Abstract
Background
Cancer is the leading cause of death in children aged 1–14 and the second in 15‐19‐year‐old adolescents in Spain. The Paediatric Population‐Based Cancer Registry of the Community of Madrid was created to monitor its incidence and survival.
Objectives
This study presents the incidence of childhood and adolescent cancer (0–19 years) in Madrid at a population level by sex, age group, type of tumour and stage at diagnosis.
Methods
This study was a retrospective analysis of the total number of cases registered in the Paediatric Population‐Based Cancer Registry of the Community of Madrid. The registry employs passive and active case finding: by cross‐referencing hospital discharge data, primary healthcare data, mortality data and administrative information; and by validation of all potential incident cases through a review of electronic medical charts. All new diagnoses of malignant neoplasms, non‐malignant neoplasms of the Central Nervous System, and uncertain and in situ neoplasms of the bladder, identified in 2015–2018 in individuals under age 20 residing in Madrid, were included. Patient information was collected along with tumour characteristics, including stage at diagnosis according to the Toronto Childhood Cancer Stage Guidelines. Age‐specific and age‐standardised incidence rates were computed with 95% confidence intervals (CI).
Results
A total of 1002 tumours were registered in 5,269,524 person‐years, yielding an age‐standardised rate of 192.7 (95% CI 184.3, 201.4) cases per million person‐years. Male/female rate ratio was 1.1. The most common cancers across all ages comprised CNS tumours, leukaemias and lymphomas (primarily Hodgkin): 45.5 (95% CI 39.9, 51.7), 41.1 (95% CI 35.7, 47.1) and 35.8 (95% CI 30.9, 41.3) cases per million person‐years, respectively. The proportion of metastatic tumours at diagnosis was similar for ages 0–14 (18.6%) and 15–19 (18.7%).
Conclusions
This study provides a comprehensive understanding of childhood and adolescent cancer incidence in Madrid. The registry provides high‐quality data and consolidates epidemiological surveillance of cancer in the region.
Keywords: adolescent cancer, childhood cancer, incidence, Paediatric cancer, population‐based cancer registry, Toronto paediatric cancer stage guidelines
Synopsis.
Study question
What is the incidence of childhood tumours in terms of stage, sex, age and tumour type among individuals aged 0–19 residing in the Community of Madrid?
What is already known
Epidemiological information for childhood cancer in Madrid only comes from hospital‐based registries or potentially biased trials, not allowing reliable information on incidence. The hospital‐based Spanish Registry of Childhood Tumours has estimated the incidence of childhood cancer in Spain to be approximately 167.2 cases per million.
What this study adds
The population‐based incidence of cancer in people under 20 years old residing in the Community of Madrid is 192.7 cases per million person‐years—or 166.8 if we only consider malignancies—and approximately four out of every five stageable neoplasms are diagnosed at early stages.
1. BACKGROUND
Cancer in children and adolescents differs biologically from cancer in adults, representing 1.4% of global cancer cases. 1 Despite this low percentage, it ranks as the leading cause of death in children aged 1–14 and the second leading cause in 15‐19‐year‐old adolescents in Spain. 2
The World Health Organisation endorses population‐based cancer registries for their unbiased and high‐quality epidemiological data on childhood cancer. 3 , 4 , 5 , 6 Aligned with this, the General Directorate of Public Health in the Community of Madrid has established the Paediatric Population‐Based Cancer Registry of the Community of Madrid, Spain (PCRM). It covers over 1.3 million people: 15% of the Spanish population under 20 years. 7
The aim of this study was to present the incidence of cancer in children aged 0–19 years in the Community of Madrid (Spain) at a population level by sex, age group, type of tumour and stage at diagnosis.
2. METHODS
2.1. Study design
Incidence data in this report were extracted from the PCRM.
This registry includes all malignancies (except non‐melanoma skin), non‐malignant tumours of the Central Nervous System (CNS) and benign and in situ tumours of the bladder, diagnosed in people under 20 years who had been residing in the Community of Madrid for at least 6 months before diagnosis (or since birth for children under 6 months of age).
The procedure manual of the registry has been published elsewhere. 8 Data collection combines passive and active casefinding. Initially, a set of reportable cases are identified by cross‐referencing data from hospital discharge registries, primary healthcare data, mortality registry data and official healthcare administrative information. Secondly, expert reviewers of the PCRM validate potential incident cases by retrospectively reviewing electronic medical charts. The PCRM collects comprehensive data following international standards for population‐based cancer registries to ensure comparability, including mandatory variables such as sex, age, date of birth and residence; number of tumours; 9 incidence date; 10 topography, morphology, behaviour and grading according to the International Classification of Diseases for Oncology, 3.1 edition (ICD‐O 3.1) 11 ; laterality; and most valid basis of diagnosis. 12 Cancer types included are grouped according to the International Classification of Childhood Cancer 3rd edition (ICCC‐3): leukaemias, lymphomas, CNS tumours, neuroblastomas, renal tumours, hepatic tumours, malignant bone tumours, soft tissue sarcomas, germ cell tumours, malignant epithelial neoplasms and other and unspecified malignant neoplasms. 13 Additionally, stage at diagnosis is recorded based on the tier 2 criteria of the Toronto Childhood Cancer Stage Guidelines. 14
For data management of cancer records, the CanReg5 software is used, and validation checks are performed using quality tools from the International Agency for Research on Cancer (IARC) and the European Network of Cancer Registries. Additional quality indicators, such as the percentage of microscopically verified cases, the percentage of Death Certificate Only cases and the percentage of non‐specified cases are analysed. 15
2.2. Statistical Analysis
For this analysis, tumours diagnosed in the period 2015–2018 were included. Age‐specific incidence rates per million person‐years were calculated for five‐year age groups using population census data as denominator, 16 and their 95% CIs were calculated using the exact method based on the Poisson distribution. Age‐standardised incidence rates per million person‐years were computed for the 0–14 and 0–19 age groups, using the world standard population weights, 17 consistent with the IARC. 18 These calculations along with male/female ratios were performed with the user‐design Stata command ‘distrate’ which calculates efficient confidence intervals. 19 Results by stage are presented as proportions.
