OBJECTIVETo analyze the clinical and biological features of familial nonmedullary thyroid carcinoma (FNMTC).

METHODSClinical data of 66 FNMTC cases of 32 pedigrees was retrospectively analyzed, compared with that of 182 control cases taken randomly from the patients with sporadic papillary thyroid carcinoma (SPTC), who were diagnosed and treated in Tianjin Cancer Hospital between January 2008 and November 2012. The features of FNMTC of the first and second generations were objectively analyzed. Some data quoted from the literature were also used for the analysis.

RESULTSThe median age at diagnosis of all the 66 FNMTC patients was 44 years, and 57 (86.4%) were females. Moreover, 71.2% (47 patients, 23 pedigrees) of the FNMTC patients exhibited a sibling relationship, and 28.8% (19 patients, 9 pedigrees) of the FNMTC patients exhibited a parent-offspring relationship, and 9 cases in the first generation and 10 cases in the second generation. There were significant differences between the FNMTC group and SPTC group in terms of tumor multicentricity, tumor bilaterality, lymph node metastasis, central lymph node metastasis, concomitant chronic thyroiditis and recurrence (P < 0.05). Compared with SPTC, sibling FNMTC presented a higher rate of central lymph node metastasis, while parent-offspring FNMTC showed frequent tumor bilaterality and a higher rate of recurrence (P < 0.05). Besides, patients in the second generation were diagnosed at an earlier age and had a higher male rate, the tumors were more frequently multifocal and bilateral, and had a higher rate of lymph node metastasis.

CONCLUSIONSFNMTC may be more aggressive than SPTC and patients in the second generation may exhibit the "anticipation" phenomenon. It's necessary to make sufficient detailed interrogation and long-term follow-up of the patients and their family for providing individual recommendations for clinical management.