Childhood Cancer
by H. V. Kosmidis, M.D., Pediatric Hematologist-Oncologist

Introduction

Childhood cancer (or pediatric cancer) is a rare disease comprising less than 1% of the case of cancer in humans. Despite its rarity, remains the main cause of death from disease in children from over 12 months to 15 years of age (10% of deaths compared to 44% attributed to accidents). In contrast to cancer in adults, presymptomatic diagnostic tests (screening) are not available in childhood cancer and early diagnosis is the main tool to effective treatment and good prognosis. Other issues making cancer in children unique and different from cancer occurring in adults are histology, site of involvement and better prognosis. In children, adenocarcinomas and epithelial types of tumors are rare as is the localization in lungs, breast, prostate etc. Three out of four children treated for cancer are cured of their disease. However long term follow up is very important in order to prevent or early diagnose late effects from treatment since children are handling acute toxicities better than adults but they are vulnerable to long term toxicities.

 

Epidemiologic and historical review

The annual incidence of cancer from birth to less than 15 years of age is 14/100,000 and for adolescents (15-19 years of age) 20/100,000. Among them, most children (45%) are diagnosed with leukemia and lymphoma, age on diagnosis is usually less than 4-5 years (40%) and boys are affected more than girls (1.2:1). Historically, cancer in children was officially documented around 1945 and shortly thereafter (1948) in Boston, a methotrexate analogue was administered in a child suffering of leukemia and is considered as the first chemotherapeutic attempt in human. Also the first “multidisciplinary team” work was organized successfully in children with Wilms’ tumor (kidney tumor), the first “prophylactic” (preventive) treatment was provided in children with leukemia (prophylactic CNS irradiation) and the first maintenance treatment was also first given in children. Soon enough, in 1960, it became evident that it is crucial to address other aspects of a cancer diagnosis beside the medical treatment, mainly the psychological and social aspects. A child suffering of cancer is firstly a child who happens to become sick, and the approach from day 1 should incorporate not only the child but his parents and siblings as well. Also, continuation of normal life should be maintained (school, friends, and home environment).

What makes childhood cancer unique is, among other things, the knowledge that the disease affects a still growing organism both somatically and psychologically.

 

Etiologic and predisposing factors

Absolute knowledge about etiology of cancer in children is missing. However, increased frequency in younger ages (< 4) and the type of the abnormal cells seen (embryonal, fetal, blastic) may suggest a possible etiology in factors involved prior to birth. Certain tumors diagnosed in infants (less than 12 months), although they exhibit rather benign clinical behavior, they may have histopathology criteria of malignancy. Some examples are aggressive fibromatosis, infantile fibrosarcoma, nephroblastomatosis and neuroblastoma in situ.

A common question asked by parents is whether cancer in their child is hereditary and what they could have done to prevent it. It is known that some pediatric syndromes are associated with higher prevalence of cancer. Some examples are hemihypertrophy syndromes (one part of the body more fat than other), Down syndrome, neurofibromatosis (café-au-lait skin spots) etc. Among pediatric cancers, retinoblastoma, a tumor affecting the retina of the eye has been extensively studied and a typical hereditary form of the disease is well documented in bilateral disease (both eyes affected).

 

Diagnosis

Diagnosis in childhood cancer is critical. This is because prevention guidelines and rules do not clearly exist, and as mentioned, presymptomatic work (screening) which is clinical and mainly laboratory investigation prior to the onset of clinical symptoms and signs is not applied in children.

It is therefore crucial to provide the pediatrician and the family physician with the appropriate knowledge and sensitivity in order to evaluate suspicious symptoms and findings, and refer the child to the specialized center for further investigations. In children, early diagnosis of cancer leads to effective treatment and therefore better prognosis.

In general 3 out of 4 children affected by cancer are cured of their disease. The number of pediatric cancer survivors is steadily increasing over the years: among adults aged 25-35, one out of 570 is a survivor of pediatric cancer.

