How common is adenocarcinoma among lung cancer cases?

Adenocarcinoma is a significant form of lung cancer that accounts for a substantial percentage of cases worldwide. In the United States, it is the most common type of lung cancer, representing approximately 40 percent of all cases.1

These tumors are classified as a type of non-small-cell lung cancer, which collectively accounts for the majority of lung cancer diagnoses, as opposed to small-cell lung cancer, which makes up only 10–20 percent of cases. Adenocarcinoma cells are characterized by their cube- or column-like shape and their tendency to form gland-like structures, often originating in the smaller, peripheral bronchi of the lungs.1