Geographical analysis of thyroid cancer in young people from northern England: evidence for a sustained excess in females in Cumbria

A geographical study of thyroid cancer incidence in north-west England following the Windscale nuclear reactor fire of 1957

The Windscale nuclear reactor fire at Sellafield, United Kingdom, in October 1957 led to an uncontrolled release of iodine-131 (radioactive half-life, 8 d) into the atmosphere. Contamination from the accident was most pronounced in the counties of Cumbria and Lancashire, north-west England. Radioiodine concentrates in the thyroid gland producing an excess risk of thyroid cancer, notably among those exposed as children, which persists into later life. For an initial investigation of thyroid cancer incidence in north-west England, data were obtained on cases of thyroid cancer among people born during 1929-1973 and diagnosed during 1974-2012 while resident in England, together with corresponding populations. Incidence rate ratios (IRRs), with Poisson 95% confidence intervals (CIs), compared thyroid cancer incidence rates in Cumbria and in Lancashire with those in the rest of England. For those aged  <20 years in 1958, a statistically significantly increased IRR was found for those diagnosed during 1974-2012 while living in Cumbria (IRR  =  1.29; 95% CI 1.09-1.52), but the equivalent IRR for Lancashire was marginally non-significantly decreased (IRR  =  0.91; 95% CI 0.80-1.04). This pattern of IRRs was also apparent for earlier births, and the significantly increased IRR in Cumbria extended to individuals born in 1959-1963, who would not have been exposed to iodine-131 from the Windscale accident. Moreover, significant overdispersion was present in the temporal distributions of the IRRs, so that Poisson CIs substantially underestimate statistical uncertainties. Consequently, although further investigations are required to properly understand the unusual patterns of thyroid cancer IRRs in Cumbria and Lancashire, the results of this preliminary study are not consistent with an effect of exposure to iodine-131 from the Windscale accident.

[Rising incidence of papillary thyroid carcinoma in Germany]

BACKGROUND

The incidence of thyroid cancer (TC), a rare malignancy, has strongly risen in recent decades. Possible causes of this rise include increasing diagnostic activity, nuclear tests after World War II, and the Chernobyl disaster.

AIM

This article presents the time trends of TC incidence between 2003 and 2008 in Germany according to histological tumor type and sex, and provides a description of TC incidence according to districts (Kreise) and sex in Germany.

METHODS

Data on persons newly diagnosed with thyroid cancer (ICD-10 code, C73) between 2003 and 2008 were obtained from the Center of Cancer Registry Data at the Robert Koch Institute. Official population and mortality data were used. Age-specific and age-standardized incidence rates (ASIR) were calculated according to sex and tumor histology.

RESULTS

Between 2003 and 2008, the ASIR of TC rose from 2.7 to 3.4 (men) and from 6.5 to 8.9 (women) per 100,000 per year. This rise can be almost completely attributed to the rising incidence of papillary TC. The steepest rise in frequency was observed in TNM-T1 tumors. A positive north-south gradient of TC incidence was found.

DISCUSSION

The cause of the marked rise of TC incidence in recent decades is unknown. The positive north-south gradient of the TC incidence may possibly be attributed in part to long-standing differences of iodine intake between different German regions.

CONCLUSION

An epidemiological study of the possible causes of the rising TC incidence and of the regional differences of TC incidence in Germany is recommended.

Recent trends in the incidence, geographical distribution, and survival from thyroid cancer in Wales, 1985-2010

BACKGROUND

Previous studies of thyroid cancer incidence in Wales have given varying results with suggestions of an excess of cases in geographic areas that were previously exposed to the radioactive fallout from the 1986 Chernobyl nuclear reactor incident. Our objective in this study was to provide an up-to-date comprehensive analysis of time trends in the incidence, geographical distribution, and survival from thyroid cancer in Wales.

METHODS

We identified thyroid cancer cases, registered from 1985 through 2010 in the Welsh Cancer Intelligence and Surveillance Unit (WCISU). Age standardized rates were determined from the European standard population. A Poisson regression model was fitted to assess temporal trends and rate ratios (RRs) and confidence intervals (CIs) were determined and compared across consecutive time periods: 1985-1997 and 1998-2010. Standardized incidence ratios were calculated for each of the 22 local authority areas. Relative survival and Kaplan-Meier curves were computed to analyze all cause and thyroid cancer-specific survival.

