Thoracic Screening & Prevention
Many individuals have a family history of lung disease, or have been exposed to substances such as smoke, asbestos, or even dust from the World Trade Center. It is important that they receive screening for lung diseases, and that after initial screening, that any abnormalities are followed up appropriately.
Detecting a disease in its early stages usually leads to a better chance of successfully treating it.
The public may be confused by mixed messages regarding screening for lung cancer, as are many physicians. While there are strong advocates of computed tomography (CT) screening for lung cancer, the American Cancer Society does not recommend screening as a routine test.
The challenge facing patients and their physicians lies in the fact that there is a good chance that a nodule will be found in the lungs, especially in patients over 55 with a history of smoking. In most cases, the nodules are eventually determined to be harmless — but many patients will experience weeks or months of anxiety until a diagnosis is established. In addition, differences in the ways that physicians manage the care of patients with nodules can make the follow-up process very challenging for both patients and their physicians.
On the other hand, it is not uncommon for a patient to have a CT scan for another reason that detects a lung tumor incidentally. Because some tumors do spread and become deadly, assessment and monitoring of any suspicious lesion is critical. Abnormalities must be monitored diligently so that lesions requiring intervention can be treated earlier rather than later. The High-Risk Lung Assessment Program at NewYork-Presbyterian Hospital/Columbia University Medical Center has established a highly refined process to do this in a very efficient manner.
We recommend CT screening for people who have a high risk of lung cancer based on family history, health, and smoking history. For those with a moderate risk, thorough discussion of the potential results of a scan and follow-up options is essential before deciding upon screening.
Genetics and Lung Disease
Unlike breast cancer, in which the presence of BRCA1 or BRCA2 is a clear predictor of risk for cancer, specific gene mutations increasing the risk for lung cancer have not yet been identified. Ninety percent of lung cancers develop in people who have smoked tobacco.
Research has found significant biologic differences in the tumors of nonsmokers compared to the tumors of smokers. This information may lead to the development of therapies that are targeted to the biologic characteristics in each group. In addition, research by Columbia doctors and colleagues, as well as other laboratories, has shown that molecular information acquired from microarray analysis of lung cancer specimens may predict tumor progression and patient survival.
Genetic causes have been linked to other lung diseases, such as alpha-1 antitrypsin deficiency for chronic obstructive pulmonary disease (COPD). The genetics program at NewYork-Presbyterian/Columbia has extensive experience in identifying individuals at risk for this and for other genetic lung diseases.
Risk Factors for Lung Cancer
The risk factors for lung cancer are both genetic and environmental, based on exposure to toxins and carcinogens. Lung cancer most often strikes people over age 50 who have a history of smoking. Even for smokers, however, screening for lung cancer is not a routine healthcare measure, and is not usually covered by insurance if a person has no symptoms.
Among healthy former smokers over age 55, screening will detect a nodule in one third of people. When nodules are found, a process follows to distinguish which may be benign and which may be cancerous; only 1.5-2% of nodules are likely to be cancerous.
To determine whether a nodule is benign or cancerous, information about the nodule itself and the patient's health history are both evaluated. Nodule properties such as size, shape, patterns of irregularity, calcification, and changes in size or shape over time are observed. Overall health factors, including general health, exposure to smoke and toxins, family history, and other factors are also considered. Together, these data are processed to determine whether the individual's nodules have a low, intermediate, or high probability of being cancerous. The determination of risk is then used to guide treatment decisions.
