November is Lung Cancer Awareness Month
There are 2 major types of lung cancer:
About 10% to 15% of all lung cancers are small cell lung cancer (SCLC), named for the size of the cancer cells when seen under a microscope. Other names for SCLC are oat cell cancer, oat cell carcinoma, and small cell undifferentiated carcinoma. It is very rare for someone who has never smoked to have small cell lung cancer.
SCLC often starts in the bronchi near the center of the chest, and it tends to spread widely through the body fairly early in the course of the disease.
About 85% to 90% of lung cancers are non-small cell lung cancer (NSCLC). There are 3 main subtypes of NSCLC. The cells in these subtypes differ in size, shape, and chemical make-up when looked at under a microscope. But they are grouped together because the approach to treatment and prognosis (outlook) are very similar.
Non-small cell lung cancer includes: squamous cell carcinoma, adenocarcinoma, large cell carcinoma, and other subtypes.
Carcinoid tumors of the lung account for fewer than 5% of lung tumors. Most are slow-growing tumors that are called typical carcinoid tumors. They are generally cured by surgery. Some typical carcinoid tumors can spread, but they usually have a better prognosis than small cell or non-small cell lung cancer. Less common are atypical carcinoid tumors. The outlook for these tumors is somewhere in between typical carcinoids and small cell lung cancer.
What are the risk factors for lung cancer?
Both smokers and non-smokers exposed to asbestos also have a greater risk of developing mesothelioma, a type of cancer that starts in the pleura (the lining surrounding the lungs).
How is lung cancer diagnosed?
Until recently, no lung cancer screening test had been shown to lower the risk of dying from this disease. Earlier studies of 2 possible screening tests, chest x-ray and sputum cytology, did find that these tests detected lung cancers at an early stage, but this did not improve a person's chance for a cure. For this reason, major medical organizations have not recommended routine screening with these tests for the general public or even for people at increased risk, such as smokers.
A newer type of CT scan, known as low-dose spiral CT (or helical CT) has shown some promise in detecting early lung cancers in heavy smokers and former smokers. Spiral CT provides more detailed pictures than a chest x-ray and is better at finding small abnormalities in the lungs. However, at this time, no major professional organizations, including the American Cancer Society, recommend routine lung cancer screening, either for all people or for those at increased risk.
The United States Preventive Services Task Force (USPSTF), a group of experts gathered together by the US government, has concluded that there's not enough evidence at this time to recommend for or against lung cancer screening in people without symptoms.
The American College of Chest Physicians (ACCP) does not recommend routine lung cancer screening at this time, advising that "individuals undergo screening only when it is administered as a component of a well-designed clinical trial.
The bottom line is -- people who are current smokers should realize that the best way to avoid dying from lung cancer is to stop smoking.
For more information on the diagnosis and treatment of lung cancer, please visit the American Cancer Society web page: www.cancer.org.
What we're doing at the Purdue University Center for Cancer Research:
The James R. Lowe Lung Cancer Research Fund