8.5 Complications of Cancer & Its Treatment

ABIM Internal Medicine Exam

Track your progress as you read

Finished sections get a check mark.

1 Chapter 0: The ABIM Exam, Blueprint & Study Strategy

0.1 Exam Format, Question Types & the 2026 Blueprint 0.2 Eligibility, Registration, Fees & Exam-Day Logistics 0.3 Scoring, the Passing Standard & Score Reports 0.4 Building a Blueprint-Weighted Study Plan

2 Chapter 1: Cardiovascular Disease (14% of Exam)

1.1 Ischemic Heart Disease & Acute Coronary Syndromes 1.2 Antithrombotic Therapy, Secondary Prevention & Mechanical Complications of MI 1.3 Atrial Fibrillation, Atrial Flutter & Stroke Prevention 1.4 Supraventricular Tachycardias, Ventricular Arrhythmias & Bradycardias 1.5 Heart Failure: Classification, Staging & Guideline-Directed Medical Therapy 1.6 Device Therapy, HFpEF & the Cardiomyopathies 1.7 Valvular Heart Disease & Endocarditis Prophylaxis 1.8 Pericardial Disease & Acute Aortic Syndromes 1.9 Hypertension: Classification, Diagnosis & Secondary Causes 1.10 Hypertensive Crises & Dyslipidemia 1.11 Adult Congenital Heart Disease & Coarctation of the Aorta 1.12 Syncope: Reflex, Orthostatic & Cardiac Causes 1.13 Cardiac Physical Examination, Murmurs & Antithrombotic Selection

3 Chapter 2: Endocrinology, Diabetes & Metabolism (9% of Exam)

2.1 Diabetes Mellitus: Diagnosis, Glycemic Targets & Pharmacotherapy 2.2 Insulin Therapy, Hyperglycemic Emergencies & Chronic Complications 2.3 Thyroid Function Testing & Hypothyroidism 2.4 Thyrotoxicosis, Thyroid Storm & Thyroid Nodules 2.5 Adrenal & Pituitary Disorders 2.6 Hypercalcemia, Hypocalcemia & Disorders of Mineral Metabolism 2.7 Osteoporosis & Paget Disease of Bone 2.8 Ovarian, Testicular & Reproductive Endocrine Disorders 2.9 Hypoglycemia, Endocrine Tumors, Polyglandular Syndromes & Severe Hypertriglyceridemia

4 Chapter 3: Gastroenterology & Hepatology (9% of Exam)

3.1 Esophageal Disease 3.2 Stomach & Duodenal Disease and Gastrointestinal Hemorrhage 3.3 Inflammatory Bowel Disease 3.4 Celiac Disease & Irritable Bowel Syndrome 3.5 Diverticular Disease & Colorectal Cancer Screening 3.6 Viral Hepatitis, Steatotic & Alcohol-Associated Liver Disease 3.7 Cirrhosis & the Complications of Portal Hypertension 3.8 Acute Pancreatitis 3.9 Chronic Pancreatitis & Biliary Tract Disease 3.10 Inherited, Autoimmune & Drug-Induced Liver Disease 3.11 Small Intestinal Disease, Ischemia & Gastrointestinal Complications of HIV

5 Chapter 4: Infectious Disease (9% of Exam)

4.1 Lower Respiratory Tract Infections & Sepsis Syndromes 4.2 Viral Respiratory Pathogens & Tuberculosis 4.3 Central Nervous System Infections 4.4 Skin, Soft Tissue, Bone & Joint Infections 4.5 Infective Endocarditis & Cardiovascular Infection 4.6 Clostridioides difficile & Catheter-Related Bloodstream Infection 4.7 HIV Diagnosis, Antiretroviral Therapy & Prevention 4.8 Opportunistic Infections & Sexually Transmitted Infections 4.9 Fever of Unknown Origin, Neutropenic Fever & Toxic Shock 4.10 Travel-Related Illness, Vector-Borne Disease & Outbreaks 4.11 Infection Prevention, Nosocomial Infection & Postexposure Prophylaxis 4.12 Rheumatic Fever, Poststreptococcal Disease, Enteric & Hepatic Infections

