Cancer incidence among children and adolescents in Brazil: first report of 14 population-based cancer registries

Global challenges in pediatric oncology

PURPOSE OF REVIEW

Reduction of child mortality is one of the Millennium Development Goals; as low-income and middle-income countries (LMICs) advance toward the achievement of this goal, initiatives aimed at reducing the burden of noncommunicable diseases, including childhood cancer, need to be developed.

RECENT FINDINGS

Approximately 200 000 children and adolescents are diagnosed with cancer every year worldwide; of those, 80% live in LMICs, which account for 90% of the deaths. Lack of quality population-based cancer registries in LMICs limits our knowledge of the epidemiology of pediatric cancer; however, available information showing variations in incidence may indicate unique interactions between environmental and genetic factors that could provide clues to cause. Outcome of children with cancer in LMICs is dictated by late presentation and underdiagnosis, high abandonment rates, high prevalence of malnutrition and other comorbidities, suboptimal supportive and palliative care, and limited access to curative therapies. Initiatives integrating program building with education of healthcare providers and research have proven to be successful in the development of regional capacity. Intensity-graduated treatments adjusted to the local capacity have been developed.

SUMMARY

Childhood cancer burden is shifted toward LMICs; global initiatives directed at pediatric cancer care and control are urgently needed. International partnerships facilitating stepwise processes that build capacity while incorporating epidemiology and health services research and implementing intensity-graduated treatments have been shown to be effective.

Childhood cancer: incidence and early deaths in Argentina, 2000-2008

INTRODUCTION

Knowledge on the epidemiology of childhood cancer in Latin America is limited. The Argentinean Oncopaediatric Registry (ROHA) has been active since 2000. Data for 2000-2008 are described in the present work.

MATERIALS AND METHODS

ROHA is fed from a network of paediatric units and population-based cancer registries. Cases are coded by the International Classification of Childhood Cancer.

RESULTS

A total of 11447 children aged 0-14 diagnosed with cancer were reported. Histologically verified cases and cases identified only through death certificates were respectively 91% and 6%. The annual age of standardised incidence rate of all cancers was 128.5 per million. Proportions of leukaemia's, lymphoma's and Central Nervous System tumours were 37%, 13% and 18%. The distribution of rates of acute lymphatic leukaemia by the year of age showed a peak around age 3. Eighty percent of the patients are treated in public hospital and around 35% migrate for some of the treatment. Deaths within a month of diagnosis were 5% in 2000 and 3% in 2008.

CONCLUSIONS

Childhood cancer incidence in Argentina is somewhat lower than in North American and in Western European countries: the deficit is mainly due to tumours of the Central Nervous system and other solid tumours. Childhood cancer incidence did not show any tendency to increase. The possible excess of Hodgkin lymphoma in the Northeast region requires additional studies. Early deaths after diagnosis indicate an unsatisfactory state of the overall organisation of childhood cancer care. Data from ROHA are used for decision making at local and national levels.

Cancer incidence among adolescents and young adults in urban Shanghai, 1973-2005

BACKGROUND

Lack of cancer incidence information for adolescents and young adults led us to describe incidence trends within the young population of 15 to 49 year-olds in urban Shanghai between 1973 and 2005.

METHODS

During 1973 to 2005, data on 43,009 (45.8%) male and 50,828 (54.2%) female cancer cases aged 15-49 years from the Shanghai Cancer Registry were analyzed. Five-year age-specific rates, world age-standardized rates, percent change (PC), and annual percent change (APC) were calculated using annual data on population size and its estimated age structure.

RESULTS

During the 33-year study period, overall cancer incidence of adolescents and young adults among males marginally decreased by 0.5% per year (P<0.05). However, overall cancer incidence for females slightly increased by 0.8% per year (P<0.05). The leading cancer for males in rank were liver, stomach, lung, colorectal, and nasopharyngeal cancers and for females were breast, stomach, colorectal, thyroid, and ovarian cancers. Among specific sites, incidence rates significantly decreased for cancers of the esophagus, stomach, and liver in both sexes. In contrast, incidence rates significantly increased for kidney cancers, non-Hodgkin lymphoma, and brain and nervous system tumors in both sexes and increased for breast and ovarian cancers among females.

