OVERVIEW OF CHILDHOOD CANCERS

1. OVERVIEW OF CHILDHOOD CANCERS TA OGUNLESI (FWACP)

2. CHILDHOOD CANCERS • Involve tissues of: CNS, bone, muscle, endothelial tissue, haemopoietic tissue • Grow in a short period of time • Unlike malnutrition and infections, cancers are not remarkable causes of childhood morbidity & mortality in the developing world TA OGUNLESI (FWACP)

3. CLASSIFICATION • Embryonal tumor arises from embryonic tissue • Neuroblastoma • Nephroblastoma • Retinoblastoma • Lymphomas= lymphatic tissue • Hodgkin’s lymphoma • Burkitt’s lymphoma TA OGUNLESI (FWACP)

4. CLASSIFICATION • Leukemias = blood • Acute Lymphoblastic Leukaemia • Acute Myeloblastic Leukaemia • Sarcoma seen in tissues other than blood: • Skeletal muscle (rhabdomyosarcoma) • Bone (osteosarcoma) • Nerve (neuroma) TA OGUNLESI (FWACP)

5. AETIOLOGY • The aetiology of most of the cancers in children are unknown. • Only very few have been associated with specific environmental and genetic factors. TA OGUNLESI (FWACP)

6. PREDISPOSING FACTORS • Viruses & their toxins Epstein-Barr Virus in Bukitt’s Lymphoma • Chemical carcinogens • Aflatoxins in hepatocellular carcinoma • Benzene in myeloid leukaemia TA OGUNLESI (FWACP)

7. PREDISPOSING FACTORS • Genetics • Autosomal dominant inheritance in Retinoblastoma • Down syndrome in leukaemia • Fanconi syndrome in leukaemia • Ataxia telangiectasia in leukaemia • Congenital aniridia in Nephroblastoma TA OGUNLESI (FWACP)

8. PREDISPOSING FACTORS • Ionizing irradiation • Leukaemia • Brain tumors • Skin carcinoma • Drugs • Phenytoin (lymphomas & neural crest tumors) • Barbiturates (brain tumors) • Cyclophosphamide (bladder cancer) • Androgens (leukaemia) TA OGUNLESI (FWACP)

9. RECOGNITION OF CHILDHOOD CANCERS • Childhood cancers can be difficult to diagnose due to: • Low index of suspicion since they are thought to be rare • Features are non-specific initially & mimic those of other common conditions like viral infections TA OGUNLESI (FWACP)

10. CARDINAL SIGNS OF CANCERS • Unusual mass or swelling • Unexplained palor and loss of energy • Spontaneous bruising • Prolonged, unexplained fever • Headaches in morning • Sudden eye or vision changes • Excessive – rapid weight loss. TA OGUNLESI (FWACP)

11. SIGNS & SYMPTOMS OF CANCERS AND CONDITIONS THEY MIMIC • Fever in leukaemia & lymphoma may mimic infections • Cough in mediastinal lymphoma & Wilm’s tumor may mimic URTI, asthma or pneumonia TA OGUNLESI (FWACP)

12. SIGNS & SYMPTOMS OF CANCERS AND CONDITIONS THEY MIMIC • Bone & muscle pain in leukaemia & bone tumor may mimic trauma, SCA or viral myalgia • Headache in brain tumor may mimic migraine • Haematuria in Wilm’s tumor may mimic UTI, AGN TA OGUNLESI (FWACP)

13. SIGNS & SYMPTOMS OF CANCERS AND CONDITIONS THEY MIMIC • Lymphadenopathy in leukaemia & lymphoma may mimic viraemia, collagen diseases • Constipation in abdominal tumors may mimic poor diet or helminthiasis TA OGUNLESI (FWACP)

14. EVALUATION OF SIGNS & SYMPTOMS OF CANCERS • Fever > 14 days with no obvious cause: FBC • Vomiting > 7 days: Brain & abdominal CT • Cough > 2 weeks: Chest X-Ray • Bone or muscle pain > 2 weeks: FBC, Plain X-Ray, CT scan TA OGUNLESI (FWACP)

15. EVALUATION OF SIGNS & SYMPTOMS OF CANCERS • Lymphadenopathy not responding to 7-day course of antibiotics: FBC, LDH • Headache associated with emesis: Brain CT • Haematuria: Abdomino-pelvic USS TA OGUNLESI (FWACP)

16. DIAGNOSTIC TESTS • X-ray • Skeletal survey • CT scan • Ultrasound • MRI • Bone marrow aspiration • Biopsy TA OGUNLESI (FWACP)

17. PRINCIPLES OF THERAPY • Chemotherapy to destroy all cells in the resting, dividing & maturing stages. • This is achieved with: • Cytotoxic drugs (alkylating agents, anti-metabolites, antibiotics, alkaloids) • Hormones (steroids, estrogens, androgens) • Major problem with chemotherapy are the sanctuary sites (testes, thyroid, CNS) • Can be used alone or with other modalities TA OGUNLESI (FWACP)

18. PRINCIPLES OF THERAPY • Surgery • Usually done to remove large masses which may have pressure effects • Debulking surgery may improve the efficacy of chemotherapy • Mostly done to obtain diagnostic material (biopsy) since chances of metastasis are high at the time of presentation TA OGUNLESI (FWACP)

19. PRINCIPLES OF THERAPY • Radiotherapy • The use of ionizing radiation to break apart bonds within a cell causing cell damage and death • Most useful for regional tumor extension or tissues like bone & the sanctuary sites which drugs may not penetrate. • Major problem is the associated destruction of normal tissues. • Need to plan a safe radiation field to minimize normal tissue destruction. TA OGUNLESI (FWACP)

20. PRINCIPLES OF THERAPY • Immunotherapy • Enhancement of normal cell-mediated immunity to destroy tumor cells • Largely experimental & disappointing • Bone marrow transplantation • Useful for myeloproliferative diseases • Major problems include getting a suitable donor & Graft Versus Host disease • Gene Therapy TA OGUNLESI (FWACP)

21. UNWANTED EFFECTS OF CANCER TREATMENT • Alopecia • Bone marrow depression with pancytopenia (anaemia, infections & abnormal bleeding) • Protracted diarrhoea • Nausea & Vomiting • Infections TA OGUNLESI (FWACP)

22. UNWANTED EFFECTS OF CANCER TREATMENT • Growth retardation • Haemorrhagic cystitis (Cyclophosphamide) • Skin necrosis (Vincristine) • Sterility • Secondary neoplasm TA OGUNLESI (FWACP)