Prevalence of Hypothyroidism in Patients with Benign Breast Disease and Effect of Thyroxine Supplementation in Intractable Mastalgia-A Prospective Study at A Tertiary Care Centre

Introduction: Benign breast diseases (BBD) constitute a heterogeneous group of lesions including developmental abnormalities, inflammatory lesions, epithelial and stromal proliferation, and neoplasms. Benign breast lesions deserve attention because of their high prevalence accounting for 36% of all breast diseases, their impact on women's life and due to cancerous potential of some histological types.Materials and Methods: This is a prospective study conducted in the Department of General Surgery,JSS Hospital, Mysuru from January 2018-June 2019. Those patients with symptomatic benign breast disease who attended Surgical OPD were screened for their thyroid function. Among those, patients with intractable mastalgia and fibroadenosis with deranged thyroid function were started on low-dose thyroxine supplementation and were followed up at a regular interval of 2 months, for a total of 6 months. Results: In our study, the prevalence of hypothyroidism in BBD was found to be 36%.BBD symptoms were alleviated in 71% of the hypothyroid patients with only thyroxine replacement. The final clinical outcomes of hypothyroid patients with mastalgia were significantly better than that of their euthyroid counterparts (0.001); 3.22 % of patients with BBD were found to be in a hyperthyroid state, which was clinically insignificant. Conclusion: Given the significant prevalence of hypothyroidism in benign breast disease at our centre, it is to be made mandatory to screen all benign breast disease patients for thyroid function. However, further larger studies are required to throw light on whether bringing such patients to a euthyroid state by thyroxine supplementation can prevent mastectomy in intractable mastalgias and also can prevent a small number of benign breast lesions turning to malignancy. Also, further studies are needed to establish a causal relationship between thyroid supplementation and symptom regression