Cancer incidence in the age range 0–34 years: Historical and actual status in Denmark

Cardiovascular toxicities after anthracycline and VEGF-targeted therapies in adolescent and young adult cancer survivors

BACKGROUND

Cancer survival rates have been steadily improving in the adolescent and young adult (AYA) population, but survivors are at increased risk for cardiovascular disease (CVD). The cardiotoxic effects of anthracycline therapy have been well studied. However, the cardiovascular toxicity associated with newer therapies, such as the vascular endothelial growth factor (VEGF) inhibitors, is less well understood.

OBJECTIVE

This retrospective study of AYA cancer survivors sought to gain insight into their burden of cardiovascular toxicities (CT) following initiation of anthracycline and/or VEGF inhibitor therapy.

METHODS

Data were extracted from electronic medical records over a fourteen-year period at a single institution. Cox proportional hazards regression modeling was used to examine risk factors for CT within each treatment group. Cumulative incidence was calculated with death as a competing risk.

RESULTS

Of the 1,165 AYA cancer survivors examined, 32%, 22%, and 34% of patients treated with anthracycline, VEGF inhibitor, or both, developed CT. Hypertension was the most common outcome reported. Males were at increased risk for CT following anthracycline therapy (HR: 1.34, 95% CI 1.04-1.73). The cumulative incidence of CT was highest in patients who received both anthracycline and VEGF inhibitor (50% at ten years of follow up).

CONCLUSIONS

CT was common among AYA cancer survivors who received anthracycline and/or VEGF inhibitor therapy. Male sex was an independent risk factor for CT following anthracycline treatment. Further screening and surveillance are warranted to continue understanding the burden of CVD following VEGF inhibitor therapy.

Parenthood among men diagnosed with cancer in childhood and early adulthood: trends over time in a Danish national cohort

STUDY QUESTION

Is the rate of fatherhood among men diagnosed with cancer in childhood and early adulthood different from men without cancer, and, if so, have the differences changed over time?

SUMMARY ANSWER

Men diagnosed with cancer have had significantly reduced rates of fatherhood compared with undiagnosed men; however, the rates of fatherhood among the cancer survivors have increased markedly over time.

WHAT IS KNOWN ALREADY

The number of children and young adolescents who survive cancer has steadily increased over recent decades, with a current 5-year survival rate of approximately 80%. Consequently, life circumstances after cancer have gained increasing importance, including the desire among survivors to have children and a family. ARTs to aid reproduction among cancer survivors have been developed, and fertility preservation is increasingly a topic being discussed before undergoing cancer treatment. But the potential for fertility preservation differs dependent on age at diagnosis and type of cancer. Earlier studies have shown a decreased fertility rate among survivors of child and adolescent cancer compared to those diagnosed in early adulthood.

STUDY DESIGN, SIZE, DURATION

This study is a national, register-based cohort study. Men diagnosed with cancer in childhood and early adulthood (<30 years of age) were registered in the Danish Cancer Register in 1978-2016 (n = 9353). According to the time of diagnosis, each cancer-diagnosed man was randomly matched with 150 undiagnosed men from the background population within the same birth year. The men were followed until having their first child, death, migration or the end of the study (31 December 2017) in medical registers and socio-demographic population registers.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Fatherhood among the boys and young men diagnosed with cancer were compared with the age-matched comparison group in all statistical analyses. Cancer diagnoses were categorised as central nervous system (CNS) cancers, haematological cancers or solid cancers. Analyses were stratified by age at diagnosis (0-9, 10-19, 20-29 years) and time of diagnosis (1978-1989, 1990-1999, 2000-2009, 2010-2016). Death was incorporated as a competing risk in all analyses.

