Cancer is a complex group of hundreds of distinct diseases, with occurrence that varies by cancer type, age, sex, race/ethnicity, socioeconomic status, geographic location, and time. This chapter describes cancer occurrence patterns in the United States for all cancers combined and for seven select cancer sites (prostate, lung and bronchus, and colorectum in men and breast, lung and bronchus, and colorectum in women). These cancers account for 42% and 50% of new diagnoses in men and women, respectively. Lung and bronchus cancer is the leading cause of cancer death in both men and women, followed by prostate and colorectal cancers in men and breast and colorectal cancers in women. The chapter focuses on these four cancer types, as well as three additional cancers (liver and intrahepatic bile duct, esophagus, and pancreas) that are unique with respect to risk factors, distribution and trends by histologic subtype, and low survival.