Comparative analysis of thyroid carcinomas in Kingston and St Andrew, Jamaica, between two consecutive 15-year periods.

OBJECTIVE: To compare the distribution of histological subtypes of thyroid cancer in Kingston and St Andrew (KSA), Jamaica, within two consecutive 15-year periods. METHODS: We extracted all cases of thyroid carcinoma archived in the Jamaica Cancer Registry files over the 30-year period from 1978 to 2007. The cases were separated into two groups: 1978-1992 (Group I) and 1993-2007 (Group II). We analysed age, gender and histological subtype distribution within each group, and then made comparative analyses between the two periods. RESULTS: There were 311 cases in which the histological subtype was documented. The patients ranged in age from 12 to 94 years, with male to female ratios of 1:4.2 (group I) and 1:5.6 (group II). The highest frequencies of cases occurred in patients between the ages of 20 and 59 years. The commonest histological subtype in group I was follicular (52.7%); in group II, it was papillary (60%), followed by follicular (26.7%) and medullary (6.7%). There was an overall 263% increase in the papillary to follicular cancer ratio from group I (0.62) to group II (2.25). The increase in papillary carcinomas was statistically significant (p < 0.001) overall, and in patients less than 50 years of age (p < 0.001). CONCLUSION: The recent KSA thyroid cancer data show a histological profile similar to that described globally, with papillary carcinomas being commonest, followed by follicular and then medullary. The significant increase in papillary cancer frequency in KSA is most likely the result of gradual recognition of the entity follicular variant of papillary cancer