CONCLUSIONS

Overall cancer incidence rates of adolescents and young adults decreased in males whereas they increased in females. Our findings suggest the importance of further epidemiology and etiologic studies to further elucidate factors contributing to the cancer incidence trends of adolescents and young adults in China.

Influence of MDM2 and MDM4 on development and survival in hereditary retinoblastoma

BACKGROUND

Retinoblastoma (RB) accounts for 3% of all childhood malignancies, with different incidences around the world. This malignancy results from loss-of-function of both RB1 alleles although other genes, like MDM2 and MDM4, have been proposed to be involved in tumor development.

PROCEDURE

We genotyped rs2279744T>G and rs937283A>G in MDM2, and rs4252668T>C and rs116197192G>A in MDM4, in 104 unrelated RB patients and 104 controls. Sixty-month survival Kaplan-Meier curves and χ(2)-tests were performed for estimating the putative effect of MDM2 and MDM4 alleles on disease progression and survival of RB patients.

RESULTS

MDM2 rs2279744G was significantly more frequent in controls, indicating an apparently protective effect on RB development. However, survival of patients who carried a constitutional RB1 mutation was significantly lower with rs2279744TG or GG than with rs2279744TT. Presence of rs2279744G and a constitutional RB1 mutation was sixfold more frequent in the 0-12 month age group than other age groups at onset of symptoms (P = 0.0401). MDM4 rs4252668C was present at a significantly higher frequency in controls while the frequency of MDM4 rs116197192G was significantly higher in RB patients, suggesting that this allele might increase the risk of developing RB.

CONCLUSION

Our results indicate that MDM2 and MDM4 polymorphisms may influence development and/or survival in RB.

Retinoblastoma in the democratic republic of congo: 20-year review from a tertiary hospital in kinshasa

Background. To determine clinical profile and management of retinoblastoma among children at Kinshasa in Democratic Republic of Congo. Patients and methods. The medical records of patients with a diagnosis of retinoblastoma seen at the University Hospital of Kinshasa from January 1985 till December 2005 were retrospectively reviewed. Demographic profile, clinical data, modes of treatment and outcome were analysed. Results. A total of 49 children, of whom 40 had adequate data on record were identified as retinoblastoma (28 males and 12 females). Nine cases had bilateral disease. The median age at the first symptoms was 9 months (range, 1 month to 6 years) for unilateral retinoblastoma and 18 months (range, 1 month to 3.5 years) for bilateral retinoblastoma. The median age at the first oncology consultation was 2.4 years (range, 6 months to 6 years) for unilateral retinoblastoma and 2.4years (range, 9 months to 4 years) for bilateral disease. Leukokoria was present in 67.5% of subjects. Seventy-five percent abandoned the treatment. The mortality was 92.5%. Conclusion. In Democratic Republic of Congo, retinoblastoma remains a life threatening disease characterized by late referral to a specialized unit and affordability of chemotherapy; all leading to an extension of the disease and high mortality.

History of Parvovirus B19 infection is associated with a DNA methylation signature in childhood acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) likely has a multistep etiology, with initial genetic aberrations occurring early in life. An abnormal immune response to common infections has emerged as a plausible candidate for triggering the proliferation of pre-leukemic clones and the fixation of secondary genetic mutations and epigenetic alterations. We investigated whether evidence of infection with a specific common myelotropic childhood virus, parvovirus B19 (PVB19), relates to patterns of gene promoter DNA methylation in ALL patients. We serologically tested bone marrow samples at diagnosis of B-cell ALL for PVB19 infection and DNA methylation using a high-throughput bead array and found that 4.2% and 36.7% of samples were seroreactive to PVB19 IgM and IgG, respectively. Leukemia samples were grouped by DNA methylation pattern. Controlling for age and immunophenotype, unsupervised modeling confirmed that the DNA methylation pattern was associated with history of PVB19 (assessed by IgG, p = 0.02), but not recent infection (assessed by IgM). Replication assays on single genes were consistent with the association. The data indicate that a common viral illness may drive specific DNA methylation patterns in susceptible B-precursor cells, contributing to the leukemogenic potential of such cells. Infections may impact childhood leukemia by altering DNA methylation patterns and specific key genes in susceptible cells; these changes may be retained even after the clearance of infection.