MAIN RESULTS AND THE ROLE OF CHANCE

The study population consisted of 9353 boys and young men diagnosed with cancer between 1978 and 2016 and 1 386 493 men in the age-matched comparison group. Those surviving CNS cancer as young men had the lowest hazard ratio (HR) of fatherhood compared with the age-matched comparison group (HR 0.67, 95% CI 0.57-0.79), followed by survivors of haematological cancers (HR 0.90, 95% CI 0.81-1.01), while the highest chance of fatherhood was among survivors of solid cancers (HR 1.16, 95% CI 1.12-1.20) with a slightly increased HR compared with undiagnosed males. The HR of becoming a father increased over time. From the first decade to the last decade 30 years later, the HR of becoming a father increased for solid tumours (HR 0.78, 95% CI 0.73-0.83 to HR 1.08, 95% CI 0.95-1.22), haematological cancers (HR 0.64, 95% CI 0.53-0.79 to HR 0.97, 95% CI 0.73-1.30) and CNS cancers (HR 0.44, 95% CI 0.34-0.57 to HR 0.98, 95% CI 0.49-1.95) compared to the age-matched comparison group. Also, when compared with the age-matched comparison group, men diagnosed with cancer when aged 20-29 years were more likely became fathers over the time of the study (HR 0.80, 95% CI 0.74-0.86 to HR 1.08, 95% CI 0.96-1.22).

LIMITATIONS, REASONS FOR CAUTION

The study was based on register data, and information was not available about the men's fertility potential, whether they had a desire to have children and whether it was possible for them to find a partner. Information about fertility preservation, e.g. sperm freezing, could also have provided additional insights. Furthermore, information about diagnosis and ART treatment would have been beneficial.

WIDER IMPLICATIONS OF THE FINDINGS

Information and education of male patients diagnosed with cancer about fertility preservation options and their chances to create their own family is crucial. Reassuringly, time trends showed more men with a previous cancer diagnosis becoming fathers in recent years than in earlier years, reflecting that survival and fertility preservation have improved over time.

STUDY FUNDING/COMPETING INTEREST(S)

R.S. received a PhD grant from the Rosa Ebba Hansen Foundation and from the Health Foundation (J.nr. 15-B-0095). The funding for the establishment of the DANAC II Cohort was obtained from the Rosa Ebba Hansen Foundation. The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Incidence and time trends of childhood cancer in Denmark, 1943-2014

Background: Surveillance of childhood cancer incidence is informative for etiologic research and health policy. However, high-quality data covering several decades of virtually complete cancer diagnosis in children is sparse.Methods: Incident cases of childhood cancer (0-19 years at diagnosis), classified according to Birch and Marsden's International Classification of Childhood Cancer, first edition (ICCC-1), were identified in the Danish Cancer Registry and used to calculate age-standardized incidence rates (ASRs) and estimated annual percentage change (EAPC) separately for 1943-1977 (early period) and 1977-2014 (recent period).Results: During 1943-2014, 15,184 childhood cancer cases were reported. The ASR for any cancer was 13.0 per 100 000 person-years in the early period (EAPC 0.55%; 95% CI 0.30-0.80) and 17.7 per 100 000 person-years in the recent period (EAPC 1.16%; 95% CI 0.96-1.36). In both periods, the increasing trend was seen in both boys (EAPC 0.69%; 95% CI 0.43-0.96/EAPC 0.96%; 95% CI 0.75-1.17) and girls (EAPC 0.37%; 95% CI -0.01-0.75/EAPC 1.41%; 95% CI 1.11-1.72) and in children aged 0-14 years (EAPC 0.53%; 95% CI 0.26-0.80/EAPC 0.86%; 95% CI 0.64-1.08) and 15-19 years (EAPC 0.60%; 95% CI 0.19-1.02/EAPC 1.97%; 95% CI 1.67-2.28). Increasing trends were observed for all main diagnostic groups.Conclusions: The incidence of childhood cancer in Denmark has increased since the 1940s, especially since 1977 and in older children. In recent years the increase has been most pronounced among girls.

Does age matter? A comparison of health-related quality of life issues of adolescents and young adults with cancer

OBJECTIVE

Health-related quality of life (HRQoL) concerns of adolescents and young adults (AYAs) aged 14-25 years were compared with those of older adults (26-60 years) with cancer.

