Download Common childhood cancers

COMMON CHILDHOOD CANCERS
PL Tan and TC Quah
In Singapore, approximately 1 in 600 children between ages 1 and 15 develops cancer
and there are about 83 new cases a year of childhood cancer nationally. As in most
developed countries, the mortality rate is approximately 30% (about 25 deaths annually
for Singapore), making childhood cancer the commonest cause of death in children
locally. Besides the local cases, we manage a significant number of childhood cancers
from the region as well.
CONTENTS
• Introduction
• Common Childhood Cancers
o Types of Cancers
o Presentation Patterns
• Making the Diagnosis
• Briefly, on Management
• Follow-Up Care
• References
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MITA (P) No: 157/06/2002
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1. COMMON CHILDHOOD CANCERS
Types of Cancers
Childhood Cancers in Singapore
Leukaemia
30%
32%
Brain Tumours
Lymphomas
Neuroblastomas
8%
10%
20%
Bone and Soft Tissue
Sarcomas and Others
• Childhood Leukaemias
Leukaemias comprise 30% of these cancers. The most common are the acute
lymphoblastic leukaemias (ALL), which make up 80% of all leukaemias.
The peak age of presentation is between 2 to 3 years of age. The second
commonest are the acute myeloid leukaemias (AML) (about 15%). Chronic
myeloid leukaemias (CML) which make up < 5% of the cases are
occasionally seen.
• Childhood Brain Tumours
Brain tumours comprise about 20% of childhood cancers and are the second
most common cancer in children. The common brain tumours include
gliomas of varying grades of aggressiveness, medulloblastomas and
craniopharyngiomas. Children of all ages are affected equally.
• Lymphomas
Non-Hodgkin’s lymphoma (NHL) and Hodgkin’s disease (HD) make up the
lymphoma group. Generally, older children who are above 10 years are
affected. NHL accounting for 6% of all cancers is commoner than HD which
contributes 4%.
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• Neuroblastomas and other infant tumours
Neuroblastomas (NB) are the next largest group and about 6 to 7 new cases
(8%) are diagnosed each year. Half of these patients are younger than 2
years and 30% younger than 1. Together with retinoblastomas, Wilms’
tumours (also known as nephroblastomas) and hepatoblastomas, these
tumours occur primarily in the infants and pre-schoolers age group (<5
years).
• Others
Bone tumours (osteosarcomas, Ewing’s sarcoma), soft tissue sarcomas
(rhabdomyosarcomas, non-rhabdomyosarcomas soft tissue sarcomas), germ
cell tumours and other rarer carcinomas comprise the rest.
2. PRESENTATION PATTERNS
Diagnosis usually does not pose a problem when symptoms and signs are
obvious and when disease is advanced. Commonly these include:
• Pallor
• Bruising and petechiae
• Lymphadenopathies (generalised or single, persistent and growing)
• Hepatosplenomegaly
• Masses in the abdomen
• Limb swellings (hard and rapidly growing masses in the long bones)
• Visual disturbances (knocking into things)
• Symptoms and signs of raised intracranial pressure or endocrine
disturbances
Constitutional symptoms are usually present with:
• Non-specific changes in behaviour
• Lethargy
• Loss of appetite and weight
• Prolonged, intermittent fevers that resolve for short periods of time but
recur, with little evidence of a source of infection (e.g. URTI), indicative of
a malignant fever.
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The “Masqueraders”
• Bone pain or aches as primary presenting complaints are not uncommon and
are usually non-articular in leukaemia and bone cancers, in contrast to the
articular involvement in rheumatologic disorders. Very small children with
these pains often present with persistent irritability and a preference for
inactivity.
• Red herring injuries are common and can delay the diagnosis of bone
tumours.
Other presentation symptoms such as gum swellings and bleeding despite good
dental hygiene (infiltration from AML) can be the first symptoms. Histories
from the main carers may suggest a white pupil (“cat’s eye”) or abdominal
masses felt while bathing the children or even an unusually protuberant
abdomen.
Unusual emergency presentations1
• Superior Mediastinal Syndrome (SMS)
Thoracic tumours such as NHL, HD, NB and germ cell tumours can cause
compression, obstruction or thrombosis of the superior vena cava with or
without tracheal compression causing respiratory embarrassment. Patients
often have oedema, cyanosis and plethora of face and neck with cervical and
thoracic venous distension. Wheezing or stridors are common and coexisting signs of pleural or pericardial effusion may be present. These signs
might be very subtle in the beginning and there were occasions where
patients were inappropriately treated for “asthmatic exacerbations” with
steroids resulting in temporary relief.