Childhood cancer and pediatric oncologic care in Brazil: access and equity

Cancer in children and adolescents is rare and highly curable if treatment is started early, yet it is still the main cause of death from disease in this age group. The aim of this study is to discuss access to health services for cancer patients under 19 years of age in Brazil, mapping deaths and treatment modalities in the Brazilian Unified National Health System (SUS). Data from 2000 to 2007 were analyzed according to health regions. Maps of cancer mortality rates and cancer care indicators - hospitalizations, chemotherapy, and radiotherapy financed by the national health system - revealed inequality in access, based on the small number of procedures for children in poorer regions of the country. Even with the usual concentration of specialized services in more heavily populated areas, access begins with clinical suspicion in primary care, followed by referral to more complex levels, where the diagnosis is made and treatment begins. Training pediatricians in clinical suspicion of childhood cancer and definition of more streamlined patient flows could improve the situation, thereby increasing the odds of cure.

Follow-up of treated osteosarcoma patient

Objective

To evaluate the value of post-treatment follow-up in osteosarcoma patients.

Methods

Data were collected through a clinical record, with socio-demographic and clinical data, and information relating to the medical appointment. Descriptive analysis of the data was carried out. The Chi-squared test was used to associate the independent variables with attendance at scheduled follow-up appointments.

Results

We found a recurrence in 59.6% of cases, of which 58% were lung related; 44% presented clinical complaints and arrived on the scheduled date of the appointment. There was no statistically significant association between the demographic characteristics and early attendance of follow-up visits. 81.3% of the cases who came for the appointment earlier than originally scheduled presented complaints compared to those who did not (p=0.005). Of the cases who presented recurrence, 12.9% attended an appointment late and those who did not present recurrence, 47.6% were late for the appointment (p=0.006).

Conclusion

It is seen that the patients who came for an earlier appointment presented more complaints and were associated with the positive result of the exams carried out. The patients who had recurrence and came for an earlier appointment did not present a statistically significant difference in recurrence-free survival. It was observed that distance was not a predominant factor in late attendance at appointments. Level of Evidence II, Retrospective Study.

Pediatric central nervous system tumors: a single-center experience from 1989 to 2009

The objective of this study was to determine the epidemiology of primary tumors of the central nervous system (CNS) in pediatric patients from a Brazilian oncology institute. We retrospectively analyzed 741 charts (415 males and 326 females) of patients under 21 years of age who were diagnosed with a CNS tumor. The analysis included patients from 1989 to 2009 and was performed using the World Health Organization criteria. We evaluated the distribution of age, sex, topography, clinical symptoms, symptom intervals, and classification of the tumors. Patients with clinical/radiologic diagnoses were included. Seven hundred forty-one patients with tumors in the CNS were reviewed, and 83% of the patients presented a histologic diagnosis. Males (56%) were more prevalent than females. In children under the age of 1 year, the supratentorial compartment was the predominant region involved (62.0%). Astrocytoma was the most frequent tumor type (37.0%), followed by medulloblastoma (13.6%), craniopharyngioma (10.5%), and ependymoma (6.8%). Headaches were the most common symptom, and the symptom intervals varied from 1 to 5010 days. Approximately 4% of the patients had associated genetic syndromes. Although it was not a population study and selection bias may have occurred, this study supplies important epidemiologic data from an emerging country in which population studies are rare.

