Incidence, clinical presentation and outcome of differentiated thyroid cancer in young patients aged 10--24 years living in the French Rhone-Alpes region
Genevieve Sassolas1, Zakia Nejjari1, Nicole Berger2, Claire Berger3, Claire Bournaud1, Jean-Louis Peix4 & Francoise Borson-Chazot1
Differentiated thyroid cancer is rare in children and adolescents. An aggressive clinical presentation, together with a high rate of recurrences contrasting with low mortality, has been reported, especially, before the age of 15 years. Data are mainly issued from historical series from hospital databases.
The aim of the study was to analyze, from a population-based registry, the clinical presentation and outcome of differentiated thyroid cancer in young subjects.
From the population-based thyroid cancer registry of the French Rhone-Alpes region, 252 cases of incident histologically proven thyroid cancers have been recorded from 1998 to 2006, They were 38 children (1014 years), 81 adolescents (1519 years) and 133 young adults (2024 years), leading to the following annual incidence rates: 0.44 and 0.92/100 000 in children, 0.81 and 3.03/100 000 in adolescents, 2.31 and 6.54/100 000 in young adults, respectively in males and females.
Of 87% were papillary cancers, with an equal proportion of classical and follicular variants. According to pTNM grading, 30% of children and adolescent and 19% of adults presented with large and/or invasive cancers (pT3). Metastatic lymph nodes were present in 40% of the children, 30% of the adolescent and adults. Microcancers, discovered in goiters, were found in 14% of the whole series. The median follow-up was 4 years. At the last visit, persistent disease was more frequently observed in patients with initial lymph node involvement than in patients without (26 vs 8.5%; P<0.01). Remission rates were 85%, comparable between the three age groups. Secondary cervical lymph nodes resection performed in 6.4% of patients led to a remission in 1/4.
In conclusion, prognosis of thyroid cancer in children has improved, clinical presentation remains aggressive but the remission rate is comparable to that observed in young people from other age-groups.