Parity and Risk of Thyroid Cancer: a Population-Based Study in Lithuania

Analysis of the Association between Female Medical History and Thyroid Cancer in Women: A Cross-Sectional Study Using KoGES HEXA Data

The purpose of this study was to evaluate the association between female medical history and thyroid cancer. Methods: Data from the Korean Genome and Epidemiology Study were collected from 2004 to 2016. Among a total of 1303 participants with thyroid cancer and 106,602 control (non-thyroid cancer) participants, the odds ratios (ORs) with 95% confidence intervals (CIs) of hysterectomy, oophorectomy, use of oral contraceptives, and number of children were evaluated. Results: The adjusted OR of hysterectomy for thyroid cancer was 1.73 (95% CI = 1.48-2.01, p < 0.001) in the minimally adjusted model. The adjusted ORs for thyroid cancer were 1.89 (95% CI = 1.06-3.37, p = 0.031), 0.89 (95% CI = 0.83-0.94, p < 0.001), and 0.85 (95% CI = 0.73-0.99, p = 0.040) for bilateral oophorectomy, number of children, and use of oral contraceptives, respectively, in the fully adjusted model. In the subgroup analysis, the adjusted ORs of bilateral oophorectomy were significant in the younger age (OR = 3.62, 95% CI = 1.45-9.03, p = 0.006), while the number of children was significant in the older age (OR = 0.86, 95% CI = 0.80-0.93, p < 0.001). Conclusions: The ORs of hysterectomy and bilateral oophorectomy were significantly higher in the thyroid cancer group in the younger age group. The adjusted ORs of the number of children were significantly low in the older age group.

Changing patterns of thyroid cancer in different stages of Universal Salt Iodization in Peking Union Medical College Hospital, 1986-2018

Backgrounds

Iodine intake may be associated with increased thyroid cancer, but its effect varied from places to places. Universal salt iodization (USI) has been introduced in China from 1996 to 2012. The effects of increased iodine intake on thyroid cancer needs to be investigated in China.

Methods

From 1986 to 2018, patients who had thyroidectomies in Peking Union Medical College Hospital (PUMCH) were retrospectively studied. The detection rate, constituent ratio, mean age, sex distribution of thyroid cancer and the pattern of papillary thyroid microcarcinoma (PTMC) were compared between different historical periods.

Results

The detection rate of thyroid cancer in thyroid surgery significantly increased from 6.77% to 75.78% post-USI, with papillary thyroid cancer (PTC) being the majority, and that of follicular thyroid cancer (FTC) and medullary thyroid cancer (MTC) showed only minor changes. There was a descending trend of female/male ratio in PTC from 3.7 to 2.8, and a slight decrease of mean age observed in PTC after USI compared with during USI. The percentage of PTMC in PTC decreased from 13.99% to 8.64%, with a lower mean age after USI (44.88±10.37 vs. 46.44±10.42). Prevalence of goiter coexisting with PTMC was also lower after USI than during USI (31% vs. 41%).

Conclusions

With the popularization of iodized salt, PTC has become the major type in surgery for thyroid cancer, and trends in other histological subtypes remained mostly stable over the periods. The increase in PTC cannot be attributed to the increase of PTMC which is smaller than 1 cm, indicating that contributing factors other than diagnostic activities, may play a role in the increase of PTC.

Thyroid cancer: incidence and mortality trends in China, 2005-2015

PURPOSE

Understanding secular trends of thyroid cancer is critical to plan strategies for cancer prevention and control. Our aim was to estimate the incidence and mortality trends of thyroid cancer in China during 2005-2015.

METHODS

A retrospective cohort evaluation of thyroid cancer cases and deaths during 2005-2015 was performed using population-based data from the Chinese Cancer Registry Annual Report. The incidence and mortality rates of thyroid cancer were stratified by gender, age group (0, 1-4, 5-9, 10-14…80-84, 85-), and area (urban or rural). A Joinpoint regression model was used to examine secular trends.

RESULTS

In China, the age-standardized incidence was 3.21/10⁵ in 2005, and increased to 9.61/10⁵ in 2015. Besides, a significant increase incidence rate was observed with the average annual percent change (AAPC) of 12.4% (95% CI: 10.5%-14.4%) in the period 2005-2015. The age-standardized mortality was 0.30/10⁵ in 2005 and 0.35/10⁵ in 2015, and the AAPC was 2.9% (95% CI: 1.3%-4.5%). For both incidence and mortality, the rates of thyroid cancer were much higher in females than in males, and in urban areas rather than rural areas; however, the rates of increasing trends showed no significant differences. With respect to the highest age-specific rates, it appeared in the age group of 50-54 years old for incidence and in the age group of 80-84 years old for mortality. Notably, the rate of increasing incidence trend was lower in older age groups, especially for people aged 70-79 years old.

CONCLUSION

A rapid increase in incidence and a moderate increase in mortality of thyroid cancer were observed from 2005 to 2015 in our study. Effective measures and tailored programs should be taken to curb the growth trend and reduce the disease burden.