Hoonsung Choi, Jung Ah Lim, Hwa Young Ahn, Sun Wook Cho, Kyu Eun Lee, Kyung Won Kim, Ka Hee Yi, Myung-Whun Sung, Yeo-Kyu Youn, June-Key Chung, Young Joo Park, Do Joon Park, and Bo Youn Cho
With the recent increasing rates of screening for thyroid cancer, the cancers now tend to be smaller and less aggressive than those that are diagnosed when presented with symptoms, suggesting changes in the clinical validity of conventional prognostic factors for outcomes. We performed the retrospective study to identify the secular trends in the prognostic factors of thyroid cancer.
We used medical records of 3147 patients diagnosed with papillary thyroid cancer (PTC) at the Seoul National University Hospital Thyroid Cancer Clinic between 1962 and 2009.
During the median 5.1-year follow-up, the overall recurrence rate was 13.3%, and male sex, tumor size, lymph node (LN) involvement, and extrathyroidal extension (ETE) were the significant prognostic factors for recurrence. Thyroid cancer-specific mortality was 1.4%, and the associated prognostic factors were older age, male sex, and LN involvement. For tumor recurrence, the hazard ratio (HR) for male sex decreased from 2.809 (95% CI, 1.497–5.269) in the pre-1989 period to 1.142 (95% CI, 0.736–1.772) in the post-1999 period. The pathologic characteristics, such as tumor size, LN involvement, and ETE, showed similar or increasing HRs over the time periods. For cancer-specific mortality, the HR for male sex decreased from 6.460 (95% CI, 1.714–24.348) in the pre-1990 period to 0.781 (95% CI, 0.083–7.379) in the post-1999 period.
The risk for poor outcomes in PTC associated with male sex decreased over time; in contrast, the risk associated with pathologic characteristics remained the same or increased over time. These trends might be associated with recent changes in the characteristics of patients with thyroid cancer.
Young Shin Song, Jung Ah Lim, Hye Sook Min, Min Joo Kim, Hoon Sung Choi, Sun Wook Cho, Jae Hoon Moon, Ka Hee Yi, Do Joon Park, Bo Youn Cho, and Young Joo Park
Changes in the clinicopathological characteristics and genetic alterations of follicular thyroid cancer (FTC) over time have not been reported. Moreover, the prognostic effects of RAS and TERT promoter mutations in FTC have not been clearly elucidated. We investigated changes in the clinicopathological characteristics of patients with FTC over four decades, as well as the clinical significance of genetic mutations of FTC.
Design and methods
This retrospective study included 690 patients with FTC who underwent thyroidectomy between 1973 and 2015 at the Seoul National University Hospital. In 134 samples, genetic tests for N/H/KRAS and TERT promoter mutations and PAX8/PPARγ rearrangement were performed.
The age at diagnosis has increased (P < 0.001) in recent decades and extrathyroidal extension of the tumor has become less common (P = 0.033). Other clinicopathological characteristics and prognosis of FTC have not significantly changed. The prevalence of RAS mutations decreased (P = 0.042) over time, whereas that of TERT promoter mutations remained stable. RAS mutations were associated with distant metastasis and persistent disease, and TERT promoter mutations were associated with distant metastasis, advanced TNM stage, recurrence and disease-specific mortality. FTC patients with coexistent RAS and TERT promoter mutations showed a higher recurrence risk than those with only one mutation.
The age at diagnosis of FTC and the frequency of extrathyroidal extension have changed over four decades. Moreover, the prevalence of RAS mutations decreased. RAS and TERT promoter mutations may be associated with poor clinical outcomes in FTC, especially when the two mutations coexist.