Oncology Essentials for NEET PG Medicine: Paraneoplastic Syndromes, Oncologic Emergencies, Tumour Lysis, Tumour Markers, Lung Cancer

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🎯 Exam priority: Medium. Expect: paraneoplastic syndrome–tumour pairs (ACTH and SCLC, PTHrP and squamous cancers, erythropoietin and renal cancer, Lambert–Eaton), cord compression, TLS laboratory criteria and treatment, neutropenia threshold and G-CSF, ondansetron, tumour markers and their misuse in screening, lung cancer subtypes and Pancoast/SVC features, LDCT screening, carcinoid syndrome, NP-NCD screening age.

CBME mapping: GM 13.1–13.19. Neoplasia biology and tumour pathology are in Pathology; anticancer drugs in Pharmacology; surgical oncology in Surgery; leukaemia/lymphoma in Pathology and article 20.

Paraneoplastic syndromes, emergencies, tumour lysis and markers. Drawn by TrackNation.

Paraneoplastic Syndromes

• Symptoms at sites distant from the tumour or its metastases — from secreted substances or cross-reacting antibodies.

• Endocrine: ectopic ACTH (Cushing features) — mostly small cell lung cancer; PTHrP (hypercalcaemia) — squamous lung, head-and-neck, bladder cancers; vasopressin (hyponatraemia) — lung cancers; erythropoietin (polycythaemia) — kidney cancer, hepatoma; IGF (hypoglycaemia).

• Neurological: peripheral neuropathy (commonest), cerebellar syndromes, Lambert–Eaton (immune, myasthenia-like, limb weakness sparing eye and bulbar muscles).

• Skin and joints: acanthosis nigricans (axillae, neck); hypertrophic osteoarthropathy with certain lung cancers.

• Carcinoid syndrome: flushing, abdominal cramps, diarrhoea, later right-sided valve disease; urinary 5-HIAA; GI tumours cause it only after hepatic metastases; somatostatin analogues.

Emergencies, Tumour Lysis and Chemotherapy Toxicity

• Spinal cord compression: back pain, leg paraesthesias, bladder and bowel dysfunction — immediate surgery or radiotherapy. Most cancer deaths come from metastases. Drain symptomatic malignant effusions.

• Tumour lysis syndrome (mainly leukaemias and lymphomas, also after CAR-T): AKI, Ca < 7, uric acid > 8, phosphate > 6.5, K⁺ > 6. Symptoms: lethargy, vomiting, seizures; arrhythmias from hyperkalaemia, tetany from hypocalcaemia. Treat with allopurinol 200–400 mg/m²/day (max 600 mg) and IV saline for urine > 2 L/day.

• Neutropenia: ANC < 500/µL markedly increases infection risk; G-CSF shortens neutropenia; selected low-risk febrile neutropenia can be treated as outpatients. Antiemetics: ondansetron/granisetron. Mucositis is common.

Lung Cancer and Screening

• Lung cancer: ~85% linked to smoking; adenocarcinoma is the commonest subtype, especially in never-smokers; diagnosis needs tissue (histology and molecular testing, e.g. EGFR). Presentations: cough, weight loss, haemoptysis, SVC syndrome, Pancoast tumour (shoulder/arm pain), hoarseness, brain metastases. Small cell lung cancer responds initially but relapses quickly.

• Annual low-dose CT screening of high-risk adults cut lung cancer deaths by 20% vs chest X-ray (NLST).

• India (NP-NCD): population-based screening of everyone ≥ 30 years for hypertension, diabetes and oral, breast and cervical cancers. Cervical screening options include Pap and HPV testing.

Traps the Examiner Sets

• Tumour markers are for diagnosis support and monitoring, not mass screening.

• Squamous lung cancer → hypercalcaemia (PTHrP); small cell → ACTH, SIADH.

• Cord compression is an emergency — treat before paralysis.

• TLS: high K, phosphate, urate; LOW calcium.

• Carcinoid syndrome from gut tumours implies liver metastases.

Memory Hooks & Shortcuts

Shortcuts to lock in this article's numbers and lists. Each one only re-packages facts proven above.

• 🧠 Small cell = 'Small hormones' (ACTH, ADH); Squamous = 'Stones' (calcium/PTHrP) — lung paraneoplastic

• 🧠 TLS 'K-P-U up, Ca down' — tumour lysis

• 🧠 Markers 'follow, don't fish' — monitor, not screen — tumour markers

• 🧠 Carcinoid needs the liver bypassed (metastases) — carcinoid

• 🧠 Cord compression: 'back pain in cancer = MRI today' — cord compression

Rapid-Revision Cards

• Paraneoplastic

  Distant effects of tumour, not metastasis.

