Evaluating access to pediatric cancer care centers of children and adolescents with rare tumors in Italy: the TREP project

Rare pediatric tumors in Germany - not as rare as expected: a study based on data from the Bavarian Cancer Registry and the German Childhood Cancer Registry

Very rare pediatric tumors (VRTs) pose a challenge for treating physicians as little is known about the best diagnostic assessment and therapeutic decision-making in these malignancies. A large proportion of these cancers occur in adolescence. Therefore, the established structures of pediatric oncology including cancer registration may partly be circumvented. This may lead to an underregistration in clinical cancer registries of yet unclear extent. The aim of this study is to increase the knowledge on the occurrence of VRTs in pediatric patients in Germany. Pseudonymized data of cases recorded in the Bavarian Cancer Registry (BCR) between 2002 and 2014 were retrieved. VRTs according to the definition of the European Cooperative Study Group for Pediatric Rare Tumors were identified using the ICD and ICD-O classification. The numbers of registered patients were compared to those reported to the German Childhood Cancer Registry (GCCR). 6.3% (n = 290) of all malignancies (n = 4615) in the age below 18 years were classified as VRTs. Median age at diagnosis was 15 years (range 0-17 years). The most common tumor types included malignant melanoma, skin carcinoma, and gonadal tumors. During the same period, 49 pediatric patients from Bavaria with matchable VRTs were reported to the GCCR, accounting for 17% of cases reported to the BCR.

CONCLUSIONS

The frequency of VRTs in Germany is underestimated in the national GCCR. With this study, we present population-based data on the incidence of VRTs in Germany for the first time. In order to gain additional knowledge about these malignancies, registration of VRTs must be improved through enhanced data exchange between the GCCR, the public cancer registries, and the clinical Registry for Rare Pediatric Tumors (STEP).

WHAT IS KNOWN

• Rare pediatric tumors pose a challenge for treating physicians as limited knowledge is available on these malignancies for diagnostic and therapeutic decision-making. • Little is known about the frequency of these rare tumors in pediatric patients.

WHAT IS NEW

• The frequency of rare pediatric tumors in Germany is distinctly underestimated in the German Childhood Cancer Registry. • We present population-based data on the incidence of these rare pediatric cancers for the first time.

Extra-appendicular neuroendocrine tumors: A report from the TREP project (2000-2020)

BACKGROUND

Extra-appendicular neuroendocrine tumors (NETs) are very rare tumors. While diagnostic and therapeutic guidelines are well established for adults, data on children and adolescents are lacking.

PATIENTS AND METHODS

Patients with a diagnosis of extra-appendicular NET registered on the Tumori Rari in Età Pediatrica - Rare Tumors in Pediatric Age (TREP) from 2000 to 2020 were analyzed. Clinical characteristics including patients' presentation, tumor features, treatment, and outcome were reviewed.

RESULTS

Twenty-seven patients with extra-appendicular NET registered on TREP with a median age of 173 months. The primary site was the pancreas (12) or bronchi (10) in the majority of cases. Other primary sites included the thymus, Meckel's diverticulum, and liver. Thirteen (48%) of tumors extended beyond the organ of origin: four invaded neighboring organs and/or regional nodes and nine involved distant metastases. The 3-year event-free survival (EFS) for those with localized disease was superior to those with metastatic disease (66.6% 95% CI 5-95% vs 33% 95% CI 5-68%, respectively; P = .005). A complete resection was feasible in 17 patients. The 3-year EFS in these patients was superior to those with no or incomplete resection (R0 vs R1/R2, respectively; P = .007). Overall, 16 children had no evidence of disease at follow-up, and one is alive with disease; five died, and five were lost to follow-up.

CONCLUSIONS

Data from our experience demonstrated a wide heterogeneity of presentation and outcome of these tumors. Localized disease and complete surgical resection were the main prognostic factors of good outcome. Other therapies may have a role in prolonging survival in metastatic disease.

Nasopharyngeal carcinoma among the pediatric patients in a non-endemic region: our experience at a tertiary care teaching hospital in Eastern India

Background

Nasopharyngeal carcinoma (NPC) is an extremely rare malignant lesion among the pediatric age group. The relative rarity of pediatric NPC makes the diagnosis difficult. This rarity is often associated with delayed diagnosis which may lead to advanced loco-regional disease. Here, we study the clinical presentations, investigations, and treatment of nasopharyngeal carcinoma in the pediatric age group in a non-endemic region.

Result

This is a retrospective study where 21 pediatric patients were enrolled with age under 18 years. They were managed at a tertiary care teaching hospital between December 2010 and January 2019. Majority of the patients in this study were boys (66.7%). All children diagnosed with NPC were treated with radiotherapy covering entire nasopharynx and some children with chemotherapy. Until the patient is in a late stage, most children diagnosed with NPC were presenting with symptoms of neck mass (90.5%), bleeding from the nose (66.7%), nasal blockage (57.1%), and hearing loss (47.6%). Pathological report revealed WHO type III in the majority of the patients. All patients were treated with radiotherapy to primary and enlarged neck nodes.

Conclusion

Children with NPC have excellent survival except for those with distant metastatic disease. NPC in the pediatric age is usually not suspected clinically until patient in late stage. The TNM staging has the most relevant prognostic factor. Unfortunately, NPC tends to be locally advanced at the time of diagnosis in the pediatric age group and is sometimes associated with distant metastasis. In our study, most children were diagnosed with NPC along with neck node enlargement and were treated with radiotherapy. The diagnosis of pediatric NPC should prompt timely treatment.

Pheochromocytomas and paragangliomas in children: Data from the Italian Cooperative Study (TREP)

BACKGROUND

Pheochromocytomas (PCs) are neuroendocrine tumors arising from the chromaffin cells of the adrenal gland, and paragangliomas (PGLs) are their extra-adrenal counterparts arising from ganglia along the sympathetic/parasympathetic chain. Surgery is the cornerstone of treatment. A sporatic or inherited germline mutation is commonly associated.

MATERIALS AND METHODS

Among over 1000 patients registered into the Tumori Rari in Età Pediatrica-rare tumors in pediatric age project-from 2000 to 2019, 50 were affected by PC/PGL. All clinical and therapeutic data were evaluated.