RESULTS

A total of 1747 thyroid cancer cases were registered from 1985 to 2010. Age standardized incidence rates were 2.8 and 1.2 per 100,000 population per year for females and males respectively. Incidence rates increased with time (RR 1.3 [CI 1.2-1.5], p < 0.001; 1998-2010 vs. 1985-1997). The incidence of papillary cancer increased progressively over the study period (RR 2.22 [CI 1.91-2.57], p < 0.001; 1998-2010 vs. 1985-1997), while rates for other (nonpapillary) histological subtypes remained static (RR 0.95 [CI 0.84-1.08], p = 0.45; 1998-2010 vs. 1985-1997). We identified two geographical areas of increased incidence, but the spatial distribution of cases was inconsistent with exposure to radioactive fallout. Five-year relative survival from all-cause mortality improved from 74.2 [CI 66.8-80.1] in 1985-1989 to 82.6 [CI 77.1-86.9] in 2000-2004, but remained poor for patients over the age of 65 years (p < 0.001, > 65 years vs. 15-64 years) and patients with anaplastic thyroid cancer (p < 0.001; anaplastic vs. other histological varieties).

CONCLUSIONS

The incidence of thyroid cancer has increased in Wales, predominantly due to an increase in papillary cancers. The current geographical distribution of cases does not support a radiation effect in the region. Survival has remained poor for patients over the age of 65 years and those with anaplastic carcinoma.

Increasing use of radioiodine in young people with thyrotoxicosis in Great Britain

OBJECTIVE

Radioiodine (RI) is an important therapeutic option in young patients with thyrotoxicosis. We wanted to determine whether RI is being used more frequently in this age group.

DESIGN

National survey of Great Britain (England, Wales and Scotland).

METHODS

Sixty-one medical physics departments were asked to provide the age and number of patients with thyrotoxicosis <21 years treated with RI (1990-2008). Information on the total number of RI treatments for thyrotoxicosis was also collected.

RESULTS

Forty-three departments (70%), with representation from 21 of the 25 most populous areas of Great Britain, provided data on 69,258 treatments. The number of treatments recorded on patients <21 years during this period was 560 (0.9%). The frequency of treatments in young people as a percentage of the total increased from 0.2% in 1990 to 1.5% in 2008 (P<0.001). When the 18 centres submitting at least 17 years of data were analysed, a similar pattern was observed. The maximum number of young people treated was greatest in 2008 (62) with a fall in the youngest age at which RI was administered from 18 years (1990) to 11 years (2008).

CONCLUSIONS

A rising proportion of patients with thyrotoxicosis receiving RI are in those <21 years. This is largely due to an increase in the number of young people treated with a reduction in the minimum age at RI administration. We suspect that European clinicians are becoming more comfortable with RI treatment in young people with thyrotoxicosis, although a changing incidence is a potential contributing factor.

Increasing incidence of thyroid cancer in Great Britain, 1976-2005: age-period-cohort analysis

Increases in the incidence of thyroid cancer have been previously reported. The purpose of the present study was to examine temporal trends in the incidence of primary thyroid cancer diagnosed in 0-49 year olds in parts of Great Britain during 1976-2005. Data on 4,337 cases of thyroid cancer were obtained from regional cancer registries. Age-standardized incidence rates (ASRs) were calculated. Negative binomial regression was used to examine effects of age, sex, drift (linear trend), non-linear period and non-linear cohort. The best fitting negative binomial regression model included age (P < 0.001), sex (P < 0.001) and drift (P < 0.001). Non-linear period (P = 0.648) and non-linear cohort (P = 0.788) were not statistically significant. For males aged 0-14, the ASR increased from 0.2 per million persons per year in 1976-1986 to 0.6 in 1997-2005. For males aged 15-29 and 30-49 the ASRs increased from 1.9 to 3.3 and from 7.4 to 12.7, respectively. For females aged 0-14, the corresponding ASR increased from 0.3 to 0.5. For females aged 15-29 and 30-49 the ASRs increased from 6.9 to 12.4 and from 21.2 to 42.3, respectively. For all age groups, there has been a linear increase in incidence of thyroid cancer, which has led to a doubling of the number of cases diagnosed over a twenty year span. The reasons for this increase are not well understood, but it is consistent with findings from other countries.

Changes in the incidence of thyroid cancer between 1991 and 2005 in Italy: a geographical analysis

BACKGROUND

The incidence of thyroid cancer (TC) has been increasing over the last 30 years in several countries, with some of the worldwide highest TC incidence rates (IRs) reported in Italy. The objectives of this study were to evaluate by histological subtypes the geographical heterogeneity of the incidence of TC in Italy and to analyze recent time trends for papillary thyroid carcinoma (PTC) in different cancer registries (CRs).