 

Types of pediatric cancers

The most frequent type of cancer in children is leukemia (approximately 35% of the total) followed by tumors of the central nervous system, lymphomas (malignant tumors of the lymph nodes and other tissues), tumors of the kidney (nephroblastoma) and the adrenal glands (neuroblastoma), sarcomas of the soft tissues (such as rhabdomyosarcoma ) and of the bones (such as osteogenic sarcoma and Ewing’s sarcoma), tumors of the liver (hepatoblastoma), tumors of the testes and ovaries (called germ cell tumors), tumors of the retina which is part of the eye (retinoblastoma). Other types of tumors exist, but they are very rare in children.

Malignant tumors of the breast, lung, prostate, malignant melanoma are adult type malignancies and they are very rarely seen in children.

 

Leukemia

Leukemia is a disease affecting the hemopoetic (blood) tissue which includes cells formed in the bone marrow which is found within every bone and in particular the large bones such as femur, tibia, pelvis, sternum etc. The hemopoetic tissue includes cells with various picture (morphology) and function. These cells are divided in 3 major groups (lines):

  1. red cell line includes a variety of cells which are forming the mature red blood cells which are very important in transporting oxygen to the tissues and play major role in the well being of the individual. If the amount of red blood cells is decreased then anemia is documented.
  2. white cell line includes a variety of cells in various steps of maturation and morphology, the most mature being the lymphocytes and the polymorphonuclear white cells also called neutrophils. The latter are very important in the defense mechanisms of the child and the successful attack of infections.
  3. megakaryocytic cell line includes cells which are producing the platelets which are cells interfering with the clotting process of the blood.

 

When a child gets leukemia, bone marrow is getting full of abnormal (in morphology and function) white cells (these cells are very immature and malignant and are called leukemic cells) which cannot accomplish their normal function which is the fight against infection.

When these leukemic cells fill the bone marrow, the production of the marrow’s normal cells (red cells, white cells, platelets) is dramatically decreased. As the number of normal cells decreases, symptoms of leukemia become evident: easy fatigue, weakness, pallor (decreased red blood cells), fever with or without infection (decreased white cells), bleeding manifestations from the skin and the mucosa (decreased platelet count).

 

Types of leukemia

In children, leukemia is more frequently acute (95%) and the malignant cells in 85% of acute leukemias belong in the lymphocytic type of the white blood cells, called lymphoblasts. The disease is therefore called acute lymphoblastic leukemia (ALL). The remaining acute leukemias (15%) are called acute non lymphocytic leukemias (ANLL) and they include various subtypes. In children, chronic leukemias are rare (5%) and the type seen is the chronic myelogenous leukemia (CML).

 

Symptoms of leukemia

Children suffering of leukemia and in particular of ALL experience symptoms related to:

  • decreased normal bone marrow cells and these are pallor, fever, fatigue, bleeding manifestations from the skin (red spots or blue-black lesions called petechiae and ecchymoses) or the mucosa (bleeding from the gums, the nose and rarely blood in urine and stools) and
  • infiltration of bone marrow cavity and other organs by the malignant cells and these are bone pain, limping and enlarged lymph nodes especially in the neck.  

On physical examination the child may be pale, may have bruises and enlarged lymph nodes and/or liver and spleen.

 

Diagnosis of leukemia

The diagnosis of leukemia is accomplished by obtaining sample from the bone marrow cavity (mainly from the pelvic bones) with special needles. This procedure is called bone marrow aspiration and requires very good local anesthesia or short general anesthesia. The sample is smeared on slides, stained and is examined under the microscope. Part of the sample is used for special studies which are called immunophenotyping and cytogenetics.

 

Treatment of leukemia

Children with leukemia should be referred to specialized pediatric oncology centers and treated by specially trained pediatric oncologists, experienced nursing personnel, psychologist and social worker. Treatment includes the administration of specific pharmaceutical agents (chemotherapy). The drug combination, the doses, the way of administration, the time sequence constitute the so-called therapeutic protocol. Chemotherapeutic agents are given intravenously via a special central venous catheter (Hickman catheter) and occasionally by mouth or subcutaneously. A very important part of leukemia treatment is called central nervous system prophylaxis and includes the administration of chemotherapy within the central nervous system. This is called intrathecal therapy and is given with the spinal tap (a puncture between two lumbar vertebrae). Therapeutic protocols for leukemia include an initial phase called induction and a final called maintenance. In-between reinduction and consolidation phases are usually part of the protocol. The majority of children with ALL have normal bone marrow after induction therapy and this is called remission of the disease. Treatment may be administered in the hospital as in-patient, in the outpatient department and at home. Total duration of treatment for the majority of ALL is 2 years.

