Post-Radiation Therapy Complications in Cancer Survivors

Primary Consideration: Endocrine Dysfunction

Radiation-induced hypothyroidism occurs in approximately 50% of long-term survivors who received neck or upper mediastinal irradiation, according to the National Comprehensive Cancer Network 1
Hypothyroidism typically manifests 5-10 years after radiation therapy but can occur earlier, as stated by the National Comprehensive Cancer Network 1
The American College of Physicians and other guideline societies recommend thyroid function tests (TSH and free T4) should be performed immediately as this is a highly treatable cause of symptoms 1, 2

Anemia must be evaluated given the heavy menstrual bleeding and fatigue, as recommended by the European Society for Medical Oncology 3, 4, 2
Complete blood count with differential is essential to assess for iron deficiency anemia from menorrhagia or other causes, according to the American Society of Clinical Oncology 2
The National Comprehensive Cancer Network states that while myelosuppression from chemotherapy typically resolves shortly after treatment completion, persistent cytopenias warrant investigation 1

Mediastinal radiation and anthracycline-based chemotherapy create significant risk for cardiac disease, which may be asymptomatic initially, as reported by the National Comprehensive Cancer Network 1
RT-induced cardiotoxicity typically emerges 5-10 years post-treatment, though cardiovascular symptoms can appear at any age, according to the National Comprehensive Cancer Network 1
Fatigue and exercise intolerance despite maintained fitness regimen could indicate subclinical cardiac dysfunction, as stated by the National Comprehensive Cancer Network 1
The American Heart Association recommends blood pressure monitoring and assessment of cardiovascular risk factors 1

Disease recurrence or development of secondary malignancies must be considered in any cancer survivor presenting with new constitutional symptoms, as recommended by the National Comprehensive Cancer Network and the European Society for Medical Oncology 5, 2
Fatigue is a common presenting symptom of recurrent lymphoma or treatment-related secondary cancers, according to the National Comprehensive Cancer Network 1

A comprehensive metabolic panel to evaluate liver and kidney function, electrolyte balance is recommended by the American Society of Clinical Oncology 2
Assessment for vitamin deficiencies (particularly B12, folate, vitamin D) that may contribute to fatigue, as stated by the National Institutes of Health 2

Evaluation of sleep quality, quantity, and potential sleep disorders (sleep apnea, insomnia) is recommended by the American Academy of Sleep Medicine 4, 5, 2
Sleep disturbances frequently cluster with fatigue and may be both cause and consequence, as reported by the National Sleep Foundation 5

Screen for depression and anxiety, which commonly co-occur with cancer survivorship and fatigue, as recommended by the American Psychiatric Association 3, 4, 5
Post-cancer emotional distress can manifest with physical symptoms including fatigue and weight changes, according to the National Institute of Mental Health 3

Do not attribute all symptoms to "cancer-related fatigue" without thorough evaluation of treatable medical conditions, as stated by the European Society for Medical Oncology and the National Comprehensive Cancer Network 3, 4
Hypothyroidism is frequently overlooked in cancer survivors despite being extremely common after thoracic radiation, according to the National Comprehensive Cancer Network and the American Thyroid Association 1, 6