RESULTS

Twenty-eight patients had PC and 22 had PGL. Age at diagnosis ranged between 5 and 17 years. Thirty-five patients had symptoms related to catecholamine hypersecretion; in 7 of 50 patients, diagnosis was incidental or done during assessment of a familial syndrome. In all cases, conventional imaging was effective to assess the presence of a tumor. In addition, 18 of 38 functional imaging studies were positive (61%). Forty-eight patients were eligible for surgery: a complete resection was more frequently achieved in PC than in PGL (26/28 vs 11/22). All relapses were treated with surgery alone, surgery plus medical treatment, or chemotherapy alone; one PC with metastasis at diagnosis received radiotherapy only. Forty-four patients were in the first, second, or third complete remission (10/50 recurred; 8/10 carried a germline mutation). Five of 50 patients were alive with disease. One patient died of disease.

CONCLUSIONS

Surgery can be curative in most tumors but it may not be always effective in removing PGLs. Severe postsurgical sequelae may affect these patients. Genetic tests should always be considered in individuals affected, and genetic counseling should be offered to their families.

Inequalities in diagnosis and registration of pediatric very rare tumors: a European study on pleuropulmonary blastoma

Very rare tumors (VRTs) account for up to 11% of childhood cancers. Dedicated national groups and registries only exist in some European countries. Pleuropulmonary blastoma (PPB) is a very rare intrathoracic pediatric tumor with a potentially severe prognosis. Due to its rarity, it sometimes goes unrecognized. We investigated PPB diagnostic capability and possible correlations between diagnostic performance and VRT-dedicated activities. The number of cases of PPB registered between 2000 and 2014 at pediatric oncology centers in Europe was compared with the number of expected cases. Data sources included VRT registries, population-based cancer registries, and hospital registries. Data were obtained for 25 countries, grouped into 4 geographical regions. The expected cases were 111, and the observed cases were 129. The observed-to-expected ratio was 1.86 for Northern Europe, 1.33 for Southern Europe, 1.22 for Central Europe, and 0.65 for Eastern Europe. More cases than expected were registered in all countries with an official VRT registry.Conclusion: The number of cases observed is consistent with expectations, but disparities exist across Europe. Difficulties in diagnosing PPB emerged in most Eastern countries. The incidence rate of PPB may be underestimated. The creation of VRT-dedicated groups and a European Registry for VRTs could help to reduce inequalities.What is Known:• Very rare pediatric tumors are often not recognized, despite representing almost 11% of childhood cancers .• Pleuropulmonary blastoma is a rare pediatric tumor with a poor prognosis.What is New:• The ability to diagnose and register pleuropulmonary blastoma varies in Europe.Registries dedicated to very rare pediatric tumors improve the diagnostic rates.• The incidence rate of pleuropulmonary blastoma may currently be underestimated.

Challenges and solutions to the study of rare childhood tumors

PURPOSE OF REVIEW

The majority of progress made in pediatric oncology over the past 50 years has been achieved in the most common cancers. Rare pediatric cancers, which collectively comprise more than 10% of all pediatric cancers, pose multiple challenges to researchers and clinicians, all which stem from the infrequency of these cancers. There has been a tremendous increase in focus on rare pediatric cancers by international consortia and registries, disease-specific clinics, and divisions of academic children's hospitals in the last 10 years. This focus, along with the progress made in cancer genomics, has changed the landscape for the study and treatment of rare pediatric cancers. This review focuses on the past, present, and future of the study and treatment of rare pediatric cancers.

RECENT FINDINGS

Cancer genomics is changing the way some cancers are being diagnosed, categorized, and treated. Rare pediatric cancers potentially stand to greatly benefit from advances in precision diagnosis and treatment.

SUMMARY

The challenges of studying rare pediatric cancers are well known. By utilizing similar techniques that allowed for progress in the common pediatric malignancies, namely collaboration, increased focus, greater funding, and utilization of cancer genomics, progress in the study and treatment of rare pediatric cancers is promising.

Pleuropulmonary blastoma: a report from the TREP (Tumori Rari in Età Pediatrica) Project

INTRODUCTION

Pleuropulmonary blastoma (PPB) is a rare, aggressive mesenchymal tumor of childhood. The Italian Tumori Rari in Età Pediatrica (TREP) Registry was the first in Europe dedicated to prospective data collection on rare pediatric tumors. We analyzed data from an Italian series of patients with PPB, focusing on the role of the TREP Project.

METHODS

We considered patients aged 0-14 with histologically confirmed diagnosis, registered in population-based cancer registries (before 2000) or the TREP Registry (2000 to 2014), and analyzed data on clinical characteristics, treatment, and outcome. Event-free survival (EFS) and overall survival (OS) were estimated. Relevant prognostic factors were identified performing a univariate analysis.

RESULTS

Thirty-seven cases were included (7 type I, 13 type II, 17 type III). The average diagnosis rate rose from 1.10 to 1.73 cases/year after the TREP Project started. All patients underwent surgery, 33 received chemotherapy, and 9 had radiotherapy. The median follow-up was 8.7 years. For type I, II, and III, respectively, the 5-year OS was 85.7% (33.4-97.9), 52.7% (23.4-75.5), and 57.8% (31.1-77.3); the 5-year EFS was 85.7% (33.4-97.9), 52.7% (23.4-75.5), and 52.9% (27.6-73.0). Favorable prognostic factors for EFS were Intergroup Rhabdomyosarcoma Study (IRS) stage I (p = 0.03) and T1 tumor (p = 0.05). A total of 78.3% of patients who had chemotherapy after 2000 received a standardized treatment.

CONCLUSIONS

The TREP Registry showed an excellent capacity for registering cases of PPB. Patients received homogeneous treatment after the TREP Project started. Long-term outcomes were excellent for type I and unsatisfactory for type II and III. Tumor invasiveness and IRS stage were of prognostic value.

Update in pediatric nasopharyngeal undifferentiated carcinoma

Many of the principles established in adults with undifferentiated nasopharyngeal carcinoma (NPC) apply to children, adolescents and young adults. However, NPC in young patients should be distinguished from the adult form by several points. This review focuses mainly on differences between adult and pediatric NPC. The role of biology and genetics in pediatric NPC is discussed. Systemic treatment modalities including type of chemotherapy induction, timing of treatment, role of immunotherapy as adjuvant treatment, or in relapsing/ metastatic diseases are reported. Radiation modalities (doses, techniques…) in children are also reviewed. Long-term effects including secondary cancers are finally be discussed in this young NPC population.

Rare cancers in childhood and adolescence in Brazil: First report of data from 19 population-based cancer registries

BACKGROUND

Rare childhood cancer is challenging to define. The Italian Pediatric Rare Tumor (TREP) Study considers rare tumors to include solid malignancies characterized by an annual incidence rate of <2 cases per 1 million and not enrolled in clinical trials. The objective of the current study was to analyze the population incidence rate of rare tumors among children and adolescents (those aged birth-19 years) in Brazil.

