Hyperthyroidism and Thyroid Cancer in the Congolese Hospital Setting

Background: Hyperthyroidism was long considered a protective factor for the development of thyroid cancer. The association between hyperactive thyroid and cancer was rare. More recent studies have highlighted an association between hyperthyroidism and development of cancers, especially thyroid cancer. Given the lack of publication on the association of hyperthyroidism and thyroid cancer in the Democratic Republic of Congo (DRC), the present study was carried out to confirm the existence of this association in Congolese hospitals. Methods: This is a retrospective and descriptive study, which involved 106 cases of thyroid cancer recorded in the anatomopathology registers of four laboratories in the city of Kinshasa between 2005 and 2019. The p-value <0.05 was considered as the threshold of statistical significance. Results: Out of 106 cases of thyroid cancer, the association of hyperthyroidism and thyroid cancer was found in 5 cases (4.7%) (3.6% for women vs. 9% for men). The mean age of patients with this association was 51 ± 11 years. Papillary carcinoma (two cases), follicular carcinoma (two cases) and lymphoma (one case) were the types of cancer encountered. Etiologically, toxic multinodular goiter (four cases: 80%) and toxic adenoma (one case: 2%) were found. Conclusion: There is an association between hyperthyroidism and thyroid cancer in the Congolese hospital setting. There is a predominance of the female gender. There were an equal number of papillary and follicular carcinomas. With this study, we hope to encourage clinicians to thoroughly evaluate any suspicious nodule associated with hyperthyroidism.