 

Complications of treatment

The most frequent and important complications (also called side-effects) of chemotherapy are related to the mechanism of its action which is the destruction of rapidly proliferating cells. Such cells are the malignant cells of leukemia and tumors and the normal hemopoetic cells (bone marrow cells) which are gradually decreasing and the child presents with anemia, bleeding diathesis and infection. This bone marrow status which follows the administration of chemotherapy is called bone marrow aplasia (empty marrow) and calls for special attention and treatment (transfusions, antibiotic therapy etc). Other side effects of chemotherapy include hair loss (alopecia) which is transient. It should be emphasized that presence or absence of alopecia does not correlate with chemotherapy effectiveness. Nausea and vomiting are quite frequent side effects and should be prevented and treated. Various chemotherapeutic agents cause specific side effects: kidney toxicity, liver toxicity, allergies, heart toxicity etc.

 

Prognosis of acute lymphoblastic leukemia

The course and the evolution of ALL is called prognosis and depends on various factors such as the age of the child (infants less than one year of age and adolescents have worse prognosis), the number of white cell blood count at the time of diagnosis (as the number increases the prognosis is getting worse), the child’s sex (boys have worse prognosis) and other factors related to the malignant cell itself (immunophenotype, cytogenetic analysis). Another very important prognostic factor relates to the speed with which malignant cells respond to treatment in the peripheral blood and the bone marrow.

With current protocols more than 80% of children with ALL survive without problems. Survival in continuous remission in the bone marrow and the central nervous system 5 years from diagnosis is considered cure of the disease.

 

Relapse of acute lymphoblastic leukemia (ALL)

The reappearance of leukemia (recurrence) is called relapse and may refer to the bone marrow, the central nervous system and the testes in boys or any combination of the above. Other rare types of relapse are documented in the eye, the ovary, the kidney etc. When leukemia is relapsed, the prognosis is related mainly to the time of occurrence of the relapse being worse if it occurs early in the course of the disease and while on chemotherapy.

 

Relapsed ALL is treated with aggressive chemotherapy, in most cases followed by allogeneic bone marrow transplantation with a compatible sibling if remission of the disease is again accomplished. Siblings are compatible in 25-30% of cases, and compatibility is determined through histocompatibility (human leukocyte antigen, or HLA) testing.

Bone marrow transplantation is not an operation but an intravenous infusion (as transfusion) of the donor’s bone marrow in the patient. This infusion follows aggressive chemotherapy. If siblings are not compatible, then a donor is searched through the international marrow pool.

Other types of leukemia such as acute non lymphocytic leukemia, chronic myelogenous leukemia are less frequent and are treated according to specific protocols.

 

Tumors of the central nervous system

Following leukemia, tumors of the Central Nervous System (CNS) are the commonest tumors in childhood affecting children from infancy to the adolescence. These tumors are located in various sites of the CNS (which includes the brain and the spinal cord) and are mainly affecting the brain. Beside the location of the tumor, tumor histology (the type of cells within the tumor), the way the tumor infiltrates the normal brain tissue and the age of the child are important prognostic factors. Location of the tumor and the infiltrative nature of the tumor are closely related to the ability of surgical removal of the tumor.

 

Symptoms of the CNS tumors

Children with CNS tumors present with symptoms which mainly depend on two main factors:

  1. age of the child : children less than 3 years of age may experience general clinical symptoms like irritability or somnolence, crying, refusal of food intake etc. Older children may experience headache, vomiting, change of behavior etc
  2. location of the tumor: symptoms are due to the direct infiltration or pressure of the normal brain structures or may produce obstruction of the flow of the cerebrospinal fluid and therefore increase of the intracranial pressure (pressure within the brain) which is an indirect action. Symptoms due to increased intracranial pressure are morning headache, vomiting, vision disturbance, weakness of arms or legs etc. If the tumor is located in anatomic structures as is the cerebellum or the brain stem (common sites of involvement), then symptoms include also difficulty in walking, equilibrium disorders and palsies of certain cranial nerves (double vision, slurred speech, difficulty in swallowing etc).