TP53 mutation p.R337H in gastric cancer tissues of a 12-year-old male child: evidence for chimerism involving a common mutant founder haplotype: case report

Background

Gastric adenocarcinoma is rare in children and adolescents, with about 17 cases under age 21 in the world's literature. We report a case of invasive well-differentiated metastatic gastric cancer in a Brazilian 12-year-old boy without documented familial history of cancer.

Case presentation

The patient, diagnosed with metastatic disease, died seven months after surgery. DNA from intra-surgical specimens revealed a TP53 mutation at codon 337 (p.R337H) in samples with neoplastic cells (dysplasia, tumor and metastasis) but not in non-transformed cells (incomplete intestinal metaplasia and non-involved celiac lymph node). In all mutation-positive tissues, p.R337H occurred on the same background, a founder allele identified by a specific haplotype previously described in Brazilian Li-Fraumeni syndrome patients. The same mutant haplotype, corresponding to a founder mutation present in 0.3% of the general population in Southern Brazil, was found in the genome of the father. Presence of this inherited haplotype in the tumor as well as in the father's germline, suggests a rare case of microchimerism in this patient, who may have harbored a small number of mutant cells originating in another individual, perhaps a dizygotic twin that died early in gestation.

Conclusion

This case represents one of the earliest ages at diagnosis of gastric cancer ever reported. It shows that cancer inheritance can occur in the absence of an obvious germline mutation, calling for caution in assessing early cancers in populations with common founder mutations such as p.R337H in Southern Brazil.

Childhood acute leukemias are frequent in Mexico City: descriptive epidemiology

Background

Worldwide, acute leukemia is the most common type of childhood cancer. It is particularly common in the Hispanic populations residing in the United States, Costa Rica, and Mexico City. The objective of this study was to determine the incidence of acute leukemia in children who were diagnosed and treated in public hospitals in Mexico City.

Methods

Included in this study were those children, under 15 years of age and residents of Mexico City, who were diagnosed in 2006 and 2007 with leukemia, as determined by using the International Classification of Childhood Cancer. The average annual incidence rates (AAIR), and the standardized average annual incidence rates (SAAIR) per million children were calculated. We calculated crude, age- and sex-specific incidence rates and adjusted for age by the direct method with the world population as standard. We determined if there were a correlation between the incidence of acute leukemias in the various boroughs of Mexico City and either the number of agricultural hectares, the average number of persons per household, or the municipal human development index for Mexico (used as a reference of socio-economic level).

Results

Although a total of 610 new cases of leukemia were registered during 2006-2007, only 228 fit the criteria for inclusion in this study. The overall SAAIR was 57.6 per million children (95% CI, 46.9-68.3); acute lymphoblastic leukemia (ALL) was the most frequent type of leukemia, constituting 85.1% of the cases (SAAIR: 49.5 per million), followed by acute myeloblastic leukemia at 12.3% (SAAIR: 6.9 per million), and chronic myeloid leukemia at 1.7% (SAAIR: 0.9 per million). The 1-4 years age group had the highest SAAIR for ALL (77.7 per million). For cases of ALL, 73.2% had precursor B-cell immunophenotype (SAAIR: 35.8 per million) and 12.4% had T-cell immunophenotype (SAAIR 6.3 per million). The peak ages for ALL were 2-6 years and 8-10 years. More than half the children (58.8%) were classified as high risk. There was a positive correlation between the average number of persons per household and the incidence of the pre-B immunophenotype (Pearson's r, 0.789; P = 0.02).

Conclusions

The frequency of ALL in Mexico City is among the highest in the world, similar to those found for Hispanics in the United States and in Costa Rica.

Socioeconomic status and the incidence of non-central nervous system childhood embryonic tumours in Brazil

Background

Childhood cancer differs from most common adult cancers, suggesting a distinct aetiology for some types of childhood cancer. Our objective in this study was to test the difference in incidence rates of 4 non-CNS embryonic tumours and their correlation with socioeconomic status (SES) in Brazil.