2.2.1. Missing data
We had complete data on sex, age, date of birth, incidence date, topography, morphology and behaviour. For six cases (0.6%), it was not possible to collect the most valid basis of diagnosis. Among the stageable tumours (n = 624), 73 (11.7%) lacked sufficient information to record the stage at diagnosis. No imputation techniques were conducted.
2.3. Ethics approval
This study complies with data protection regulations established by the Spanish Law 41/2002, of November 14, concerning patient autonomy, rights and obligations regarding information and clinical documentation. 20 Article 16.3 of this law stipulates that informed consent is not required for accessing patients' identifying data for epidemiological or public health reasons, provided anonymity is maintained. In this report, we present aggregate anonymised data to prevent the identification of individuals.
3. RESULTS
3.1. Quality indicators
Between 2015 and 2018, 1002 tumours were registered in 5,269,524 person‐years (53.7% in boys). Among these, 865 (86.3%) were malignant, 133 non‐malignant intracranial/intraspinal neoplasms (13.3%) and the remaining four cases were not classified by the ICCC‐3 (one in situ neoplasm of the bladder and three acoustic schwannomas, morphology not included in the ICCC‐3). Table 1 presents quality indicators of the PCRM.
TABLE 1.
Quality indicators and number of cancer cases of the paediatric population‐based cancer registry of the community of Madrid, overall and by sex, age and ICCC‐3 group.
| N | % | MV (%) a | DCO (%) a | NOS (%) | |
|---|---|---|---|---|---|
| Sex | |||||
| Boys | 538 | 53.7 | 93.4 | 0.6 | 2.2 |
| Girls | 464 | 46.3 | 85.9 | 0.4 | 2.2 |
| Age (years) | |||||
| <1 | 66 | 6.6 | 78.8 | 1.5 | 4.5 |
| 1–4 | 220 | 22.0 | 90.0 | ‐ | 0.9 |
| 5–9 | 214 | 21.4 | 94.8 | ‐ | 1.9 |
| 10–14 | 227 | 22.7 | 88.9 | 0.9 | 3.5 |
| 15–19 | 275 | 27.4 | 89.7 | 0.7 | 1.8 |
| ICCC‐3 group | |||||
| I. Leukaemias, Myeloproliferative And Myelodysplastic Diseases | 209 | 20.9 | 99.5 | 0.5 | 2.9 |
| II. Lymphomas and reticuloendothelial neoplasms | 191 | 19.1 | 100.0 | ‐ | 0.5 |
| III. CNS and Miscellaneous Intracranial and Intraspinal Neoplasms | 240 | 24.0 | 68.9 b | 1.3 | 2.9 |
| 80.7 c | |||||
| IV. Neuroblastoma And Other Peripheral Nervous Cell Tumours | 43 | 4.3 | 90.7 | ‐ | ‐ |
| V. Retinoblastoma | 20 | 2.0 | 45.0 | ‐ | ‐ |
| VI. Renal Tumours | 33 | 3.3 | 90.6 | ‐ | 3.0 |
| VII. Hepatic Tumours | 9 | 0.9 | 100.0 | ‐ | ‐ |
| VIII. Malignant Bone Tumours | 75 | 7.5 | 97.3 | 1.3 | 2.7 |
| IX. Soft Tissue And Other Extraosseous Sarcomas | 52 | 5.2 | 100.0 | ‐ | 7.7 |
| X. Germ Cell Tumours. Trophoblastic Tumours And Neoplasms Of Gonads | 57 | 5.7 | 94.7 b | ‐ | 1.8 |
| 94.4 c | |||||
| XI. Other Malignant Epithelial Neoplasms And Malignant Melanomas | 65 | 6.5 | 100.0 | ‐ | ‐ |
| XII. Other And Unspecified Malignant Neoplasms | 4 | 0.4 | 100.0 | ‐ | ‐ |
| Not classified by ICCC‐3 or in situ | 4 | 0.4 | 75.0 | ‐ | ‐ |
| Total | 1002 | 100 | 89.9 | 0.5 | 2.2 |
Abbreviations: DCO, Death Certificate Only; MV, Microscopically Verified; NOS, Not Otherwise Specified.
The percentages of microscopically verified and Death Certificate Only cases are calculated excluding cases with basis of diagnosis ‘unknown’.
Malignant and non‐malignant.
Only malignant.
3.2. Cancer incidence
The world standardised incidence rate of cancer in children aged 0–19 years was 192.7 per million person‐years (95% CI 184.3, 201.4), or 166.8 per million person‐years (95% CI 159.0, 174.9) if we only included malignant cancers.
The most common cancers across all ages (0–19) comprised CNS tumours, leukaemias and lymphomas (mainly Hodgkin lymphomas): 45.5 (95% CI 39.9, 51.7), 41.1 (95% CI 35.7, 47.1) and 35.8 (95% CI 30.9, 41.3) cases per million person‐years, respectively. Leukaemias showed a decreasing pattern with age, with an age‐specific incidence rate of 62.4 cases per million person‐years for children aged 0–4 years, and 24.9 cases per million person‐years for adolescents aged 15–19 years. Lymphomas, however, exhibited an increasing pattern with age, with an age‐specific incidence rate of 24.4 and 59.8 cases per million person‐years for children aged 0–4 and 15–19 years, respectively. Neuroblastomas, retinoblastomas and renal tumours were predominantly present in early childhood (Table 2).
TABLE 2.