In other locations, other symptoms are headache, convulsions and various palsies.   

 

Types of CNS tumors

The most common CNS tumors are the gliomas which are subdivided in various degrees of malignancies (grades) followed by the medulloblastomas which are presently   classified in the PNET group (primitive neuroectodermal tumors).

 

Diagnosis of CNS tumors

CNS tumors are suspected when the above described symptoms are documented. Imaging studies are then obtained (computerized tomography i.e. CT, magnetic resonance imaging i.e. MRI) and neurosurgical consultation is requested. Surgical removal of the tumor whenever feasible, (complete, partial or simply biopsy) will lead to the final diagnosis.

In certain occasions, as in the case of brain stem tumors, biopsy is avoided and diagnosis is made on clinical and imaging rounds.

 

Treatment of CNS tumors

The most reliable and effective therapeutic approach is the surgical removal of the tumor which is not always feasible as is the case of brain stem tumors, optic pathway tumors etc

Radiotherapy is used in certain tumors however it should be taken into account   that this therapeutic approach may cause serious damage in the developing brain whereas chemotherapy is limited in tumors of high degree of malignancy (such as medulloblastoma) or in certain tumors which cannot be treated surgically and radiotherapy due to young age (less than 3 years) should be avoided (such as optic pathway tumors) due to severe late toxicity. In some young children in whom radiotherapy is the standard treatment, chemotherapy is started in order to delay the time of radiotherapy administration.

 

Lymphoma

Lymphomas are malignant tumors which are third in frequency after leukemias and CNS tumors; they are subdivided in Hodgkin’s and non Hodgkin’s lymphomas.

Lymphomas are tumors which involve the peripheral lymph nodes and the lymphoid tissue of various organs such as the tonsils, the adenoid tissue, the spleen, the intestine and lymph nodes of the chest and of the abdomen.

 

Hodgkin’s lymphoma

In the majority of children, Hodgkin’s lymphoma is manifested with painless swelling of the cervical lymph nodes associated in certain occasions with swelling of the lymph nodes which are located in the chest, between the two lungs, an anatomic area called mediastinum. Other sites of involvement are lymph nodes located in the abdomen, the spleen and less frequently the liver. In certain children, general symptoms such as fever, weight loss and excessive sweating are noted those called B symptoms.

Staging of Hodgkin’s lymphoma includes investigations such as imaging studies of the chest, the abdomen, the bones and (in some children beyond stage 2A) the bone marrow as well. Recent protocols use Positron Emission Tomography studies (PET) in the initial diagnostic survey. Biopsy of suspicious lymph nodes is the main diagnostic tool. Treatment of Hodgkin’s lymphoma in children is the combination of chemotherapy and radiotherapy of the involved areas. Children whose PET becomes negative after two cycles of chemotherapy may avoid radiotherapy. More extensive radiotherapy is chosen if general clinical symptoms are also present. The prognosis of Hodgkin’s lymphoma is very good although long term follow up is crucial for early diagnosis for late effects.

 

Non-Hodgkin’s lymphoma

Non Hodgkin’s lymphoma is the commonest type of lymphoma in children. The disease involves peripheral lymph nodes or the lymphoid tissue of various organs which are infiltrated by malignant cells. Non-Hodgkin’s lymphomas are divided according to the histological picture of the tumor, the immunophenotyping and cytogenetics and the site of involvement.

