Risk of onset of second neoplasms and successive neoplasms in patients with a head and neck index tumour.

Objective: To analyse the incidence of appearance of second and successive neoplasms in a cohort of head and neck squamous carcinoma patients.

Material And Methods: We conducted a retrospective study with 4,458 patients with an index tumour located in the head and neck diagnosed during the 1985-2016 period. We evaluated the incidence of appearance of second neoplasms and successive neoplasms over a period of 30 years.

Results: During the follow-up, 1,203 patients (27.0%) had a second neoplasm, 242 patients (5.4%) a third neoplasm, 58 patients (1.3%) a fourth neoplasm, and 8 patients (0.2%) 5 or more successive neoplasms. The incidence of appearance of second neoplasms was 3.5% per year, remaining relatively constant throughout the follow-up period. The patients with a second neoplasm had a higher risk of appearance of a third neoplasm, and those with a third neoplasm had a higher risk of a fourth. Seventy-eight percent of the second neoplasms, 88% of the third neoplasms, and 89.6% of the fourth neoplasms appeared in locations epidemiologically related to tobacco and alcohol use.

Conclusions: Second neoplasms after a head and neck index tumour appeared at a constant rate of 3.5% per year throughout the entire follow-up period.