Abstract
Purpose: To investigate the association between lymph node (N) stage and clinical outcome in thyroid cancer patients with initial distant metastasis.Methods: A total of 3,198 cases (1,435 males and 1,763 females) between 2004 and 2015 with initial distant metastasis were obtained from the surveillance, epidemiology, and end results (SEER) database. Patients with a median follow up time of 13 months and a median age of 66 years were analyzed. A total of 1,407 cases had detailed information regarding the four most common metastatic organs after the year 2010. Kaplan-Meier (KM) analyses, log-rank tests, Cox regression, and logistic regression analyses were used.Results: Among the whole cohort, 33.4% (1,069/3,198), 14.5% (464/3,198), 10.1% (322/3,198), 34.2% (1,094/3,198), and 7.8% (249/3,198) of the patients were at the stage of N0, NX, N1a, N1b, and N1NOS (referring to metastasis to regional lymph nodes but not otherwise specified), respectively. The KM curves demonstrated that the patients at the NX stage had the worst survival. The NX and N1b groups had the highest hazard ratios (HRs) of 1.83 (95%CI 1.46-2.31) and 1.78 (95%CI 1.52-2.10) after adjusting age, race, gender, and tumor size (p < 0.001) compared with N0 group. The lung was the most common metastatic site, with a rate of 51.2% (720/1,407). Compared with the N0 group, N1 patients had higher odds (OR 1.63, 95%CI 1.31-2.01, p < 0.001) for lung metastasis. Similar results were obtained in papillary thyroid cancer (PTC) sub-cohort.Conclusions: Overall, the TC patients at the NX stage had the highest mortality risk, followed by N1b, N1a, and N0 groups. Compared with N0 patients, N1 patients were more likely to have lung metastasis. The poor prognosis for TC patients with the NX stage may make more aggressive treatment reasonable.
Highlights
The incidence of thyroid cancer (TC) has continued to rise in the United States over the last four decades [1], and TC was reported to be the fifth most common malignant tumor in women in 2018 [2]
The objective of this study is to investigate the prognosis of TC patients at the NX stage and to determine the association between N stages and distant metastasis in TC based on the surveillance, epidemiology, and end results (SEER) database
Data on TC patients were retrieved from the SEER database, which is maintained by the National Cancer Institute
Summary
The incidence of thyroid cancer (TC) has continued to rise in the United States over the last four decades [1], and TC was reported to be the fifth most common malignant tumor in women in 2018 [2]. Based on the recent data, the American Cancer Society has predicted that the number of new TC cases and deaths due to TC will become the sixth most common cause of malignant tumors for women in 2019 [3]. Among several variants of TC, papillary thyroid cancer (PTC) takes up 85-90% of all cases [4]. Anaplastic thyroid cancer (ATC) originates from follicular cells and is an aggressive, undifferentiated, and rapidly fatal tumor [6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