6 Chapter 5: Pulmonary Disease (9% of Exam)

5.1 COPD: Diagnosis, GOLD Classification & Initial Pharmacotherapy 5.2 Interventions That Reduce COPD Mortality & Exacerbation Management 5.3 Asthma: Diagnosis, Stepwise Therapy & Status Asthmaticus 5.4 Interstitial Lung Disease & Idiopathic Pulmonary Fibrosis 5.5 Sarcoidosis, Hypersensitivity Pneumonitis & Occupational Lung Disease 5.6 Pulmonary Embolism: Diagnosis, Risk Stratification & Anticoagulation 5.7 Pulmonary Hypertension & Sleep-Disordered Breathing 5.8 Acute Respiratory Distress Syndrome & Mechanical Ventilation 5.9 Pleural Disease, Empyema & Pneumothorax 5.10 Bronchiectasis, Cystic Fibrosis & Restrictive Lung Disease 5.11 Evaluation of Cough, Dyspnea, Hemoptysis & the Solitary Pulmonary Nodule

7 Chapter 6: Rheumatology & Orthopedics (9% of Exam)

6.1 Rheumatoid Arthritis: Diagnosis & Systemic Manifestations 6.2 Antirheumatic Pharmacotherapy & the Spondyloarthropathies 6.3 Gout: Pathophysiology & Acute Management 6.4 Urate-Lowering Therapy & Calcium Pyrophosphate Deposition Disease 6.5 Osteoarthritis 6.6 Systemic Lupus Erythematosus 6.7 Systemic Sclerosis, Sjogren Syndrome & Inflammatory Myopathies 6.8 The Vasculitides 6.9 Regional Musculoskeletal Syndromes, Back Pain & Sports Injuries 6.10 Other Primary Rheumatic Disorders & Mixed Connective Tissue Disease 6.11 Osteonecrosis & Metabolic Bone Disease

8 Chapter 7: Hematology (6% of Exam)

7.1 Approach to Anemia & the Microcytic Anemias 7.2 Macrocytic, Normocytic & Hemolytic Anemias 7.3 Hemoglobinopathies, Thalassemias & Paroxysmal Nocturnal Hemoglobinuria 7.4 Platelet Disorders, Thrombocytopenia & the Bleeding Patient 7.5 Coagulation Factor Disorders, Thrombophilia & Anticoagulant Reversal 7.6 Acute Leukemias, Chronic Leukemias & Myeloproliferative Neoplasms 7.7 Lymphomas & Plasma Cell Disorders 7.8 Myelodysplastic Syndrome, Myeloproliferative Neoplasms & Porphyria 7.9 Transfusion Medicine & Late Complications of Transplantation

9 Chapter 8: Medical Oncology (6% of Exam)

8.1 Breast, Lung, Colorectal & Prostate Cancer 8.2 Oncologic Emergencies 8.3 Genitourinary & Gynecologic Malignancies 8.4 Head and Neck, Bone & Soft Tissue Cancer and Cancer of Unknown Primary 8.5 Complications of Cancer & Its Treatment 8.6 Cancer Prevention, Survivorship & Psychosocial Care

10 Chapter 9: Nephrology & Urology (6% of Exam)

9.1 Acute Kidney Injury: Staging, Etiology & Urine Microscopy 9.2 Glomerular Disorders & Nephrotic Syndrome 9.3 Nephritic Syndromes, RPGN & Indications for Renal Replacement Therapy 9.4 Chronic Kidney Disease: Staging & Progression Retardation 9.5 Complications of Chronic Kidney Disease: Anemia, CKD-MBD & Acidosis 9.6 Hyponatremia, Hypernatremia & Water Balance 9.7 Potassium Disorders & Systematic Acid-Base Analysis 9.8 Renal Tubular Acidosis & Nephrolithiasis 9.9 Prostate Disorders, Urinary Incontinence & Other Urologic Conditions 9.10 Cystic Kidney Disease, Obstructive Uropathy, Tubulointerstitial Disease & Hematuria

11 Chapter 10: Neurology (4% of Exam)

10.1 Acute Ischemic Stroke: Syndromes & Reperfusion 10.2 Transient Ischemic Attack, Secondary Prevention & Hemorrhagic Stroke 10.3 Headache & Facial Pain 10.4 Seizures, Epilepsy & Movement Disorders 10.5 Multiple Sclerosis & Neuromuscular Junction Disorders 10.6 Motor Neuron Disease & Acute Peripheral Neuropathy 10.7 Cranial Neuropathies & Neuro-Ophthalmology 10.8 Peripheral Neuropathies, CNS Tumors & Other Neurologic Disorders

12 Chapter 11: Psychiatry & Behavioral Health (4% of Exam)

11.1 Major Depressive Disorder & Medical Mimics 11.2 Antidepressant Pharmacotherapy & Treatment-Resistant Depression 11.3 Bipolar Disorder, Mood Stabilizers & Lithium Toxicity 11.4 Anxiety, Stress-Related & Obsessive-Compulsive Disorders 11.5 Alcohol Use Disorder & Withdrawal 11.6 Pharmacotherapy for Alcohol & Opioid Use Disorder 11.7 Toxidromes, Psychiatric Emergencies & Suicide Risk Assessment 11.8 Psychotic, Somatic Symptom, Factitious & Personality Disorders 11.9 Eating Disorders, Sleep Disorders & Sexual Health