• Ectopic ACTH

  Small cell lung cancer.

• PTHrP

  Squamous lung, head-neck, bladder → hypercalcaemia.

• Ectopic EPO

  Kidney cancer, hepatoma → polycythaemia.

• SIADH (tumour)

  Lung cancers.

• Lambert–Eaton

  Limb weakness, spares eyes/bulbar; presynaptic.

• Commonest neuro PNS

  Peripheral neuropathy.

• Hypertrophic OA

  Lung cancer; painful joints.

• Cord compression

  Back pain, leg symptoms, sphincters → surgery/RT now.

• TLS criteria

  Ca < 7, urate > 8, PO4 > 6.5, K > 6, AKI.

• TLS Rx

  Allopurinol + IV saline (urine > 2 L/d).

• Neutropenia risk

  ANC < 500.

• G-CSF

  Shortens neutropenia.

• Chemo antiemetic

  Ondansetron/granisetron.

• AFP

  HCC, non-seminoma.

• CEA

  Colon — monitor, not screen.

• CA 125

  Ovary.

• β-hCG

  Trophoblastic disease.

• Lung cancer & smoking

  ~85%.

• Commonest lung cancer

  Adenocarcinoma (never-smokers too).

• Pancoast

  Shoulder/arm pain.

• LDCT screening

  20% fewer deaths.

• Carcinoid

  Flushing, diarrhoea; 5-HIAA; liver mets; octreotide.

• NP-NCD screening

  ≥ 30 y: oral, breast, cervix, HTN, DM.

Sources

Facts in this article were checked against these documents.

• MSD Manual Professional: Paraneoplastic Syndromes; Sequelae of Cancer; Management of Adverse Effects of Cancer Therapy; Tumor Immunodiagnosis; Lung Carcinoma; GI Neuroendocrine Tumors and Carcinoid Syndrome; Cancer Screening — Merck & Co. (MSD Manuals), reviewed 2024–26 (link)

• National Programme for Prevention and Control of Non-Communicable Diseases — Operational Guidelines — Ministry of Health and Family Welfare, 2023 (link)

• Competency Based Undergraduate Curriculum, General Medicine (GM 13) — National Medical Commission, 2024

Test Yourself: Practice Questions

Thirty questions in NEET PG style, most of them clinical vignettes.

Practice Questions (NEET PG pattern)

Original questions written in the style of the exam: +4 for a correct answer, −1 for a wrong one. Every answer was checked against the sources listed above. NEET PG papers are not published by NBEMS, so these are not past-paper questions.

Q1. A paraneoplastic syndrome is defined as

• (a) chemotherapy toxicity

• (b) symptoms at sites distant from the tumour or its metastases

• (c) metastatic spread

• (d) direct tumour invasion

Q2. A smoker with a lung mass develops Cushing features. The likely tumour is

• (a) carcinoid of appendix

• (b) squamous cell carcinoma

• (c) adenocarcinoma of lung

• (d) small cell lung cancer (ectopic ACTH)

Q3. Hypercalcaemia from PTH-related peptide is typical of

• (a) basal cell carcinoma

• (b) small cell lung cancer only

• (c) squamous cell lung, head-and-neck and bladder cancers

• (d) seminoma

Q4. Paraneoplastic polycythaemia from ectopic erythropoietin is associated especially with

• (a) breast cancer

• (b) prostate cancer

• (c) kidney cancer and hepatoma

• (d) melanoma

Q5. A patient with lung cancer has limb weakness that spares the eyes and bulbar muscles; the syndrome is immune-mediated and presynaptic. It is

• (a) Lambert–Eaton syndrome

• (b) myasthenia gravis

• (c) polymyositis

• (d) GBS

Q6. The most common neurological paraneoplastic syndrome is

• (a) cerebellar degeneration

• (b) limbic encephalitis

• (c) peripheral neuropathy

• (d) opsoclonus

Q7. Painful swelling of knees, wrists and ankles in a patient with certain lung cancers suggests

• (a) septic arthritis

• (b) hypertrophic osteoarthropathy

• (c) gout

• (d) rheumatoid arthritis

Q8. Hyponatraemia in lung cancer can result from tumour production of

• (a) renin

• (b) vasopressin (ADH)

• (c) insulin

• (d) aldosterone

Q9. A patient with known prostate cancer develops new back pain, leg paraesthesia and urinary retention. Management is

