Second cancer following cancers of the buccal cavity and pharynx in Connecticut, 1935-1982.

Patients diagnosed in Connecticut from 1935 to 1982 with cancers of the tongue, gum, floor, and other parts of the mouth, or pharynx experienced twofold to threefold increased risks of developing a second primary cancer. The excesses were most prominent [relative risk (RR) greater than or equal to 10] for subsequent oral and esophageal cancers but also were observed for cancers at other sites in the digestive and respiratory tracts. The increased risks, which affected both men and women and persisted over time, are most likely related to increased alcohol and tobacco consumption in the patients developing second primaries. The proportion of persons developing a new primary was 9% among the 2,120 patients with cancer of the tongue, 14% for the 3,063 patients with cancer in the gum, floor, or other parts of the mouth, and 8% among the 2,637 persons with pharynx cancer. If one considers that the average length of follow-up was only 3.4 years, these percentages are high and indicate the need for continued surveillance of patients with oral and pharyngeal cancers. Small overall excesses of subsequent cancer occurred among patients with initial lip (RR = 1.3) or salivary gland cancers (RR = 1.2), with twofold risks of oral and respiratory cancers evident for both tumors.