The debate surrounding lung cancer screening addresses the slow developing nature of the disease and the benefits of early detection. Non small-cell and small-cell lung cancers are the number one cancer killer worldwide. Many researchers believe the high mortality rate can be reduced with earlier detection protocols in place.
The screening process will search for pre-symptomatic cancer if the patient knows to get checked. The importance of catching the disease early is evident in several research studies. According to the Lung Cancer Alliance, survival rates increase by as much as 35% when lung carcinomas are found in early stages. Scientists have determined certain groups to be better candidates for screening than others. Risk factors include current and past smokers, and people exposed to asbestos, excessive radon gas and other environmental agents.
A majority of lung carcinomas, including adenocarcinoma and squamous cell can be attributed to cigarette and cigar smoking. Up to 15% of worldwide NSCLC and SCLC cases involve non-tobacco users and those exposed to other carcinogens. Risk factors include tar and soot, heavily polluted air and second-hand smoke.
Doctors currently use the same diagnostic tests to screen for non small-cell or small-cell (NSCLC & SCLC, resp.) cancers as they do for patients who are symptomatic. Chest x-rays, sputum (throat culture) cytology and CT scans are the preferred methods.
Conclusive test results have yet to show the benefit of cancer screening in decreasing mortality rates. Theories are based on studies showing early detection has led to decreased mortality rates in other types of this disease, including breast and cervical cancers. Although conclusive results have not been recorded, early stages of NSCLC or SCLC are statistically easier to cure than late stages.
According to Jim Mulshine (Insight; Expert Thinking from Milliman) a pre-emptive approach to screening would be more effective in reducing the number of deaths from this disease. He goes on to note the difficulty in doing this for a number of reasons. The medical framework is generally set up to treat patients when they have symptoms, not for a disease which isn’t yet causing problems. Also, detecting the cancer early on will mean changing the medical infrastructure to support the process.