Incidence of thyroid cancer: can we assume its increase only based on over diagnosis?

M. RUSSO PICASSO, ; VICENS JIMENA; GIMENEZ GIULIANI C.; JAEN A.; CABEZON C.; FIGARI MARCELO; GOMEZ SALDAÑO ANA MARIA; FIGAR SILVANA

Boston

Congreso; 3rd World Congress on Thyroid Cancer. Boston, Massachusetts; 2017

AECAT (Asociación española de cáncer de tiroides)

Background: Thyroid cancer is the most common endocrine cancer, and has increased its incidence worldwide in the past 20 years. Two hypotheses attempt to explain this rapid increase: over diagnosis of small, clinically irrelevant disease by excessive diagnostic scrutiny, or a true increase in new cases brought about by environmental factors. Objective: To compare the epidemiological profile of thyroid cancer (TC) along two time frames in a private University Hospital in the city of Buenos Aires, oriented to understand the phenomenon of increased incidence reported in the last decades. Methods: Retrospective cohort study, identifying incident cases of TC from the pathological report of patients in the Hospital health system. Clinical records were reviewed recording patients and tumor characteristics. The results were analyzed in periods: 2003-2007 and 2008-2012. A descriptive and analytical analysis was performed comparing periods (significance level 0.05). Incidence rates adjusted for each 100,000 person-years (with 95% CIs) and relative risk of incidence rates of incidental and non-incidental CT were estimated. Results: We diagnosed 189 patients with TC treated in 2003-2012. The mean age (57 years, ±15) and the percentage of women (83.6%) were similar in both periods. The tumor mean size was significantly lower in the most recent period (10 vs 14 mm, p