Chapter 14: Cancer in Children

What is diethylstilbestrol [DES]?

A drug previously used to decrease the frequency of spontaneous miscarriages in women that had previously had a miscarriage Was found that it leads to increased occurrence of vaginal cancer of female offspring of mothers who used the drug while pregnant.

A nurse recalls that the most common genetic abnormality linked to the development of acute leukemia is: 1. Down syndrome 2. Tuberous sclerosis 3. Gorlin syndrome 4. N-myc gene

ANS: 1 Down syndrome or trisomy 21 is associated with a 10-20-fold increase in risk for leukemia. 2. Tuberous sclerosis is associated with glial tumors. 3. Gorlin syndrome is linked to medulloblastoma. 4. N-myc is associated with neuroblastoma.

A nurse knows that most childhood cancers primarily arise from the 1. Mesodermal germ layer 2. Central nervous system 3. Respiratory tract system 4. Diploblastic germ layer

ANS: 1 Most childhood cancers originate from the mesodermal germ layer that gives rise to connective tissue, bone cartilage, muscle, blood, blood vessels, gonads, kidney, and the lymphatic system. Thus the more common childhood cancers are leukemias, sarcomas, and embryonic tumors. 2. CNS tumors are the most common types of solid tumors in children and account for 27% of all childhood cancers. 3. The blood and lymphatic systems are the most common for children, not the respiratory tract. 4. Diploblastic refers to organisms with a double germ layer.

A woman begins radiation therapy in an attempt to kill the cancer cells while minimizing damage to normal structures. Effective cell killing by radiation also requires: 1. Oxygen 2. Follicle-stimulating hormone 3. Cytokines 4. Adhesion molecules

ANS: 1 Oxygen is needed for effective cell killing. This is not always locally available in large cancers. Oxygen is utilized by normal tissue to turn glucose into energy. And tumors consume large amounts of glucose to make cellular building blocks, supporting rapid proliferation. Oxygen decreases the amount of glucose available to tumors. Follicle stimulating hormone regulates the development, growth, pubertal maturation and reproductive processes of the body. There is no direct correlation with FSH assisting with radiation therapy. Cytokines are utilized for modulating the immune system, which does not affect cell killing by radiation. Adhesion molecules are proteins located on the cell surface involved in binding with other cells. Radiation therapy does not utilize adhesion molecules to destroy cancer cells.

A nurse recalls that the most common childhood cancers are: 1. Sarcomas 2. Colon tumors 3. Leukemias 4. Thyroid cancers

ANS: 3 Leukemias are the most common childhood cancer. Acute lymphocytic leukemia is the most common type of leukemia in childhood. Children (0-14 years of age) with leukemias and brain tumors account for 61% of childhood cancers. 1. Sarcomas are one type of childhood cancer, but not the most common. Leukemias and brain tumors account for 61% of cancer in children 0-14 years of age, with neuroblastoma and soft tissue or bone sarcomas less common. 2. The most common types of cancer among adults include prostate, breast, lung, and colon. 4. Thyroid cancer is not the most common childhood cancer. The most common cancers among the 15-39-year-old population in the United States are Hodgkin lymphoma, leukemia, germ cell tumors (particularly testicular), central nervous system (CNS) tumors, non-Hodgkin lymphoma, thyroid cancer, melanoma, sarcomas, and breast, cervical, liver, thyroid and colorectal cancers.

The adolescent's parents ask the nurse if adolescent boys of color also get lymphoma. Which statement made by the nurse is true? 1. "Lymphoma is more prominent in teen girls of color." 2. "Lymphoma typically affects only children." 3. "Lymphoma is more common in white boys." 4. "Lymphoma affects Asians more than other groups."

ANS: 3 Overall, cancer (including lymphoma) is 10% to 25% more common in white than in black children and adolescents. Boys are more likely to develop cancer than girls. Lymphoma is not more prominent in teen girls of color nor in Asians. Lymphoma affects children, adolescents, and adults.

A nurse understands which statement to be true regarding non-Hodgkin lymphoma in adolescents? 1. It is a type of embryonal tumor 2. It is the most common solid tumor type 3. It is slow growing 4. It is the most common cancer of this age group

ANS: 4 Lymphomas (including Hodgkin and non-Hodgkin subtypes) are the most common type of cancer among adolescents (15-19 years of age). Embryonal tumors originate during uterine life and are typically diagnosed by age 5. The most common type of solid tumor in adolescents is a central nervous system tumor (typically a brain tumor). Non-Hodgkin lymphoma is not a type of solid tumor. The majority of adolescent cancers are fast growing with 80% showing metastasis at diagnosis.