METHODS

Incidence data were obtained from 19 population-based cancer registries covering the 5 geographic regions in Brazil. Newly diagnosed cases were selected according to the TREP definition, using the International Classification of Diseases for Oncology. To calculate the crude incidence rate, the numbers of incident children and adolescents with a specific rare cancer were divided by the corresponding person-years lived for the population aged <20 years during the same period.

RESULTS

Two tumors had an incidence rate that was >2 cases per 1 million (thyroid and skin cancers) in adolescents only. Several tumors demonstrated variations in incidence across the Brazilian regions. Adrenocortical carcinoma had a high incidence rate (4 cases per 1 million) in the south region among children aged <10 years. Thyroid and skin carcinoma had higher incidence rates in the midwest, southeast, and south regions.

CONCLUSIONS

Due to the extraordinary rarity of these events, networking is important for improving basic research, clinical studies, and trials. Centralization of diagnosis is the only way to improve the diagnosis and treatment of children affected by these rare diseases. The registration and surveillance of rare pediatric cancers are crucial from a public health point of view, and therefore the quality of registration has to be improved.

Pediatric patients with cutaneous melanoma: A European study

INTRODUCTION

Cutaneous melanoma is rare in childhood and published studies have mainly been retrospective single-institution series or small case series. Given the absence of clinical protocols dedicated to pediatric melanoma, the treatment approach is generally extrapolated from the ones applied to adults.

METHODS

Coordinated by the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT), this study collected patients prospectively registered between 2002 and 2012 under national cooperative projects dedicated to rare pediatric tumors in Italy, Poland, Germany, and France. Additional cases were collected from dermatology registries in Germany and Israel.

RESULTS

A total of 219 patients aged 0-18 years (median 14.4) were included in the analysis. Sentinel lymph node biopsy was performed in 112 patients (76% of those with Breslow thickness > 0.75 mm) and was positive in 37.5%. Systemic therapy was used in 33 cases. In stage III cases, survival rates were similar for patients who received (23 cases) or not (21 cases) adjuvant therapy. For the whole series, 3-year overall and disease-free survival rates were 91.4% and 84.0%, respectively (median follow-up 41.8 months). Tumor site, tumor stage, and ulceration influenced survival rates. Patients treated by pediatric oncologists (n = 140) were more likely to have advanced disease than those treated by dermatologists (n = 79).

DISCUSSION

This study would suggest that the clinical history of melanoma in children and adolescents might resemble that of adult counterpart. Cooperative efforts are needed to make new drugs more readily available to pediatric patients to increase the outcome of patient with advanced disease.

Rare cancers: Challenges & issues

Rare cancers account for about 22 per cent of all cancers diagnosed worldwide, disproportionately affecting some demographic groups, with an occurrence of less than 6 per 100,000 individuals annually. Many rare cancers in adults, adolescents and children are not curable, and patients and care providers have little option to take therapeutic decisions. The epidemiology of rare cancers is a challenging area of study but is inadequately addressed. Despite efforts mainly in some European nations, a few improvements have been observed in the management of rare cancers. Reasons for this obvious stagnation are multifactorial and are mainly inherent to logistical difficulties in carrying out clinical trials in very small patient populations, hesitation of the pharmaceutical industry to spend in small markets and complexity in creating adequate information for the development of cost-effective drugs. Rare cancers also face specific challenges that include late and incorrect diagnosis, lack of clinical expertise and lack of research interest and development of new therapies. The utilization of nationally representative study findings for the patients' evaluation may possibly offer chances to find out pathogenesis and prevalence, and this will eventually lead to control and prevention. Currently, advancing targeted therapies offer a great opportunity for the better management of rare cancers. Conducting clinical trials with small patient population, innovative clinical trial approach, prevailing controlling obstacles for international cooperation and financial support for research are the present challenges for rare cancers. The International Rare Cancers Initiative functions as a main platform for achieving new international clinical trials in rare tumours. This review delineates the current challenges and issues in the interpretation, management and research scenarios of rare cancers.

Gastrointestinal tract carcinoma in pediatric and adolescent age: The Italian TREP project experience

BACKGROUND

Gastrointestinal (GI) carcinomas are very rare in the pediatric and adolescent age range. We report the clinical features, treatment, and outcome of a series of children and adolescents with GI carcinoma prospectively registered in the Italian Tumori Rari in Età Pediatrica (TREP) project.

METHODS

The TREP project developed diagnostic and therapeutic guidelines based on recommendations currently in use for adults. Clinical data were centrally registered and reviewed.

RESULTS

Fifteen patients were registered over the years 2000-2016. Most of the tumors were colorectal carcinomas (12 cases). All but one patient had advanced-stage disease (American Joint Committee on Cancer stages III-IV), and the majority of patients had aggressive histological subtypes, i.e. poorly differentiated (G3) (five patients), mucinous (four patients), and signet ring (two patients) adenocarcinomas. Surgery was performed in 13 of 15 patients, and was radical in nine of 13 patients. Only one patient received postoperative radiotherapy. All patients received chemotherapy, with the addition of bevacizumab in two cases. Nine patients were still alive at the time of the present report, but two of them had only just completed their treatment program and one patient is still on treatment. Six patients died due to disease progression.

CONCLUSIONS

This prospective report on pediatric GI tract carcinomas confirms the rarity and biological aggressiveness of these diseases in pediatric and adolescent age. Further prospective studies are needed to explore the distinct biology of tumor in this age group in order to find new therapeutic targeted agents.

Epithelial Tumors of the Ovary in Children and Teenagers: A Prospective Study from the Italian TREP Project

STUDY OBJECTIVE

To report the clinical findings and treatment results of a series of patients with epithelial tumors of the ovary, registered and treated prospectively in a multi-institutional Italian network (TREP project) on rare tumors in children and adolescent between 2000 and 2014.

DESIGN, SETTING, AND PARTICIPANTS

Data on 16 patients, aged 22 to 206 months, from 7 centers were reviewed. All patients were grouped on the basis of the results of the first surgical approach, according to the Children Oncology Group staging system.

RESULTS

The most frequent symptom was abdominal pain; 3 patients were hospitalized for acute pain after ovarian torsion. Initial surgical treatment was complete in 15 of 16, and a biopsy was performed in 1 of 16. The histology examination revealed 8 benign tumors (7 mucinous cystadenomas and 1 serous cystadenoma) and 8 borderline tumors (2 serous and 6 mucinous). Fifteen of 16 patients maintained the complete remission after surgical treatment alone; 1 affected by Proteus syndrome died consequent to the progression of a synchronous Wilms tumor, after a delayed incomplete surgery.

