La Situación Del cáncer Infantil En Uruguay

Childhood cancer in Uruguay at the beginning of the XXIst century

Silveira A 2,3, Garau M 1,3 , Musetti C 1, Alonso R 1,3, Castillo L 2, Barrios E 1,3

1 National Cancer Registry _CHLCC, Montevideo, Uruguay

2 Centre of Pediatric Hemato-Oncology, Montevideo, Uruguay

3 Department of Quantitative Methods. Faculty of Medicine, Montevideo, Uruguay

Background: Uruguayan Cancer Registry works since 1992 collecting data from the whole country. It has full details of childhood cancer through collaboration with the Center of Pediatric Hemato-Oncology. A report describing incidence and prevalence of childhood malignancies describing 1992-1994 incident cohort was published in 2001. This communication updates figures for the period 1996 to 2010.

Methods: Data from the Uruguayan Cancer Registry regarding incidence and mortality of children (ages 0 to 14) for the period 1995-2010 was analyzed. Age standardized incidence rates (ASIR) and age standardized mortality rates (ASMR) were calculated. Trends were analyzed using Joinpoint Regression method.

Results: Data from 1290 patients were included in the analysis. The overall ASIR was 11.37(girls 10.18, boys 12.52). Age specific rates were higher among children aged 0 to 4 years: 13.13 vs. 10.06 in the 5-9 group and 10.49 in the 10 to 14 group. The most frequent malignancy group was the haematological one 41.9% (leukemia 29.8%, lymphoma 11.9%) followed by central nervous system tumors (18,6%), sarcomas 8,5%. ASMR in this period was 3.71 (M/I ratio 0.33) showing a decrease comparing 1996-2000 (ASMR=4.2) period and 2001-2005(ASMR=3.30), no significant difference was found between 2001-2005 and 2006-2010 (ASMR=3.56) periods. Mortality showed a decreasing but not significant trend (APC=-1.21); that becomes significant when prior years are included in the analysis (1992-2010)

Conclusions: As it has been observed in many countries, cancer incidence in childhood is increasing steadily while mortality shows a significant decrease, reaching in 2006-2010 the half that in 1992-1994.

Background.

Uruguay is a country in South America that stretches over 176.215 km2 and has a total population of 3.285.877 inhabitants according to 2011 Census (1). Of these population 696.481 (21.2%) are between 0 to 14 years. The country is divided in 19 regions called Departments; in the capital city Montevideo lives half of the population.

The majority of Uruguayans have Spanish and Italian origins, followed by French, German and others; 87.4% of the population is Caucasian, 9.1% are Afro-descendants and 2.9% others. The male/female ratio is 0.92(1). The levels of demographic variables follow the same tendencies as those observed in developed countries (2). Access to drinking water, education and sewage services is almost universal.

According to 2007 data from the United Nations Program of Development, Uruguay ranked third in Latin America and 50th among 182 countries, with a Human Development Index (HDI) of 0.865(3).

Health care is provided by public and private subsystems. Until 2005, both systems attended half of the population respectively. Since then, with the creation of the National Integrated Health System more people were included in the private subsystem. In addition, the 2011 Census showed that 97.2% of the population living in towns of 5.000 or more inhabitants has some kind of medical care coverage.

The Centre of Pediatric Hemato-Oncology (CPHO) is a National Reference Centre. It is a Public Centre that provides a high quality care to children covered by the public system, but is also open for interconsultation and outpatient care for those who have private healthcare.

Childhood cancer should be studied separately of the adult cancer. It presents differences in primary localization, histological origin and clinical behaviour. Tends to have lower latency periods, to grow rapidly, becoming invasive. Most of the pediatric tumors show similar histological findings as fetal tissues at different stages of embryonic development. This similarity with embryonic structures generates a large morphological diversity due to of constant cell transformations. For this reason, the classifications used in childhood tumors differ from those used in adults, being the morphology, the main aspect to consider.

To describe the epidemiology of cancer in a population, it is necessary to know the incidence and mortality. The incidence is known for the National Cancer Registry of Uruguay (NCRU), a population based cancer registry, created in 1984 who started to record cancer incidence in the capital city Montevideo in 1987. Since 1992 the Registry gathers information from the whole country, which means a continuous and systematic data collection, records all new cancer cases occurring in a defined population in a defined geographical area. Mortality is obtained from vital registration of the Ministry of Public Health.

A report describing incidence and prevalence of childhood malignancies from 1992-1994 was published in 2001. This Communication updates figures for the period 1996 to 2010.

Methods.

NCRU collects incident pediatric cancer cases through the CPHO and cancer related mortality from death certificates. Cases are codified according to the International Classification of Diseases for Oncology (ICD-O) (4).

All cases diagnosed in 1996-2010 in children (0 to 14) were selected for this study. Incidence rates adjusted by age and mortality rates were calculated. Reference population was obtained by linear interpolation from national censuses held in 1996, 2004 and 2011 (1). Direct standardization method with the world standard population as defined by Segi (5) was used for calculate standardized incidence rates (ASIR) and standardized mortality rates (ASMR) by age.

Analysis of five years survival was performed with Kaplan-Meier method. Statistical

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