Volume 13
A study guide to oncology.
For the internal medicine resident who'd rather stage it than guess at it, keeping your differentials in check and your confidence from metastasizing into doubt.
Oncologic Urgencies & Emergencies
Definition: T ≥38.3 °C once, or ≥38 °C sustained >1 h, with ANC ≤1. Severe ANC ≤0.5; typically 7–14 days post-chemotherapy.
Workup: blood cultures ×2, central-line cultures, urine culture; CXR, sputum culture, stool culture, C. difficile.
Risk (MASCC): ≥21 low risk → ciprofloxacin + co-amoxiclav (or clindamycin); <21 high risk → IV pip-tazo / cefepime / carbapenem.
Escalation: still febrile 4–7 days → add antifungal; continue antibiotics until ANC ≥5; prophylaxis G-CSF.
Clinical: dehydration, AKI, nausea/vomiting, constipation, weakness, altered LOC.
Mechanisms: osteolytic (breast, multiple myeloma); PTHrP (lung SCC); vitamin D production (lymphoma); kidney, head & neck.
Management: IV hydration → ± furosemide → IV bisphosphonate / denosumab.
Severe: calcitonin for rapid effect (tachyphylaxis ≤48 h) — a bridge to the bisphosphonate effect that takes 4–7 days.
When: within ≤7 days of chemotherapy · ↑ LDH. Spontaneous: leukemia, lymphoma, large tumor burden. Post-treatment: sensitivity to steroids / chemotherapy.
Treatment & prophylaxis: IV fluids → target UO 2 mL/kg/h + rasburicase. G6PD deficiency → rasburicase contraindicated → allopurinol. Prophylaxis: allopurinol, rasburicase, or febuxostat.
TLS — The Metabolic Quartet
| Derangement | Consequences |
|---|---|
| Hyperkalemia | Muscle weakness, cardiac arrhythmias, sudden death |
| Hyperphosphatemia | AKI, secondary hypocalcemia, nausea/vomiting, lethargy, seizures |
| Hyperuricemia | AKI, renal stones, nausea/vomiting, anorexia |
| Hypocalcemia | Tetany, paresthesia, altered LOC |
Clinical: facial/arm edema, distended neck & chest veins, dyspnea, cough, facial plethora, hoarseness, stridor, altered LOC.
Workup & causes: CT chest with contrast; NSCLC, thrombosis, fibrosis.
By acuity: life-threatening → stenting, steroids, radiation; not life-threatening → tissue biopsy first. Chemo-sensitive (SCLC, lymphoma, germ-cell) respond to chemotherapy.
Clinical: back pain, LL weakness/paresthesia, urinary retention, bowel incontinence. Cauda equina: LMN signs, saddle paresthesia.
Approach: MRI whole spine + contrast → IV dexamethasone + analgesia; urgent oncology + neurosurgery consults.
Primaries: lung, breast, prostate, MM, lymphoma.
Clinical: headache, vomiting, altered LOC, seizures, focal deficits. Primaries: breast, lung, melanoma.
Approach: MRI brain (or CT + contrast) → IV dexamethasone ± mannitol / hypertonic saline; mild → PO dexamethasone.
Definitive: single lesion → surgical excision + adjuvant RT; multiple solid → RT; hematological → chemo.
DVT / PE
2nd most common cause of death in cancer.
Treatment LMWH; DOACs → ↑ GI bleeding risk.
Recurrent Pleural Effusion
Rapidly recurrent → indwelling pleural catheter or pleurodesis.
Screening for Cancer
Screening Schedule
| Cancer | Population | Test & interval |
|---|---|---|
| Breast | Age 50–74 | Mammogram every 2 years |
| Lung | Age 50–80 + ≥20 pack-years | Annual low-dose CT chest |
| Colorectal | Age 50–75 | FOBT/FIT annual–2-yearly · colonoscopy 10-yearly · sigmoidoscopy 5–10-yearly |
| Cervical | Age 21–65 | Pap smear every 3 years |
| Prostate | Shared decision | Weigh benefit vs harm |
FH of BRCA1/2 or strong family history of cancer → genetic testing.
Breast Cancer
Workup: mammogram, US breast + axilla, core needle biopsy; DCIS → calcifications.
Staging: PET/CT.
Options: mastectomy / lumpectomy + sentinel node biopsy or axillary dissection.
Lumpectomy indications: tumor ≤5 cm, no skin involvement, clear surgical margins.
Adjuvant RT indications: tumors >5 cm, positive margins, skin/chest-wall involvement, inflammatory breast cancer, ≥4 positive axillary nodes.
Axillary dissection sequela: lymphedema → lymphatic drainage, compression, exercise, skincare, surgery.
Bilateral mastectomy: no radiotherapy or hormonal therapy required afterward.
≤3 positive nodes → high multigene recurrence assay → adjuvant chemotherapy.
Inflammatory / locally advanced → neoadjuvant chemo → surgery → adjuvant RT (inflammatory: biopsy first).
By Molecular Subtype
| Subtype | Therapy | Watch for |
|---|---|---|
| HER2 + | Chemo (doxorubicin, epirubicin) + anti-HER2 (trastuzumab, pertuzumab) | Anthracyclines → cardiomyopathy, acute leukemia · anti-HER2 → reversible CM, infusion reactions |
| Triple − | Chemotherapy + immunotherapy | — |
Post-menopausal: tamoxifen (↑ endometrial cancer, ↑ thrombosis, hot flushes); aromatase inhibitor (letrozole, anastrozole, exemestane) — arthralgia, bone pain, dyslipidemia, ↑ osteoporosis → 2-yearly DEXA.
