Overview
Definition:
Late effects of childhood cancer refer to adverse health conditions that arise as a consequence of cancer treatment (chemotherapy, radiation, surgery) or the cancer itself, occurring months or years after diagnosis and completion of therapy
These effects can impact virtually any organ system and may range from mild, asymptomatic conditions to severe, life-threatening sequelae.
Epidemiology:
With cure rates for childhood cancers exceeding 80% in many high-income countries, a large population of survivors now exists
Approximately two-thirds of childhood cancer survivors experience at least one late effect, and one-third report severe or life-threatening late effects
The cumulative incidence of any late effect increases with time since diagnosis, reaching over 70% by 30 years post-diagnosis
Risk is influenced by the type of cancer, treatment intensity, age at diagnosis, and specific treatment modalities used.
Clinical Significance:
Effective surveillance for late effects is critical to detect, manage, and potentially prevent serious health problems in childhood cancer survivors
Early identification and intervention can improve quality of life, reduce morbidity and mortality from treatment-related sequelae, and prevent secondary malignancies
These guidelines are essential for pediatricians, oncologists, and other healthcare professionals involved in the long-term care of these patients, and are a key area tested in DNB and NEET SS examinations.
Surveillance Principles
Risk Stratification:
Survivors are stratified into risk groups based on their original diagnosis, treatment modalities received (type, dose, duration of chemotherapy and radiation, surgical interventions), and age at diagnosis
Specific treatment protocols (e.g., PTCOG, COG, NOPHO protocols) provide detailed risk-stratified recommendations.
Multidisciplinary Approach:
Surveillance requires a multidisciplinary team including pediatric oncologists, primary care physicians, specialists in cardiology, pulmonology, endocrinology, neurology, audiology, ophthalmology, and reproductive health
Regular communication between the survivor, family, and healthcare providers is crucial.
Age Appropriate Screening:
Screening strategies evolve with the survivor's age, moving from childhood-specific concerns to adult-onset conditions
General health maintenance, including immunizations and screenings for common adult diseases, is integrated alongside cancer-specific surveillance.
Patient Education And Empowerment:
Survivors and their families must be educated about potential late effects and the importance of ongoing surveillance
Empowering survivors to actively participate in their healthcare promotes adherence to follow-up recommendations and early symptom recognition.
Common Late Effects And Screening
Cardiac Toxicity:
Risk factors include anthracyclines, chest radiation
Screening: Echocardiogram (baseline, periodic based on risk), ECG, clinical assessment for dyspnea, palpitations, chest pain
Specific recommendations vary by cumulative dose of anthracyclines and radiation fields.
Pulmonary Toxicity:
Risk factors include bleomycin, lung radiation
Screening: Pulmonary function tests (PFTs) (spirometry, DLCO), chest X-ray, clinical assessment for dyspnea and cough
Periodic monitoring starting 2-5 years post-treatment, depending on exposure.
Endocrine Dysfunction:
Risk factors include cranial/neck radiation, high-dose chemotherapy, surgery of endocrine glands
Screening: Growth monitoring, thyroid function tests (TSH, fT4), evaluation for diabetes mellitus (HbA1c, fasting glucose), assessment of gonadal function (hormonal assays, fertility counseling), bone mineral density scans (DEXA) for osteopenia/osteoporosis
Regular checks from childhood through adulthood.
Neurological Sequelae:
Risk factors include cranial radiation, intrathecal chemotherapy, neurotoxic agents
Screening: Neuropsychological evaluations (cognitive function, learning disabilities), assessment for endocrine dysfunction (pituitary), cranial nerve deficits, seizures, peripheral neuropathy
Early and ongoing assessment is vital.
Ototoxicity And Vision Impairment:
Risk factors include platinum agents (cisplatin, carboplatin), cranial radiation
Screening: Audiometry (baseline, annual or biannual based on risk), ophthalmological examination (visual acuity, visual fields, slit-lamp examination for cataracts, fundus examination for retinopathy) recommended annually or biannually.
Musculoskeletal Issues:
Risk factors include radiation to bone, corticosteroid therapy, surgery affecting growth plates
Screening: Monitoring of growth, skeletal surveys, assessment for scoliosis, joint stiffness, limb length discrepancies, and risk of fractures
DEXA scans for bone density.
Secondary Malignancies:
Risk factors include alkylating agents, radiation
Screening: Comprehensive physical examination, age-appropriate cancer screening guidelines (e.g., mammography for female survivors of chest radiation, colonoscopy), and prompt investigation of any suspicious symptoms
Surveillance typically continues lifelong.
Surveillance Guidelines By Age Group
Childhood And Adolescence:
Focus on immediate post-treatment effects: growth, endocrine function, neurocognitive development, ototoxicity, cardiac function
Regular physical exams, growth charts, basic lab tests (CBC, LFTs, RFTs), audiometry, ophthalmology, PFTs for high-risk individuals
Education on sun protection and healthy lifestyle.
Young Adulthood:
Transition to adult care
Continued monitoring of major organ systems (cardiac, pulmonary, endocrine)
Introduction of age-appropriate cancer screening
Fertility counseling and management of reproductive health issues
Psychological support and management of psychosocial adjustments
Emphasis on lifestyle modifications.
Adult Survivorship:
Lifelong surveillance for chronic conditions and secondary malignancies
Regular specialist consultations as needed based on identified risks
Management of age-related comorbidities alongside cancer-related late effects
Continued patient education for self-advocacy.
Key Points
Exam Focus:
Understand the specific treatment modalities (chemotherapy agents, radiation fields) that predispose to particular late effects
Know the recommended screening tests and their frequency for common late effects like cardiac, pulmonary, and endocrine dysfunction
Recognize the importance of risk stratification for personalized surveillance plans.
Clinical Pearls:
Always maintain a high index of suspicion for late effects in childhood cancer survivors presenting with vague symptoms
Integrate general health maintenance with cancer-specific surveillance
Empower survivors with knowledge about their treatment history and follow-up needs
Facilitate smooth transitions to adult care.
Common Mistakes:
Underestimating the cumulative toxicity of combined treatment modalities
Inadequate risk stratification leading to under- or over-screening
Lack of coordinated care between primary care and specialists
Failing to educate survivors about their long-term risks and the importance of adherence to surveillance
Not considering psychosocial aspects of survivorship.