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

Abstract

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 metas‑ tasis, oncogenes such as B‑RAF proto‑oncogene, ad‑ vanced age and male sex. However, many studies have failed to associate many of these data with relapse. The objective of the study was to evaluate the re‑ lationship between some histopathological and mor‑ phological findings with thyroid cancer relapse or per‑ sistent 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 papil‑ lary 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 sub‑ jects 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<0.001). Male sex, nodule diameter, and tumor diameter were detected to be independent parameters for relapse or persistent disease (p=0.002; p<0.0001, p<0.001 respectively). Conclusion. We demonstrated that tumor diameter and male sex were the only parameters affecting re‑ lapse or persistent disease in our cohort. A possible reason for different reports from different studies may be non‑standardization of study protocols and surgical cure rates.