Studies suggest that physical activity may reduce the risk for several different cancers, independent of weight changes. The protective effects of physical activity includes: 1. Changing gastric absorption of carcinogenic compounds 2. Increasing the insulin-like growth factor. 3. Decreasing free radicals. 4. Improving gastric motility.

ANS: 4 Physical activity utilizes many biologic mechanisms to protect the body from cancer. Physical activity decreases obesity and improves gastric motility. This may decrease the amount of time that the bowel lining is exposed to potential mutagens. This does not affect the absorption of potentially carcinogenic compounds. Insulin and insulin-like growth factor are decreased with physical activity. Additionally, it increases free radical scavenger systems, but does not itself decrease the amount of free radicals circulating within the body.

What drugs can increase risk fo cancer in children?

Anabolic androgenic steroids (cause hepatocellular carcinoma, brain tumors) Cytotoxic chemotherapy (cause leukemia) Immunosuppressive agents (cause lymphoma)

How do chromosome aberrations and single-gene defects contribute to cancer?

Aneuploidy, amplifications, deletions, translocations Trisomy 21 (Down syndrome)

What is the prognosis for the future of childhood cancer? Cures? Mortality rates? Clinical trials?

Approximately 85% of children with cancer are now cured Mortality rates have declined Children are more likely to be enrolled in clinical trials Research centers have been developed for comprehensive childhood cancer treatment. Attempts to determine the long-term effects of treatment are being made. Clinical trials are continually focusing on more effective, targeted therapies with fewer side effects.

What gender is more affected?

Boys are affected more than girls

Epstein-Barr virus is associated with what cancer? Where is this an endemic?

Burkitt's Lymphoma, endemic to SubSaharan Africa

What are the most common childhood cancers?

Central nervous system tumors and leukemias

High dose and high dose rate of ionizing radiation closely related to what cancer?

Childhood leukemias

Childhood encompasses what ages? Adolescence?

Childhood: up to 14 Adolescent 15-19

Childhood exposures include?

Drugs Ionizing radiation Viruses Pesticides/insecticides

Prenatal exposure to what can increase the risk of cancer?

Drugs (diethylstilbestrol [DES]) Pesticides Environmental toxins Maternal exposure to hair dyes/occupational exposures

When do embryonal tumors originate? What is an embryonal tumor?

During intrauterine life. Immature embryonic tissue is unable to mature or differentiate into fully developed cells.

When are childhood cancers are often diagnosed?

During peak times of physical growth

Childhood cancers are usually _________________ and have ________________ before a diagnosis is made.

Fast growing, metastasized

Where do most childhood cancers originate? What does this layer give rise to?

From the mesodermal germ layer. This layer gives rise to connective tissue, bone, cartilage, muscle, blood, blood vessels, gonads, kidneys, and lymphatic system.

Trisomy 21 (Down syndrome) is linked to what cancer?

Leukemia Trisomy 21 demonstrates a 10-20 fold increase in risk of ALL/AML leukemia usually 1-4 yrs of age

Pesticides are linked to what cancer?

Leukemias

What are the most common adolescent cancers?

Lymphomas (including Hodgkin and non-Hodgkin)

Etiology of childhood cancers is? What factors are considered causes?

Multifactorial Genetic factors (proto-oncogenes to oncogenes, ex. MYCN; tumor suppressor genes) Congenital factors (Chromosomal alterations, Hereditary syndromes, Immune deficiency disorders, Congenital malformation syndromes) Environmental factors including both prenatal exposures (DES) and childhood exposure (radon, electromagnetic radiation, drugs, toxins)

How do oncogenes and tumor-suppressor genes contribute to cancer?

Mutated proto-oncogenes: change to oncogenes and promote cancer (ex. MYCN in neuro/glioblastoma) Tumor-suppressor genes: Lose their suppressor function, which promotes cancer growth (ex. RB1 retinoblastoma)

Genetic factors of cancer include?

Oncogenes and tumor-suppressor genes Chromosome aberrations and single-gene defects Familial risk

Environmental exposure is split into?

Prenatal or childhood exposures

What cancers are considered familial?

Wilms tumor Retinoblastoma WAGR syndrome

How are embryonal tumors are commonly named?

with the suffix, -blast -blast refers to the immature nature of the cells retinoblastoma, neuroblastoma, nephroblastoma