Age‐specific and world‐standardised incidence rates per million person‐years, by age, sex, ICCC‐3 group and ICCC‐3 subgroup.
| ICCC‐3 diagnostic group and subgroup | Age‐specific incidence rates | World‐standardised incidence rates by sex | World‐standardised incidence rates by age groups | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 0–4 | 5–9 | 10–14 | 15–19 | Boys | Girls | M/F (95% CI) | 0–14 | 0–19 | |
| ASR (95% CI) | ASR (95% CI) | ASR (95% CI) | ASR (95% CI) | WSR (95% CI) | WSR (95% CI) | WSR (95% CI) | WSR (95% CI) | ||
| I. Leukaemias, Myeloproliferative And Myelodysplastic Diseases | 62.4 (49.6, 77.5) | 38.7 (29.1, 50.3) | 31.6 (22.8, 42.7) | 24.9 (16.8, 35.6) | 46.5 (38.5, 55.5) | 35.5 (28.3, 43.9) | 1.3 (1.0, 1.7) | 45.8 (39.3, 53.1) | 41.1 (35.7, 47.1) |
| (a) Lymphoid leukaemias | 48.0 (36.8, 61.4) | 27.4 (19.5, 37.5) | 16.5 (10.4, 25.0) | 11.6 (6.4, 19.5) | 33.0 (26.3, 40.8) | 21.9 (16.3, 28.7) | 1.5 (1.1, 2.2) | 32.2 (26.7, 38.4) | 27.6 (23.1, 32.6) |
| (b) Acute myeloid leukaemias | 8.4 (4.2, 15.0) | 6.3 (2.9, 12.0) | 6.8 (3.1, 12.8) | 8.3 (4.0, 15.3) | 7.0 (4.2, 11.0) | 8.0 (4.8, 12.3) | 0.9 (0.4, 1.8) | 7.2 (4.8, 10.4) | 7.5 (5.3, 10.3) |
| (c) Chronic myeloproliferative diseases | ‐ | 2.1 (0.4, 6.2) | 3.8 (1.2, 8.8) | 3.3 (0.9, 8.5) | 2.4 (1.0, 5.1) | 1.8 (0.6, 4.3) | 1.4 (0.4, 5.5) | 1.8 (0.8, 3.5) | 2.1 (1.1, 3.7) |
| (d) Myelodysplastic syndrome and other myeloproliferative diseases | 4.6 (1.7, 9.9) | 2.1 (0.4, 6.2) | 2.3 (0.5, 6.6) | 1.7 (0.2, 6.0) | 3.0 (1.3, 6.0) | 2.5 (0.9, 5.5) | 1.2 (0.4, 4.2) | 3.1 (1.6, 5.4) | 2.8 (1.5, 4.7) |
| (e) Unspecified and other specified leukaemias | 1.5 (0.2, 5.5) | 0.7 (0.0, 3.9) | 2.3 (0.5, 6.6) | ‐ | 1.0 (0.2, 3.0) | 1.3 (0.3, 3.7) | 0.8 (0.1, 6.0) | 1.5 (0.5, 3.2) | 1.1 (0.4, 2.5) |
| II. Lymphomas and reticuloendothelial neoplasms | 24.4 (16.7, 34.4) | 30.9 (22.5, 41.5) | 32.3 (23.4, 43.5) | 59.8 (46.8, 75.4) | 43.1 (35.6, 51.6) | 28.1 (22.0, 35.4) | 1.5 (1.1, 2.1) | 28.8 (23.8, 34.5) | 35.8 (30.9, 41.3) |
| (a) Hodgkin lymphomas | ‐ | 4.9 (2.0, 10.1) | 15.8 (9.8, 24.1) | 44.9 (33.7, 58.6) | 15.7 (11.4, 21.0) | 14.1 (10.0, 19.3) | 1.1 (0.7, 1.8) | 6.2 (4.1, 9.0) | 14.9 (11.8, 18.5) |
| (b) Non‐Hodgkin lymphomas (except Burkitt lymphoma) | 4.6 (1.7, 9.9) | 7.7 (3.9, 13.8) | 5.3 (2.1, 10.8) | 12.5 (7.0, 20.6) | 8.5 (5.5, 12.7) | 6.0 (3.3, 9.9) | 1.4 (0.7, 2.9) | 5.8 (3.7, 8.6) | 7.3 (5.2, 10.0) |
| (c) Burkitt lymphoma | 6.1 (2.6, 12.0) | 10.5 (5.9, 17.4) | 3.8 (1.2, 8.8) | 0.8 (0.0, 4.6) | 9.0 (5.7, 13.4) | 1.8 (0.6, 4.3) | 5.0 (1.9, 16.8) | 6.9 (4.5, 9.9) | 5.5 (3.7, 7.9) |
| (d) Miscellaneous lymphoreticular neoplasms | 13.7 (8.1, 21.7) | 7.7 (3.9, 13.8) | 7.5 (3.6, 13.8) | 0.8 (0.0, 4.6) | 9.5 (6.1, 14.1) | 6.2 (3.5, 10.3) | 1.5 (0.8, 3.1) | 10.0 (7.1, 13.7) | 7.9 (5.6, 10.8) |
| (e) Unspecified lymphomas | ‐ | ‐ | ‐ | 0.8 (0.0, 4.6) | 0.4 (0.0, 2.1) | 0.0 (0.0, 1.4) | ‐ | 0.0 (0.0, 0.9) | 0.2 (0.0, 1.1) |
