(HealthDay News) – Family history of thyroid cancer in a first-degree relative may be associated with an increased risk of sporadic differentiated thyroid carcinoma (DTC), according to a study published in the March 1 issue of Cancer.
Li Xu, PhD, from the University of Texas M.D. Anderson Cancer Center in Houston, and colleagues investigated the correlation between sporadic DTC and family history of cancer in a hospital-based study. A questionnaire was completed by 288 patients with sporadic DTC, and 591 cancer-free controls, to estimate the DTC risk.
The researchers found that family history of thyroid cancer in a first-degree relative correlated with an elevated DTC risk (adjusted odds ratio [OR], 4.1). In patients with a first-degree relative with thyroid cancer, all DTC cases were papillary thyroid carcinoma (PTC; adjusted OR, 4.6). In individuals with a family history of thyroid cancer among siblings, the risk of PTC was highest (OR, 7.4). Among PTC patients with first-degree family history of thyroid cancer, multifocal primary tumor was more common than in those with no first-degree family history (68.8 vs. 35.5%; P=0.01).
“Here we provide evidence suggesting that family history of thyroid cancer in first-degree relatives is associated with a significant increase in sporadic PTC risk and that risk is greater for people whose siblings were diagnosed with thyroid cancer. Such results should be interpreted with caution, and confirmation by larger prospective studies is warranted,” the authors write.