METHODS

AYAs and older adults receiving curative intent treatment or supportive palliative care for cancer were recruited from eight research centres across Europe. Participants used a rating scale to score the relevance and importance of a list of 77 issues covering 10 areas of HRQoL concern: symptoms; activity restrictions; social; emotional; body image; self-appraisals; outlook on life; lifestyle; treatment-related and life beyond treatment.

RESULTS

HRQoL issues were reviewed by 33 AYAs and 25 older adults. Several issues were recognised as relevant and important across all age groups: symptoms, emotional impact, outlook on life, lifestyle and treatment-related. A number of issues were more relevant or important to AYAs including interrupted education, greater motivation to achieve academic goals, increased maturity, boredom, fertility and change in living situation.

CONCLUSION

While there is overlap in several of the HRQoL concerns across the age span, it is important that HRQoL measures used with AYAs capture the diverse and unique psychosocial aspects of this developmental stage.

Utilisation of primary care before a childhood cancer diagnosis: do socioeconomic factors matter?: A Danish nationwide population-based matched cohort study

OBJECTIVES

Early diagnosis of childhood cancer is critical. Nevertheless, little is known about the potential role of inequality. This study aims to describe the use of primary care 2 years before a childhood cancer diagnosis and to investigate whether socioeconomic factors influence the use of consultations and diagnostic tests in primary care.

DESIGN

A national population-based matched cohort study.

SETTING AND PARTICIPANTS

This study uses observational data from four Danish nationwide registers. All children aged 0-15 diagnosed with cancer during 2008-2015 were included (n=1386). Each case was matched based on gender and age with 10 references (n=13 860).

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was additional rates for consultations and for invoiced diagnostic tests for children with cancer according to parental socioeconomic factors. Furthermore, we estimated the association between socioeconomic factors and frequent use of consultations, defined as at least four consultations, and the odds of receiving a diagnostic test within 3 months of diagnosis.

RESULTS

Children with cancer from families with high income had 1.46 (95% CI 1.23 to 1.69) additional consultations 3 months before diagnosis, whereas children from families with low income had 1.85 (95% CI 1.60 to 2.11) additional consultations. The highest odds of frequent use of consultations was observed among children from low-income families (OR: 1.94, 95% CI 1.24 to 3.03). A higher odds of receiving an invoiced diagnostic test was seen for children from families with mid-educational level (OR: 1.46, 95% CI 1.09 to 1.95).

CONCLUSION

We found a socioeconomic gradient in the use of general practice before a childhood cancer diagnosis. This suggests that social inequalities exist in the pattern of healthcare utilisation in general practice.

Systematic review of the health-related quality of life issues facing adolescents and young adults with cancer

PURPOSE

For adolescents and young adults (AYAs), the impact of a cancer diagnosis and subsequent treatment is likely to be distinct from other age groups given the unique and complex psychosocial challenges of this developmental phase. In this review of the literature, we report the health-related quality of life (HRQoL) issues experienced by AYAs diagnosed with cancer and undergoing treatment.

METHODS

MEDLINE, EMBASE, CINAHL, PsychINFO and the Cochrane Library Databases were searched for publications reporting HRQoL of AYAs. Issues generated from interviews with AYAs or from responses to patient reported outcome measures (PROMs) were extracted.

RESULTS

166 papers were reviewed in full and comprised 72 papers covering 69 primary studies, 49 measurement development or evaluation papers and 45 reviews. Of the 69 studies reviewed, 11 (16%) used interviews to elicit AYAs' descriptions of HRQoL issues. The majority of the PROMs used in the studies represent adaptations of paediatric or adult measures. HRQoL issues were organised into the following categories: physical, cognitive, restricted activities, relationships with others, fertility, emotions, body image and spirituality/outlook on life.

CONCLUSION

The HRQoL issues presented within this review are likely to be informative to health care professionals and AYAs. The extensive list of issues suggests that the impact of a cancer diagnosis and treatment during adolescence and young adulthood is widespread and reflects the complexities of this developmental phase.

