By Todd E. Williams, M.D
Lung cancer is the number one cause of cancer death in the United States. The American Cancer Society estimated approximately 157,000 deaths in the year 2001 from lung cancer alone. These rates far exceed death rates from any other type of cancer, including breast cancer, prostate cancer or colon/rectal cancer.
Approximately 85 percent of all lung cancer deaths can be directly attributed to tobacco use. There are more than 40 known cancer causing agents (carcinogens) in tobacco smoke and varying amounts of tar. The development of lung cancer generally takes years before it becomes clinically detectable.
A patient with lung cancer can present varying problems, which can include shortness of breath, cough, hemoptysis (coughing up blood); the symptoms can be caused by the cancer invading structures in the chest and/or compressing airways.
The development of lung cancer can often be silent until it is quite large or has metastasized (spread outside its site of origin); in fact, the majority of patients diagnosed with lung cancer have more advanced disease.
Generally, lung cancer is divided into two groups: one is small cell lung cancer, the other is nonsmall cell lung cancer. The reason for this division is that each group has a different natural history and is treated differently. In the nonsmall cell group, the most common cancers include squamous cell carcinoma, adenocarcinoma, and large cell carcinoma. The small cell group consists of only small cell carcinoma. Small cell lung cancer tends to be a very aggressive tumor and often spreads elsewhere early in its course. It is the type of lung cancer that has the strongest correlation with tobacco use.