Methods

Data was obtained from 13 Brazilian population-based cancer registries (PBCRs) of neuroblastoma (NB), Wilms'tumour (WT), retinoblastoma (RB), and hepatoblastoma (HB). Incidence rates by tumour type, age, and gender were calculated per one million children. Correlations between social exclusion index (SEI) as an indicator of socioeconomic status (SES) and incidence rates was investigated using the Spearman's test.

Results

WT, RB, and HB presented with the highest age-adjusted incidence rates (AAIRs) in 1 to 4 year old of both genders, whereas NB presented the highest AAIR in ≤11 month-olds. However, differences in the incidence rates among PBCRs were observed. Higher incidence rates were found for WT and RB, whereas lower incidence rates were observed for NB. Higher SEI was correlated with higher incidences of NB (0.731; p = 0.0117), whereas no SEI correlation was observed between incidence rates for WT, RB, and HB. In two Brazilian cities, the incidence rates of NB and RB were directly correlated with SEI; NB had the highest incidence rates (14.2, 95% CI, 8.6-19.7), and RB the lowest (3.5, 95% CI, 0.7-6.3) in Curitiba (SEI, 0.730). In Natal (SEI, 0.595), we observed just the opposite; the highest incidence rate was for RB and the lowest was for NB (4.6, 95% CI, 0.1-9.1).

Conclusion

Regional variations of SES and the incidence of embryonal tumours were observed, particularly incidence rates for NB and RB. Further studies are necessary to investigate risk factors for embryonic tumours in Brazil.

Clinical presentation and outcome of retinoblastoma among children treated at the National Cancer Institute (NCI) in Gezira, Sudan: a single Institution experience

BACKGROUND

Retinoblastoma (RB) is a rare and unique cancer that affects the eyes of very young children. There are few reports on RB in Sudan.

MATERIALS AND METHODS

We performed a retrospective study of data from patients diagnosed with retinoblastoma between January 1999 and December 2009 at the National Cancer Institute in Gezira (NCI-Gezira).

RESULTS

Of the 519 cases of childhood cancer treated at NCI-Gezira during the study period, 25 (4.8%) were retinoblastoma. Of these 25 patients with retinoblastoma, there were 13 boys and 19 cases were unilateral. The median age at diagnosis was 36 months (range, 8-60 months). The disease was localized in 9 patients, regional in 5 patients, and metastatic in 11 patients. The most frequent symptoms were enlarged eye (n = 14) and leukocoria (n = 8). Nine patients (36%) have been lost to follow-up; 9 were alive at last follow-up (7 in remission, 2 progressed); and 7 have died (5 from disease and 2 from unrelated causes). Twenty-two eyes were enucleated in 16 patients (6 bilateral and 10 unilateral). Pathologic examination of the enucleated eyes could only be completed in 11 patients. Diagnostic imaging in the form of computerized tomography scans or ultrasonography of the brain and orbit was done for 10 patients (40%).

CONCLUSIONS

Although these findings are not surprising, and similar to reports from other developing countries, we hope our work will provide a foundation for strategies to improve outcome for retinoblastoma in our center such as proper training, public awareness, team approach, and twinning.

Strategies to manage retinoblastoma in developing countries

Survival of retinoblastoma is >90% in developed countries but there are significant differences with developing countries in stage at presentation, available treatment options, family compliance, and survival. In low-income countries (LICs), children present with advanced disease, and the reasons are socioeconomic and cultural. In middle-income countries (MICs), survival rates are better (>70%), but there is a high prevalence of microscopically disseminated extraocular disease. Programs for eye preservation have been developed, but toxicity-related mortality is higher. Although effective treatment of microscopically extraocular disease improved the outcome, worldwide survival will be increased only by earlier diagnosis and better treatment adherence.

Discrimination of acute lymphoblastic leukemia from systemic-onset juvenile idiopathic arthritis at disease onset

OBJECTIVE

To assess clinical and laboratory features that differentiate acute lymphoblastic leukemia from systemic juvenile idiopathic arthritis at disease onset.

