Decreasing tumor size of thyroid cancer in Germany: institutional experience 1995-2009.
OBJECTIVE
Decreasing tumor size in a population over time is widely interpreted as a measure of effectiveness of cancer screening programs. Nonetheless, thyroid cancer size is rarely analyzed as a function of time. This study aimed to explore secular trends of thyroid cancer diameter in Germany.


METHODS
Retrospective analysis of 1644 thyroid cancer patients from a large referral center for thyroid cancer (1995-2009).


METHODS
Calculation of largest tumor diameters for each type of cancer as a function of time periods and birth cohorts.


RESULTS
Over the past 25 years, subdivided into 5-year periods by year of thyroidectomy (1985-1989; 1990-1994; 1995-1999; 2000-2004; 2005-2009), tumor diameters diminished from 25 to 16 mm (P=0.025) for medullary thyroid cancer and from 28 to 18 mm (P=0.017) for papillary thyroid cancer. This reduction was greater for hereditary medullary thyroid cancer (from 27 to 11 mm; P=0.088) than sporadic medullary thyroid cancer (from 23 to 19 mm; P=0.11). No decline was observed for follicular thyroid cancer (means of 45 to 42 mm; P=0.52). From the first (1921-1940) to the most recent birth cohort (1981-2000), tumor size fell from 22 to 10 mm (P<0.001) for medullary thyroid cancer, from 24 to 22 mm (P<0.001) for papillary thyroid cancer, and from 49 to 38 mm (P=0.011) for follicular thyroid cancer. The reduction of medullary thyroid cancers affected exclusively patients with hereditary disease (from 20 to 7 mm; P<0.001).


CONCLUSIONS
The consistency and robustness of these data signify powerful secular trends toward smaller papillary, follicular, and medullary thyroid cancers. The causes and consequences of these trends warrant further investigation.
Machens
Andreas
A
Department of General, Visceral and Vascular Surgery, Martin Luther University Halle-Wittenberg, Ernst-Grube-Strasse 40, D-06097 Halle, Saale, Germany. andreasmachens@aol.com
Dralle
Henning
H
D000328:Adult; D005260:Female; D005858:Germany; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy