Thyroid cancers in Ibadan, Nigeria

Recent reviews of thyroid malignancies indicate an increasing incidence with suggestions that incidence and regional variation in histological types may be related to socioeconomic and environmental factors. We studied 137 cases of thyroid cancer occurring in the University College Hospital, Ibadan over a 20-year period (1965-1984), consisting of 45 males and 92 females. The ages ranged from 8-85 years with a mean age of 40 years. Papillary carcinoma constituted 45.3% cases, whilst follicular carcinoma made up 44.5% with a frequency ratio of 1:1. Seven cases (5%) of medullary carcinoma were seen and these had a male/female ratio of 1.3:1 with an average age of occurrence of 34 years. In contrast to previous studies from this environment, there is a suggestion of an increasing trend in the incidence of papillary carcinoma in our centre. The significance of changing socio-economic and environmental factors in the region are highlighted.