METHODS

Fifty-seven leukemia patients with musculoskeletal involvement, without blasts on peripheral blood and without glucocorticoid therapy at disease onset and 102 systemic juvenile idiopathic arthritis patients (International League of Associations for Rheumatology criteria) were retrospectively evaluated. The following features were examined: fever, rheumatoid rash, arthritis, limb pain, hepatomegaly, splenomegaly, pericarditis, myocarditis, pleuritis, weight loss, bleeding, anemia, leukopenia, neutropenia, thrombocytopenia, erythrocyte sedimentation rate, and lactic dehydrogenase levels.

RESULTS

The median age at disease onset was significantly higher in leukemia patients than in those with systemic-onset juvenile idiopathic arthritis (5.8 vs. 3.8 years). In addition, the frequencies of limb pain, hepatomegaly, weight loss and hemorrhagic manifestations were significantly higher in leukemia patients than in systemic-onset juvenile idiopathic arthritis patients (70% vs. 1%, 54% vs. 32%, 30% vs. 8%, and 9% vs. 0%, respectively). Likewise, the frequencies of anemia, leukopenia, neutropenia, thrombocytopenia and high lactic dehydrogenase levels were statistically higher in leukemia patients than in patients with systemic-onset juvenile idiopathic arthritis (88% vs. 57%, 39% vs. 1%, 60% vs. 1%, 77% vs. 1%, and 56% vs. 14%, respectively). Remarkably, multivariate analysis revealed that limb pain (OR = 553; 95% CI = 46.48-6580.42) and thrombocytopenia (OR = 754.13; 95% CI = 64.57-8806.72) were significant independent variables that differentiated leukemia from systemic-onset juvenile idiopathic arthritis. The R2 of the Nagelkerke test was 0.91, and the Kaplan-Meier survival curves were similar for acute lymphoblastic leukemia patients with and without limb pain.

CONCLUSION

Our study emphasizes the importance of investigating leukemia in patients presenting with musculoskeletal manifestations and, in particular, limb pain associated with thrombocytopenia.

Childhood leukemia incidence in Brazil according to different geographical regions

BACKGROUND

Resource-rich countries tend to have a higher incidence of childhood acute lymphoblastic leukemia (ALL), whereas lower rates are seen in more deprived countries. This study describes the incidence of childhood acute leukemia in Brazil, an upper middle-income country, based on data from 16 population-based cancer registries (PBCRs).

PROCEDURE

Data were examined from 16 PBCRs in Brazilian cities located in five geographical regions during the period from 1997 to 2004. Incidence rates were analyzed according to gender, age, and type of leukemia. The Wilcoxon test was performed to evaluate for gender-age based difference between by leukemia type.

RESULTS

The median age-adjusted incidence rate (AAIR) of leukemia in children aged 0-14 years old was 53.3 per million. A different AAIR was found regarding ALL and myeloproliferative disorders (MPD) that ranged from 24.8 to 76.84 per 1,000,000 children. Manaus, although located in a poor area of Brazil, exhibited the highest AAIR (56.6 per million) of ALL. Goiania had the highest AAIR (24.5 per million) of MPD. The median age-specific incidence rate (ASIR) for the 16 Brazilian PBCRs demonstrated a marked peak in incidence of ALL at age 3 years old, in both genders.

CONCLUSIONS

This population-based study of childhood leukemia demonstrates that substantial regional differences exist regarding the incidence of acute leukemia in Brazil, which warrants further ecological study.

Childhood cancer mortality in America, Asia, and Oceania, 1970 through 2007

BACKGROUND

Over the last 4 decades, childhood cancer mortality declined in most developed areas of the world. However, scant information is available from middle-income and developing countries. The authors analyzed and compared patterns in childhood cancer mortality in 24 developed and middle-income countries in America, Asia, and Oceania between 1970 and 2007.