METHODS

The study included cases of TC (<85 years of age) reported to 25 Italian CRs between 1991 and 2005. Age-standardized IRs were computed for all histological subtypes of TC according to CRs. Estimated annual percent change and joinpoint regression analysis were used for analysis of PTC.

RESULTS

In women, IRs of PTC ranged between 3.5/100,000 in Latina and 8.5/100,000 in Sassari for the period 1991-1995 (a 2.4-fold difference) and between 7.3/100,000 in Alto Adige and 37.5/100,000 in Ferrara for 2001-2005 (a 5.1-fold difference). In men, IRs ranged between 0.7/100,000 in Latina and 3.4/100,000 in Sassari for the period 1991-1995 (a 4.9-fold difference) and between 2.0/100,000 (Alto Adige, Trento) and 10.6/100,000 in Ferrara for 2001-2005 (a 5.3-fold difference). In both sexes, IRs significantly higher than the pooled estimates emerged for the most recent period in the majority of CRs located within the Po River plain and in Latina, but they were lower in the Alpine belt. For women, CRs reported higher IRs than pool estimates showed, between 1991 to 2005, a significantly more marked annual percent change (+12%) than other CRs (+7%). For men the corresponding estimates were +11% and +8%.

CONCLUSIONS

The distribution of PTC does not lend support to a role of environmental radiation exposure due to the Chernobyl fallout, iodine deficiency, or (volcanic) soils. Between 1991 and 2005, wide geographic variations in the incidence of PTC and heterogeneous upward trends emerged, suggesting that the heterogeneity was a relatively recent phenomenon; this appeared to be mainly explained by variations, at a local level, in medical surveillance.

Increasing incidence of differentiated thyroid cancer in South East England: 1987-2006

There has been a worldwide increase in the incidence of thyroid cancer (TC). Documenting these recent trends is of immense value to cancer control measures, monitoring policies, improving clinical outcomes, resource allocation and stimulating research. Hence this study aimed to analyse the changes in incidence, staging and morphologic types of TC in South East England (1987-2006) by means of a retrospective, descriptive epidemiological study using anonymized data obtained from the Thames Cancer Registry (TCR) of all patients registered with TC in the period 1987-2006. Ethical approval was obtained from the Kent Research Ethics Committee. 4,880 anonymized datasets using the ICD-10 code for thyroid cancer (C73) were analyzed using SPSS v.17. TC was commoner amongst females 3,560 (73%) than males 1,320 (27%) with a 2.7:1 ratio. Mean age at diagnosis was 53 years (Range 5-99) years. An increasing incidence trend was observed in early stage disease (p < 0.001), in young adults aged ≤ 49 years (p < 0.001) and in well-differentiated TC (papillary p < 0.001 and follicular p = 0.03). The results showed that TC is commoner in females than males in SE England with a 2.7:1 ratio. The results also indicate that TC incidence has increased in SE England over the 20 years studied, with the greatest increase occurring in early stage disease, in females, young adults and well-differentiated types (papillary and follicular). This may be due to widespread usage of ultrasound with detection of incidental nodules. Further studies are required to explain the trend.

Neck nodule and thyroid cancer in young without radiation exposure history

PURPOSE

The aim of this study was to analyze the results of histopathological studies in neck masses observed in young patients. The neck masses were detected using ultrasonography and fine-needle aspiration cytology (FNAC).

METHODS

In this retrospective study, we analyzed 234 young patients who were surgically treated for neck masses at Chang Gung Medical Center in Linkou. The mean age of the 234 young patients was 16.3 +/- 4.0 years (range 1-20 years). Neck ultrasonography studies were conducted using a real-time ultrasonographic machine and a 10 MHz transducer. FNAC was performed for the suspected neck nodules.

RESULTS

Of the 234 cases, 187 (79.9%) were surgically confirmed to be benign lesions, including four cases that were diagnosed as atypical adenoma. Malignant thyroid masses were identified in 47 patients. Surgery confirmed 22 cases to be lesions that were non-thyroid in origin, including those developing from a cyst, soft tissue, and with a lymphatic origin. Diagnostic accuracies of the FNAC and frozen section examination were found to be 91.1 and 97.7%, respectively.

CONCLUSIONS

In the study population, 20.1% of the neck masses were malignant. Except in cases of follicular thyroid neoplasm, neck ultrasonography with FNAC could effectively identify the thyroid or non-thyroid origin of these masses with high-diagnostic accuracy.