Peds Oncology Flashcards
Cancer mortality rates in the US
Although cancer in children is rare it is the leading cause of death by disease past infancy among children in the United States
Care for children and adolescents after cancer diagnosis
Children and adolescents who have been treated for cancer need regular follow-up care for the rest of their lives because they are at risk of late side effects that can occur many years later including second cancers
Which cancer makes up the majority of childhood cancer?
Leukemia - MC**
Leukemia pathophysiology
- results from an event in a bone marrow precursor cell which gives rise to immature progeny that have lost the capacity to differentiate and proliferate in an uncontrolled manner
- immature progeny (blasts) expand in marrow and impair normal hematopoiesis
List the leukemia types that make up the majority of childhood cancer
- Acute Lymphoblastic Leukemia (ALL)
- Acute Myeloid Leukemia (AML)
Which population has higher risk of developing acute leukemia compared to other children?
Children with Down Syndrome have 20x greater risk
- ALL: 12x risk
- AML 46x risk
Which other groups have increased risk of developing acute leukemia?
- siblings of children with leukemia
- those with genetic disorders such as:
- -neurofibromatosis
- -Li-Fraumeni syndrome
- -Fanconi’s anemia
Leukemia - common presenting s/sx
- Expanding blast population in bone marrow causes bone and joint pain
- Pallor and fatigue due to anemia
- Bruising, petechiae and bleeding due to thrombocytopenia and coagulopathy
- Fever due to infection and cytokines from leukemia
- Adenopathy, hepatomegaly and splenomegaly due to blasts migrating out of marrow
- Gingivitis/gingival hyperplasia
Lab findings in acute leukemia
-CBC
- Leukocytosis or leukopenia with or without circulating blasts
- Anemia
- Thrombocytopenia
- CBC may also be completely normal
Lab findings in acute leukemia
Coagulopathy/DIC is common in AML
Lab findings in acute leukemia
-metabolic derangement
- due to rapid cell growth and turnover
- Elevated creatinine, potassium, phosphorus and uric acid
- Elevated lactate dehydrogenase
Approaching new leukemia cases
- Need to obtain diagnosis by flow cytometry on peripheral blood or marrow
- Need bone marrow samples for cytogenetics
- Need diagnostic LP to assess CNS status
Epidemiology of Childhood ALL
**MC pediatric cancer
-Peak age 2-5 years
>90% overall survival on modern therapy regimens
ALL morphology under the microscope
Blasts are much larger than regular lymphocytes and RBCs
ALL therapy
- Majority of therapy is outpatient
- IV chemotherapy given in clinic and oral chemotherapy given at home
- CNS directed chemotherapy via lumbar puncture**
- Therapy lasts 2.5 years for girls and 3.5 years for boys
- Bone marrow transplant (BMT) reserved only for certain very high risk patients and in relapse
Define B precursor ALL
MC subtype of acute lymphoblastic leukemia (ALL)
-has the highest cure rate
How does T cell ALL present?
- Patients frequently have WBC >100K, are male (4X more than female), and >10 years old
- Anterior mediastinal mass is often present at diagnosis and can cause severe cardio-respiratory compromise so often have to make diagnosis from peripheral blood or from biopsy done under minimal sedation
What patients should make you concerned for T cell ALL?
- adolescents who present with asthma-like symptoms/respiratory distress who have never had respiratory problems or been diagnosed with asthma as a child
- asthma does not typically appear in adolescence
Acute myeloid leukemia (AML) morphology
- 15-20% of childhood leukemia
- Malignant precursors of the myeloid, monocyte, erythroid and megakaryocytic cell lineages
- MC leukemia seen in children with bone marrow failure syndromes like Fanconi’s Anemia
- Can result from exposure to chemotherapy
Which kind of AML is MC in Down Syndrome?
M7 AML - acute megakaryoblastic leukemia
Pediatric AML Therapy
- 4-5 cycles of high-dose IV chemotherapy given inpatient every 4-5 weeks
- Associated with lengthy periods of severe neutropenia and mucositis
- Remain hospitalized for most of therapy due to high risk of life threatening bacterial infections
When is bone marrow transplant considered in
- Used frequently in kids who have a sibling match, have poor response to Induction or have unfavorable cytogenetics
- Almost always used in cases due to bone marrow failure syndromes or chemotherapy exposure
Relationship between AML and Trisomy 21
- 20-30% of neonates will have Transient Myeloproliferative Disorder (TMD) and may need low dose chemo if liver of pulm dysfunction
- these neonates have 20-30% chance of developing AML
What is the MC leukemia in children with trisomy 21?
AML is MC***
- majority are M7
- is associated with better outcomes than other children with less intensive therapy and without BMT**
Define Chronic myeloid leukemia (CML)
- accounts for 1-3% of childhood cancer (20% in adults)
- most peds cases occur after 4 years old
- Myeloproliferative disorder characterized by an increased proliferation of the granulocytic cell line without the loss of their capacity to differentiate
What is the Philadelphia chromosome?
- associated with CML
- reciprocal translocation of the long arms of chromosomes 22 and 9
- produces tyrosine kinase
CML presentation
- Very high WBC (often >100K) with small percentages of circulating blasts, myelocytes, metamyelocytes and promyelocytes
- often otherwise well appearing
- tx now includes tyrosine kinase inhibitors
Define Juvenile Myelomonocytic Leukemia (JMML)
- Rare myeloproliferative syndrome in very young children
- Increased risk in certain inherited genetic disorders:
- Neurofibromatosis type 1
- Noonan’s syndrome
- Cardio-facio-cutaneous congenital disorders
JMML Prognosis
- typically runs an aggressive clinical course
- Allogeneic BMT is only curative option
- Median duration of survival without SCT is < 12 months from diagnosis
Define lymphomas
- malignant proliferation of white blood cells derived from peripheral lymphoid tissue
- make up 15% of childhood cancers
When to Worry About Lymphadenopathy
-History
- Rapidly growing
- Stay enlarged >2 months
- No response when treated with antibiotics
- Shrinks with steroids but then grows again
- Associated fever, weight loss, fatigue
- Causing respiratory distress bad enough to consider steroids
When to Worry About Lymphadenopathy
-Physical
- Supraclavicular nodes always require more evaluation
- > 3 cm is worrisome
- Hard, immobile, non-tender or irregular are worrisome
When to Worry About Lymphadenopathy
-Labs
High LDH and uric acid are worrisome (these are signs of high cell turnover)
Radiology imaging CT vs. PET CT
CT: Look at size, location and extent
PET CT: Looks at metabolic activity
Incidence of Lymphoma by Age
- Majority of lymphomas in younger children are NHL (non-Hodgkin’s lymphoma)
- Incidence of Hodgkin’s Lymphoma increases with age
Hodgkin’s Lymphoma Presentation
- Usually painless adenopathy (80%) commonly in the supraclavicular or cervical area
- The enlarged nodes are typically firmer than inflammatory nodes and have a rubbery texture.
- Many have some mediastinal involvement at presentation (silhouette present on CXR)
Etiology of Non-Hodgkin’s Lymphoma
- Incidence increases steadily with age
- Most commonly in the second decade of life
- Most frequent malignancy in children with AIDS
- Several subtypes in children:
- Lymphoblastic Lymphomas
- Burkitt’s Lymphomas
- Large Cell Lymphomas
- Tx: generally just chemo without radiation
Presentation of lymphoblastic lymphoma
- a subtype of non-Hodgkin’s lymphoma
- frequently initially presents with “asthma” (~75% present with anterior mediastinal mass)
- 85-90% are Precursor T-Cell Origin