CONCLUSION

Our analysis documented the rarity of these tumors in children and adolescents. No malignant histologies were found. Surgery alone was effective to cure the majority of patients. Considering the rarity of malignant entities, ovary-sparing surgery may be planned when an epithelial tumor is suspected on the basis of the preoperative work-up and intraoperative findings.

Management and follow-up of urothelial neoplasms of the bladder in children: a report from the TREP project

BACKGROUND

Urothelial neoplasms of the bladder (UNB) are rare in patients under 20 years of age, and even rarer in the first decade of life. The present series was investigated to provide recommendations on patient management in terms of therapeutic strategy and follow-up.

PROCEDURE

This is a retrospective analysis on 12 patients with UNB under 18 years of age. Data were extracted from the national database of the TREP (Tumori Rari in Età Pediatrica) Project.

RESULTS

Ten of the 12 patients presented with a single episode of hematuria, while the discovery of the lesion was incidental in two. Eleven of the 12 lesions were G1 and one was G2/G3; none of the lesions invaded the lamina propria. All lesions were removed completely by transurethral resection. No further treatment was administered in nine children but three received a single dose of intravesical chemotherapy (epirubicin in 2, mitomycin in 1). Only one patient experienced a recurrence and all patients are alive in complete remission with a median follow-up of 30 months (range 4-112). Follow-up investigations varied at the different centers and included abdominal ultrasound in nine patients, cystoscopy in seven, and additional radiological investigations in a few cases.

CONCLUSIONS

UNB in children seems to be a low-grade, scarcely aggressive disease with an excellent prognosis. The role of intravesical chemotherapy is debatable. Follow-up can be based on ultrasound. The adoption of shared recommendations should enable unnecessary treatment and invasive investigations to be avoided.

Selected case from the Arkadi M. Rywlin International Pathology Slide Club: carcinoma of the transverse colon in a young girl

We report a case of a 14-year-old female with primary adenocarcinoma of the transverse colon. She was hospitalized after presenting with abdominal pain and signs of intestinal obstruction. There was no health antecedent or family history of neoplasia. Physical examination revealed a distended abdomen. Tenderness was elicited to palpation of the right lower quadrant. Magnetic resonance imaging of the abdomen revealed obstructive signs, with a constricting lesion in the mid-transverse colon of probable neoplastic nature. Laparoscopic segmental resection of the colon was followed by standard right hemicolectomy. A circumferential mid-transverse tumor was diagnosed as primary colorectal carcinoma (CRC) of signet-ring cell type, AJCC stage IIIC, Dukes' C stage. On the basis of immunohistochemistry and clinical data, hereditary nonpolyposis and hamartomatous colorectal cancer syndromes were excluded. Involvement of either the p53, BRAF, or K-RAS genes was ruled out by immunohistochemistry profiling and genetic testing. The neoplasm was categorized as sporadic. The possibility of activation of the Wnt signaling pathway was suspected, because of a defective turnover of the β-catenin protein. Postoperatively, the patient was treated with both systemic and intra-abdominal adjuvant chemotherapy, including oxaliplatin. Between 18 and 24 months after diagnosis, intra-abdominal tumor recurrences were detected. The patient underwent bilateral oophorectomies for Krukenberg tumors and received salvage chemotherapy. Recently, additional recurrent metastatic retroperitoneal disease caused hydronephrosis. The retroperitoneal mass was debulked and a ureteric stent was placed. At the time of this writing, 43 months after diagnosis, the patient is receiving FOLFOX chemotherapy combined with panitumumab. CRC of childhood is exceedingly rare, generally develops in the setting of unrecognized genetic predisposing factors to cancer, presents with advanced disease, is high grade, and tends to have dismal prognosis.

Salivary gland carcinomas in children and adolescents: the Italian TREP project experience

BACKGROUND

Salivary gland carcinomas are extremely rare in pediatric age. We report the clinical features of a series of children/adolescents with salivary gland carcinomas prospectively registered in the Italian TREP (Rare Tumors in Pediatric Age) project.

PROCEDURES

Diagnostic/therapeutic guidelines were developed and shared among Italian pediatric oncology/surgical centers.

RESULTS

Seventeen patients were registered between 2000 and 2012, representing 19% of the cases expected to be seen based on epidemiological data. Tumors arose mainly in the parotid gland (14 cases). In most cases they were low-grade tumors (14 cases), often with a favorable clinical presentation, and low-stage disease. All patients underwent surgical resection, achieving histologically free margins in 9/17 cases. Thirteen of the 14 patients with parotid gland tumors had parotidectomy (10 total, 3 superficial), while one had a tumorectomy. Postoperative facial nerve lesions were reported in two cases. Adjuvant radiotherapy was given to 6 patients. The overall prognosis was good: only one patient with a huge high-grade tumor experienced disease progression and died of the disease. The other 16 patients were alive in first continuous remission 1-8 years after diagnosis. In 4/17 cases, the salivary gland carcinoma was a second tumor occurring 6-9 years after another primary cancer.

CONCLUSIONS

This is the first reported prospective national cooperative series of pediatric salivary gland carcinoma patients. Compliance with the TREP recommendations was high. These tumors are rarely managed by pediatric oncologists/surgeons. A broader international cooperation and better networking with otolaryngologists and head-neck surgeons expert on adult salivary gland carcinomas would be advisable.

Adrenocortical tumors in Italian children: analysis of clinical characteristics and P53 status. Data from the national registries

AIM

Adrenocortical tumors are very rare in children. The distinction between adenoma and carcinoma is complex because of their clinical/histological characteristics. The analysis of the cases registered in two consecutive Italian Studies is described, in order to provide additional insight into their nature and possibly identify benign and malignant lesions.

MATERIALS AND METHODS

The analysis includes patients registered from?? 1.1982 to 6.2011 into two consecutive Italian protocols.

RESULTS

Fifty-eight children (age 2-210months) were evaluated. Endocrine manifestations were the most frequent symptoms. Stage distribution at diagnosis was: ST I 35, ST II 17, ST III 1, ST IV 5. Treatment consisted in mitotane for ST II, mitotane+chemotherapy for ST III/IV. Forty-four patients are alive without evidence of disease, 1 is alive with disease, 12 died of disease and 1 because of cardiomyopathy. The Wienecke score system was applied in 24 patients with good significance. A p53 mutation was found in 7 cases, and it was diagnostic for Li-Fraumeni syndrome in 2 benign tumors.

