Number of tumor foci predicts prognosis in papillary thyroid cancer

Abstract

BackgroundPapillary thyroid cancer (PTC) often presents as multifocal. However, the association of multifocality with poor prognosis remains controversial. The aim of this retrospective study was to identify the characteristics of PTC with multiple foci and to evaluate the association between multifocality and prognosis.MethodsWe reviewed the medical records of 496 patients who underwent total thyroidectomy for PTC. Patients were classified as G1 (1 tumor focus), G2 (2 foci), and G3 (3 or more foci). We analyzed the clinicopathological features and clinical outcomes in each classification. A Cox regression model was used to assess the relationship between multifocality and recurrence or cancer mortality.ResultsThe G1, G2 and G3 groups included 287, 141 and 68 patients, respectively. The mean age was 47.1 ± 16.1 yr in G1, 41.1 ± 18.4 yr in G2, and 35.5 ± 15.9 yr in G3 and differed significantly among the 3 groups (p = 0.001). The proportion of extrathyroidal extension, central lymph node metastasis (CLNM), and lateral lymph node metastasis (LLNM) in the G1 to G3 groups increased with increasing number of tumor foci. The Kaplan–Meier curves revealed that G3 had the shortest recurrence-free survival, and differences were significant among the 3 groups (p = 0.001, Log Rank test). Furthermore, cancer-specific survival rates decreased significantly with increasing number of tumor foci (p = 0.041). Independent predictors of recurrence by multivariate Cox analysis included >3 tumor foci [HR 2.60, 95% confidence interval (CI) 1.53-4.39, p = 0.001] and extrathyroidal extension (HR 1.95, CI 1.12-3.38, p = 0.018).ConclusionAn increase in the number of tumors is associated with a tendency toward more aggressive features and predicts poor prognosis in PTC.

The impact of marital status at diagnosis on cancer survival in patients with differentiated thyroid cancer

“…Results from the Cox proportional hazards regression models identified and verified a series of risk predictors for mortality in DTC, including sex, age, and advanced stage, which were consistent with previous studies 19, 20. Then, we conducted subgroup analysis for the effects of marital status on survival in patients stratified by them.…”

Comparison of the clinicopathologic features of solitary and multifocal papillary thyroid carcinoma and the utility of testing an additional tumor nodule for BRAFV600E in multifocal cases

“…The increased proportion of follicular variant PTC in the solitary cases in our study may explain why these aggressive features were less frequent in this group. These findings allude to previous reports correlating multifocality with a more aggressive behavior [7,9,22,25]. Various endeavors to elucidate the origin and behavior of mPTC include both independent clonal origin of these tumors as well as intraglandular spread and subsequent clonal evolution to acquire a more aggressive phenotype [4,11,24,26].…”

“…Disease progression and recurrence have been associated with unfavorable pathologic features such as extrathyroidal extension, lymph node and distant metastasis, advanced pathologic stage (Stage III/IV), as well as the presence of BRAF V600E mutation [29,30]. There are also reports associating multifocality with a more aggressive behavior [9,25].…”

“…Except for those with discordant mutational status, the microcarcinomas were not further subtyped. Given there are reports associating multifocality with adverse prognosis [9,25], we recommend continued efforts towards elucidating the adverse features specific to multifocal cases, at both the histologic and molecular levels. Of note, all the cases of follicular variant papillary thyroid carcinoma were classified under the old nomenclature as reported in the original diagnosis.…”

The synergic effect of BRAF^V600E mutation and multifocality on central lymph node metastasis in unilateral papillary thyroid carcinoma

“…Certain studies have indicated that multifocal carcinoma in PTC is positively associated with the incidence of CLNM [14,15], while other studies have argued that there is no association between multifocality and CLNM [16]. In addition, multifocality has found to significantly increase the incidence of recurrence [17].…”