In the Rhône Alpes region, that hosts more than 5.6 million inhabitants; thyroid illnesses are still rather common with 3,600 operations on the thyroid gland per year, comprising 650 incident cases of cancer. A progressive increase in the incidence of thyroid cancer was suspected in the 1990 s and a population based register was initiated. The collection consists of histological data validated and obtained directly from pathologists, surgical wards and controlled through hospital claims databases from care units. The register (19982004) comprises 3,800 cases, 77% were women. The incidence rates standardized for European and World populations were 5.97 and 4.89/100 000 for men, and 17.63 and 14.12/100 000 for women respectively. Most of these cancers were papillary (85%). pT1, pT2, pT3, pT4 states represented 51%, 25%, 17%, 6.4% respectively. This distribution varied in function of age groups with a higher proportion of pT2 in younger ages and of pT4 after 50 years. 14% had lymph nodes (N1a=11%, N1b=3%). A large proportion (37%) was microcancers, 52% of them having a diameter less than 0.5 cm. As a whole, the proportion of cancers incidentally discovered was 25%. The proportion of cancers discovered in goiters varied from 5% in the youngest group to 44% in the oldest one. Considering all goiters operated in our region, the mean proportion of cancers in this setting was 13%. The geographic distribution of incidence rates by canton showed a significant heterogeneity with higher rates in urban versus rural plus semi rural cantons, mainly for men. The influence of the density of general practioners, and of the geographic distribution of the incidence rates of benign thyroid pathologies that had led to surgery, is under study.
01 - 05 Apr 2006
European Society of Endocrinology