What is Pediatric Oncology & Hematology ?
Childhood cancer is the common term for a group of diseases that is secondary to uncontrolled proliferation of cells at any region of body, impairs healthy by spreading to different body regions through lymph system in a short time and threat life. Although those conditions develop at any period of life, ranging from infancy to childhood, they are most prevalent in first 5 years of life. However, it is possible to speculate that 60 to 70 percent of children with cancer can be completely recovered, if the condition is early diagnosed and appropriate treatment is started.
Etiologic Factors of Pediatric Oncologic & Hematologic Cancers
Leukemia, also known as blood cancer, is the most common cancer and it is principally the disease of bone marrow (there are essentially two groups, namely lymphoblastic and non-lymphoblastic, along with their subgroups). This condition can be diagnosed at any age, starting at birth, and it demonstrates age-specific distribution by the type of cancerous cell. However, incidence is higher in boys.
Iron deficiency anemia,
Family history notable for recurrence,
What are Diagnostic Methods in Pediatric Oncology & Hematology ?
Although diagnostic methods vary depending on complaint of the patient and symptoms and signs, principal diagnostic methods are used to differentiate bacterial and viral infections, traumatic bleeding and swelling and growth pains that are manifested by similar signs and symptoms. These are as follows:
CBC (Complete Blood Count)
Blood smear (cell typing and cellular rates),
Sedimentation (erythrocyte sedimentation rate),
Viral serology (to identify some viral diseases),
Differential diagnosis of tuberculosis (PPD, cultures),
Tests to clarify cancer suspect
Bone marrow aspirate and biopsy,
Computed Tomography (CT) Scan of Chest,
Magnetic Resonance Imaging (MRI) Scan of Brain,
MRI Scan of Abdomen,
CT and MRI Scans of relevant bones and other body regions,
Positron emission tomography (PET/CT) scan for some tumors, particularly lymphomas,
Enzymes and protein markers specific to particular tumors (LDH, Alkaline Phosphatase, NSE, alpha-fetoprotein, beta HCG, ferritin, dopamine, noradrenalin, VMA, HVA etc.).
For definitive diagnosis, it is necessary to biopsy diseased site, while pathology, immunology and molecular genetics reports are required to make histopathological diagnosis. It is not appropriate to start therapy based on diagnosis of cancer in cases who do not have histopathological diagnosis. Tissue examination is a necessity to make definitive diagnosis of cancer and to identify types and sub-groups.
Diagnosis takes 2 to 10 days after biopsy specimen is taken. Biopsy is required to be repeated in some cases. After definitive diagnosis of cancer is made, a team of healthcare professionals is assigned who will start and supervise therapy process and father and mother of the patient should be informed about the process and the outcome. Staging exams are started in the same period in order to determine stage of the disease.
Moreover, extra imaging studies, including but not limited to CT, MRI and scintigraphy, are put into action in order to scan tissues and organs that are at risk of metastasis.
Blood tests, urine tests, ECG, ECHO and hearing tests can be requested to determine functional status of other organs before therapy is started.
After Staging studies are completed, it is necessary to start appropriate therapy that is worldwide recognized as standard treatment. Family is informed by relevant physicians about treatment modality, administration route, contribution to recovery, chance of success and early and late side effects of treatment, and a consent is obtained.
Therapeutic Methods in Pediatric Oncology & Hematology
Chemotherapy: This therapeutic modality involves use of medicaments that exert effect on rapidly proliferating cells. In general, more than one drug is intravenously administered using special catheters. Patient receives this therapy under supervision of pediatric oncologists and experienced oncology nurses in sessions at frequent intervals. Children should be given chemotherapies at fully-equipped hospitals in order to cope with side effects that develop before, during or after chemotherapy.
Chemotherapy is immediately started after diagnosis of leukemia or lymphoma is made, but onset time may vary in other cancers by the stage of disease. However, it is usually maintained for 6 months to 3 years before and/or after surgical management.
Since chemotherapeutic agents have very serious side effects, family is informed in detail by primary physician.
Surgical treatment: This treatment modality is reserved for tumors that are also known as solid tumors, excluding leukemia and lymphoma. The tumor is usually completely removed without a resultant organ loss, if it can be diagnosed at early stage. This treatment is followed by chemotherapy. If cancer is at advanced stage or if removal of the organ will result with organ loss or unacceptable dysfunction, tumor size is first reduced with chemotherapy, followed by surgical management.
Radiotherapy: High-energy X-ray beams are used in this modality. High-dose radiation may kill rapidly proliferating cells or stop proliferation. Therefore, those agents are not used in children aged 3 to 5 years, since body growth is rapid at this period. It is used adjunct to surgery and chemotherapy in treatment of particular solid tumors, especially brain tumors. Since it has significant side effects, physicians are responsible for duly informing the family in detail before treatment is started. However, aim of radiotherapy is to influence the tumor using different devices and radiation sources with no damage on intact peripheral tissues.
Bone Marrow /Stem Cell Transplantation This treatment modality is applied following very high-dose chemotherapy in high-risk or recurrent lymphomas and solid tumors that are responsive to chemotherapy, especially leukemia. Native bone marrow or stem cell of the patient can be transplanted (autologous transplantation) or tissues or cells of a matched donor can be used (allogeneic transplantation) that are especially preferred in leukemias. While donor tissue transferred or tissue is recognized by receiver’s body, patients may face very significant side effects, including but not limited to tissue rejection, hemorrhage and infection, due to very high-dose chemotherapy that is given before transplantation. Although bone marrow transplantation is a treatment modality that increases chance of recovery, recurrence of the disease is always a risk.
Supportive therapies: Most important ones include chemotherapy premedication, anti-nausea and anti-emetic agents, medications therapies that aim protecting organs vulnerable to destructive effects of chemotherapy, anemia secondary to the disease or chemotherapy, febrile infection and nutritional supports as well as blood and blood products that are transfused to minimize risk of hemorrhage, psychological support and social services.
For childhood cancers, treatment modalities such as herbal medicines, also known as complementary medicine or alternative medicine, cannot replace standardized therapies as patient may face damages and injuries.
In management of childhood cancers, one or more than treatment modality is used in combination or sequentially depending on the age of patient, type of disease, location and near or distant metastasis (stage). If more than one treatment modality is used, management is supervised by more than one physician, including but not limited to pediatric oncologist and hematologist, pediatric surgeon, oncologic surgeons and radiation oncologists. Those specialists play a significant role in treatment process by establishing a “Tumor Council” and making joint decisions.