title: Analysis of clinical outcome of patients with poorly differentiated thyroid carcinoma.
abstract: Background. We retrospectively analyzed whether poor differentiation is the independent prognostic factor for thyroid carcinoma or not. Methods. The subjects were 29 patients with PDTC who were treated between April 1996 and March 2006 to compare with those of well-differentiated papillary carcinoma patients (n = 227). Results. The relapse free (RFS), distant relapse-free survival and cause-specific survival, rates were significantly lower in patients with PDTC (P < .0001, P < .001, and P < .05). After classification into focal (<10%) and diffuse type (over 10%) of PDTC, there were no significant differences in RFS and cause-specific survival due to component type or proportion of poorly differentiated component. On multivariate analysis, poor differentiation (P < .0005, RR = 4.456, 95% CI; 1.953-10.167) and extrathyroidal infiltration (P < .05, RR = 2.898, 95% CI; 1.278-6.572) showed a significant impact on DFS, and poor differentiation (P < .05, RR = 9.343, 1.314-66.453) and age (P < .005, RR = 1.306, 1.103-1.547) significantly impacted cause-specific survival. Conclusion. Poor differentiation was an independent factor for survival. Distant relapse was significantly more common among PDTC patients, and systemic therapy might be warranted.
authors.affiliation: Department of Breast and Thyroid Surgery, Kawasaki Medical School, 577 Matsushima, Kurashiki 701-0192, Japan.
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Tanaka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sonoo
authors.forename: Wataru
authors.initials: W
authors.lastname: Saito
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Ohta
authors.forename: Toshiro
authors.initials: T
authors.lastname: Shimo
authors.forename: Mai
authors.initials: M
authors.lastname: Sohda
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Junichi
authors.initials: J
authors.lastname: Kurebayashi