Screening with the goal of early lung cancer detection enables disease detection in its earliest fazes when treatment options and treatment success are the best. In order for a screening program to be accepted by expert medical societies, numerous criteria have to be met including a disease mortality rate. Screening method for early lung cancer detection in people with high disease risk is computer tomography (CT) of the chest using devices that are able to detect numerous abnormalities using minimal radiation dose. Low dose CT (LDCT) devices use up to 90% less radiation in comparison with conventional CT chest exams.
In the past, doctors were using classic x-ray images of thoracic organs and a cytological secretion analysis. Summation image of thoracic organs shows heart, lungs, airways, blood vessels and spinal/chest bones. Body exposure to radiation is low but the structure summation often disables finding small changes. Cytological secretion analysis is a method that tries to detect cancer sells among secretion cells. However, both of these methods have failed to lower lung cancer mortality rate.
On November 24th, 2015 the FDA (Food and Drug Administration – K142955) authorized the use of CT device from Siemens SOMATOM EDGE series in the USA for screening of people with a high risk of developing lung cancer.
In the USA, the annual low dose CT screening for lung cancer is advised for:
1. Long term heavy smokers
2. Current smokers and those that stopped smoking in the last 15 years
3. Age group of people between 55 and 80 years
Heavy smokers are considered to be people that smoke 30 packs/years a day. Pack/year indicates the average smoking of one cigarette pack a day for a year. For example, a person can have 30 packs/years if he or she smokes one pack a day for 30 years or two packs a day for 15 years. American Association for Thoracic Surgery advises annual screening for people over 50 years for people that smoke 20 packs/years and that also have work environment risk factors and whose first-degree relatives have lung cancer.
Risks in lung cancer screening can be false positive findings when a suspicious mutation that is not cancer is labeled as cancer which leads to additional tests or even a procedure that were unnecessary.
Prediagnosis is the discovery of neoplasm cases that do not present a problem for the patient but lead to further unnecessary procedures.
1. Internet Citation: Final Update Summary: Lung Cancer: Screening. U.S. Preventive Services Task Force. July 2015.