INTRODUCTION: Thyroid cancer (TC) is diagnosed in several histological types which differ in their clinical characteristics and survival. We aim to describe how they influence TC survival in Sweden. METHODS: Cancer data were obtained from the Swedish cancer registry between years 1999 and 2018, and these were used to analyze relative survival. RESULTS: Relative survival for all TC improved when analyzed in 10-year periods, and female survival improved more than male survival. Female survival advantage appeared to be present also for specific histological types, although case numbers were low for rare types. Female 5-year relative survival for TC was 100% for follicular, 95.1% for oncocytic, 93.4% for papillary, 89.7% for medullary, and 6.1% for anaplastic cancer. Among the clinical TNM classes, only T4 and M1 stages were associated with decreased survival compared to T1-3 and M0. Anaplastic cancer presented most often at high T and M1 stages, in contrast to other TC. Curiously, the diagnostic age for anaplastic M1 patients was lower than that for M0 patients. Both anaplastic and medullary cancers did not show age-dependent increases in the probability of metastases, in contrast to the main histological types. This could indicate the presence of several types of anaplastic and medullary cancers. CONCLUSION: The poor survival for anaplastic TC is an extreme contrast to the excellent survival of differentiated TC. As less than 20% of anaplastic cancer patients survived one year, urgent diagnosis and initiation of treatment are important. Facilitated treatment pathways have been instituted in Denmark resulting in improved survival. Anaplastic cancer should be a target of a major research focus.

• Keywords
• anaplastic cancer, metastasis, prognosis, relative survival, trends,
• Publication type
• Journal Article MeSH

BACKROUND: We wanted to characterize conditional survival in prostate cancer (PC) in Sweden around and after 2005 when the vast increase in incidence due to the opportunistic testing for prostate specific antigen (PSA) culminated. We hypothesize that analyzing survival data during that time period may help interpret survival trends. We focus on stage-specific analysis using conditional survival in order to define the periods when deaths most commonly occurred. METHODS: Data on PC patients were obtained from the Swedish cancer registry for analysis of 1-, 2.5- and 5-year relative survival and conditional relative survival between years 2004 and 2018. Tumor-node-metastatic stage classification at diagnosis was used to specify survival. RESULTS: Small improvements were observed in stage- and age-related relative survival duriring the study period. Applying conditional relative survival showed that survival in stage T3 up to 2.5 years was better than survival between years 2.5 and 5. Survival in stage T4 was approximately equal in the first and the subsequent 2.5-year period. For M1, the first 2.5 year survival period was worse than the subsequent one. The proportion of high risk and M1 disease in old patients (80+ years) remained very high and their survival improved only modestly. CONCLUSIONS: The data indicate that M1 metastases kill more patients in the first 2.5 years than between years 2.5 and 5 after diagnosis; T4 deaths are equal in the two periods, and in T3 mortality in the first 2.5-year period is lower than between years 2.5 and 5 after diagnosis. Conditional survival could be applied to explore critical survival periods even past 5 years after diagnoses and to monitor success in novel diagnostic and treatment practices. Improvement of survival in elderly patients may require clinical input.

• Keywords
• age, conditional relative survival, prognosis, stage, treatment,
• MeSH
• Survival Analysis MeSH
• Humans MeSH
• Survival Rate MeSH
• Prostatic Neoplasms * MeSH
• Prostate-Specific Antigen MeSH
• Registries MeSH
• Aged MeSH
• Neoplasm Staging MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Aged MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Sweden epidemiology   MeSH
• Names of Substances
• Prostate-Specific Antigen MeSH