What defines a high-risk patient for lung nodule screening with computed tomography (CT) scans?

From the Guidelines

High-risk patients for lung nodule screening with computed tomography (CT) scans are primarily defined as individuals with a significant smoking history, occupational exposures to carcinogens, and other potential risk factors, as outlined in the NCCN guidelines 1. The definition of a high-risk patient for lung nodule screening involves several key factors, including:

• Age, with consideration for screening in individuals aged 50-80 years
• Smoking history, with a focus on those with at least 20 pack-years of smoking, who are current smokers or have quit within the past 15 years
• Occupational exposures to carcinogens such as arsenic, asbestos, beryllium, cadmium, chromium, coal smoke, diesel fumes, nickel, silica, soot, and uranium 1
• Personal history of other smoking-related cancers, or a family history of lung cancer
• Certain lung diseases, such as COPD or pulmonary fibrosis
• Documented sustained and substantially elevated radon exposure, which increases the risk for lung cancer 1 The NCCN guidelines recommend using a multidisciplinary approach for nodule management, including specialties such as thoracic radiology, pulmonary medicine, and thoracic surgery 1. The screening approach should prioritize low-dose CT scans, with a CT dose index volume (CTDIvol) threshold of 3 mGy or less for a patient of average size, unless evaluating mediastinal abnormalities or lymph nodes 1. It is essential to consider the potential benefits, limitations, and harms associated with screening for lung cancer with low-dose computed tomography, and to engage in a process of informed and shared decision-making with a clinician before initiating lung cancer screening 1. Smoking cessation counseling remains a high priority for clinical attention in discussions with current smokers, who should be informed of their continuing risk of lung cancer 1.

From the Research

Definition of High-Risk Patient

A high-risk patient for lung nodule screening with computed tomography (CT) scans is typically defined as an individual with a history of heavy smoking, older age, and other risk factors that increase the likelihood of developing lung cancer.

• According to the study 2, high-risk individuals are those over 50 years of age, with more than 20 pack-year smoking histories, living in an urban setting, and with a potential for asbestos exposure.
• The National Lung Screening Trial (NLST) criteria, as mentioned in 3, define high-risk patients as those aged 55-74 years, with at least 30 pack-years of smoking, and smoking cessation less than 15 years.
• Another study 4 suggests that an accurate risk prediction model is more efficient than age and pack years of smoking alone at identifying those who will develop lung cancer and die from the disease.

Risk Factors for Malignancy

Several risk factors are associated with an increased probability of malignancy in lung nodules, including:

• Increasing age 2
• Size and number of nodules 2
• Reduced FEV1 and FVC 2
• Increased pack-years smoking 2
• Presence of patient comorbidities, such as chronic obstructive pulmonary disease and coronary artery disease 5

Management of Lung Nodules

The management of lung nodules depends on the estimated probability of malignancy, the presence of patient comorbidities, and patient preferences.

• Nodules that are 6 mm to 8 mm can be followed with a repeat chest CT in 6 to 12 months, depending on the presence of patient risk factors and imaging characteristics associated with lung malignancy 5.
• Solid pulmonary nodules 8 mm or larger may require surveillance imaging, positron emission tomography-CT imaging, nonsurgical biopsy, or surgical resection 5.