13 Chapter 12: Dermatology (3% of Exam)

12.1 Dermatitis, Papulosquamous & Inflammatory Dermatoses 12.2 Acne, Rosacea & Cutaneous Infections 12.3 Herpes Zoster & Autoimmune Blistering Diseases 12.4 Nodules, Tumors & Cutaneous Oncology 12.5 Dermatologic Emergencies & Severe Cutaneous Adverse Reactions 12.6 Pigment Disorders, Alopecia, Nail Disease & Photosensitivity 12.7 Vascular Dermatoses, Environmental Injury & Cutaneous Signs of Systemic Disease

14 Chapter 13: Obstetrics & Gynecology / Women's Health (3% of Exam)

13.1 Contraception, Preconception Care & Teratogenicity 13.2 Hypertensive Disorders of Pregnancy & Gestational Diabetes 13.3 Thyroid Disease & Venous Thromboembolism in Pregnancy 13.4 Menopause & Menopausal Hormone Therapy 13.5 Abnormal Uterine Bleeding, Endometrial Disease & Gynecologic Cancer Screening 13.6 Breast Disorders & Diseases of the Vulva and Vagina 13.7 Menstrual Disorders, Fibroids, Endometriosis & Early Pregnancy Complications

15 Chapter 14: Geriatric Syndromes (3% of Exam)

14.1 Comprehensive Geriatric Assessment & Frailty 14.2 Falls, Gait Assessment & Polypharmacy 14.3 Urinary Incontinence & Pressure Injuries in Older Adults 14.4 Mild Cognitive Impairment, Dementia & Its Subtypes 14.5 Delirium & the Pharmacotherapy of Cognitive Disorders 14.6 Palliative Care, Hospice & Advance Care Planning 14.7 Chronic Wounds, Nutrition, Swallowing, Constipation & Hip Fracture 14.8 Sensory Impairment, Dizziness, Elder Mistreatment & Care Settings

16 Chapter 15: Allergy & Immunology (2% of Exam)

15.1 Anaphylaxis: Recognition & Emergency Management 15.2 Urticaria & Angioedema 15.3 Drug Allergy, Desensitization & Adult Immunodeficiency 15.4 Food Allergy, Insect Venom Hypersensitivity, Serum Sickness & Contrast Reactions 15.5 Rhinitis, Conjunctivitis, Eosinophilic & Mast Cell Disorders

17 Chapter 16: Preventive Medicine, Immunization & Clinical Epidemiology

16.1 The USPSTF Framework & Evidence-Based Cancer Screening 16.2 Cardiovascular & Metabolic Screening and Primary Prevention 16.3 Adult Immunization & Vaccines in Special Populations 16.4 Clinical Epidemiology, Biostatistics & Study Design

18 Chapter 17: Miscellaneous - Ethics, Patient Safety & Quality Improvement (2% of Exam)

17.1 Principles of Bioethics & Decisional Capacity 17.2 Informed Consent, Treatment Refusal & Special Scenarios 17.3 Surrogate Decision-Making, Advance Directives & Confidentiality 17.4 Patient Safety Science, Medical Error & Diagnostic Reasoning 17.5 Quality Improvement Methods, Health Disparities & Health Equity

19 Chapter 18: Perioperative Medicine & Medical Consultation

18.1 Preoperative Cardiovascular Risk Assessment 18.2 Preoperative Pulmonary Risk & Perioperative Medication Management 18.3 Perioperative Anticoagulation, Bridging & Postoperative Complications

20 Chapter 19: Ophthalmology (1% of Exam)

19.1 The Acute Red Eye & Ophthalmic Emergencies 19.2 Painless Vision Loss & Chronic Ophthalmic Disease 19.3 Uveitis, Scleritis & Orbital Disease

21 Chapter 20: Otolaryngology & Dental Medicine (1% of Exam)

20.1 Dizziness, Vertigo & Epistaxis 20.2 Ear Disorders, Hearing Loss & Upper Respiratory Infections 20.3 Oral Cavity, Salivary Gland, Laryngeal & Taste and Smell Disorders

8.5 Complications of Cancer & Its Treatment

Key Takeaways Explain This Topic AI

Pain including neuropathy, dyspnea, paraneoplastic syndromes, lymphedema, gastrointestinal toxicity, cardiotoxicity, radiation toxicity and immunotherapy are the enumerated complication topics.

