Male sex and tumor diameter are independent risk factors for relapse or persistent disease in differentiated thyroid cancer

Background. Differentiated thyroid cancer (DTC) is one of the most frequently observed neoplasms today. Recurrence of DTC has been previously reported to be dependent on tumor characteristics, the tumor size, the presence of lymph node metastasis, the presence of extra thyroid invasion, the presence of distant metastasis, oncogenes such as B-RAF proto-oncogene, advanced age and male sex. However, many studies have failed to associate many of these data with relapse. In this study, we aimed to evaluate the relationship between some histopathological and morphological findings with thyroid cancer relapse or persistent disease in a cohort of 393 DTC patients. Methods. We retrospectively analyzed 393 subjects with DTC, diagnosed in our institution between January 2000 and December 2010. Results. Histopathological analysis indicated papillary carcinoma in 362 (92.1%) subjects and follicular carcinoma in 31 (7.9%) subjects. Eighty-two (20.9%) of the subjects relapsed or had persistent disease. Male subjects had a higher trend for relapse (RR 1.739 %95 CI: 1.059-2.856) p=0.029). 18.8% of female subjects relapsed or had persistent disease, whereas the relapse rate was 30.4% in male subjects. Every 1 cm increase in tumor size increased the risk of relapse by 25% (RR=1.25, 95% CI: 1.11-1.41, p