Fortunately, childhood cancer is very rare, appearing in about 125 children out of every one million youngsters. Looking at the statistics another way, cancer develops in about one in 300 boys and one in 333 girls under the age of 20.
Cancers in children are often tricky to diagnose. Signs and symptoms can mimic those found in far less serious diseases. Yet, parents know their children better than anyone else and should take note of unusual symptoms that don't get better or occur frequently.
This article reviews the types of signs and symptoms that parents shouldn’t ignore.
dailyRx News spoke with Thomas Seman, MD, president of North Shore Pediatrics in Boston, Massachusetts, who has diagnosed cancer in his young patients.
“Cancers can present in any variety of ways, some slow and insidious and some quick and rapidly progressing,” Dr. Seman said.
In a recent review that appeared in the journal American Family Physician, the authors pointed out that the red flags of childhood cancer, such as fever, vomiting and pallor (paleness), are also seen in common ailments and rarely result from a tumor.
Most common symptoms
“The most common symptoms", Dr. Seman continued, "occur when the child has the most common type of cancer, leukemia, which makes up more than one-third of all childhood cancers.“
Dr. Seman explained how leukemia — a blood cancer — starts. “These are cancers that start from a single cell and grow in the bone marrow where all of the elements in the blood are made.”
This means that a child may look pale or be very tired due to anemia — a condition defined by low levels of red blood cells which carry oxygen around the body.
“Easy bruising is also seen, often with multiple bruises on the body in areas with limited likelihood of trauma,” Dr. Seman noted.
“This does not mean that a very active 5-year-old boy who lives to jump and play who has bruises in his knees and arms is necessarily showing signs of cancer. The child who is less active over the last three months who now is bruising on his underarm or back of his knees is more of a concern.”
Other signs of leukemia can appear in the mouth or bones.
“Bleeding from the gums after brushing teeth or eating hard or scratchy foods is the result of low platelets, the blood clotting cells. And, since all of this is happening in the bone marrow where the leukemia cells are growing rapidly and occupying more space, this added mass causes bone pain that is very difficult to control,” Dr. Seman said.
Lymph node changes
The lymph nodes are found throughout the body and are essential parts of the immune system. Lymph nodes fight off invaders.
Changes in the lymph nodes such as enlargement or feeling hard are seen in a number of childhood cancers. Another blood cancer called lymphoma starts in the lymph nodes and accounts for about 11 percent of childhood malignancies (cancers).
“Those that are most concerning are those nodes coming from the area where the neck meets the clavicle [collarbone]. Coughing, shortness of breath and even chest pain can also occur since there can also be involved lymph nodes inside the chest cavity,” Dr. Seman said.
Central nervous system cancers
The central nervous system includes the brain, nerves and spinal cord. Cancers involving the central nervous system (CNS) are the second most common forms of childhood cancer, making up about 25 percent of the malignancies found in kids.
Dr. Seman said that headaches may be a symptom of concern, especially when they occur upon awakening and are accompanied by vomiting.
"Another symptom that can be seen is a change in the way the eyes move. At first, the eye can turn in or out and then the whole eye is pushed outward,” Dr. Seman explained.
Other CNS cancer warning signs are vision problems. The child may begin to squint because of loss of vision, blurred vision or double vision.
If a child starts to have trouble walking or handling objects (fine motor skills), a visit to the pediatrician is warranted.
It could be a tumor
“Other cancers cause tumors that can grow and cause loss of function, pain or other sensations based on their location in the body,” Dr. Seman said.
In addition to brain tumors, children can have tumors that form in the kidney (Wilms' tumor), muscles (rhabdomysarcoma) and bones (osteosarcoma and Ewing sarcoma).
Swelling or pain in the abdomen and loss of appetite are two common signs of Wilms' tumor.
Bone pain is the most common symptom for bone cancers. Pain at the ends of the long bones of the arms and legs is most common with osteosarcoma.
Ewing sarcoma, a rare cancer which appears mostly in teens, can cause bone pain in the pelvis, shoulder blades and ribs.
“Furthermore, bloody urine, at first once and then with every void, can occur from a bladder wall tumor," Dr. Seman said.
Babies can be born with cancer or develop the disease shortly after birth. The primary cancer in this age group is neuroblastoma that begins in the nerve cells and develops usually before the baby reaches age three.
Dr. Seman cautioned, “A [swollen] abdomen in an infant along with irritability, poor weight gain and vomiting can sometimes be due to an abdominal solid mass tumor."
Neuroblastoma can also cause fever and bone pain in babies.
Other red flags
Along with the symptoms Dr. Seman mentioned, a recent review that appeared in the journal American Family Physician listed other signs that something may be seriously wrong with a child. These potential signs included the following:
- Prolonged fever with no obvious cause
- Night sweats without accompanying fever
- Weight loss
- Ongoing constipation
- Leg weakness
- Vaginal bleeding
- Nausea and vomiting unrelated to illness
- Mass in scrotum (testicular cancer)
- General lack of energy (malaise)
- Unusual tired or fatigue that lingers
“This [American Family Physician] study should help family physicians to more easily identify children and adolescents who may have cancer," Kathleen Ruddy, chief executive officer of the St. Baldrick’s Foundation, told dailyRx News. "If this leads to an earlier diagnosis and referral to a pediatric oncology specialist, more lives will be saved.”
Parents know best
“Over the years, I have learned to really pay attention to a parent's concern since they know their child the best,” Dr. Seman said.
“Some of the more subtle or slowly developing symptoms may not be very obvious to the physician, so understanding the changes will help speed up the diagnosis,” he said.
While vigilance is necessary, Dr. Seman says parents need to remember that the statistics are on the child’s side.
“Parents must remember that cancer is very rare, found in only approximately 0.015 percent of children. But many of the symptoms we have talked about, such as fever, fatigue, pallor [paleness], swollen lymph nodes and bruising, are very common, seen every day and are usually related to less severe illnesses.”