Cardiovascular disease in survivors of adolescent and young adult cancer: a Danish cohort study, 1943-2009

BACKGROUND

Cardiovascular disease has emerged as a serious late effect in survivors of adolescent and young adult cancer, but risk has not been quantified comprehensively in a population-based setting.

METHODS

In the Danish Cancer Registry, we identified 43153 1-year survivors of cancer diagnosed at ages 15 to 39 years (1943-2009) and alive in 1977; from the Danish Civil Registration System, we randomly selected a comparison cohort of the same age and sex. Subjects were linked to the Danish Patient Register, and observed numbers of first hospitalizations for cardiovascular disease (International Classification of Diseases, Tenth Revision codes I10-I79) were compared with the expected numbers derived from the comparison cohort. We calculated the absolute excess risks attributable to status as a survivor of cancer and standardized hospitalization rate ratios (RRs). All statistical tests were two-sided.

RESULTS

During follow-up, 10591 survivors (24.5%) were discharged from the hospital with cardiovascular disease, whereas 8124 were expected (RR = 1.30; 95% confidence interval [CI)] = 1.28 to 1.33; P < .001). The absolute excess risks were 400 and 350 extra cases of cardiovascular disease per 100000 person-years for people aged 20 to 59 and 60 to 79 years at discharge, respectively. Survivors of Hodgkin lymphoma experienced high risks for being hospitalized with valvular disease (RR = 12.2; 95% CI = 9.9 to 15.0; P < .001). Survivors of leukemia had high risks for cerebral hemorrhage (RR = 10.3; 95% CI = 5.5 to 19.1; P < .001) and cardiomyopathy (RR = 8.6; 95% CI = 4.3 to 17.3; P < .001).

CONCLUSIONS

Survivors of adolescent and young adult cancer are at increased risk for cardiovascular disease throughout life, although each main type of adolescent and young adult cancer had its own risk profile.

Cancer in adolescents and young adults (15-29 years): a population-based study in the Netherlands 1989-2009

BACKGROUND

Cancer among adolescents and young adults (AYAs; 15-29 years old) is relatively rare but its incidence is increasing worldwide. To define the extent and nature of the AYA patients, this population-based study was performed to explore trends in cancer incidence, survival and risk of second primary cancers in AYAs.

MATERIAL AND METHODS

Data from all AYAs diagnosed with cancer between 1989 and 2009 were obtained from the Netherlands Cancer Registry. Age-standardized incidence rates with estimated annual percentage of change (EAPC) and five-year relative survival rates were calculated. Relative survival was used as a good approximation of cause-specific survival. All analyses were stratified by gender, five-year age group and calendar period. In addition, Standardized Incidence Ratios were determined to evaluate the risk of second primary cancers.

RESULTS

23 161 AYAs were diagnosed with cancer between 1989 and 2009. Since 1989 the cancer incidence has increased significantly from 28 to 43 per 100 000 person years in males (EAPC: 1.9) and from 30 to 40 per 100 000 person years in females (EAPC: 1.4). The most frequently diagnosed cancers in male AYAs included testicular cancer, melanoma and Hodgkin's disease, whereas in females melanoma, breast cancer and Hodgkin's disease were the most frequently occurring cancers. Five-year relative survival rates were 80% and 82% for males and females, respectively. Over time, the five-year relative survival increased from 74% to 86% and from 79% to 86% in males and females, respectively. The risk of developing a second primary cancer was increased three to six times in males and two to five times in females, depending on rules for counting second primary cancers.

CONCLUSIONS

Although the overall survival has improved over time, the progress made in AYAs for specific cancers is still less compared to improvements made in children and adults. This and the increasing incidence and high risk of second primary cancers warrants further research.

Birth outcome in women with breast cancer, cutaneous malignant melanoma, or Hodgkin's disease: a review

BACKGROUND

Data on birth outcome in women diagnosed with cancer before, during, or shortly after pregnancy are very sparse. The purpose of this review was to summarize the existing epidemiologic evidence of the adverse effect of breast cancer, cutaneous malignant melanoma, and Hodgkin's disease on birth outcome.