| III. CNS and Miscellaneous Intracranial and Intraspinal Neoplasms a | 43.4 (32.9, 56.2) | 38.7 (29.1, 50.3) | 48.1 (44.5, 52.0) | 53.2 (41.0, 67.9) | 39.4 (32.3, 47.7) | 51.8 (43.3, 61.5) | 0.8 (0.6, 1.0) | 43.2 (37.0, 50.2) | 45.5 (39.9, 51.7) |
| (a) Ependymomas and choroid plexus tumour | 3.0 (0.8, 7.8) | 2.8 (0.8, 7.2) | 2.3 (0.5, 6.6) | 5.8 (2.3, 12.0) | 3.6 (1.7, 6.6) | 3.3 (1.4, 6.4) | 1.1 (0.4, 3.2) | 2.7 (1.4, 4.9) | 3.4 (2.0, 5.4) |
| (b) Astrocytomas | 24.4 (16.7, 34.4) | 12.0 (7.0, 19.1) | 13.5 (8.0, 21.4) | 6.6 (2.9, 13.1) | 13.4 (9.3, 18.6) | 16.4 (11.7, 22.3) | 0.8 (0.5, 1.3) | 17.2 (13.3, 21.9) | 14.8 (11.6, 18.6) |
| (c) Intracranial and intraspinal embryonal tumours | 5.3 (2.1, 11.0) | 7.0 (3.4, 12.9) | 3.0 (0.8, 7.7) | 5.8 (2.3, 12.0) | 5.2 (2.8, 8.7) | 5.5 (3.0, 9.3) | 0.9 (0.4, 2.1) | 5.2 (3.2, 8.0) | 5.3 (3.5, 7.7) |
| (d) Other gliomas | 6.9 (3.1, 13.0) | 5.6 (2.4, 11.1) | 13.5 (8.0, 21.4) | 5.8 (2.3, 12.0) | 6.6 (4.0, 10.4) | 9.0 (5.7, 13.6) | 0.7 (0.4, 1.4) | 8.4 (5.8, 11.7) | 7.8 (5.6, 10.6) |
| (e) Other specified intracranial and intraspinal neoplasms | 2.3 (0.5, 6.7) | 9.8 (5.4, 16.5) | 14.3 (8.6, 22.3) | 28.3 (19.6, 39.5) | 9.7 (6.3, 14.1) | 15.9 (11.5, 21.5) | 0.6 (0.4, 1.0) | 8.2 (5.7, 11.4) | 12.7 (9.9, 16.1) |
| (f) Unspecified intracranial and intraspinal neoplasms | 1.5 (0.2, 5.5) | 1.4 (0.2, 5.1) | 1.5 (0.2, 5.4) | 0.8 (0.0, 4.6) | 1.0 (0.2, 3.0) | 1.7 (0.5, 4.3) | 0.6 (0.1, 3.7) | 1.5 (0.5, 3.2) | 1.3 (0.5, 2.8) |
| IV. Neuroblastoma And Other Peripheral Nervous Cell Tumours | 28.9 (20.5, 39.7) | 1.4 (0.2, 5.1) | 2.3 (0.5, 6.6) | ‐ | 12.2 (8.1, 17.6) | 6.7 (3.7, 11.0) | 1.8 (0.9, 3.7) | 12.3 (8.9, 16.5) | 9.5 (6.9, 12.8) |
| (a) Neuroblastoma and ganglioneuroblastoma | 28.9 (20.5, 39.7) | 1.4 (0.2, 5.1) | 2.3 (0.5, 6.6) | ‐ | 12.2 (8.1, 17.6) | 6.7 (3.7, 11.0) | 1.8 (0.9, 3.7) | 12.3 (8.9, 16.5) | 9.5 (6.9, 12.8) |
| (b) Other peripheral nervous cell tumours | ‐ | ‐ | ‐ | ‐ | 0.0 (0.0, 1.4) | 0.0 (0.0, 1.4) | ‐ | 0.0 (0.0, 0.9) | 0.0 (0.0, 0.7) |
| V. Retinoblastoma | 15.2 (9.3, 23.5) | ‐ | ‐ | ‐ | 3.1 (1.3, 6.3) | 6.1 (3.2, 10.3) | 0.5 (0.2, 1.4) | 5.9 (3.6, 9.0) | 4.6 (2.8, 7.0) |
| VI. Renal Tumours | 18.3 (11.7, 27.2) | 6.3 (2.9, 12.0) | ‐ | ‐ | 6.4 (3.6, 10.4) | 7.8 (4.6, 12.3) | 0.8 (0.4, 1.7) | 9.1 (6.3, 12.8) | 7.1 (4.8, 9.9) |
| (a) Nephroblastoma and other non‐epithelial renal tumours | 18.3 (11.7, 27.2) | 5.6 (2.4, 11.1) | ‐ | ‐ | 6.4 (3.6, 10.4) | 7.4 (4.3, 11.9) | 0.9 (0.4, 1.8) | 8.9 (6.1, 12.5) | 6.9 (4.7, 9.7) |
| (b) Renal carcinomas | ‐ | ‐ | ‐ | ‐ | 0.0 (0.0, 1.4) | 0.0 (0.0, 1.4) | ‐ | 0.0 (0.0, 0.9) | 0.0 (0.0, 0.7) |
| (c) Unspecified malignant renal tumours | ‐ | 0.7 (0.0, 3.9) | ‐ | ‐ | 0.0 (0.0, 1.4) | 0.4 (0.0, 2.1) | 0.0 (0.0, 40.0) | 0.2 (0.0, 1.3) | 0.2 (0.0, 1.0) |
| VII. Hepatic Tumours | 3.8 (1.2, 8.9) | 0.7 (0.0, 3.9) | 1.5 (0.2, 5.4) | 0.8 (0.0, 4.6) | 2.0 (0.7, 4.7) | 1.6 (0.4, 4.2) | 1.3 (0.3, 6.3) | 2.1 (0.9, 4.2) | 1.8 (0.8, 3.5) |
