Second neoplasms in patients with carcinomas of the vocal cord: incidence and implications for survival.

A retrospective analysis was performed for 218 patients who were managed for carcinomas of the glottic larynx from 1975 to 1988. With a median follow-up of 51 months (range: 24 to 120 months), 41 patients developed a second malignant neoplasm. Six patients had synchronous and 35 had metachronous second malignant neoplasms. The median interval between the diagnosis of glottic carcinoma and a second malignant neoplasm was 31 months. This median interval increased to 43 months when only the metachronous tumors were analyzed. The average annual risk of developing a second malignant neoplasm (SMN) in a 10-year period was 3.1%. Seventy-one percent of them occurred in the upper aerodigestive tract or lungs. When analyzed according to the initial stage of the glottic carcinoma, 23 of 145 (16%) patients with T1 or T2 glottic carcinomas developed a second malignant neoplasm, whereas 18 of 73 (25%) patients T3 or T4 lesions did so. For the T1/T2 group, the average annual risk was 2.5%, as compared to 4.8% for the T3/T4 group (p = 0.023). The development of a second malignant neoplasm adversely affected survival. The 10-year actuarial survival for these patients who did not develop a second malignant neoplasm was 45%, as compared to 19% for those who did develop a second malignant neoplasm (p = 0.008). Although second malignant neoplasms occurred in only 19% of the total patient population, their impact on the survival rate of the overall population was equal to that of glottic carcinomas. The median survival after the diagnosis of a SMN was 6 months. The high incidence of second malignant neoplasms in patients with glottic carcinomas warrants careful follow-up and clinical investigation of the use of chemopreventive agents.