Therapeutic Outcome of Second Primary Malignancies in Patients with Well-Differentiated Thyroid Cancer.
Background. The aims of this study were to analyze the clinical characteristics of SPM in patients with well-differentiated thyroid cancer and to determine the long-term prognosis in patients with double malignancies. Materials and Methods. We retrospectively analyzed 2,864 patients with well-differentiated thyroid cancer and a mean age of 44.0 ± 14.4 years. Of these, 200 (7.0%) were diagnosed with SPM, 115 of which were diagnosed with metachronous SPM. Results. Of 2,864 patients, 163 (5.7%) patients died of thyroid cancer and 301 (10.5%) died of any cause by the end of the follow-up period. Multivariate analysis identified age, SPM, external radiotherapy, TNM stage, and postoperative serum Tg level to be factors independently associated with decreased survival. Of 200 patients with SPM, 74 (37.0%) died. In comparison to the anachronous and synchronous groups, the metachronous SPM group had a higher mean age; more advanced tumor, node, and metastasis stage; lower remission rate; higher postoperative radioactive iodide ((131)I) accumulated dose; a higher proportion of patients who underwent external radiotherapy; and higher thyroid cancer and total mortality rates. Conclusions. Patients with well-differentiated thyroid carcinoma and metachronous SPM had worse prognoses compared to patients without SPM.
Division of Endocrinology and Metabolism, Department of Internal Medicine, Chang Gung Memorial Hospital, Chang Gung University, No. 5, Fu-Shin Street, Guishan District, Taoyuan 333, Taiwan.
Miaw-Jene
MJ
Liou
Department of Radiation Oncology, Chang Gung Memorial Hospital, Chang Gung University, No. 5, Fu-Shin Street, Guishan District, Taoyuan 333, Taiwan.
Ngan-Ming
NM
Tsang
Department of Pathology, Chang Gung Memorial Hospital, Chang Gung University, No. 5, Fu-Shin Street, Guishan District, Taoyuan 333, Taiwan.
Chuen
C
Hsueh
Department of General Surgery, Chang Gung Memorial Hospital, Chang Gung University, No. 5, Fu-Shin Street, Guishan District, Taoyuan 333, Taiwan.
Tzu-Chieh
TC
Chao
Division of Endocrinology and Metabolism, Department of Internal Medicine, Chang Gung Memorial Hospital, Chang Gung University, No. 5, Fu-Shin Street, Guishan District, Taoyuan 333, Taiwan.
Jen-Der
JD
Lin