 

Symptoms of non-Hodgkin’s lymphomas

 

Depending on the involved site, the child suffering from non-Hodgkin’s lymphoma presents the following symptoms:

  • Thoracic involvement: the disease is usually located in the mediastinum (the area between the two lungs in the chest) and the child presents with shortness of breath, cough, difficulty of breathing especially when lying down, swelling in the neck and the face etc. This type of lymphoma is called lymphoblastic lymphoma.
  • Abdominal involvement: children exhibiting pain, swelling, vomiting or picture of bowel obstruction. In some other instances the lymphoma is located in the lymphoid tissue of the head and neck and children present with visible swelling in the involved area, difficulty in breathing and occasionally with other symptoms such as change in the quality of voice etc. This type of lymphomas are called undifferentiated lymphomas most of which belong to the group of Burkitt’s lymphomas.
  • A third group of non-Hodgkin’s lymphomas is seen less frequently they may involve any site such as skin, bones, lungs and abdomen, and are called large cell lymphomas.

 

Diagnosis and treatment of non-Hodgkin’s lymphoma

The diagnosis of non-Hodgkin’s lymphoma is made by using the least invasive procedures. Major surgical operations such as open-chest surgery and abdominal operations are to be avoided, if possible. The reason is that there is always danger when administering general anesthesia in large thoracic tumors and risk of delaying treatment when the abdomen is operated. It is therefore important to obtain diagnosis by using biologic material such as thoracic or abdominal fluid and if this is not possible by taking biopsies from peripheral lymph nodes.

Treatment of choice is aggressive chemotherapy the type and the duration of which depend on the type of the tumor. Lymphoblastic lymphomas are treated more or less as ALL and undifferentiated lymphomas require short but very aggressive treatment. The prognosis of non Hodgkin’s lymphomas is very good.

 

Abdominal tumors

In children, the most common abdominal tumors are kidney tumors and tumors arising from cells of the sympathetic nervous system.

  • The tumor of the kidney is called nephroblastoma (Wilms’ tumor) and it usually affects children aged less than 5 years. Children present with abdominal mass (which is usually seen or felt by the mother), abdominal pain, discomfort and less frequently fever and hematuria (bloody urine). If the clinical and imaging studies are in favor of nephroblastoma, then depending on the therapeutic protocol, either chemotherapy precedes surgical removal of the tumor (nephrectomy) or vice versa. After nephrectomy, treatment depends on various factors such as the extension of the disease within the kidney and the surrounding tissues, the specific histologic type of the tumor and the presence or absence of metastatic disease especially in the lungs. In certain occasions, besides chemotherapy and surgery, radiotherapy is added. Children with nephroblastoma respond very well to the treatment and most of them are cured of their disease.
  • Tumors arising from the sympathetic nervous system are called neuroblastomas and are located either in the adrenal gland (endocrine gland located on the top of the right or left kidney) or in the ganglionic cells of the sympathetic chain (located in the right or left side of the spine). Neuroblastoma may also be located in the thorax or neck. The disease affects young children less than 5 years of age. Children older than one year of age, very frequently present with distant metastases in the bones and in the bone marrow. In the majority of children, there is increased amount of certain substances in the urine which are called catecholamines such is the urinary VMA. Treatment of children with neuroblastoma depends on the age of the child, the location of the tumor and the stage of the disease. Chemotherapy is the treatment of choice in the majority of children followed by surgical removal of the tumor and autologuous bone marrow or peripheral stem cell transpalantation in certain instances. The prognosis is very good in infants less than one year of age (in whom treatment is minimal if any) and poor in older children with metastatic disease. In this group, beside marrow transplantation, treatment with differentiating agents as is cis-retinoid acid and certain monoclonal antibodies may be used but prognosis remain poor.

 

Sarcoma

Sarcomas are malignant tumors of fetal origin located in the soft tissues (called soft tissue sarcomas) or in the bones. Soft tissue sarcomas are further subdivided in rhabdomyosarcomas and in the non rhabdo-soft tissue sarcomas. The second group is more frequently diagnosed in older children and adolescents and the disease is named after the tissue of origin i.e. liposarcoma (arising from the fatty tissue), leiomyosarcoma (arising from the smooth muscles), fibrosarcoma (arising from the fibrous tissue), synovial sarcoma (arising from the synovium) etc. These tumors are best treated with complete surgical excision.

