Governing Bodies and Societal Recommendations
Following the NLST 2011 publication the National Comprehensive Cancer Network (NCCN) quickly responded with guidelines for lung cancer screening. NCCN now defines two populations recommended for annual LDCT screening based on risk. Group 1 is defined by NLST eligibility (age, 55–77 years, ≥ 30-pack years, and smoking cessation <15 years) and group 2 is less conservative and defined by age ≥50-, ≥20-pack year, having quit at any time, and at least one additional risk factor: (family history of lung cancer, diagnosis of COPD, occupational exposure to known carcinogen or personal history of tobacco-related malignancy). In 2013, the U.S. Preventative Services Task Force (USPSTF) recommended annual screening with LDCT in asymptomatic adults aged 55 to 80 years with ≥30-pack year smoking history and currently smoking or have quit <15 years, who are healthy enough to tolerate cancer treatment. It assigned a grade of B (high certainty that the net benefit is "moderate," or there is moderate certainty that the net benefit is moderate to substantial) to the recommendation. In 2015 the Center for Medical Services (CMS) approved reimbursement for a similar cohort (age, 55–77 years, ≥30-pack years, and <15 years since quitting). CMS placed several stipulations on reimbursement which are unique to lung cancer screening (Table 2), these include a shared decision-making visit, smoking cessation services, and participation in a CMS approved registry. Each of these well-intentioned stipulations may hinder the widespread application of lung cancer screening in the United States. LDCT screening is currently covered by many commercial insurers and by Medicare and Medicaid in 31 states for eligible individuals. It is covered as a preventative service and, therefore, has no copay or cost sharing by the patient. The American Cancer Society, American Association for Thoracic Surgery, American College of Chest Physicians, American Lung Association, American Society of Clinical Oncology, and American Thoracic Society, all endorse screening for populations studied in the NLST or expanded populations similar to the NCCN group 2. The American Academy of Family Practitioners (AAFP) is currently the only major outlier with regard to recommendations on lung cancer screening and state that the evidence is insufficient to recommend for or against screening for lung cancer with LDCT in persons at high risk for lung cancer based on age and smoker history.
The Canadian Task Force on Preventative Health care recently issued a "weak" recommendation for LDCT screening in high-risk individuals. The task force recognized that, although research shows that screening reduces lung cancer deaths, there are associated harms and some high-risk patients will reasonably choose not to participate in screening.
Who to Screen
Debate exists amongst many LDCT stakeholders regarding what constitutes the ideal screening population. The USPSTF and CMS use eligibility adapted from the NLST, while the recent European trials included younger patients and those with fewer pack years. Many argue that the current USPSTF screening recommendations are too conservative and should be broadened to include patients within the NCCN's group 2. Recent evidence from the Lahey Clinic suggests that lung cancer rates detected cancer stage and histology were equivalent in NCCN group-1 and -2 patients, suggesting a comparable benefit to screening in that population. More importantly, the current USPST eligibility recommendations may be too conservative to capture at-risk African Americans. Only 4% of NLST participants were African American. African American men smoke at similar rates as European American men but have higher rates of lung cancer and lung cancer mortality.[32,33] They are also diagnosed with lung cancer at a younger age and with fewer pack years than European Americans. Race-specific guidelines may be needed to more equitably screen African Americans.
Semin Respir Crit Care Med. 2020;41(3):447-452. © 2020 Thieme Medical Publishers