A. R. Marcadis1, S. Liu1, M. Rodriguez1, J. I. Lew1 1University Of Miami Miller School Of Medicine,Division Of Endocrine Surgery,Miami, FL, USA
Introduction: Thyroid malignancy is the most common endocrine cancer in the United States. Papillary thyroid cancer (PTC) is the most common form, comprising 85% of all thyroid cancers. Although most PTC occurs sporadically, about 5% may be familial in origin. Furthermore, family history has shown to be an influential risk factor for papillary thyroid cancer (PTC). Whether these familial forms of PTC are more aggressive than its sporadic form, however, remains unclear. This study determines if patients with a family history of thyroid cancer harbor more aggressive variants of PTC than patients without a positive family history.
Methods: A retrospective review of prospectively collected data of 1822 consecutive patients who underwent thyroidectomy at a single institution was performed. Patients with malignancies other than PTC were excluded from the study (n=447). Remaining patients were divided into 2 groups: those patients who had a history of PTC in first degree relatives (n=39), and those who did not (n=1336). Patients with PTC on final pathology were further subdivided into those with less aggressive (classic and follicular), and those with more aggressive (diffuse sclerosing and tall cell) variants of PTC. A two tailed Z test at a significance level of 0.05 was used to compare both groups.
Results: Of the 1375 patients included, 3% (39/1375) of patients had a family history of PTC in first degree relatives. Of these patients with a positive family history, 54% (21/39) had PTC on final pathology whereas 28% (374/1336) of patients with no family history had PTC on final pathology. Patients with a family history of PTC had 21% (8/39) follicular, 10% (4/39) diffuse sclerosing, 10% (4/39) classic, 8% (3/39) combined follicular and classic, and 5% (2/39) tall cell variants of PTC. Patients with no familial history of PTC had 19% (257/1336) follicular, 4% (55/1336) classic, 2% (25/1336) both classic and follicular, 1% (9/1336) both diffuse sclerosing and tall cell, 1% (10/1336) tall cell only, and 1% (18/1336) diffuse sclerosing only variants of PTC. Of those patients with a positive family history, there was a significantly increased incidence of more aggressive variants (diffuse sclerosing and tall cell) of PTC at 15% (6/39) compared to those patients with no family history of PTC at 3% (37/1336) (p<0.05).
Conclusion: Patients with a positive family history of PTC have a significantly higher incidence of more aggressive PTC variants. Any positive PTC family history, therefore, should be considered a risk factor for more aggressive disease that may necessitate earlier recognition and treatment for PTC in these patients and their affected family members.