Primary Squamous Cell Carcinoma of Thyroid Gland: 11 Case Reports and a Population-based Study

Background: Primary squamous cell carcinoma of thyroid gland (PSCCT) is a highly aggressive malignant tumor associated with a poor prognosis. Due to the rare case, there is a knowledge gap on the features of PSCCT. There is limited understanding of the treatment and molecular biology of this tumor. More genomic work and relevant perspective work need to be done.

Methods: We retrospectively reviewed the medical information of patients with PSCCT diagnosed from December 2009 to December 2020 at The First Affiliated Hospital of Guangxi Medical University. In addition, we conducted an electronic search of the paper in CNKI, Wanfang, VIP, PubMed, Embase, Web of Science, and ProQuest databases by recently updated articles. Survival analysis was conducted using the Kaplan-Meier method.

Results: There were only 11 patients met the study's inclusion criteria in our institution. The patients ranged in age from 25 to 68 years old and female preponderance (M:F = 1:1.7). The median survival time was 6 months, and 1-year survival rate was 33.3%. Fifty-three patients' individual data from 45 articles were selected for analysis. The median age at diagnosis was 63 years and female preponderance (M:F = 1:2.5). The commonest complaint was the anterior neck mass (77.3%), followed by hoarseness (32.1%). The median survival time was 9 months, and the overall 1-, 2-, and 5-year survival rate was 39.8%, 33.7%, and 26.9%, respectively. The log-rank method shows that age, tumor size, lymph node status, M stage, surgical range, and tracheal status were the relevant factors affecting the prognosis. In contrast, gender, treatment modality, and resection margin were not prognostic factors. On multivariable analysis, age and M stage were associated with overall survival.

Conclusion: The median overall survival was 6-9 months of PSCCT. Age and M stage are predictors of PSSCT.