| (a) Hepatoblastoma and mesenchymal tumours of liver | 3.8 (1.2, 8.9) | 0.7 (0.0, 3.9) | 0.8 (0.0, 4.2) | ‐ | 1.7 (0.5, 4.2) | 1.3 (0.3, 3.7) | 1.3 (0.2, 8.9) | 1.9 (0.8, 3.9) | 1.5 (0.6, 3.0) |
| (b) Hepatic carcinomas | ‐ | ‐ | 0.8 (0.0, 4.2) | 0.8 (0.0, 4.6) | 0.4 (0.0, 2.1) | 0.3 (0.0, 2.1) | 1.1 (0.0, 83.4) | 0.2 (0.0, 1.3) | 0.4 (0.0, 1.3) |
| (c) Unspecified malignant hepatic tumours | ‐ | ‐ | ‐ | ‐ | 0.0 (0.0, 1.4) | 0.0 (0.0, 1.4) | ‐ | 0.0 (0.0, 0.9) | 0.0 (0.0, 0.7) |
| VIII. Malignant Bone Tumours | 0.8 (0.0, 4.2) | 15.5 (9.7, 23.4) | 25.6 (17.7, 35.7) | 15.0 (8.9, 23.6) | 15.2 (11.0, 20.5) | 11.1 (7.6, 15.8) | 1.4 (0.8, 2.2) | 12.7 (9.6, 16.5) | 13.2 (10.4, 16.6) |
| (a) Osteosarcomas | ‐ | 7.0 (3.4, 12.9) | 12.0 (6.9, 19.5) | 8.3 (4.0, 15.3) | 7.9 (5.0, 11.9) | 4.7 (2.5, 8.0) | 1.7 (0.8, 3.7) | 5.8 (3.8, 8.5) | 6.3 (4.4, 8.8) |
| (b) Chondrosarcomas | ‐ | ‐ | ‐ | 1.7 (0.2, 6.0) | 0.7 (0.1, 2.7) | 0.0 (0.0, 1.4) | ‐ | 0.0 (0.0, 0.9) | 0.4 (0.0, 1.4) |
| (c) Ewing tumour and related sarcomas of bone | ‐ | 8.4 (4.4, 14.7) | 13.5 (8.0, 21.4) | 3.3 (0.9, 8.5) | 5.4 (3.1, 8.8) | 6.5 (3.8, 10.3) | 0.8 (0.4, 1.7) | 6.6 (4.5, 9.5) | 5.9 (4.1, 8.3) |
| (d) Other specified malignant bone tumours | ‐ | ‐ | ‐ | 0.8 (0.0, 4.6) | 0.4 (0.0, 2.1) | 0.0 (0.0, 1.4) | ‐ | 0.0 (0.0, 0.9) | 0.2 (0.0, 1.1) |
| (e) Unspecified malignant bone tumours | 0.8 (0.0, 4.2) | ‐ | ‐ | 0.8 (0.0, 4.6) | 0.8 (0.1, 2.9) | 0.0 (0.0, 1.4) | ‐ | 0.3 (0.0, 1.5) | 0.4 (0.0, 1.5) |
| IX. Soft Tissue And Other Extraosseous Sarcomas | 12.2 (7.0, 10.8) | 8.4 (4.4, 14.7) | 9.8 (5.2, 16.7) | 9.1 (4.6, 16.4) | 10.0 (6.6, 14.6) | 10.0 (6.5, 14.8) | 1.0 (0.6, 1.8) | 10.3 (7.3, 14.0) | 10.0 (7.5, 13.2) |
| (a) Rhabdomyosarcomas | 9.9 (5.3, 16.9) | 5.6 (2.4, 11.1) | 3.0 (0.8, 7.7) | 1.7 (0.2, 6.0) | 5.3 (2.9, 8.9) | 5.6 (3.0, 9.5) | 0.9 (0.4, 2.2) | 6.5 (4.2, 9.6) | 5.4 (3.6, 7.9) |
| (b) Fibrosarcomas. peripheral nerve sheath tumours and other fibrous neoplasms | 1.5 (0.2, 5.5) | 0.7 (0.0, 3.9) | 0.8 (0.0, 4.2) | 1.7 (0.2, 6.0) | 2.3 (0.8, 5.0) | 0.0 (0.0, 1.4) | ‐ | 1.0 (0.3, 2.6) | 1.2 (0.4, 2.6) |
| (c) Kaposi sarcoma | ‐ | ‐ | ‐ | ‐ | 0.0 (0.0, 1.4) | 0.0 (0.0, 1.4) | ‐ | 0.0 (0.0, 0.9) | 0.0 (0.0, 0.7) |
| (d) Other specified soft tissue sarcomas | 0.8 (0.0, 4.2) | 2.1 (0.4, 6.2) | 3.8 (1.2, 8.8) | 5.0 (1.8, 10.9) | 1.7 (0.6, 4.1) | 3.7 (1.8, 6.9) | 0.5 (0.1, 1.5) | 2.1 (0.9, 4.0) | 2.7 (1.5, 4.5) |
| (e) Unspecified soft tissue sarcomas | ‐ | ‐ | 2.3 (0.5, 6.6) | 0.8 (0.0, 4.6) | 0.7 (0.1, 2.6) | 0.7 (0.1, 2.6) | 1.0 (0.1, 14.2) | 0.7 (0.1, 2.0) | 0.7 (0.2, 1.8) |
| X. Germ Cell Tumours. Trophoblastic Tumours And Neoplasms Of Gonads | 8.4 (4.2, 15.0) | 5.6 (2.4, 11.1) | 6.8 (3.1, 12.8) | 24.1 (16.1, 34.6) | 13.1 (9.2, 18.2) | 8.5 (5.3, 13.1) | 1.5 (0.9, 2.8) | 7.0 (4.6, 10.2) | 10.9 (8.2, 14.1) |
| (a) Intracranial and intraspinal germ cell tumours b | 0.8 (0.0, 4.2) | 4.2 (1.5, 9.2) | 4.5 (1.7, 9.8) | 2.5 (0.5, 7.3) | 3.8 (1.9, 6.8) | 1.9 (0.6, 4.4) | 2.0 (0.6, 7.5) | 3.0 (1.6, 5.1) | 2.9 (1.6, 4.7) |