METHODS

The MEDLINE database was used to review the literature systematically. Studies that examined the following outcomes were included: preterm birth, low birth weight, low birth weight at term, stillbirths, congenital abnormalities, male proportion of newborns, and mean birth weight. Studies were grouped according to whether the woman had been diagnosed with the specific cancer before, during, or shortly after pregnancy.

RESULTS

Few data exist on birth outcome in women with breast cancer, melanoma, or Hodgkin's disease. The overall results from the limited number of studies, which included a comparison group for birth outcome, were reassuring. However, for women diagnosed with breast cancer before pregnancy, the only 2 studies that included comparison groups for birth outcome had conflicting results regarding the risk of preterm birth and congenital abnormalities. Furthermore, a recent cohort study of birth outcome in women who were diagnosed with Hodgkin's disease before pregnancy indicated a slightly increased risk of congenital abnormalities among the newborns.

CONCLUSION

Overall, the existing studies offer reassuring results concerning the risks of adverse birth outcome for women diagnosed with breast cancer, melanoma, or Hodgkin's disease before, during or shortly after pregnancy. A limitation of most studies was the imprecise risk estimates caused by the small number of adverse birth outcomes and the lack of results stratified by treatment. Therefore, international collaboration is necessary in the future, to obtain more precise risk estimates for adverse birth outcomes, and to allow stratified analyses according to, for example, treatment.

Health-related quality of life in long-term survivors of childhood brain tumors

BACKGROUND

To identify predictors for health-related quality of life (HRQOL) in survivors of childhood brain tumors and its relationship to cognitive function.

PROCEDURE

One hundred twenty-six consecutive Danish childhood brain tumor patients treated 1970-1997 and being 7.9-40.4 years at follow-up were assessed for general intelligence (IQ) and administered the Minneapolis-Manchester Quality of Life (MMQL) questionnaire.

RESULTS

In multivariate linear regression treatment with RT was the most important risk factor for reduced HRQOL. Lower scores for physical functioning and energy, social functioning, cognitive functioning, body image, outlook of life, and intimate relations were significantly related to RT. Tumor location in the posterior fossa was associated with lower scores for physical functioning and energy, and tumor site in the third ventricle region was associated with lower scores for body image. Younger age at diagnosis was associated with lower scores for social functioning and intimate relations, and younger age at follow-up was associated with more physical symptoms. When IQ was included as a covariate, RT only remained significant for social functioning and intimate relations while tumor location in the third ventricle region remained significant for body image, younger age at diagnosis for social functioning and intimate relations, and younger age at follow-up for physical symptoms. In contrasts, neither gender nor presence of hydrocephalus requiring shunt inserted predicted significantly reduced HRQOL in the multivariate analyses.

CONCLUSION

RT is an important predictor of HRQOL primarily due to its effect on general intelligence, which suggests that IQ is a strong determinant of HRQOL.

Lifelong cancer incidence in 47,697 patients treated for childhood cancer in the Nordic countries

BACKGROUND

The pattern of cancer in long-term survivors from childhood cancer has not been investigated comprehensively.

METHODS

We obtained a cohort of 47,697 children and adolescents aged 0-19 years with cancer as defined by the country-wide cancer registries of Denmark, Finland, Iceland, Norway, and Sweden during 1943-2005. Cohort members were followed through age 79 years for subsequent primary cancers notified to the registries, and the age-specific risk pattern of the survivors was compared with that of the national populations using country and sex standardized incidence ratios (SIRs). We used a multiplicative Poisson regression model to estimate relative risk of cancer for attained age, with adjustment for calendar period and age at diagnosis of primary cancer. We also calculated excess absolute risk (EAR) attributable to status as childhood cancer survivor and determined the cumulative incidence of second primary cancer as a function of attained age for three subcohorts defined by period of treatment for childhood cancer.

