[Diversity of incidence trend patterns: implications for carcinogenesis?].

Objective: Cancers of the ENT, oesophagus and lungs are caused mainly by alcohol and/or tobacco consumption but have potentially heterogeneous latencies and dose-incidence relationships. The incidence of cancers having the same risk factors may vary in a similar way over time and space. The aim of the study was to identify groups of cancers with similar spatio-temporal incidence trends.
Methods: Fifty thousand nine hundred and eighty cases of ten cancer types were collected between 1982 and 2002 in six French departments. The incidence levels and trends were assessed using an age-cohort random-effect model that took into account heterogeneity of incidence levels and trends between departments.
Results: Three groups of cancer sites/types with similar spatio-temporal incidence trends were identified: (1) oral cavity, oropharynx, hypopharynx, larynx, oesophagus, and lung squamous cell carcinomas in which the incidence decreased similarly in time and space; (2) other types of lung cancer and lung adenocarcinomas whose incidence increased similarly; and (3) lung large- and small-cell carcinomas whose incidence trends were heterogeneous.
Conclusion: Using the tools of descriptive epidemiology different cancer groups with different temporal and spatial incidence trends were identified. This diversity suggests different latencies and different sensitivities of those groups to the main risk factors, alcohol and tobacco.
(Copyright © 2010 SPLF. Published by Elsevier Masson SAS. All rights reserved.)