Childhood and adolescent cancer corresponds to a group of various diseases characterized by the uncontrolled proliferation of abnormal cells, which can occur in any part of the body. Unlike adult cancer, childhood and adolescent cancer usually affects the cells of the blood system and supporting tissues (while in adults it typically involves the epithelial cells lining various organs).
In most cases, tumors in children and adolescents are composed of undifferentiated cells, which allows for a better response to treatments. The chances of cure, survival, and quality of life for the patient are greater the earlier the cancer is diagnosed.
Treatment should be carried out in a specialized pediatric center by a multidisciplinary team, tailored to each specific histological type and according to the clinical extent of the disease.
With current therapeutic regimens, approximately 80% of children can be cured.
Types of childhood and adolescent cancer
The most frequent tumors in childhood and adolescence are:
- Leukemia – it is the most common type of cancer in childhood. It affects the bone marrow and other organs outside the bone marrow, such as the central nervous system, testicles, and eyes;
- Brain and central nervous system tumors – the second most common type in children, accounting for 26% of childhood cancers. There are many types of brain tumors, with different treatments and prognoses; and
- Lymphomas that affect the lymphatic system – often affect the lymph nodes and lymphatic tissues, such as the tonsils or thymus. They can also affect the bone marrow and other organs.
Children and adolescents are also affected by:
- Neuroblastoma – a type of tumor of the peripheral nervous system cells, often located in the abdomen. It accounts for about 6% of childhood cancers. This type of cancer occurs in infants and babies, being rare in children over 10 years old;
- Wilms tumor – begins in one of the kidneys, rarely affecting both organs. Most often diagnosed in children aged 3 to 4 years. It represents 5% of childhood cancers;
- Retinoblastoma – a tumor that affects the retina, the back of the eye. It represents about 2% of childhood cancers. It usually occurs in children around 2 years old and is rarely diagnosed after the age of 6. When directing a light into a child’s eye, the normal response is for the pupil to appear red, due to the blood vessels in the back of the eye. In the eye with retinoblastoma, the pupil has a white or pinkish appearance. This white glow in the eye is often noticed in flash photographs;
- Germ cell tumor – occurs in cells that originate in the ovaries and testicles;
- Bone tumor: the two main types are osteosarcoma and Ewing sarcoma. Osteosarcoma develops in areas where bone is growing, such as the long bones of the legs or arms. Ewing’s tumor can affect bones, muscles, or cartilage; and
- Rhabdomyosarcoma – begins in cells that normally develop in skeletal muscles, which are involved in body movement. It can occur in the head and neck, groin, abdomen, pelvis, or limbs (arms or legs). It represents about 3% of childhood cancers.
Symptoms and signs of childhood cancer
In most cases, the symptoms are related to common childhood illnesses, which emphasizes the importance of regular visits to the pediatrician for monitoring children’s health.
The main warning signs for childhood cancer are:
- Pallor;
- Bruising or bleeding without apparent cause;
- Bone pain;
- Lumps or swelling without trauma;
- Unexplained weight loss;
- Fever;
- Persistent cough or shortness of breath;
- Night sweats;
- Eye changes (white pupil, recent onset strabismus, visual loss, bruises or swelling around the eyes);
- Abdominal distension;
- Headaches associated with vomiting (especially in the morning or worsening over days);
- Limb pain;
- Fatigue, lethargy, or changes in behavior; and
- Dizziness, loss of balance, or coordination.
Diagnosis of childhood cancer
Childhood cancers are rare, and there are no recommended screening tests to detect the disease in children who are not at increased risk. Children who are at higher risk of developing a specific type of cancer due to certain inherited genetic alterations from one of their parents may need careful and regular medical exams.
When childhood or adolescent cancer is suspected, imaging studies guide the initial procedure for solid tumors. In some cases, surgical removal of the tumor may be possible. When this is not possible, a biopsy will be performed to provide a histopathological diagnosis and enable the start of chemotherapy; tumor removal will occur at a later stage. The goal is always to avoid surgeries that cause significant harm to the patient.
Treatment
The treatment for pediatric and adolescent tumors comprises three therapeutic modalities: surgery, chemotherapy, and radiotherapy. Each patient will have their treatment plan tailored individually, according to the diagnosed tumor and the extent of the disease.
Children with cancer have special needs that may be best addressed in specialized pediatric cancer centers. Treatment involves a multidisciplinary team that should include: pediatricians (oncologists, surgeons, cardiologists, nephrologists, endocrinologists, ophthalmologists, gastroenterologists), radiation oncologists, pediatric nurses, psychologists, social workers, nutritionists, physiotherapists, dermatologists, orthopedists, neurologists, neurosurgeons, dentists, and occupational therapists.
Prevention
Childhood and adolescence are critical periods of development. During these stages, besides forming lifestyle habits, exposure to environmental factors can affect the structure or function of organs or tissues, compromising adult health.
Therefore, prevention of tumors in childhood and adolescence is crucial, as well as guidance on known cancer risk factors related to long-term exposures, such as lack of regular physical exercise, inadequate diet, exposure to ultraviolet radiation without protection (UVA and UVB rays from the sun), tobacco and alcohol use, non-vaccination against infectious agents (such as hepatitis B and HPV), and unprotected sexual intercourse.