• Spinal Cord Compression
Acute retention of urine or constipation with refusal to walk due to lower
limbs weaknesses are often the presenting features of acute spinal cord
compression. Dumb-bell neuroblastomas in the spinal cord and lymphomas
are the commonest causes. These signs may be difficult to detect as young
children often cannot tell or cooperate for good neurological examination.
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3. TRENDS AND SURVIVAL
In the USA, the incidence of all childhood cancers have remained relatively
constant from 1975 to 1997 for children younger than 15 years.2 There was
an apparent increase in the incidence of childhood brain tumours in the late
1970s to mid-1980s, but the incidence has not increased since the widespread
availability of magnetic resonance imaging in the mid-1980s suggesting that
improvements in diagnosis and reporting may have accounted for that
apparent increase.3 In Singapore, the trend has been similar.4, 5
With risk-adapted, dose-intensified therapies, survival rates have improved
dramatically for childhood cancers in general since the 1960s from an overall
5-year survival rate of 28% to rates exceeding 75% in the 1990s for children
less than 15 years old. 6
4. MAKING THE DIAGNOSIS
Making a diagnosis of childhood cancer can be complex but if attention are
given to these areas, the risks of missing or delaying the diagnosis might be
reduced significantly.
• Thorough history and examination
1. Identify the actual main carer
2. Sedation might be needed to examine a fretful child (caution with very
young children)
3. Always check the for red reflexes for well baby visits
• High index of suspicion
‘The eye don’t see what the mind don’t think’
• Repeated reviews
New findings or progression can be detected earlier
• Do simple investigations (e.g. blood counts, simple X-rays) if in doubt
• Pay attention to the concerns of ‘highly anxious’ parents
Understand the background for any disagreement with regards to further
investigations, as intangibly, parents often intuitively know something is
wrong with their child.7
• Consult with a GP or a specialist colleague
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Our Paediatric oncologists here are always happy to provide advice and are
just a phone call away.
5. REFERRAL
Once a child with a suspected cancer is referred to a Paediatric oncologist
here, he or she will be seen within 24 hours.
6. BRIEFLY, ON MANAGEMENT
The chief aims in the initial periods include attending to immediate medical
problems or emergencies. Upon counselling of parents and the main carers,
diagnostic tests including a series of blood tests, radiological tests and
biopsies will be arranged. Treatment usually starts within a day or a week
after confirmation of the diagnosis. Referrals are made concurrently to
medico-social workers and play therapists to assist in parental / patient
education and support. Often in the course of the first admission, the options
of indwelling central venous catheters are offered to parents/ patients. Having
such an access allows safe administration of chemotherapy and easy blood
sampling and significantly reduces distress and anxiety for all patients.
These catheters are usually inserted under general anaesthesia (GA) when the
child is stable or at the same sitting of a biopsy that is done under GA.
7. FOLLOW-UP CARE
Generally, the patients stay for 5 days to 3 weeks for the diagnosis
admission, depending on presence or absence of complications. Most
therapies are outpatient based and follow-ups are once or twice a week and as
needed. There will be requirements for inpatient therapies and these vary
with different protocols. Patients have 24 hours access to the doctors and
nurses in the team and admissions if needed are arranged directly. Patients
can choose to see their regular family doctor for common illnesses if they
prefer. Detailed letters of the diagnosis and management plans are prepared
for this purpose and as standby for emergencies.
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REFERENCES
1. Rheingold SR, Lange BJ. In: Pizzo PA, Poplack DG eds. Principles and
Practice of Pediatric Oncology (4th edition): Oncologic Emergencies pp
1177.
2. Surveillance, Epidemiology, and End Results (SEER) program, National
Cancer Institute.
3. Smith M, Freidlin B, Ries L, et al. Trends in reported incidence of primary
malignant brain tumours in USA [see comments]. J Natl Cancer Inst 1998;
90:1269-1277.
4. Chia KS, Seow A, Lee HP, Shanmugaratnam. Cancer Incidence in Singapore
1993-1997. Singapore Cancer Registry Report No.5.
5. Chia KS, Seow A, Lee HP, Shanmugaratnam. Trends in Cancer Incidence in
Singapore 1968-1992. Singapore Cancer Registry Report No.4.
6. Ries LA. In: Harras A, Edwards BK, Blot WJ, et al., eds. Cancer: rates and
risks. Bethesda, MD: National Cancer Institute, 1996:9-54.
7. Mary Dixon-Woods, Michelle Findlay, Bridget Young, Helen Cox, David
Heney. Parents' accounts of obtaining a diagnosis of childhood cancer.
Lancet 2001; 357: 670-74.
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