| (b) Malignant extracranial and extragonadal germ cell tumours | 4.6 (1.7, 9.9) | ‐ | ‐ | 0.8 (0.0, 4.6) | 0.8 (0.1, 2.9) | 2.3 (0.8, 5.3) | 0.3 (0.0, 2.1) | 1.8 (0.6, 3.8) | 1.6 (0.6, 3.2) |
| (c) Malignant gonadal germ cell tumours | 3.0 (0.8, 7.8) | 1.4 (0.2, 5.1) | 2.3 (0.5, 6.6) | 19.1 (12.1, 28.7) | 8.1 (5.1, 12.3) | 3.9 (1.9, 7.2) | 2.1 (0.9, 4.9) | 2.3 (1.0, 4.3) | 6.1 (4.1, 8.6) |
| (d) Gonadal carcinomas | ‐ | ‐ | ‐ | 0.8 (0.0, 4.6) | 0.0 (0.0, 1.4) | 0.4 (0.0, 2.2) | 0.0 (0.0, 37.8) | 0.0 (0.0, 0.9) | 0.2 (0.0, 1.1) |
| (e) Other and unspecified malignant gonadal tumours | ‐ | ‐ | ‐ | 0.8 (0.0, 4.6) | 0.4 (0.0, 2.1) | 0.0 (0.0, 1.4) | ‐ | 0.0 (0.0, 0.9) | 0.2 (0.0, 1.1) |
| XI. Other Malignant Epithelial Neoplasms And Malignant Melanomas | ‐ | 4.2 (1.5, 9.2) | 11.3 (6.3, 18.6) | 36.6 (26.6, 49.1) | 8.5 (5.5, 12.7) | 15.3 (11.0, 20.7) | 0.6 (0.3, 0.9) | 4.6 (2.9, 7.1) | 11.8 (9.1, 15.1) |
| (a) Adrenocortical carcinomas | ‐ | ‐ | ‐ | ‐ | 0.0 (0.0, 1.4) | 0.0 (0.0, 1.4) | ‐ | 0.0 (0.0, 0.9) | 0.0 (0.0, 0.7) |
| (b) Thyroid carcinomas | ‐ | 0.7 (0.0, 3.9) | 7.5 (3.6, 13.8) | 19.1 (12.1, 28.7) | 3.9 (1.9, 7.0) | 8.6 (5.4, 12.9) | 0.5 (0.2, 1.0) | 2.4 (1.2, 4.4) | 6.2 (4.3, 8.6) |
| (c) Nasopharyngeal carcinomas | ‐ | ‐ | ‐ | 0.8 (0.0, 4.6) | 0.0 (0.0, 1.4) | 0.4 (0.0, 2.2) | 0.0 (0.0, 37.8) | 0.0 (0.0, 0.9) | 0.2 (0.0, 1.1) |
| (d) Malignant melanomas | ‐ | 2.1 (0.4, 6.2) | 1.5 (0.2, 5.4) | 3.3 (0.9, 8.5) | 1.4 (0.4, 3.7) | 1.8 (0.6, 4.3) | 0.8 (0.2, 3.7) | 1.1 (0.4, 2.7) | 1.6 (0.7, 3.1) |
| (e) Skin carcinomas | ‐ | ‐ | ‐ | ‐ | 0.0 (0.0, 1.4) | 0.0 (0.0, 1.4) | ‐ | 0.0 (0.0, 0.9) | 0.0 (0.0, 0.7) |
| (f) Other and unspecified carcinomas | ‐ | 1.4 (0.2, 5.1) | 2.3 (0.5, 6.6) | 13.3 (7.6, 21.6) | 3.2 (1.5, 6.2) | 4.5 (2.3, 7.9) | 0.7 (0.3, 1.9) | 1.1 (0.4, 2.6) | 3.9 (2.4, 5.9) |
| XII. Other And Unspecified Malignant Neoplasms | ‐ | ‐ | 0.8 (0.0, 4.2) | 2.5 (0.5, 7.3) | 0.0 (0.0, 1.4) | 1.5 (0.4, 3.9) | 0.0 (0.0, 1.5) | 0.2 (0.0, 1.3) | 0.7 (0.2, 1.9) |
| (a) Other specified malignant tumours | ‐ | ‐ | 0.8 (0.0, 4.2) | 2.5 (0.5, 7.3) | 0.0 (0.0, 1.4) | 1.5 (0.4, 3.9) | 0.0 (0.0, 1.5) | 0.2 (0.0, 1.3) | 0.7 (0.2, 1.9) |
| (b) Other unspecified malignant tumours | ‐ | ‐ | ‐ | ‐ | 0.0 (0.0, 1.4) | 0.0 (0.0, 1.4) | ‐ | 0.0 (0.0, 0.9) | 0.0 (0.0, 0.7) |
| Not classified by ICCC‐3 or in situ | ‐ | ‐ | 0.8 (0.0, 4.2) | 2.5 (0.5, 7.3) | 1.1 (0.2, 3.1) | 0.4 (0.0, 2.2) | 2.8 (0.2, 147.3) | 0.2 (0.0, 1.3) | 0.7 (0.2, 1.9) |
| Total | 217.7 (193.2, 244.4) | 150.5 (131.0, 172.0) | 170.6 (149.2, 194.3) | 228.6 (202.3, 257.2) | 200.6 (183.9, 218.5) | 184.5 (167.9, 202.2) | 1.1 (1.0, 1.2) | 182.3 (173.0, 192.1) | 192.7 (184.3, 201.4) |
Abbreviations: ASR: Age‐specific incidence rates; WSR: World‐standardised incidence rates; M/F: male/female rate ratio; 95% CI: 95% Confidence Interval; CNS: Central Nervous System; ICCC‐3: International Classification of Childhood Cancer 3rd edition.