Pre-menopausal: low risk → tamoxifen; high risk → aromatase inhibitor + ovarian suppression (leuprolide, goserelin, triptorelin).
Symptom control: hot flushes → gabapentin.
Follow-up: annual breast exam + mammogram; high risk → MRI breast.
Prevention: age ≥35 → preventative tamoxifen; post-menopausal → tamoxifen + raloxifene or AI.
BRCA carriers: age 25–30 → annual MRI breast; age 30–75 → annual MRI + mammogram; → prophylactic bilateral mastectomy + salpingo-oophorectomy.
Biopsy mets → re-check ER/PR, HER2. Bone mets: chemotherapy + bisphosphonate/denosumab; pain → radiotherapy.
Lung Cancer
Tissue: CT-guided or EBUS biopsy; metastatic → biopsy the mets.
Staging: PET/CT chest-abdo-pelvis + MRI brain ± bone scan.
Profile: smoking · central · rapidly progressive.
Paraneoplastic: SIADH, Cushing's (ectopic ACTH), LEMS (anti-VGCC), limbic encephalomyelitis (anti-Hu), peripheral neuropathy, cortical cerebellar degeneration.
Treatment: limited → platinum chemo + RT + immunotherapy; extensive → chemo + immunotherapy + MRI brain surveillance. Responder → prophylactic cranial irradiation (risk: cognitive impairment); symptomatic brain mets → radiotherapy.
Squamous Cell
Smoking · central. Hypercalcemia (PTHrP).
Adenocarcinoma
Peripheral · non-smoker. Hypertrophic osteoarthropathy.
Other Histologies
Neuroendocrine, adenosquamous, sarcomatoid, large-cell (LCLC).
Profiling: EGFR, ALK, ROS1, RET, KRAS, HER2; PD-L1 >50% → pembrolizumab.
Pre-op: functional reserve testing — FEV1, DLCO.
NSCLC — Treatment by Stage
| Stage | Treatment |
|---|---|
| 1 | Surgery or radiotherapy |
| Resectable 2/3 | Surgery + adjuvant cisplatin-based chemo |
| 3 | Chemoradiotherapy + immunotherapy |
| Metastatic | Platinum-based chemo ± immunotherapy; stereotactic RT if chemo-responsive |
Lymphoid Malignancies
Risk Factors
Also: DMARDs, biologics
| Exposure | Associated lymphoma |
|---|---|
| HIV | Hodgkin's, DLBCL, primary CNS lymphoma, Burkitt, primary effusion lymphoma |
| EBV | Burkitt |
| H. pylori | Gastric MALT |
| C. psittaci | Ocular MALT |
| HCV | NHL |
| Post-transplant | PTLD |
| Sjögren's | Salivary gland MALT |
| Celiac / Crohn's | GI lymphoma |
| SLE / RA | NHL |
| HTLV-1 | ATLL |
Excisional biopsy (or FNA / core needle) · PET/CT; ± bone marrow biopsy · ± lumbar puncture.
Treatment: classical & nodular lymphocyte-predominant → chemotherapy (ABVD).
Classical: bimodal age, aggressive, firm lymphadenopathy, B symptoms, splenomegaly, hepatomegaly; secondary malignancies (breast, lung, skin), MDS.
Findings: CXR → mediastinal mass; lymph node biopsy → Reed-Sternberg cells.
Non-Hodgkin — Aggressive B Cell
Classes: B cell (aggressive/indolent), T cell, NK cell, lymphoblastic
| Type | Treatment / feature |
|---|---|
| DLBCL | Chemotherapy (R-CHOP) |
| Mantle | Combined chemotherapy |
| Burkitt | African, young, rapidly growing jaw mass, ↑ TLS, c-MYC translocation → aggressive multiagent chemo + rituximab |
| Double-hit | Aggressive chemotherapy (not R-CHOP) |
Overview: follicular, CLL, hairy cell — often observation; symptomatic/complications → chemotherapy ± radiotherapy.
Follicular: t(14;18) BCL2 → rituximab + multiagent chemo / lenalidomide; transformation → DLBCL (poor prognosis).
Hairy cell: pancytopenia, splenomegaly → purine nucleoside agents (cladribine, pentostatin).
Peripheral T Cell
Elderly, male, poor prognosis.
Cutaneous T Cell
Mycosis fungoides: prodrome, maculopapular eruptions, plaques, ulceration, erythroderma.
Sézary: erythroderma, aggressive, circulating malignant T cells.
Limited to skin → topical GC; advanced → chemoradiotherapy.
Clinical: elderly · lymphocytosis · lymphadenopathy · splenomegaly · cytopenias · ITP/AIHA · hypogammaglobulinemia · secondary malignancies.
Diagnosis: flow cytometry CD19, CD20, CD23; B-cell lymphocyte count ≥5; PBS → small mature lymphocytes, smudge cells. Richter's transformation: CLL → DLBCL (poor prognosis).
Treatment indications: lymphadenopathy >10 cm or symptomatic; splenomegaly >6 cm or symptomatic; BM failure (Hb <100, Plt <100); AIHA/ITP unresponsive to steroids; extranodal involvement; significant constitutional symptoms.
Treatment: → BTK inhibitor (ibrutinib, acalabrutinib, zanubrutinib); asymptomatic → observation, avoid live vaccines.
Across the board: bulky disease → radiotherapy; TLS prophylaxis → IVF + allopurinol/febuxostat.
Relapsed & aggressive: → autologous HSCT.