Practice Essentials
Cancer of the lung is the leading cause of cancer mortality in men and women in the United States.
Cancer staging, which defines the extent of disease, is crucial in guiding treatment and determining prognosis. Staging also facilitates the assessment of response to therapy, communication between cancer centers, and clinical research.
Tumor, node, metastasis (TNM) staging is a consistent, reproducible description of cancers according to the extent of anatomic involvement. This system is based on defining the characteristics of the primary tumor (T), regional lymph node involvement (N), and the presence of distant metastases (M).
Imaging (especially computed tomography [CT], magnetic resonance imaging [MRI], and positron emission tomography [PET]) plays an important role in determining the pretreatment clinical staging (TNM or cTNM). CT of the chest alone is sufficient for stagin patients with pure ground glass opacities and an otherwise normal study, adn for patients with perpheral IA diease. Otherwise, PET/CT is recommended for patietns potentially eligible for curative treatment
. This clinical classification is a critical step in selecting and evaluating treatment. The pathological (postsurgical histopathological) classification (pTNM) is more precise in defining prognosis.
Guidelines on lung cancer screening have been issued by the following organizations:
American Cancer Society (ACS)
American College of Chest Physicians (ACCP)
National Comprehensive Cancer Network (NCCN)
U.S. Preventive Services Task Force (USPSTF)
The guidelines are in agreement that annual screening with low-dose, computed tomography (LDCT) scanning should be offered to patients aged 55 to 74 years and who have at least a 30 pack-year smoking history and either continue to smoke or have quit within the past 15 years. The USPSTF extends the recommended age range to 80 years, while the NCCN notes the existence of uncertainty about the upper age limit for screening and advises that screening beyond age 74 years may be considered as long as the patient’s functional status and comorbidity allow consideration for curative intent therapy.
In addition, the NCCN guidelines recommend considering screening starting at age 50 in patients with at least a 20 pack-year smoking history and one or more of the following risk factors
:
Radon exposure (documented sustained and substantial)
Occupational exposure to lung carcinogens (eg, silica, cadmium, asbestos, arsenic, beryllium, chromium, diesel fumes, nickel, coal smoke, soot)
Cancer history (lung cancer, lymphomas, cancers of the head and neck, or smoking-related cancers)
Family history of lung cancer in first-degree relatives
Chronic obstructive pulmonary disease or pulmonary fibrosis