130 non‐malignant.
3 non‐malignant.
Incidence rates were slightly higher in boys than in girls [male/female rate ratio of 1.1 (95% CI 1.0, 1.2)] with the highest difference observed in malignant gonadal germ cell tumours albeit with low incidence rates (Table 2).
3.3. Stage at diagnosis
Out of the 1002 tumours, 624 (62.3%) were stageable. Of those, the total completeness of Toronto Guidelines' tier 2 was 88.3% (n = 551).
The proportion of metastatic tumours at diagnosis did not vary between those aged 0–14 years (18.6%) and those aged 15–19 years (18.7%). As shown in Figure 1, the highest proportion of metastatic‐stage tumours corresponded to neuroblastomas, with a percentage of 34.2% and a further 10.5% of metastatic disease confined to skin, liver and/or bone marrow in children under 18 months old (stage MS).
FIGURE 1.
Stage at diagnosis of all tumours included in the Toronto childhood cancer stage guidelines, tier 2. Numbers in the bars indicate absolute number of cases in each staging category within the tumour type. Only indicated for counts ≥5.
4. COMMENT
4.1. Principal findings
Using data from the PCRM, we observed that the global incidence of cancer in people under 20 years old residing in the Community of Madrid was 192.7 cases per million person‐years (166.8 only malignancies). Boys exhibited a slightly higher incidence than girls. The most frequent neoplasms were CNS tumours, leukaemias and lymphomas. Approximately four out of every five stageable neoplasms were diagnosed at early stages, with no differences observed between children aged 0–14 years and 15–19 years.
4.2. Strengths of the study
The main strength of the study is its use of high‐quality data from the PCRM. The proportion of verified cases, Death Certificate Only cases and unspecified cases fell within the expected ranges. 21 The registry's inclusion in the European Network of Cancer Registries despite its relative youth further underscores the quality of its data.
Another strength is the systematic collection of stage at diagnosis using the Toronto Staging Guidelines. The ongoing BENCHISTA multicenter project is utilising these guidelines to analyse survival by stage. 22 However, to date, this is the first paper in Spain and one of the pioneers in Europe and worldwide that provide incidence data according to said guidelines.
4.3. Limitations of the data
A limitation of our study is the completeness of staging information, which stood at 88.3%, not providing a comprehensive picture of the stage at diagnosis for the 100% of the cases. However, this falls within the range reported in other studies (74.3–93%). 23 , 24 , 25 , 26
4.4. Interpretation
Globally, the PCRM exhibits a higher incidence of cancer in children aged 0–19 years than other European countries. 27 The interpretation of these differences can be attributed to three main reasons. Firstly, Langerhans cell Histiocytosis, which exclusively comprises the Miscellaneous lymphoreticular neoplasms group, was not included in the ICD‐O until the third edition (year 2000) and was only assigned a malignant behaviour code in the first revision (2013). Since several long‐standing European registries dating back to the 1990s have never recorded this neoplasm following ICD‐O's first and second editions, the PCRM is expected to have a higher incidence rate for this neoplasm. The second reason is the reporting of non‐malignant neoplasms. The PCRM, unlike most registries, includes primary healthcare records, capturing more neoplasms diagnosed primarily in primary care, such as adenomas and prolactinomas. Only two Italian registries surpass PCRM's proportion of non‐malignant CNS neoplasms (51.9% over ICCC‐3 groups 3 and 10a) at 55.4%. 28 Thirdly, pilocytic astrocytomas, constituting 71% of group 3b ‘Astrocytomas’, have been categorised with malignant and uncertain behaviour codes across different ICD‐O editions, which complicates comparisons among registries.
4.5. Conclusions
The Community of Madrid is committed to childhood cancer surveillance and prevention and proves it with the development of the PCRM. Thanks to this registry, we know the true incidence and stage at diagnosis of childhood cancer in the Community of Madrid.
AUTHOR CONTRIBUTIONS
Raquel López‐González: Formal analysis, investigation, visualization, writing—original draft. David Parra‐Blázquez: Methodology, validation, writing—review and editing. Daniel Moñino: Software. Candela Pino‐Rosón: Data curation, writing—review and editing. Marina Pollán: Conceptualization, writing—review and editing, supervision. Nuria Aragonés: Conceptualization, writing—review and editing, supervision, funding acquisition.
FUNDING INFORMATION
This work was supported by the Carlos III Health Institute and co‐financed by the European Union (Project PI18/01038).
CONFLICT OF INTEREST STATEMENT
Authors declare no conflict of interest.
ACKNOWLEDGEMENTS
We want to thank our colleagues from the Public Health Division, especially Belén Zorrilla, Natalia de Frutos and Felicitas Domínguez for their help and support in the development of the Registry. We also want to thank Blanca López‐Ibor for her selfless and generous contribution and support.
López‐González R, Parra‐Blázquez D, Moñino D, Pino‐Rosón C, Pollán M, Aragonés N. Cancer incidence and stage at diagnosis in children and adolescents in the Community of Madrid, 2015–2018. Paediatr Perinat Epidemiol. 2025;39:445‐455. doi: 10.1111/ppe.13144
DATA AVAILABILITY STATEMENT
The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.