CONCLUSIONS

The results highlight the importance of a complete excision to obtain the cure of patients. The efficacy of chemotherapy is controversial, however it was able to control the disease in 4 patients in ST II. The value of the Wienecke score system in predicting patients' outcome was confirmed. p53 mutation was more frequent in malignant tumors and represented the sentinel of the Li-Fraumeni syndrome.

Rare malignant pediatric tumors registered in the German Childhood Cancer Registry 2001-2010

BACKGROUND

The German Childhood Cancer Registry (GCCR) annually registers approximately 2,000 children diagnosed with a malignant disease (completeness of registration >95%). While most pediatric cancer patients are diagnosed and treated according to standardized cooperative protocols of the German Society for Pediatric Oncology and Hematology (GPOH), patients with rare tumors are at risk of not being integrated in the network including trials and reference centers.

PROCEDURE

A retrospective analysis of all rare extracranial solid tumors reported to the GCCR 2001-2010 (age <18 years) was undertaken using a combination of the International Classification of Childhood Cancer (ICCC-3) and the International Classification of Diseases-Oncology (ICD-O-3). Tumors accounting for <0.3% of all malignancies were defined as rare (approx. 6 cases/year and registered malignancy).

RESULTS

According to this definition 1,189 rare extracranial solid tumors (18.2% of all malignant extracranial solid tumors) were registered, among these 232 patients (19.5% of rare tumor cases), were not included in preexisting GPOH studies/registries. Within 10 years, the number of registered non-GPOH-trial patients with a rare tumor increased.

CONCLUSIONS

Though most of the GCCR-registered patients with rare malignant tumors are treated within GPOH trials, there is a considerable number of patients that have been diagnosed and treated outside the structures of the GPOH. These patients should be reported to the recently founded German Pediatric Rare Tumor Registry (STEP). Active data accrual and the development of appropriate structures will allow for better registration and improvement of medical care in these patients.

Myoepithelial carcinoma treatment in children: a report from the TREP project

BACKGROUND

Myoepithelial carcinoma (MC) of soft tissues is an aggressive tumor that rarely affects children, for whom no established treatment protocols exist. As part of the TREP (Tumori Rari in Età Pediatrica) project - an Italian network dedicated to children and adolescents with very rare tumors - we present a series of patients with MC, who were treated homogeneously and achieved a satisfactory outcome.

PROCEDURE

From 2005 to 2012, seven patients (age 0.5-9.2 years) with a diagnosis of MC were registered in the TREP study. After one patient treated with ifosfamide, cisplatin, and etoposide showed tumor shrinkage and experienced long-term disease remission, all subsequent patients were treated with the same chemotherapy regimen. All patients also received radiotherapy.

RESULTS

Initial surgical management involved a biopsy in three cases and tumor resection in 4. Response to initial chemotherapy was evaluable in four patients: two had a partial remission, one a minor response and one stable disease. Four patients received external-beam radiotherapy and three had brachytherapy. Overall, six patients are alive in first complete remission with a median follow-up of 2.5 years (0.9-5.1 years).

CONCLUSIONS

Though our experience is limited to a small number of patients, our treatment strategy for patients with MC is appears clinically useful and demonstrates how cooperation within the TREP project has enabled enough data to be collected to propose treatment recommendations for pediatric patients with this very rare tumor.

Rare childhood tumors in a Turkish pediatric oncology center

Background:

It has been estimated that rare tumor rate is about 15% of all childhood cancer in United States. According to Turkish Pediatric Oncology Group (TPOG) datas, 8889 children were diagnosed between 2002 and 2008 in our country and 3.7% of them were diagnosed as rare tumors.

Aim:

To investigate the frequency and clinical features of rare tumors in our pediatric oncology center.

Materials and Methods:

A total of 43 cases that have diagnosed as rare tumor in 574 cancer patients between the yaer 2002 and 2012 were reviewed retrospectively. All cases definitive diagnosis were established by histopathological and immunohistochemical studies.

Results:

Frequency of rare tumors was 7.4% in our center. Benign and border line rare tumors were 27 (62.7%) cases, malignant rare tumor were 16 (37.2%) cases. Median follow-up period was 48 months (between 1 and 110 months). Six of the malignant rare tumors were died with progressive disease (synovial sarcoma, mixed malignant mesenchymal tumor, undifferentiated sarcoma, plexus choroideus carcinoma, renal peripheral primitive neuroectodermal tumor, adrenocortical carcinoma). Malignant rare tumor mortality rate was found 37.5% in our clinic.

Conclusion:

We have found that our rare tumor rate (7.4%) was higher than Turkish rare tumor rate (3.7%) according to TPOG's datas. However, it was still lower than rare tumor rates of western countries (15%), probably due to difficulties of diagnosis and referral problems.

Appendiceal neuroendocrine tumours in childhood: Italian TREP project

BACKGROUND

Neuroendocrine tumours (NETs) of the appendix are slow-growing tumours and, although rare, they are the most common gastrointestinal epithelial tumours in childhood and adolescence. The treatment and the follow-up screenings have not been standardised. In addition to this, although tumour size is considered the main prognostic variable to define the aggressiveness of approach, a precise cutoff needs to be established.

METHODS

A total of 113 patients younger than 18 years with a diagnosis of appendiceal NETs were registered as of January 1, 2000, until May 30, 2013, within the Rare Tumors in Pediatric Age (TREP) project, an Italian multi-institutional network dedicated to rare tumours in children and adolescents. The recommendations of the Rare Tumors in Pediatric Age study included imaging and laboratory investigations. The treatment after appendectomy was decided on the basis of histology, tumour size, and imaging; primary reexcision (PRE) was not recommended in completely excised tumours, regardless of tumour size and invasiveness.

RESULTS

A total of 113 of 113 patients had a diagnosis of well-differentiated NETs; in 108 of 113 the tumour was smaller than 2 cm and in 5, larger than 2 cm. Excision margins were free in 111 of 113 patients. In 3 of 113 a PRE was performed, and in 1 residual tumour was detected. All 113 of 113 patients are alive in complete remission (median follow-up of 41 months).

CONCLUSIONS

Reported data and our experience showed that no relapse or death occurred in children and adolescents affected by appendiceal NETs. Appendectomy alone should be considered curative for most patients, and a more aggressive surgical approach is warranted in the cases with incompletely excised tumours.

