Endocrine Abstracts

There is a specific unit specialised in treating differentiated thyroid cancer (DTC) at the Endocrinology Department from a hospital the southwest of Spain that attends patients from two different provinces. Owing to environmental pollution, one of them has higher incidence of cancer.

To evaluate the changes in the clinical presentation of DTC over time and analyse possible differences between patients from the two provinces, we designed a descriptive retrospective study, including all DTC cases admitted from January 1970 to March 2014. Quantitative variables are expressed as median (interquartile range). All the results were standardized using specific population records from the National Institute for Statistics for each time period.

Results: Total population 1289 (255 males/1034 females). Age at diagnosis: 43 years (33–55); 82.2% were papillary thyroid cancer (PTC) while 17.5% were follicular thyroid cancer (FTC). We found a progressive increase in PTC since 1970, more marked from 1996 to the present in both sexes (mainly between 21 and 65 years at diagnosis), in tumours >1 cm (T1b-T4), as well as papillary microcarcinoma, following the same trend. A similar pattern was observed in FTC. There were no differences regarding unfavourable histological subtypes. In the 1970’s, PTC and FTC tended to be >4 cm and/or with extrathyroid extension, N1 and M1, in comparison with the current presentation (<4 cm, limited to the thyroid and N0 M0). In patients from the most polluted province we detected a non-significant slightly higher percentage of high-risk tumours (8.85% vs 7.55%) without any other differences.

Conclusion: DTC clinical presentation has shifted from high-risk tumours at diagnosis (1970’s and 1980’s) to a low-risk profile (T1-3, N0, and M0) in the last years, with a steadily increase in the number of cases per year, mainly PTC. Men have a tendency to have higher risk tumours than women.