RESULTS

A total of 1180 asynchronous second primary cancers were observed in 1088 persons, yielding an overall SIR of 3.3 (95% confidence interval = 3.1 to 3.5). The relative risk was statistically significantly increased in all age groups, even for cohort members approaching 70 years of age. The EAR for second primary cancer among survivors increased gradually from one additional case per 1000 person-years of observation in early life to six additional cases per 1000 person-years in the age group 60-69 years. For children treated in the prechemotherapy era (1943-1959), the cumulative risk for a second primary cancer reached 18%, 34%, and 48% at ages 60, 70, and 80 years, respectively. The age-specific incidence rates were highest for cohort members treated in the era of intensive, multiple-agent chemotherapy (1975-2005).

CONCLUSION

Survivors of childhood cancer have a persistent excess risk for a second primary cancer throughout their lives, accompanied by continuous changes in the risk of cancers at specific sites.

Probability of parenthood after early onset cancer: a population-based study

We evaluated in a population-based setting the postdiagnosis parenthood among survivors compared with the fertility patterns of siblings. Cancer patients aged 0-34 years at diagnosis were identified from the Finnish Cancer Registry (N = 25,784), and their siblings (N = 44,611) by registry linkage. Further linkage identified the offspring of the patient and sibling cohorts. The relative probabilities of parenthood for first and second births separately were estimated for male and female survivors in different diagnostic age-groups and subsites using a Cox proportional hazards model, with age as the time variable and adjusting for the birth cohort of parents. In addition, estimates were calculated for 5 diagnostic eras in all subsites combined. Compared to siblings, both female and male cancer survivors were less likely to parent at least 1 child (RR 0.46, 95% CI 0.44-0.48 and RR 0.57, 95% CI 0.54-0.60, respectively). The relative probability of parenthood was especially low in male childhood cancer survivors and female young adult cancer survivors. However, cancer patients were only slightly less likely than siblings to parent a second child, with RR 0.91, 95% CI 0.86-0.97 and RR 0.95, 95% CI 0.89-1.01 for females and males, respectively. The relative probability of parenthood increased over calendar time among young adult cancer patients. The relative probability of parenthood following early onset cancer was overall significantly reduced by approximately 50%. Parenting a second child, however, was not reduced among pediatric and adolescent survivors, and only slightly reduced among early adulthood cancer survivors compared to siblings.

Birth outcome in Danish women with cutaneous malignant melanoma

Several factors may affect birth outcome in women with cutaneous malignant melanoma. We examined whether maternal cutaneous malignant melanoma affects birth outcome (preterm birth, low birth weight at term, stillbirth, congenital abnormalities, mean birth weight, and male proportion of newborns) in a nationwide cohort study of 1059 births from 1973 to 2002 to women with cutaneous melanoma, compared with 50,794 births from a cohort of mothers without cancer. We found no increased risk of adverse birth outcome for the 620 newborns born to women with a diagnosis of melanoma before pregnancy or the 88 newborns born to women diagnosed during pregnancy. Among 351 births of women diagnosed with melanoma within 2 years from the time of delivery, the prevalence odds ratio of stillbirth was 4.6 (95% confidence interval: 1.7; 12). This estimate was, however, based on only five stillbirths in the exposed group and was an unexpected finding. With this exception, our data suggest no substantially increased risk of adverse birth outcome for women with melanoma.

Testicular cancer and male infertility

PURPOSE OF REVIEW

Testicular cancer and infertility affect a similar age group of patients and have common biologic, epidemiologic, and environmental backgrounds. In this review, we provide current literature on links between infertility and testicular cancer, and new developments in the management of testicular cancer aimed at improving quality of life in men with testicular cancer.

RECENT FINDINGS

In-utero environmental exposure to endocrine disruptors modulates the genetically determined fate of primitive gonad and results in testicular dysgenesis syndrome, which may result in infertility and testicular cancer. Excellent response of testicular cancer to radiation and chemotherapy results in over 90% of survival and quality of life--fertility and sexual function--is of significant concern to patients and clinicians. The testicular-sparing management of testicular masses emerges as a sound alternative to radical orchiectomy and allows for preservation of spermatogenesis and hormonal function, and at the same time achieving similar survival rates. Secondary malignancies, pulmonary, and cardiovascular complications are recognized as late complications of treatment for testicular cancer.