Cutaneous melanoma in children and adolescents: the Italian rare tumors in pediatric age project experience

OBJECTIVE

To describe a series of cutaneous melanoma in children collected by the Italian Rare Tumors in Pediatric Age project.

STUDY DESIGN

From 2000 to 2012, 54 patients younger than 18 years of age were prospectively registered and treated at 12 Italian pediatric centers on the basis of the same diagnostic/therapeutic recommendations and with the same forms to record clinical data.

RESULTS

Considering the estimated annual incidence in Italy, the registered cases accounted for 30% of those expected in children and 10% of adolescents. Clinically, 47% of the tumors were amelanotic and 81% were raised, 39% of cases had tumor thickness >2 mm, and 36% had lymph node involvement. For the whole series, 5-year event-free survival and overall survival rates were 75.2% and 84.6%, respectively. Patient survival correlated with tumor stage and ulceration. No relapses were recorded for T1-2 (thickness <2 mm), N0, and stage 0-I-II cases.

CONCLUSION

We suggest that the variables influencing survival in children with melanoma are the same as for adults, the clinical approach used in adults is feasible in children, and pediatric cases are more likely to have advanced disease at diagnosis but similar survival. New effective drugs are needed for advanced disease, and biological studies and international cooperative schemes are warranted.

GATA-4 and FOG-2 expression in pediatric ovarian sex cord-stromal tumors replicates embryonal gonadal phenotype: results from the TREP project

AIM

GATA proteins are a family of zinc finger transcription factors regulating gene expression, differentiation and proliferation in various tissues. The expression of GATA-4 and FOG-2, one of its modulators, was studied in pediatric Sex Cord-Stromal tumors of the ovary, in order to evaluate their potential role as diagnostic markers and prognostic factors.

MATERIALS AND METHODS

Clinical and histological data of 15 patients, enrolled into the TREP Project since 2000 were evaluated. When available, immunostaines for FOG-2, GATA-4, α-Inhibin, Vimentin and Pancytokeratin were also analyzed.

RESULTS

In our series there were 6 Juvenile Granulosa Cell Tumors (JGCT), 6 Sertoli-Leydig Cell Tumors (SLCT), 1 Cellular Fibroma, 1 Theca Cell Tumor and 1 Stromal Sclerosing Tumor (SST). Thirteen patients obtained a complete remission (CR), 1 reached a second CR after the removal of a metachronous tumor and 1 died of disease. Inhibin was detectable in 11/15, Vimentin in 13/15, Pancytokeratin in 6/15, GATA-4 in 5/13 and FOG-2 in 11/15. FOG-2 was highly expressed in 5/6 JGCT, while GATA-4 was weakly detectable only in 1 of the cases. SLCT expressed diffusely FOG-2 (4/6) and GATA-4 (3/5). GATA-4 and FOG-2 were detected in fibroma and thecoma but not in the SST.

CONCLUSIONS

Pediatric granulosa tumors appear to express a FOG-2/GATA-4 phenotype in keeping with primordial ovarian follicles. High expression of GATA-4 does not correlate with aggressive behaviour as seen in adults, but it is probably involved in cell proliferation its absence can be associated with the better outcome of JGCT. SLCTs replicate the phenotype of Sertoli cells during embryogenesis in normal testis. In this group, the lack of expression of FOG-2 in tumors in advanced stages might reveal a hypothetical role in inhibiting GATA-4 cell proliferation pathway. In fibroma/thecoma group GATA-4 and FOG-2 point out the abnormal activation of GATA pathway and might be involved in the onset of these tumors.

Treating rare cancer in children: the importance of evidence

The study of pediatric rare cancers, which account for approximately 9% of all childhood malignancies, has been hindered by their histologic heterogeneity and by their preferential occurrence in adolescents, a population that has been underrepresented in clinical trials sponsored by the National Cancer Institute. The use of cooperative group and investigator-initiated registries can help improve our ability to identify and select populations of patients with rare cancers that can benefit from single-arm studies, and incorporation of biologic aims and tissue banking can accelerate our understanding of the biology of these cancers. These studies should be promoted further through expansion of international outreach efforts. Well-designed preclinical models that accurately recapitulate human disease offer an attractive alternative to the study of rare cancers and may accelerate the process of target identification and drug discovery and development. The concept of specialized clinics for selected rare cancers has proven to be very successful in pediatric gastrointestinal tumors. This paradigm should be further explored in other rare cancers because it offers an unprecedented opportunity to collaborate closely with interested investigators. In addition, it offers patients an opportunity to discuss their disease with specialists, allows these patients to provide tissue for further research, and ultimately can promote the development of clinical trials that are unique for that specific disease.

A prospective protocol for nasopharyngeal carcinoma in children and adolescents: the Italian Rare Tumors in Pediatric Age (TREP) project

BACKGROUND

Nasopharyngeal carcinoma (NPC) is very rare in childhood. It differs from its adult counterpart in the prevalence of the nonkeratinizing, undifferentiated subtype and by an advanced clinical stage at onset and better chances of survival. The risk of long-term treatment-related toxicity also may be a more important issue in younger individuals.

METHODS

A prospective chemoradiotherapy protocol for pediatric NPC was started in Italy in 2000 within the framework of the Rare Tumors in Pediatric Age (TREP) project. Three courses of cisplatin/5-fluorouracil induction chemotherapy were followed by radiotherapy (doses up to 65 grays) with concomitant cisplatin.

RESULTS

Forty-six patients (ages 9-17 years) were considered eligible for the study over a 10-year period. The ratio of observed to expected cases based on epidemiological data was approximately 1 for both children and adolescents. All but 1 patient had lymph node involvement, and 5 patients had distant metastases. The rate of response to primary chemotherapy was 90%. The 5-year overall and progression-free survival rates were 80.9% and 79.3%, respectively (median follow-up, 62 months). The only statistically significant prognostic variable was the presence or absence of distant metastases. A 65% incidence of late sequelae was reported.

CONCLUSIONS

This study demonstrates the feasibility and efficacy of a prospective protocol even for such rare tumors as pediatric NPC. The use of lower radiotherapy doses than those used in adults did not affect locoregional failure rates. Long-term follow-up will be needed to obtain more information on both survival and treatment sequelae. The next objective will be to establish broader, international prospective cooperation schemes.

Sex cord stromal tumors of the ovary in children: a clinicopathological report from the Italian TREP project

BACKGROUND

Ovarian sex-cord stromal tumors (SCST) are rare in childhood and include a variety of neoplasms with different clinical features and biologic behavior. Aim of the analysis was to report the clinical findings and treatment results of a series of patients with SCST of the ovary, registered in a multi-institutional Italian network on rare tumors in children and adolescent between 2000 and 2009.