METHODS

Childhood age-standardized annual mortality rates were derived from the World Health Organization (WHO) database for all neoplasms, bone and kidney cancer, non-Hodgkin lymphoma (NHL), and leukemias.

RESULTS

Since 1970, rates for all childhood cancers dropped from approximately 8 per 100,000 boys to 3 per 100,000 boys and from 6 per 100,000 girls to 2 per 100,000 girls in North America and Japan. Latin American countries registered rates of approximately 5 per 100,000 boys and 4 per 100,000 girls for 2005 through 2007, similar to the rates registered in more developed areas in the early 1980s. Similar patterns were observed for leukemias, for which the mortality rates were 0.81 per 100,000 boys and 0.55 per 100,000 girls in North America, 0.86 per 100,000 boys and 0.68 per 100,000 girls in Japan, and 1.98 per 100,000 boys and 1.65 per 100,000 girls in Latin America for 2005 through 2007. Bone cancer rates for 2005 through 2007 were approximately 2-fold higher in Argentina than in the United States. During the same period, Mexico registered the highest rate for kidney cancer and Colombia registered the highest rate for NHL, whereas the lowest rates were registered by Japan for kidney and by Japan and the United States for NHL.

CONCLUSIONS

Improvements in the adoption of current integrated treatment protocols in Latin American and other lower- and middle-income countries worldwide would avoid a substantial proportion of childhood cancer deaths.

Retinoblastoma - current treatment and future direction

Retinoblastoma is the commonest primary ocular malignancy of childhood. There are two forms - heritable and non heritable. Heritable retinoblastoma is a cancer susceptibility syndrome. Presentation is in the first few years of life, sometimes in the neonatal period. Early detection and prompt treatment can give cure rates up to 95% for intraocular tumours, but extraocular disease carries a very high mortality. The diagnosis is essentially clinical and biopsy is contraindicated due to the risk of extraocular spread. Treatment requires significant multidisciplinary input, with local ophthalmic treatment, systemic chemotherapy and external beam or plaque radiotherapy, or surgery to remove the affected eye. Screening of family members is essential for early detection. Lifelong surveillance of mutation carriers is needed due to the risk of second cancers. Newer treatment modalities including intra-arterial chemotherapy have been added to the therapeutic armamentarium in recent years.

Pediatric lymphomas in Brazil

OBJECTIVE

This study provides the clinical pathological characteristics of 1301 cases of pediatric/adolescent lymphomas in patients from different geographic regions of Brazil.

METHODS

A retrospective analyses of diagnosed pediatric lymphoma cases in a 10-year period was performed. We believe that it represents the largest series of pediatric lymphomas presented from Brazil.

RESULTS

Non-Hodgkin lymphomas represented 68% of the cases, including those of precursor (36%) and mature (64%) cell origin. Mature cell lymphomas comprised 81% of the B-cell phenotype and 19% of the T-cell phenotype. Hodgkin lymphomas represented 32% of all cases, including 87% of the classical type and 13% of nodular lymphocyte predominant type. The geographic distribution showed 38.4% of the cases in the Southeast region, 28.7% in the Northeast, 16.1% in the South, 8.8% in the North, and 8% in the Central-west region. The distribution by age groups was 15-18 years old, 33%; 11-14 years old, 26%; 6-10 years old, 24%; and 6 years old or younger, 17%. Among mature B-cell lymphomas, most of the cases were Burkitt lymphomas (65%), followed by diffuse large B-cell lymphomas (24%). In the mature T-cell group, anaplastic large cell lymphoma, ALK-positive was the most prevalent (57%), followed by peripheral T-cell lymphoma, then not otherwise specified (25%). In the group of classic Hodgkin lymphomas, the main histological subtype was nodular sclerosis (76%). Nodular lymphocyte predominance occurred more frequently than in other series.

CONCLUSION

Some of the results found in this study may reflect the heterogeneous socioeconomical status and environmental factors of the Brazilian population in different regions.