Lung cancer is the most frequently diagnosed cancer in Indiana. In addition to the primary lung cancers, for which information is available in this report, the lung is a frequent site of metastasis for other cancers. In the five years from 1996 to 2000, there were 22,486 cases of primary lung cancer diagnosed in Indiana. In males, 13,335 lung cancers were diagnosed and there were 9,151 in females, making lung cancer the second most commonly diagnosed cancer for both men and women. Lung cancer is, by far, the most common cause of cancer death in Indiana, as it is in the rest of the United States, accounting for 30% of all cancer deaths. From 1996 - 2000, there were 19,142 deaths in Indiana from lung cancer, 11,487 in males and 7,653 in females.
Lung cancer is not a single disease; rather, it is a group of cancers that have in common the lung and associated respiratory tissues as the site of origin. There are several classification schemes for lung cancer. On a practical basis, lung cancers are clinically divided into two major types, small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC). SCLC (also called oat cell cancer) represents approximately 20% of all lung cancers. It is an aggressive cancer, growing rapidly and metastasizing early to other parts of the body. SCLC is strongly associated with cigarette smoking; it is extremely rare for this cancer to occur in someone who has never smoked. NSCLC is the most common type of lung cancer accounting for nearly 80% of all lung cancers. There are three sub-types of NSCLC: squamous cell carcinoma, adenocarcinoma, and large-cell undifferentiated carcinoma accounting for approximately 30%, 40%, and 10% of lung cancers respectively. Other tumors of the lung are uncommon. Carcinoid tumors are most often benign and account for less than 5% of all lung tumors. Adenocystic carcinomas, hamartomas, lymphomas, and sarcomas occur even more rarely as primary lung tumors.
The most important risk factor for lung cancer is tobacco smoking. About 90% of the lung cancers in men are considered to be caused by cigarette smoking. In women, 80% of lung cancers are attributed to smoking. (Clinical Oncology, RE Lenhard, Jr., RT Osteen, and T. Gansler. American Cancer Society, Atlanta, GA, 2001.)
African-Americans have both higher incidence and mortality rates for lung cancer than do whites (87.7 cases/100,000 vs. 75.5/100,000, and 78.0 deaths/100,000 vs. 64.3/100,000). The stage at diagnosis, however, is similar between blacks and whites.
