Thyroid hormones and obesity in Nigerian women with breast cancer

Abstract

Background: Africans have breast cancer expressions different from Caucasians. Interactions between oestradiol (E2), adiposity and thyroid hormones in breast cancer development have been reported but controversial. The study was designed to investigate the relationships among thyroid hormones, E2 and adiposity in Nigerian pre and postmenopausal women with breast cancer (pre cases and post cases respectively). Methods: One hundred and sixty-nine non-pregnant women aged 48.3±1.3 years were recruited for this study. They comprised of 85 histologically confirmed breast cancer patients (pre-therapy) matched with 84 apparently healthy women without breast cancer (controls) according to age and menstrual phase. Anthropometry was obtained by standard methods. Blood (10ml) was obtained from participants for determination of free thyroxine (fT4), free triiodothyronine and thyroid stimulating hormone (TSH) by enzyme immunoassay (EIA). Data analysed by chi-square, students t-test and multiple regression were significant at p<0.05. Results: 16(29.63%), 18 (33.96%); 12 (22.22%), 4 (7.55%) pre cases and controls were overweight and obese respectively. 12 (38.71%), 15(48.39%); 8 (25.81%), 4 (12.90%) post cases and controls were overweight and obese respectively. The fT4, was significantly higher in pre and postmenopausal cases than controls (p<0.05). Only waist circumference had inverse relationships with TSH in both pre cases and post cases (â=-8.790, p=0.005). E2was elevated in post cases only (p<0.05) but had no relationship with any of the thyroid hormones in all groups. Conclusion: Altered adiposity and subclinical hyperthyroidism may be associated with breast cancer. Weight control and thyroid hormone testing may improve associated morbidity and mortality.