METHODS

Data on 23 patients, 5-176 months old, from 13 Centers were reviewed. All patients were grouped on the basis of the results of the first surgical approach, according to the Children Oncology Group staging system. A cisplatin based chemotherapy was recommended in patients with a localized disease, who had undergone an incomplete excision/initial biopsy, and in case of metastatic spread.

RESULTS

A frequent symptom was abdominal pain; 9/23 cases had signs of hormonal secretion and two patients were hospitalized for acute pain following ovarian torsion. Twelve patients had a Juvenile-Granulosa Cell tumor, six a Sertoli-Leydig Cell tumor, three a Fibrothecoma, and two a Sclerosing-Stromal tumor. Twenty-one patients maintained the complete remission (follow-up: 9-91 months), 2 with a ST II Sertoli-Leydig Cell tumor relapsed and one of them died. Immonohistochemical studies could be done in 10 cases.

CONCLUSIONS

Completeness of resection and histology were important prognostic factors; in our series the Sertoli-Leydig Cell tumor was the most aggressive variety. Hormonal signs (precocious puberty, telarca, menarche) were common in younger patients and led to an early diagnosis. Cisplatin based chemotherapy seemed to be effective for locally advanced tumors.

Epithelial thymic tumours in paediatric age: a report from the TREP project

BACKGROUND

Thymic epithelial tumours (thymoma and carcinoma) are exceptionally rare in children. We describe a national multicentre series with a view to illustrating their clinical behaviour and the results of treatment.

METHODS

From January 2000 all patients under 18 years of age diagnosed with "rare paediatric tumours" were centrally registered by the Italian centres participating in the TREP project (Tumori Rari in Età Pediatrica [Rare Tumours in Paediatric Age]). The clinical data of children with a thymic epithelial tumour registered as at December 2009 were analyzed for the purposes of the present study.

RESULTS

Our series comprised 4 patients with thymoma and 5 with carcinoma (4 males, 5 females; median age 12.4 years). The tumour masses were mainly large, exceeding 5 cm in largest diameter. Based on the Masaoka staging system, 3 patients were stage I, 1 was stage III, 1 was stage IVa and 4 were stage IVb.All 3 patients with stage I thymoma underwent complete tumour resection at diagnosis and were alive 22, 35 and 93 months after surgery. One patient with a thymoma metastasizing to the kidneys died rapidly due to respiratory failure.Thymic carcinomas were much more aggressive, infiltrating nearby organs (in 4 cases) and regional nodes (in 5), and spreading to the bone (in 3) and liver (in 1). All patients received multidrug chemotherapy (platinum derivatives + etoposide or other drugs) with evidence of tumour reduction in 3 cases. Two patients underwent partial tumour resection (after chemo-radiotherapy in one case) and 4 patients were given radiotherapy (45-54 Gy). All patients died of their disease.

CONCLUSIONS

Children with thymomas completely resected at diagnosis have an excellent prognosis while thymic carcinomas behave aggressively and carry a poor prognosis despite multimodal treatment.

Renal cell carcinoma in children and adolescents

Although rare in children and adolescents, renal cell carcinomas (RCCs) raise important questions concerning the best treatment approach and accurate pathologic classification. The differences emerging between childhood and adulthood RCC probably prevent any direct generalized application of therapies to children that are validated for adults. The translocation type of RCC, which forms a distinct category characterized by translocations involving Xp11.2 or, less frequently, 6p21, has recently emerged as the predominant type of RCC in children and adolescents, whereas it is rarely diagnosed in adults. This new finding emphasizes how important it is to prospectively classify RCCs in children with standardized 'modern' diagnoses. The standard cornerstone of therapy for RCC in children and adolescents remains radical nephrectomy. Nephron-sparing surgery is currently recommended in adults for selected small-volume tumors, but additional data are needed before this experience can be extensively transferred to the pediatric population. The therapeutic value of complete retroperitoneal lymph node dissection is still controversial, especially in patients without suspected nodal involvement, be they adults or children. The backbone of systemic therapies for adult RCC has recently been changed by the introduction of drugs designed to target tumor-related angiogenesis and signal transduction. It is worth noting that the largest clinical efficacy trials on targeted molecules have been conducted on clear-cell RCC. While targeted drugs have become the standard of care for adult metastatic RCC, there are currently no published reports on their role in children, and their use should be considered for patients with unresectable metastatic or advanced-stage RCC. On the other hand, the utility of targeted therapies in the adjuvant setting remains to be seen for both adults and children.

Salivary gland carcinomas in children and adolescents: a population-based study, with comparison to adult cases

BACKGROUND

Salivary gland carcinomas are rare malignancies, particularly in young individuals in whom only scanty data are available from published studies.

METHODS

We searched the SEER database (1973-2006) for patients with a reported diagnosis of salivary gland carcinoma; children/adolescents (<20 years old) were compared with adults.

RESULTS

We identified 263 children/adolescents (58% girls) and 12,571 adults (43% women). The most common histology was mucoepidermoid carcinoma in both groups, but the percentages of other histologies were different. Children/adolescents had more favorable features with most tumors being localized, with no extension to adjacent tissues or lymphatic spread (76% vs 50% in adults, p < .001). Also most tumors were well differentiated or moderately differentiated (88% vs 49% in adults, p < .001). The 5-year overall survival for children/adolescents was 95% ± 1.5%, compared with 59% ± 0.5% for adults (p < .001).

CONCLUSION

When compared with adults, salivary gland carcinomas in children/adolescents are less advanced, and have more favorable features and better outcome.

Infrequent tumor initiative of the Children's Oncology Group: initial lessons learned and their impact on future plans

The merger of the Pediatric Oncology Group, Children's Cancer Group, the Intergroup Rhabdomyosarcoma Study Group, and the National Wilms Tumor Study Group in 2000 offered the newly formed Children's Oncology Group (COG), an opportunity to study rare cancers that had not been the subject of organized evaluation within the context of a cooperative group. In 2002, the COG formed the rare tumor committee which is comprised of four subcommittees. This article details the experience of the infrequent tumor subcommittee for the period of 2002 to 2007. During the initial implementation of this strategy, we have observed low rates of registration within the COG registry and low levels of participation in open banking, biology, and first-line therapeutic studies. This initial experience has allowed us to develop alternative strategies to increase registration rates and clinical trial enrollments. It is hoped that these new plans will allow us to increase our ability to better understand the biology and improve the treatment outcome of young patients with infrequent cancers. Furthermore, our initial experience has demonstrated to us the potential power of expanded cooperation and collaboration at a global level.