Immune-related adverse events can affect any organ, may begin weeks to months after therapy starts, and are treated with corticosteroids rather than with symptomatic measures alone.

Immune checkpoint inhibitor hypophysitis and thyroiditis cause endocrinopathies that usually require lifelong hormone replacement even after the drug is stopped.

Anthracycline cardiotoxicity is dose-dependent and largely irreversible, whereas trastuzumab cardiotoxicity is not dose-dependent and is usually reversible.

Anti-emetic prophylaxis must be matched to the emetogenic potential of the regimen and given before treatment rather than as rescue.

Last updated: August 2026

1. Immune Checkpoint Inhibitor Toxicity

Checkpoint inhibitors release the brakes on T cells, and the resulting immune-related adverse events can involve any organ. They are the fastest-growing source of oncology questions on internal medicine examinations because patients present to general internists and emergency departments, not to oncology clinics.

Three principles govern management:

Timing is variable. Events may begin within weeks or months after therapy has stopped . A patient who received pembrolizumab four months ago and now has diarrhea still has drug-attributable colitis until proven otherwise.

Treatment is immunosuppression, not symptom control. Grade 2 or higher events require corticosteroids (typically prednisone 1 to 2 mg/kg), escalating to infliximab, mycophenolate or other agents if refractory. Treating checkpoint-inhibitor colitis with loperamide alone risks perforation.

Infection must be excluded before immunosuppression — C. difficile in colitis, viral hepatitis in hepatitis, and pneumonia in suspected pneumonitis.

• Organ Manifestation Notes
• Colon Diarrhea, colitis Most common serious event; exclude C. difficile
• Skin Rash, pruritus, rarely SJS/TEN Most common overall, usually mild
• Thyroid Thyroiditis then hypothyroidism Often permanent
• Pituitary Hypophysitis Headache, fatigue, hyponatremia; check morning cortisol
• Liver Transaminitis Exclude viral and biliary causes
• Lung Pneumonitis Cough and dyspnea with ground-glass opacities; can be fatal
• Pancreas Lipase elevation, new diabetes May present as DKA from fulminant insulin deficiency
• Neuromuscular Myositis, myasthenia-like syndrome, neuropathy Myocarditis frequently coexists with myositis
• Heart Myocarditis Rare but high mortality; check troponin with new myositis

Endocrine events are the exception to the reversibility rule. Corticosteroids do not restore thyroid or pituitary function; these patients need lifelong hormone replacement , and the checkpoint inhibitor is often continued once replacement is established. In contrast, colitis, pneumonitis and hepatitis usually require holding or permanently discontinuing the drug.

Adrenal insufficiency from hypophysitis is the diagnosis not to miss. Fatigue, nausea, hyponatremia and hypotension in a patient on immunotherapy warrant a morning cortisol. Give glucocorticoid before levothyroxine if both deficits are present, to avoid precipitating adrenal crisis.

2. Cardiotoxicity

• Anthracyclines (doxorubicin) Trastuzumab
• Mechanism Oxidative myocyte injury HER2 blockade in cardiomyocytes
• Dose relationship Dose-dependent, cumulative Not dose-dependent
• Reversibility Largely irreversible Usually reversible on withdrawal

Monitoring Baseline and periodic echocardiography Baseline and serial echocardiography, typically every 3 months

Risk rises steeply above a cumulative anthracycline dose threshold and with concurrent trastuzumab, prior chest radiation, hypertension and pre-existing cardiac disease. Management of declining ejection fraction follows standard heart failure therapy with renin-angiotensin blockade and beta-blockade.

Other cardiac toxicities: 5-fluorouracil and capecitabine cause coronary vasospasm with chest pain and ischemic ECG changes; tyrosine kinase inhibitors cause hypertension and QT prolongation; VEGF inhibitors cause hypertension, proteinuria, arterial thrombosis and impaired wound healing.

3. Chemotherapy-Induced Peripheral Neuropathy

A dose-limiting , often permanent toxicity, and a major determinant of long-term quality of life.

Agent Pattern

Platinum (cisplatin, oxaliplatin) Large-fiber sensory neuropathy, sensory ataxia ; oxaliplatin causes acute cold-triggered dysesthesia

• Taxanes Stocking-glove sensory neuropathy
• Vincristine Sensorimotor neuropathy, autonomic constipation and ileus
• Bortezomib Painful small-fiber neuropathy
• Thalidomide Sensory neuropathy

No agent prevents it. Dose reduction or discontinuation is the only effective intervention, and duloxetine has the best evidence for established painful neuropathy. Gabapentinoids and tricyclics are used but with weaker support.

