The mutation profile of differentiated thyroid cancer coexisting with undifferentiated anaplastic cancer resembles that of anaplastic thyroid cancer but not that of archetypal differentiated thyroid cancer

Clinicopathological features and prognostic factors analysis of multiple synchronous distinct subtypes of primary thyroid carcinoma

PURPOSE

To investigate the clinicopathological features, diagnosis, treatment, and prognosis of multiple synchronous distinct subtypes of primary thyroid carcinomas.

METHODS

The clinical data of 68 cases of synchronous carcinomas of the thyroid (STC) admitted to the Department of Thyroid Surgery in our hospital from January 2013 to December 2021 were reviewed. According to the pathological type, they were divided into the Synchronous differentiated and differentiated thyroid Carcinoma (SDDTC) group (42 cases), the Synchronous medullary and differentiated thyroid Carcinoma (SMDTC) group (18 cases), and the Synchronous Anaplastic and differentiated thyroid Carcinoma (SADTC)group (8 cases). The diagnosis, treatment, and survival of patients in each group were analyzed.

RESULTS

Women with coexisting thyroid cancer were predominant (59 cases). Most of the symptoms were found on physical examination (47.1%) and neck mass (45.6%). The median age of patients in the SDDTC group, SADTC group, and SMDTC group was 47.5 (28-74) years old, 68.5 (26-75) years old, and 56.5 (39-74) years old. The age of the SADTC group and SMDTC group was older than that of the SDDTC group (P = 0.04, P = 0.03), and the rate of lymph node metastasis in groups SADTC (62.5%) and SMDTC (55.6%) was higher than in group SDDTC (21.4%). The disease course time, tumor location, clinical stage, and mortality of the SADTC group were significantly different from those of the SDDTC group and SMDTC group (P < 0.05). The overall survival of patients with synchronous carcinomas of the thyroid was 6-105 months, and the median overall survival was 38.5 months. The tumor-free survival was 0-90 months, 19.1% of patients developed distant metastasis, 11.8% of patients had postoperative recurrence, as well as the survival rate was estimated 91.18%. Cox model multivariate analysis showed that cervical lateral lymph node metastasis and tumor stage III/IV were independent risk factors for progression-free survival(PFS). The comparison results of the survival curves showed that the overall survival (OS)of the patients in the SADTC group was significantly worse (P < 0.01), while there was no significant difference in the PFS of different pathological types (χ2 = 5.024, P = 0.081).The OS of different treatment methods was significantly different (P = 0.002), but there was no significant difference in OS between local recurrence and distant metastases with or without surgery (χ2 = 0.954, P = 0.329).

CONCLUSIONS

The STC has relatively unique clinical characteristics, and most patients can get a better prognosis after radical surgery. Pathological type, lateral cervical lymph node metastasis, tumor stage, and treatment are important factors which affect the prognosis of the disease. Since there are two distinct tumors with different aggressiveness, treatment options, and prognosis, individualized management is required.

Anaplastic Transformation of Differentiated Thyroid Carcinoma

OBJECTIVES

Anaplastic thyroid carcinoma (ATC) is a rare but highly aggressive form of thyroid cancer. Increasingly, patients with ATC present with concurrent foci of well-differentiated thyroid carcinoma (WDTC); however, the significance of these pathologic findings remains unclear. The objective of this study is to determine whether the presence of WDTC within anaplastic tumors is a prognosticator of survival.

METHODS

A retrospective cohort study of all cases of biopsy-proven ATC managed at a tertiary care academic medical center from 2002 to 2020 was performed. Mean age at diagnosis, median survival time, and locations of distant metastases were assessed. The impact of clinical markers such as presence of differentiation, demographic variables, and oncologic information on overall survival was also determined via univariate and multivariate analysis.

RESULTS

Forty-five patients were included in this study. The mean age at diagnosis was 69.1 years. Median survival time was 6.1 months after diagnosis. The most common location of distant metastases was the lung (40%). The presence of limited areas of WDTC in patients with predominantly anaplastic thyroid tumors was not significantly associated with improved outcomes (p = 0.509). Smaller tumor size and use of chemotherapy in ATC patients were significantly associated with prolonged survival (p = 0.026 and 0.010, respectively).

CONCLUSIONS

Clinical outcomes for ATC remain poor. The presence of foci of differentiation within anaplastic thyroid tumors does not appear to improve overall survival-the anaplastic component evidently drives outcomes. Further studies into novel therapies are needed to improve survival in ATC.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:437-442, 2023.