The overall survival rate for non-small cell lung cancer has not improved in over 3 decades, which underscores the importance of lung cancer screening. The goal is to identify high-risk and asymptomatic patients with unrecognized disease, allowing us to diagnose and treat patients at an earlier stage, thus improving survival. In August 2011,The New England Journal of Medicine published research proving a survival benefit for screening high-risk patients with a low-dose screening CT scans. They looked at 53,454 patients ranging between 55-74 years of age who were current smokers or had quit within the previous 15 years and had a 30 pack year history of smoking, or a 20 pack year history of smoking with an additional risk factor. A pack year is calculated as the number of packs of cigarettes per day one has smoked, multiplied by the number of years they have smoked. The results showed a 20% relative reduction in lung cancer deaths in those screened with the low-dose CT scan.
The National Comprehensive Cancer Network (NCCN) guidelines recommend that institutions performing lung cancer screening use a multidisciplinary approach that includes the specialties of thoracic radiology, pulmonary medicine, and thoracic surgery, along with smoking cessation resources. An important part of the process is to advise current smokers to quit smoking, and advise former smokers to remain abstinent from smoking. Lung cancer screening is most appropriate for high-risk patients who are potential candidates for definitive treatment. The NCCN has defined high-risk as a patient 55-74 years of age with a >30pack year history of smoking who is currently smoking or has quit within the last 15 years; OR a patient >50 years of age with a >20 pack year history of smoking with one additional risk factor other than second-hand smoke. Additional risk factors include radon exposure, occupational exposures (silica, cadmium, asbestos, arsenic, beryllium, chromium, diesel fumes, nickel, coal smoke, and soot), a personal cancer history (lung cancer, lymphoma, cancers of the head and neck, or other smoking related cancers), a family history of lung cancer, and chronic lung disease (COPD or pulmonary fibrosis). Exposure to carcinogens from second-hand smoke is highly variable, with varying evidence for increased risk from this exposure; therefore, second-hand smoke alone is not considered a risk factor for lung cancer screening.
During consultation, patients are made aware that there is a 4% chance of detecting a lung cancer on the initial screening CT scan, half of which will be inoperable. There is a 2 % chance of detecting a lung cancer on subsequent screening CT scans, but most of these will be curable. The scan is a low-dose screening CT with only 1.5 mSV of radiation, as compared to the diagnostic CT scan, which is 8 mSV of radiation. This means there is much less radiation exposure with screening CT scans, but this also means not as much detail will be obtained. No contrast is used for these scans, which also decreases possible complications. There is a 24% chance of finding some abnormality that requires further follow up or work up, which may include benign nodules, coronary artery calcifications, emphysema, renal, liver, or adrenal abnormalities. Recommendations are made based on the size and character of the nodules found. They can range from annual follow up for small nodules, to short interval follow up at 3-6 months for moderate sized nodules, or further testing for larger, more worrisome nodules. For more details, please review the NCCN guidelines.
The coronary artery calcification score looks at the degree of calcification found in the 4 main blood vessels supplying the heart. Each vessel is given a score of 1-3, for a maximum score of 12. Those patients with a score of 4 or higher will be referred to a cardiologist.
The emphysema score looks at the degree of lung destruction from COPD. Scores are given based on splaying of the blood vessels and the degree of lung tissue involved. The maximum score is 3, and scores of 2 or greater are referred to a pulmonary medicine specialist.
The key to any successful lung cancer screening program, is smoking cessation, and Penrose Hospital recently received a grant to support our in-patient and out-patient smoking cessation services. Since 90% of lung cancers are thought to be associated with smoking, the best thing you can do for yourself is to quit today.
Some of the historic arguments against lung cancer screening are the futile detection of small aggressive tumors or indolent disease, the anxiety associated with screening or benign findings, false negative and false positive results, unnecessary testing and procedures that result from benign findings, complications from work up, radiation exposure, and costs. The benefits are the decreased number of deaths from lung cancer, reduction in disease related deaths, reduction in treatment related deaths, improvement to a healthier lifestyle, and reduction in anxiety related to the unknown. With publication of the landmark study in the New England Journal of Medicine in 2011, lung cancer screening has become the norm, not the exception. Today, most lung affiliated organizations across the country recommend lung cancer screening for high risk patients, so call today to see if you qualify.
Advocates of Screening
- American Cancer Society
- American Lung Association
- American College of Chest Physicians
- American Society of Clinical Oncology
- National Comprehensive Cancer Network
- U.S. Preventive Services Task Force
- Society of Thoracic Surgeons
- American Association for Thoracic Surgery
Penrose-St. Francis Health Services
- Lung Nodule Clinic
- Smoking Cessation Assistance
- Robotic-Assisted Minimally Invasive Thoracic Surgery
- Specialized Radiation / Medical Oncologists
- Cutting Edge Diagnostic Techniques
- Certified Nurse Navigators