Sex cord-stromal tumors of the testis in children. A clinicopathologic report from the Italian TREP project

PURPOSE

Testicular sex cord-stromal tumors (SCSTs) are very rare in children and include a variety of neoplasms with different clinical features and biologic behavior. Aim of the study was to report the clinical findings and results observed in a series of patients with testicular SCST, registered in a multi-institutional Italian network on rare tumors in children and adolescents.

MATERIALS AND METHODS

The records of 11 patients, enrolled in 6 Italian centers from January 2000 to December 2008, were reviewed. The Children's Oncology Group (COG) staging system was adopted. Chemotherapy was recommended in patients with incomplete surgery or metastatic disease.

RESULTS

A testicular mass was the most common symptom. All patients underwent primary removal of the tumor; orchiectomy with high ligation of spermatic cord was performed in 7 and tumor enucleation in 4. At histology, 4 patients had Leydig cell tumors, 4 juvenile granulosa cell tumors, 1 Sertoli cell tumor, 1 incompletely differentiated SCST, and 1 SCST with an intermediate pattern Sertoli cell tumor/mixed form. The histology of 8 of 11 cases was reviewed and investigated through immunohistochemical stains. Ten children were in stage I; 1 patient, who did not undergo hemiscrotectomy after enucleation through a transscrotal access, was considered stage II. All the patients are in first complete remission (mean follow-up, 59 months; range, 8-94).

CONCLUSIONS

Our experience confirmed the rarity of testicular SCST. They have to be considered in the differential diagnosis of testicular solid masses, taking into account that hormonal signs are present in a minority of cases. All patients were cured with surgery alone. The sparing surgery represented a choice in selected cases.

Differential features of nasopharyngeal carcinoma in children and adults: a SEER study

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a rare malignancy in the United States, which is considered a low-risk country.

METHODS

We searched the surveillance, epidemiology, and end results (SEER) database for patients with NPC who were diagnosed from 1988 to 2006. We compared the clinical features and outcomes of children and adolescents (<20 years old) and adults.

RESULTS

The incidence for children and adolescents was 0.5 per million person-years versus 8.4 in adults. NPC was less rare in black children and adolescents (incidence, 1.5 per million person-years). Our search criteria retrieved 129 children and adolescents and 5,885 adults. Black children and adolescents represented 34.9% of patients below the age of 20 years. Younger patients had distinct features with advanced stages more frequently observed (31% and 46% of children and adolescents had stages III and IV, respectively) and 87% had WHO type III histology. Outcome was better in children and adolescents with 5-year NPC-specific survival of 83% +/- 3.9% compared to 62% +/- 0.8% in adults (P < 0.001). In a multivariate model, the following factors affected the outcome: age, race, stage, and histologic type. Young adults (20-45 years old) had almost double the risk of NPC-specific mortality when compared to children and adolescents [hazards ratio (HR), 1.93; P = 0.0077]. Children and adolescents with NPC were at higher risk of getting second cancer than adults (observed-to-expected ratio of 4.36 in children and adolescents; vs. 1.41 in adults; both were significantly higher than general population).

CONCLUSION

Despite the use of similar treatment approaches, NPC in children and adolescents may have different biologic features. Young patients are at higher risk of developing therapy related complications, including second cancer.

Pancreatic tumors in children and adolescents: the Italian TREP project experience

INTRODUCTION

Malignant pancreatic tumors are exceedingly rare in pediatric age and their clinical features and treatment usually go unappreciated by most pediatric oncologists and surgeons.

METHODS

From January 2000 to July 2009, 21 patients <18 years old with pancreatic tumors were prospectively registered in the Italian cooperative TREP project dedicated to very rare pediatric tumors.

RESULTS

Tumor types were 4 pancreatoblastomas, 2 pancreatic carcinomas, 3 neoplasms of the endocrine pancreas, and 12 solid pseudopapillary tumors. Three of the four patients with pancreatoblastoma had advanced disease at diagnosis and were given chemotherapy; at the time of this report, three patients were alive in first remission, while one died due to treatment toxicity. Both the cases of pancreatic carcinoma had the acinar cell subtype and successfully underwent pancreaticoduodenectomy with complete tumor resection, remaining without evidence of disease at the time of this analysis. The histological diagnoses of the three endocrine tumors were a malignant islet cell tumor, a gastrinoma, and a well-differentiated tumor. All 12 patients with solid pseudopapillary tumors underwent complete tumor resection and were given no adjuvant treatment; 11 were alive in first remission, while one experienced a local and distant relapse 5 years after diagnosis.

CONCLUSIONS

Surgery remains the keystone of treatment for pancreatic tumors in pediatric age as in adults. The TREP project shows that prospective cooperative studies are feasible even for such very rare tumors as these and may serve as a model for developing international cooperative schemes.

Distinct features of colorectal cancer in children and adolescents: a population-based study of 159 cases

BACKGROUND

Colorectal cancer is exceedingly rare in children and adolescents. Reports from small series indicate that poor prognostic factors are more common in children than in adults, resulting in worse outcome for the pediatric population.

METHODS

The Surveillance, Epidemiology, and End Results database was searched for records of children/adolescents with colorectal cancer, and the features and outcomes were compared with those of adults.

RESULTS

From January 1973 through December 2005, only 159 children/adolescents (ages 4-20 years) were reported with a diagnosis of colorectal cancer. The most common sites of involvement were the rectum (27%) and the transverse colon (26%). Adenocarcinoma was the most common histotype in both adults and pediatric patients; however, children/adolescents had more unfavorable histotypes (ie, mucinous adenocarcinoma [22%] and signet ring cell carcinoma [18%]) when compared with adults (10% and 1%, respectively; P < .001). Poorly differentiated and undifferentiated tumors (grades III and IV, respectively) and distant stage were more common in children/adolescents (P < .001). The 5-year relative survival estimates in children/adolescents and adults were 40% +/- 4.2% and 60% +/- 0.10%, respectively, confirming a worse outcome in the pediatric age group (P < .001).

CONCLUSIONS

Children/adolescents represent a minority of patients with colorectal cancer and have high-risk features and worse outcome than adults. The small number of patients in this age group was an impediment to the development of meaningful clinical trials. Thus, the principles of management for adult colorectal cancer should be used in the treatment of children and adolescents.