Pediatric cancer - Overview: Nursing pathophysiology

Childhood cancer is a collection of conditions occurring in children and adolescents that are characterized by abnormal cells that divide and grow uncontrollably.

Now, the cause of childhood cancer is multifactorial, meaning a child’s unique genetic factors and environmental factors interact to promote the development of cancer. Even so, these factors are often not known at the time of diagnosis, so in many cases the exact cause of cancer in children is unknown.

Genetic factors involved in cancer can be mutations that are either inherited or acquired. These include mutations that typically occur in genes that regulate cell division, including proto-oncogenes, which promote cell division, or tumor suppressor genes, that inhibit uncontrolled cell division.

For example, mutations to the MYCN proto-oncogene can predispose children to neuroblastoma and glioblastoma, both cancers of the nervous system. On the other hand, mutations to the RB1 tumor suppressor gene are associated with retinoblastoma, a type of cancer in the light-sensing layer of cells in the back of the eye called the retina. This mutation can be spontaneous, or it can be a familial cancer resulting from a germline mutation, meaning the mutation occurred in a reproductive cell, either the sperm or egg, so it becomes part of the DNA of each of the body’s cells.

Other genetic changes such as chromosomal translocations, where pieces of two chromosomes split off and swap places, like with the Philadelphia chromosome, are also associated with an increased risk of leukemia, a cancer of blood-forming tissues that disrupts the normal function of bone marrow.

Leukemia can also occur in children born with certain congenital conditions like Down syndrome, or trisomy 21, a condition where there’s an extra copy of chromosome 21.

Environmental risk factors can include exposure to carcinogens, or substances that can promote the development of cancer, like tobacco smoke and certain chemicals and medications. For example, taking anabolic androgenic steroids increases the risk of hepatocellular carcinoma and brain tumors.

Also, while in utero, exposure to agents such as ionizing radiation, like from X-rays, and certain medications, like diethylstilbestrol, or DES, can increase cancer risk. And even before conception, parental exposure to carcinogens can increase the risk of cancer in their offspring by initiating epigenetic changes.

Lastly, some viruses can heighten cancer risk. For example, strains of the Epstein-Barr virus are associated with Burkitt lymphoma and Hodgkin lymphoma, which are cancers affecting the lymphatic and immune systems.