REFERENCES
- 1. Pritchard‐Jones K, Pieters R, Reaman GH, et al. Sustaining innovation and improvement in the treatment of childhood cancer: lessons from high‐income countries. Lancet Oncol. 2013;14:e95‐e103. [DOI] [PubMed] [Google Scholar]
- 2. Instituto Nacional de Estadística . Defunciones por causas (lista reducida) por sexo y grupos de edad. Accessed January, 2023. https://www.ine.es/jaxiT3/Tabla.htm?t+7947
- 3. World Health Organization . CureAll Framework: WHO global initiative for childhood cancer. 2020.
- 4. Parkin DM, Bray F. Evaluation of data quality in the cancer registry: principles and methods part II. Completeness. Eur J Cancer. 2009;45:756‐764. [DOI] [PubMed] [Google Scholar]
- 5. Bray F, Parkin DM. Evaluation of data quality in the cancer registry: principles and methods. Part I: comparability, validity and timeliness. Eur J Cancer. 2009;45:747‐755. [DOI] [PubMed] [Google Scholar]
- 6. Tucker TC, Durbin EB, McDowell JK, Huang B. Unlocking the potential of population‐based cancer registries. Cancer. 2019;125:3729‐3737. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7. Instituto Nacional de Estadística . Población por comunidades, edad (grupos quinquenales), Españoles/Extranjeros, Sexo y Año. Accessed February 2023. https://www.ine.es/jaxi/Tabla.htm?path+/t20/e245/p08/l0/&file+02002.px&L+0
- 8. Registro Poblacional de Cáncer en la Infancia y Adolescencia de la Comunidad de Madrid (RECAM‐i). Manual de Procedimientos 2022. 2022.
- 9. Curado MP, Okamoto N, Ries L, Sriplung H, Young J, Carli PM, et al. International rules for multiple primary cancers (ICD‐0 third edition). Eur J Cancer Prev 2005;14:307–308. [DOI] [PubMed] [Google Scholar]
- 10. Eden M, Crocetti E, Van Eycken E, et al. Coding Incidence Date 2022:1–7.
- 11. World Health Organization . ICD‐O: International Classification of Diseases for Oncology. World Health Organization; 2013. [Google Scholar]
- 12. Visser O, Caetano dos Santos FL, Cuccaro F, et al. Basis of Diagnosis 2022:1–8.
- 13. Steliarova‐Foucher E, Stiller C, Lacour B, Kaatsch P. International classification of childhood cancer, third edition. Cancer. 2005;103:1457‐1467. [DOI] [PubMed] [Google Scholar]
- 14. Gupta S, Aitken JF, Bartels U, et al. Paediatric cancer stage in population‐based cancer registries: the Toronto consensus principles and guidelines. Lancet Oncol. 2016;17:e163‐e172. [DOI] [PubMed] [Google Scholar]
- 15. Bray F, Znaor A, Cueva P, et al. Chapter 5.Quality control at the population‐based cancer registry. In: Müller K, Lesage S, eds. Planning and Developing Population‐Based Cancer Registration in Low‐ or Middle‐Income Settings. International Agency for Research on Cancer; 2014. [PubMed] [Google Scholar]
- 16. Instituto Nacional de Estadística . Padrón anual. Resultados Detallados Series Anuales 2015, 2016, 2017, 2018. Accessed June 2024. http://www.madrid.org/iestadis/fijas/estructu/demograficas/padron/estructupcrd.htm
- 17. Segi M, Fujisaku S, Kurihara M, Narai Y, Sasajima K. The age‐adjusted death rates for malignant neoplasms in some selected sites in 23 countries in 1954‐1955 and their geographical correlation. Tohoku J Exp Med. 1960;72:91‐103. [DOI] [PubMed] [Google Scholar]
- 18. Steliarova‐Foucher E, Colombet M, Ries LAG, et al. International incidence of childhood cancer, 2001‐10: a population‐based registry study. Lancet Oncol. 2017;18:719‐731. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19. Consonni D, Coviello E, Buzzoni C, Mensi C. A command to calculate age‐standardized rates with efficient interval estimation. Stata J. 2012;12:688‐701. [Google Scholar]
- 20. BOE‐A‐2002‐22188‐consolidado .
- 21. International Agency of Research on Cancer. Indicators of data quality .
- 22. Botta L, Gatta G, Didonè F, Lopez Cortes A, Pritchard‐Jones K. International benchmarking of childhood cancer survival by stage at diagnosis: the BENCHISTA project protocol. PLoS One. 2022;17:e0276997. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23. Sacerdote C, Mosso ML, Alessi D, et al. An application of the Toronto childhood cancer stage guidelines in three population‐based cancer registries: the case of central nervous tumors. Pediatr Blood Cancer. 2020;67:e28303. [DOI] [PubMed] [Google Scholar]
- 24. Parkin DM, Youlden DR, Chitsike I, et al. Stage at diagnosis and survival by stage for the leading childhood cancers in three populations of sub‐Saharan Africa. Int J Cancer. 2021;148:2685‐2691. [DOI] [PubMed] [Google Scholar]
- 25. Aitken JF, Youlden DR, Moore AS, et al. Assessing the feasibility and validity of the Toronto childhood cancer stage guidelines: a population‐based registry study. Lancet Child Adolesc Health. 2018;2:173‐179. [DOI] [PubMed] [Google Scholar]
- 26. Businge L, Hagenimana M, Motlhale M, et al. Stage at diagnosis and survival by stage for the leading childhood cancers in Rwanda. Pediatr Blood Cancer. 2024;71:71. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 27. International Agency of Research on Cancer . Registry‐specific tables. Accessed February 2023. https://iicc.iarc.fr/results/registry‐specific‐tables/
- 28. International Agency of Research on Cancer . ITALY, 2 paediatric registries (1998–2011). Accessed February 2023. https://iicc.iarc.fr/results/registry‐specific‐tables/europe‐italy‐2‐paediatric‐adolescents‐registries.pdf
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.