• (a) analgesics and review in a month

• (b) bed rest only

• (c) physiotherapy

• (d) immediate surgery or radiotherapy for spinal cord compression

Q10. Most cancer deaths are due to

• (a) chemotherapy

• (b) metastases rather than the primary tumour

• (c) the primary tumour only

• (d) surgery

Q11. After the first chemotherapy cycle for lymphoma, a patient develops oliguria and seizures with high potassium, phosphate and uric acid and low calcium. The diagnosis is

• (a) tumour lysis syndrome

• (b) hypercalcaemia of malignancy

• (c) septic shock

• (d) SIADH

Q12. Diagnostic laboratory criteria of tumour lysis syndrome include

• (a) low potassium

• (b) calcium < 7, uric acid > 8, phosphate > 6.5, potassium > 6 and AKI

• (c) high calcium and low phosphate

• (d) high sodium

Q13. Treatment of tumour lysis syndrome per MSD includes

• (a) allopurinol 200–400 mg/m²/day with IV saline for urine output > 2 L/day

• (b) fluid restriction

• (c) thiazides

• (d) calcium infusion first

Q14. Infection risk rises markedly in chemotherapy-induced neutropenia when the granulocyte count falls below

• (a) 2000/µL

• (b) 500/µL

• (c) 5000/µL

• (d) 1500/µL

Q15. A drug used to shorten the duration of chemotherapy-induced neutropenia is

• (a) erythropoietin

• (b) G-CSF

• (c) vitamin B12

• (d) interferon

Q16. Antiemetics with virtually no toxicity apart from headache, used for chemotherapy nausea, are

• (a) haloperidol

• (b) metoclopramide high dose

• (c) ondansetron and granisetron

• (d) promethazine

Q17. A raised CEA is best used to

• (a) monitor colon cancer after treatment, not to screen

• (b) diagnose hepatitis

• (c) diagnose lung cancer

• (d) screen the population for colon cancer

Q18. Alpha-fetoprotein is raised in

• (a) hepatocellular carcinoma and non-seminomatous germ cell tumours

• (b) colon cancer

• (c) seminoma only

• (d) prostate cancer

Q19. The tumour marker used to diagnose and monitor ovarian cancer is

• (a) AFP

• (b) CA 19-9

• (c) PSA

• (d) CA 125

Q20. The main marker for gestational trophoblastic neoplasia is

• (a) CA 125

• (b) CEA

• (c) LDH

• (d) β-hCG

Q21. About what proportion of lung cancers are related to cigarette smoking?

• (a) 10%

• (b) 85%

• (c) 99%

• (d) 40%

Q22. The commonest histological subtype of lung cancer, especially in never-smokers, is

• (a) small cell carcinoma

• (b) large cell carcinoma

• (c) adenocarcinoma

• (d) squamous cell carcinoma

Q23. An apical lung tumour causing shoulder and arm pain is

• (a) carcinoid

• (b) Pancoast tumour

• (c) mesothelioma

• (d) hamartoma

Q24. Small cell lung cancer is characteristically

• (a) always curable by surgery

• (b) resistant to chemotherapy

• (c) initially responsive to treatment but relapses quickly

• (d) slow-growing

Q25. Annual low-dose CT screening of high-risk adults reduced lung cancer deaths compared with chest X-ray by about

• (a) 20%

• (b) 2%

• (c) 80%

• (d) 50%

Q26. Diagnosis of lung cancer requires

• (a) sputum culture

• (b) tumour markers

• (c) pathological confirmation by tissue sampling

• (d) CT appearance alone

Q27. A patient has episodic flushing, abdominal cramps and diarrhoea with a right-sided heart murmur. The investigation of choice is

• (a) serum CEA

• (b) VMA

• (c) urinary 5-hydroxyindoleacetic acid (5-HIAA)

• (d) serum calcitonin

Q28. A small intestinal neuroendocrine tumour usually causes carcinoid syndrome only when

• (a) it is smaller than 1 cm

• (b) hepatic metastases are present

• (c) the patient is young

• (d) it is in the appendix

Q29. Symptoms of carcinoid syndrome are controlled with

• (a) insulin

• (b) propranolol only

• (c) allopurinol

• (d) somatostatin analogues (octreotide, lanreotide)

Q30. Under India's NP-NCD, population-based screening for oral, breast and cervical cancer covers people aged

• (a) 60 years and above

• (b) 18 years and above

• (c) 50 years and above

• (d) 30 years and above

Active Recall

From memory: match paraneoplastic syndromes to their tumours, describe spinal cord compression and tumour lysis criteria and treatment, the neutropenia threshold and G-CSF, uses and limits of tumour markers, lung cancer subtypes, presentations and LDCT screening, carcinoid syndrome and NP-NCD cancer screening.