Prognostic factors of papillary and follicular thyroid cancer: differences in an iodine-replete endemic goiter region.

Abstract

Papillary (PTC) and follicular thyroid carcinoma (FTC) are known as differentiated thyroid carcinoma (DTC). Nevertheless, according to the UICC/AJCC (TNM) classification PTC and FTC are frequently analyzed as one cancer. The aim of this study is to show differences in outcome and specific prognostic factors in an iodine-replete endemic goiter region.Six hundred and three patients with DTC treated within a 35-year-period were retrospectively analyzed with respect to carcinoma-specific survival. Prognostic factors were tested for their significance using univariate and multivariate analysis.The histological type (PTC versus FTC) was found to be a highly significant factor -carcinomaspecific survival both in univariate ðP < 0:001Þ and multivariate analyses ðP ¼ 0:003Þ was significantly different. Univariate analysis revealed patients' age, extra-thyroid tumor spread, lymph node and distant metastases, increasing tumor size, and the tall cell variant to be significant prognostic factors for PTC patients. Age !45 years, positive lymph nodes and increasing tumor size were confirmed as independent prognostic factors. Univariate analysis of FTC patients revealed age at presentation, gender, extrathyroidal tumor spread, lymph node and distant metastases, increasing tumor size, multifocality, widely invasive tumor growth and oxyphilic variant to be factors bearing prognostic significance. The presence of distant metastases and increasing tumor size could be identified as independent prognostic factors for FTC patients.This study shows distinctive differences in prognostic factors of PTC and FTC: independent factors predicting poor prognosis are age !45 years, positive lymph nodes and increasing tumor size for PTC, and distant metastases and increasing tumor size for FTC. PTC and FTC patients should be analyzed and reported separately.

Staging systems for follicular thyroid carcinoma: application to 171 consecutive patients treated in a tertiary referral centre

“…(2007) 14 29-42 www.endocrinology-journals.org separately for PTC and FTC. As shown in previous studies, there were potential biases if PTC and FTC were not reported separately because of the relative dominance of PTC in DTC (Mazzaferri & Jhiang 1994, Chow et al 2002, Passler et al 2004, Machens et al 2005, Lang et al 2007a. Only the AIM, Clinical Class, NTCTCS and 6th edition TNM systems reported 5-year actuarial survival data separately for FTC.…”

“…Perhaps, this may be because the number of FTC accumulated within a single institution is relatively fewer than that of PTC. This may also be the reason why despite the distinct differences between PTC and FTC as shown in previous studies (Mazzaferri & Jhiang 1994, Chow et al 2002, Passler et al 2004, Besic et al 2005, Machens et al 2005, Lang et al 2007a, the majority of the presently available staging systems including the 6th edition TNM system still make no distinction in staging between PTC and FTC.…”

“…In AMES,OSU, GAMES, Munster, UAB&MDA and Ankara, the survival outcome of DTC were reported collectively as a group. Again, this made comparison difficult and confusing because PTC and FTC exhibited different clinical behaviour and outcome (Mazzaferri & Jhiang 1994, Chow et al 2002, Passler et al 2004, Machens et al 2005, Lang et al 2007a Apart from this, some systems such as AMES, Clinical Class, OSU and Munster only reported cancer-related mortality rate instead of the preferred actuarial CSS. This made it difficult for direct comparison because mortality rate depends on the length of follow-up.…”

Latin American Thyroid Society recommendations for the management of thyroid nodules

“…Also, a progressive increase in recurrence and causespecific death rates has been reported in patients with malignant lesions progressing in size from < 1 cm to 1-4 cm and > 4 cm (8,9). Rossi and cols.…”

Prognostic factors of minimally invasive follicular thyroid carcinoma: Extensive vascular invasion significantly affects patient prognosis

“…Previous studies showed that widely invasive FTC displays a significantly poorer prognosis than minimally invasive FTC [4,5]. To date, other conventional prognostic factors of FTC such as distant metastasis at diagnosis (M1), old age, and large tumor size have also been identified [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. However, prognostic factors of minimally invasive FTC have not been intensively investigated and, to our knowledge, only one manuscript has been published for a large series of patients [23].…”