 

Rhabdomyosarcoma

Rhabdomyosarcoma is soft tissue tumor whose the cells resemble cells of the muscles of the fetus. The clinical symptoms depend on the site of involvement at the time of diagnosis. Children with tumors in the head and neck region, which is the commonest site of involvement, are presented with swelling of the orbit, of the cheek, of the neck, they may complain of nasal congestion or obstruction and in certain types, called parameningeal tumors, may develop neurological signs (double vision, squint, and other nerve palsies). Children with involvement of the urogenital tract or the abdomen may develop abdominal swelling, pain, urination problems, constipation etc. Finally children with tumors of the thoracic wall or the extremities, which are less common sites of involvement, may present with local swelling with or without pain. The site of the disease, the extension of the tumor (stage) and the specific histologic subtype are the main prognostic factors. For example tumors involving the neck and neck area are embryonal rhabdomyosarcomas and they have better prognosis compared to tumors of the extremities with histology called alveolar and have worse prognosis.

 

Treatment of rhabomyosarcoma

Rhabdomyosarcoma is a tumor best approached and treated by a team of specialists: pediatric oncologist, pediatric surgeon, pathologist (the doctor who “reads” biopsies”), radiologist and in certain occasions (such as parameningeal tumors, inoperable tumors, alveolar tumors etc) radiotherapist. Chemotherapy is the initial treatment of choice and therapeutic results depend on the site, stage and histology of the tumor and the possibility of complete surgical removal of the tumor.

 

Bone sarcomas

The most common tumors of the bones among children are the osteogenic sarcoma and the Ewing’s sarcoma.

  • Ewing’s sarcoma is a tumor of the adolescents and young adults which less commonly affects younger children as well. Boys are more frequently affected than girls and the disease involves mainly the pelvic bones, the thorax (ribs, clavicle), the femur and less commonly the other bones. Children experience pain in the involved area, have local swelling and dysfunction and may have fever. The disease may give metastases to the lungs and less frequently to the other bones. Imaging studies include plain films, computed tomography, magnetic imaging, evaluation of the lungs and bone scan. The diagnosis is made by biopsy of the involved area. Treatment includes chemotherapy followed by local surgery and radiotherapy if there is residual tumor and/or inadequate necrosis (dead cells) of the tumor.
  • Osteogenic sarcoma is a tumor seen in adolescents 10-20 years of age and boys are  affected more commonly than girls (as in Ewing’s). The disease involves the bones around the knee joint and presents with local pain and swelling whereas fever is very uncommon. The disease frequently spreads to the lungs and diagnosis is made as described in Ewing’s sarcoma. Treatment also follows the rules of Ewing’s tumor with the exception of radiotherapy which is not active in osteogenic sarcoma.

It should also clearly noted that although radical surgical procedures like amputation are to be avoided in both types of tumors, they may be chosen in certain rare occasions.

Limb salvage procedures are chosen for the majority of children suffering of bone tumors.

 

Liver tumors

Liver tumors are very rare in children and may be benign or malignant. Malignant liver tumors are more frequent and the majority of them are hepatoblastomas whereas less frequently are hepatocellular carcinomas which is a tumor seen in the adult life. The most frequent clinical manifestation is the presence of enlarged abdomen with or without pain in the right side. Hepatoblastoma usually affects young children whose the general condition may be affected (fever, loss of appetite, weight loss, jaundice). Imaging studies are very helpful in showing tumor in the right or left or both liver lobes. In these tumors a laboratory blood test may confirm the diagnosis and this is the measurement of a substance called alpha-fetoprotein. This is a protein produced by the embryonal (fetal) liver and the cells of the yolk sac in the embryo (fetus). The production stops at the time of birth. Increased levels of alpha-fetoprotein are seen in malignant liver tumors and in another type of tumors called germ cell tumors. If present, biopsy of the liver may not be necessary and the child is placed on chemotherapy followed by surgical excision of the involved part of the liver. If the tumor responds to treatment this protein is gradually dropping and is a marker for monitoring the disease since it increases again if the tumor recurs. Hepatocellular carcinoma is more aggressive tumor and is seen in older children; the usual treatment of choice is surgery.

