OBJECTIVES We analyze survival in thyroid cancer from Denmark (DK), Finland (FI), Norway (NO), and Sweden (SE) over a 50-year period (1971-2020), and additionally consider concomitant changes in incidence and mortality. DESIGN Population-based survival study. METHODS Relative 1-, 5/1 (conditional)-, and 5-year survival data were obtained from the NORDCAN database for years 1971-2020. Incidence and mortality rates were also assessed. RESULTS A novel consistent observation was that 1-year survival was worse than 5/1-year survival but the difference between these decreased with time. Relative 1-year survival in thyroid cancer (mean for the 4 countries) reached 92.7% for men and 95.6% for women; 5-year survival reached 88.0% for men and 93.7% for women. Survival increased most for DK which started at a low level and reached the best survival at the end. Male and female incidence rates for thyroid cancer increased 3- and 4-fold, respectively. In the same time, mortality halved for men and for women, it decreased by 2/3. CONCLUSIONS We documented worse relative survival in the first year than in the 4 subsequent years, most likely because of rare anaplastic cancer. Overall survival in thyroid cancer patients increased in the Nordic countries in the course of 50 years; 5-year survival was close to 90% for men and close to 95% for women. Even though overdiagnosis may explain some of 5-year survival increase, it is unlikely to influence the substantial increase in 1-year survival. The unmet need is to increase 1-year survival by diagnosing and treating aggressive tumors before metastatic spread.

中文翻译：

---

半个世纪以来，早期死亡严重阻碍了甲状腺癌生存率的提高。

目的 我们分析了丹麦 (DK)、芬兰 (FI)、挪威 (NO) 和瑞典 (SE) 50 年期间（1971-2020）甲状腺癌的生存情况，并另外考虑了发病率和死亡率的伴随变化。设计基于人群的生存研究。方法 从 NORDCAN 数据库获取 1971-2020 年的相对 1 年、5/1（条件）和 5 年生存数据。还评估了发病率和死亡率。结果 一项新的一致观察结果是，1 年生存率低于 5/1 年生存率，但两者之间的差异随着时间的推移而减小。甲状腺癌的相对 1 年生存率（4 个国家的平均值）男性达到 92.7%，女性达到 95.6%；男性5年生存率为88.0%，女性为93.7%。生存率增加最多的是DK，从低水平开始，到最后达到最好的生存率。男性和女性甲状腺癌的发病率分别增加了 3 倍和 4 倍。与此同时，男性死亡率减半，女性死亡率下降 2/3。结论 我们记录了第一年的相对生存率低于随后 4 年的相对生存率，很可能是由于罕见的间变性癌症。50 年来，北欧国家甲状腺癌患者的总生存率有所提高；男性的 5 年生存率接近 90%，女性的 5 年生存率接近 95%。尽管过度诊断可以解释部分 5 年生存率的增加，但它不太可能影响 1 年生存率的大幅增加。未满足的需求是通过在转移扩散之前诊断和治疗侵袭性肿瘤来提高一年生存率。