65 year old former smoker, quit 6 years ago, and smoked 40 pack- years B. A 79 year old current smoker with COPD, res6ng hypoxemia on oxygen, chronic kidney failure and coronary artery disease C. A 55 year old woman with COPD and a family history of lung cancer, smoked for 25 years, 1.5 ppd, quit 10 years ago D. A 75 year old man with a 55 pack year tobacco history, who quit 5 years ago.

8 Your pa6ent asks you about CT screening for lung cancer a^er seeing a newspaper add by a local imaging center. Which of the following can you tell him, based on results of the NLST A. CT screening cuts the risk of lung cancer death by 50% among high risk smokers B. CT screening uses radia6on doses similar to an abdominal CT scan C. CT screening is as effec6ve as tobacco cessa6on in reducing lung cancer mortality D. The risk of a false posi6ve screen over 3 years of screening is 30-40%

9 Cumulative Deaths from Lung Cancer. 20% The National Lung Screening Trial Research Team. N Engl J Med DOI: /NEJMoa

10 Invasive procedures 16 deaths within 3 months of screen 6 did not have cancer 0.06% of the false posi6ve vs 11.2% of true posi6ves CT screens were associated with a major complica6on Surgical Mortality (1%) Na6onal average 3-5%

11 TOBACCO CESSATION IS THE MOST EFFECTIVE MEANS TO THE END SOUGHT THROUGH LUNG CANCER SCREENING Effec6ve tobacco cessa6on cuts risk for lung cancer mortality up to 90%

12 How effec6ve? LDCT screening Absolute risk of 1.9% Screened group lung cancer mortality rate was 1.6% 20% RRR, but Need to screen 320 people to save one life Cost? 50-70k Tobacco cessa0on Absolute risk of 1.9% in NLST ~ 80-90% RRR ~80-90% RRR Need to get 60 people to quit tobacco to save one life from lung cancer Cost? $300- $3000

13 Factors affec6ng cost effec6veness of LDCT screening Increasing costs Decreases Costs Higher cost of LDCT Screening lower risk individuals (Steep) Increased frequency of follow up CTs Higher lung ca risk Tobacco cessa6on Further catch up cases in CXR arm Efficacy of CXR screening (none) Fewer follow up CTs Increasing rate of tobacco cessa6on

14 Variability in risk among smokers

15 Lung Cancer Risk?

16 Who is at risk?

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18 When the Average Applies to No One: Personalized Decision Making About Potential Benefits of Lung Cancer Screening Projected 6 Year Likelihood of Lung Cancer Death With or Without Screening per 1000 Persons Screened Ann Intern Med. 2013;157(8):

19 Radia6on Comparison Radiation Type Amount Low-dose CT 1-2 msv CT, full body msv CT, chest 4-8 msv Background Radiation, sea level 3 msv/yr Background Radiation highaltitude 6 msv/yr Mammogram 1-2 msv Frequent flying ( k/yr) 1-7 msv CXR msv DEXA msv Dental x-ray 0.02 msv

20 Your pa6ent asks you about CT screening for lung cancer a^er seeing a newspaper add by a local imaginng center. Which of the following can you tell him, based on restulst of the NLST A. CT screening cuts the risk of lung cancer death by 50% among high risk smokers B. CT screening uses radia6on doses similar to an abdominal CT scan C. CT screening is as effec6ve as tobacco cessa6on in reducing lung cancer mortality D. The risk of a false posi6ve screen over 3 years of screening is 30-40%

21 Which of the following are demonstrate the effec6veness of a cancer screening test? (Assume all differences meet sta6s6cal significance) A. 3x more screened individuals have stage I cancer than those diagnosed unscreened B. Survival rate at 5 years in screened individuals are 70% compared to 30% among those unscreened C. Disease specific mortality in the screened group is 1.5% as compared to 3% in an unscreened group D. More cancers detected in a screened group as compared to an unscreened group

22 For screening to be effec6ve A disease must have a pre- symptoma6c phase It must be detectable with high reliability at a 6me when treatment will alter the natural history ONLY a mortality reduc6on for the disease being screened for can demosntrate benefit

23 Bias in screening trials Length bias Heterogeneity in the rate of disease progression Screening preferen6ally detects more indolent cases Affects both stage distribu6on and survival, even if the screening test does not reduce mortality, it will look beker

24 Bias in screening trials Lead 6me (A clinically silent phase during which treatment alters the natural history) Detec6on of disease during lead 6me forms the ra:onale for screening of all diseases Lead 6me bias leads to survival in a screened group exceeding the control group by an amount of 6me equal to the lead 6me interval Survival is not a valid measure of screening effec6veness

25 From: Do Physicians Understand Cancer Screening Statistics? A National Survey of Primary Care Physicians in the United States Lead-time bias. Survival rates are inflated by earlier diagnosis even if mortality remains unchanged

26 Bias in screening trials Overdiagnosis bias (Infinite lead 6me) A propor6on of pa6ents have a clinically insignificant form of disease If not screen detected, these pa6ents would never have known of their disease Improves survival and stage distribu6on The only bias that can account for improved stage distribu6on, and survival, with no difference in mortality

27 From: Do Physicians Understand Cancer Screening Statistics? A National Survey of Primary Care Physicians in the United States Overdiagnosis bias. Survival rates are inflated by the detection of nonprogressive cancer even if mortality remains unaltered.

28 Are these biases real? Three NCI CXR screening trials in 1970s > 30,000 subjects CXR detected more cases (Length Bias) More early stage disease (Length and Lead 6me Bias) Improved survival in the screened group (Length and Lead 6me bias) No difference in mortality (Overdiagnosis?) Q: How many compared CXR screening to no screening?

29 Which of the following are demonstrate the effec6veness of a cancer screening test? (Assume all differences meet sta6s6cal significance) A. 3x more screened individuals have stage I cancer than those diagnosed unscreened B. Survival rate at 5 years in screened individuals are 70% compared to 30% among those unscreened C. Disease specific mortality in the screened group is 1.5% as compared to 3% in an unscreened group D. More cancers detected in a screened group as compared to an unscreened group