Vincristine must never be given intrathecally — it is uniformly fatal — and must be avoided or used with extreme caution in Charcot-Marie-Tooth disease .

4. Nausea, Vomiting and Gastrointestinal Toxicity

Prophylaxis matched to emetogenic risk, given before treatment, is the principle. Rescue-only dosing is inferior and is a common wrong answer.

• Emetogenic risk Regimen
• High (cisplatin, AC) NK1 antagonist + 5-HT3 antagonist + dexamethasone, with or without olanzapine
• Moderate 5-HT3 antagonist + dexamethasone
• Low Single agent

Anticipatory nausea is a conditioned response occurring before the infusion; it responds to benzodiazepines and behavioral therapy, not to additional anti-emetics. Delayed emesis beyond 24 hours is characteristic of cisplatin and is prevented by NK1 antagonists and dexamethasone.

Mucositis — pain and ulceration from rapid epithelial turnover, worst with 5-fluorouracil, methotrexate and radiation. Managed with oral care, analgesia, and evaluation for superimposed candidal or herpetic infection.

Diarrhea — irinotecan causes an early cholinergic diarrhea during infusion (treated with atropine) and a late secretory diarrhea (treated with high-dose loperamide). Always distinguish chemotherapy-related diarrhea from C. difficile and from checkpoint-inhibitor colitis, because the treatments are opposite.

Constipation from vincristine, opioids and 5-HT3 antagonists requires a scheduled bowel regimen.

5. Cancer Pain

Managed by mechanism as well as severity.

Around-the-clock long-acting opioid with a short-acting breakthrough dose for continuous pain, with breakthrough dosing at roughly 10 to 20% of the total daily dose.

Bone pain responds to NSAIDs, radiation to a symptomatic site, and bone-modifying agents.

Neuropathic pain requires an adjuvant — duloxetine, gabapentinoid or tricyclic; opioids alone are less effective.

Constipation prophylaxis is mandatory with every opioid prescription; tolerance does not develop to it.

Never combine a partial agonist or mixed agonist-antagonist with a full agonist, which precipitates withdrawal.

Meperidine is avoided because normeperidine accumulates and causes seizures.

6. Paraneoplastic Syndromes

• Syndrome Mechanism Classic tumor
• Hypercalcemia PTHrP Squamous cell lung, head and neck, renal
• SIADH Ectopic ADH Small cell lung cancer
• Cushing syndrome Ectopic ACTH Small cell lung, carcinoid
• Lambert-Eaton syndrome Anti-P/Q calcium channel antibody Small cell lung cancer
• Dermatomyositis Autoimmune Ovarian, lung, gastric, colorectal
• Acanthosis nigricans (sudden, extensive) Growth factors Gastric adenocarcinoma
• Migratory thrombophlebitis (Trousseau) Hypercoagulability Pancreatic adenocarcinoma
• Hypertrophic osteoarthropathy — Lung cancer
• Erythrocytosis Ectopic erythropoietin Renal cell , hepatocellular

Ectopic ACTH differs from pituitary Cushing syndrome : it produces marked hypokalemic metabolic alkalosis and hyperpigmentation with rapid onset and often without the classic cushingoid habitus, because there has not been time to develop it.

Lambert-Eaton myasthenic syndrome shows improvement in strength with repeated effort and an incremental response on high-frequency repetitive nerve stimulation , the opposite of myasthenia gravis, and warrants a search for small cell lung cancer.

7. Lymphedema and Radiation Toxicity

Lymphedema — an enumerated blueprint topic — follows nodal dissection or regional irradiation, most commonly after axillary surgery for breast cancer. It is managed with complete decongestive therapy : manual lymphatic drainage, compression garments, exercise and meticulous skin care. Cellulitis is the major complication , and recurrent episodes worsen the lymphedema, creating a cycle. Diuretics are ineffective. Late-onset or rapidly worsening lymphedema warrants evaluation for recurrent disease or angiosarcoma.

Radiation toxicity is divided into acute and late effects:

Acute (during or shortly after treatment): dermatitis, mucositis, esophagitis, diarrhea, cystitis, fatigue — generally reversible.

Late (months to years): fibrosis , xerostomia, radiation pneumonitis (typically 1 to 6 months after thoracic radiation, responsive to corticosteroids), constrictive pericarditis, accelerated coronary disease, hypothyroidism after neck irradiation, bowel strictures and chronic proctitis , and second malignancies including sarcoma and, after mantle irradiation, breast cancer.

Radiation recall — an inflammatory reaction in a previously irradiated field precipitated by later chemotherapy — is a distinctive phenomenon worth recognizing.