SUMMARY

Better understanding of common mechanisms involved in infertility and testicular cancer, and scientifically driven evidence-based treatment options should improve quality of life in young men faced with this potentially life-threatening disease.

Cutaneous malignant melanoma in children and adolescents in Sweden, 1993–2002: The increasing trend is broken

The incidence of cutaneous malignant melanoma rose rapidly in teenagers in Sweden during 1973-1992, while it remained low in younger children. To study the further trends and characteristics of melanoma in this young population, data on all cases in individuals under 20 years of age reported to the Swedish Cancer Registry during 1993-2002, and the corresponding pathology reports were examined. Seventy-nine cases were reported to the Registry. There were 24 males and 55 females. Most melanomas occurred on the trunk followed by the legs in both genders. The median tumor thickness was 0.8 mm. Children under age 15 had thicker melanomas than individuals aged 15-19. Superficial spreading melanoma was the most common histological subtype (43/78, 55%). The melanoma-specific 5-year survival rate was 90%. During 1993-2002, the age-standardized incidence fell to 3.6/million from 5.0/million in 1983-1992 (RR 0.74, 95% CI 0.58-0.92). The most pronounced decrease was for melanomas on the trunk in boys and on the legs in girls. The incidence for 15-19-year-old boys peaked for the cohort born between 1968 and 1972 and for girls between 1973 and 1977. The decrease in incidence may be a result of public health campaigns aiming at reducing sun exposure in childhood. A contributing effect from an increased immigration of individuals with darker complexions and at a lower melanoma risk is probable.

Cancer in children and adolescents in Europe: developments over 20 years and future challenges

This special issue contains 18 articles describing population-based analyses of incidence and survival for cancer among children and adolescents in Europe over the period 1978-1997. The analyses were derived from the large database of the ACCIS project (Automated Childhood Cancer Information System), which was built through collaboration of 62 population-based cancer registries in 19 European countries. Data on 88,465 cancers in children and 15,369 in adolescents (age 15-19 yrs) were included in the various analyses, making this the largest database on cancer in these age-groups in the world. National data were grouped into five European regions to allow comparisons of incidence and survival, for all cancers and by tumour type, including analysis of trends in both over time. This overview paper focuses on the comparability of the data from multiple registries and describes the potential confounding factors. Age-standardised annual incidence rates of many, but not all, cancers in children and adolescents are clearly rising. There are geographical differences in survival for the majority of tumour types. Survival rates increased for nearly all types of cancer in children and adolescents. The implications of these findings for aetiological factors and treatment delivery for cancer in children and adolescents are discussed.

Thyroid cancer incidence and survival among European children and adolescents (1978-1997): report from the Automated Childhood Cancer Information System project

Data on 1690 childhood and adolescent cases of thyroid cancer registered in 61 European cancer registries were extracted from the database of the Automated Childhood Cancer Information System (ACCIS) and included in analyses of incidence and survival. In 1988-1997, the age-standardised incidence rates (ASR) for children aged 0-14 years varied in European regions from 0.5 to 1.2 per million and the age-specific incidence in adolescents aged 15-19 years ranged from 4.4 to 11.0 per million. Over the age-span 0-19 years, the female to male ratio increased from 1 to around 3. Papillary thyroid cancer accounted for almost 65% of cases in children and 77% in adolescents. In the childhood population of Belarus, the ASR for 1989-1997 was 23.6 per million and the proportion of papillary tumours was 87%. No association was found between thyroid cancer risk and national dietary iodine status across 16 countries. Incidence of thyroid carcinoma among children and adolescents in Europe (excluding Belarus) increased during 1978-1997 by 3% per year, largely due to papillary carcinoma. Survival of children and adolescents was high over the entire study period and in all regions of Europe. Children with medullary carcinoma had slightly lower 5-year survival (95%, 95% CI 81-99), than those with papillary carcinoma (99%, 95% CI 95-100). More than 90% of patients survived 20 years after diagnosis. Further standardisation of diagnostic, classification and registration criteria will be fundamental for future studies of thyroid carcinomas in young people.