 

Germ cell tumors

Germ cell tumors are relatively rare childhood tumors originating from very primitive cells found in the normal fetus and are called germ cells. These cells “migrate” in the fetus and form the testes or the ovaries or are “misplaced” in the midline of the body. These tumors are therefore located in the testes or the ovaries and in the midline as is the posterior aspect of the abdomen such is the sacrococcygeal region, the area between the two lungs in the chest (called mediastinum) and the brain in an area called epiphysis. Symptoms depend on the location and tumors: in the testis there is painless swelling, in the ovary there is pain and abdominal swelling, in the mediastinum there is cough or shortness of breath, in the sacroccygeal region there is a visible and palpable mass (sometimes diagnosed during pregnancy with ultrasound), in the epiphysis symptoms are from the central nervous system. Alpha-fetoprotein is very valuable substance in this group of patients as in the liver tumors. An additional substance is measured in this group of patients, the beta chorionic gonadotropin which is normally produced by the placenta. The treatment approach depends on the location of the tumor, the age of the patient, the presence or not of these two blood substances, the histologic type of tumor (biopsy) and the operability of the tumor. Chemotherapy and surgery are the main types of treatment. Among these tumors, benign teratomas requiring only surgical removal are also included.

 

Retinoblastoma

Retinoblastoma is a malignant tumor of the eye arising from the retina and is seen exclusively in children. This is a type of tumor that may be seen in more than one member within the same family and therefore may be hereditary. This type is usually affecting both eyes and is diagnosed earlier in life. The child with retinoblastoma may have white eye in the dark called leukocoria or cat’s eye reflex, squint, red eye etc. The eyes must then be examined under general anesthesia and the diagnosis is made without requiring biopsy. The extend of the disease within the affected eye, the other eye and outside the eye globe (bone marrow, bones, spinal fluid etc) is important in defining the type of treatment chosen. Enucleation may be the treatment of choice followed by placement of prosthetic eyeball. Chemotherapy, radiotherapy and other types of local treatment such as cryotherapy, laser etc may be used as well.

 

Langerhans cell histiocytosis

Langerhans cell histiocytosis, called in the past Histiocytosis X, is a disease characterized by accumulation of cells called dendritic in various tissues and organs and is rather a reactive process attributed to cytokines. The disease may affect any organ in single or multiple sites. Bones, mucous membranes and skin are affected as are lymph nodes, liver, spleen and less commonly bone marrow, lungs and brain. When the disease affects bones, children complain of pain or have swellings especially in the skull or ear drainage. Affected skin may resemble acne or non specific dermatitis and become ulcerative in moist areas such as the axillae, the groin etc and lymph nodes may be swollen. General symptoms include fever, weakness, loss of appetite, weight loss etc.  A distinct expression of the disease is the so-called diabetes insipidus, which is presented with extreme thirst and water drinking followed by frequent urination with increased quantity of urine, requiring treatment with the missing pituitary hormone throughout the child’s life. Treatment (chemotherapy) and prognosis depend on various factors such as age, number of organs involved and dysfunction of the organs (such is low blood counts, abnormal liver function etc). The disease may have ups and downs without making the prognosis bad with the exception of infants and young children with organ dysfunction, whose prognosis is poor.

 

General conclusions

Cancer in children is a very rare disease with various clinical manifestations. If the disease is suspected, then diagnosis is made without delay and most children are successfully treated. Children with cancer should be referred in specially organized pediatric oncology units and treated by a team of well trained physicians and sensitive nurses who collaborate in order to offer the best available medical and psychosocial care not only to the suffering child but to the entire family. This care should be provided not only during treatment but also after its completion and the achievement of the goal (which is the cure of the child), but also afterwards, during the period of the reintegration. Children who were treated for cancer require long-term follow-up for investigation of late effects of treatment the commonest of which are toxicities of the endocrine glands (thyroid, testes, ovaries), heart, skeletal and neurological system.

With current therapeutic modalities, 3 out of 4 children with cancer are cured of their disease. Also today 1 out of 570 young individuals has had cancer as a child, and is cured.

 

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