328.3 🏥 內科專科考前版

328.3.1 Mechanistic Deep Dive

328.3.1.1 Hematogenous Metastasis Mechanism

  • Tumor cells in venous return
  • Pulmonary capillary bed first capillary network
  • Filtered out
  • Subsequent extravasation

328.3.1.2 Lymphangitic Spread

  • Cancer cells in lymphatic vessels
  • Pleural + peribronchovascular involvement
  • Direct extension into lung

328.3.1.3 EMT + Metastasis Biology

  • Epithelial-mesenchymal transition
  • Cancer cells gain migratory phenotype
  • Invasion → intravasation → circulation → extravasation → metastatic colonization

328.3.2 Recent Trials & Updates

328.3.2.1 SABR-COMET (2019) — Oligometastatic Disease

  • N = 99 oligometastatic various cancers
  • SABR to all mets vs standard care
  • ↑ OS (28% vs 18% at 5 yr)
  • Practice-changing for oligometastatic

328.3.2.2 PulMiCC (2020) — Colorectal Lung Metastasectomy

  • Pulmonary metastasectomy vs no metastasectomy in colorectal
  • Limited benefit shown
  • Controversial — has changed practice in some
  • Future randomized trials needed

328.3.2.3 CTC (Circulating Tumor Cells)

  • Research for metastasis monitoring
  • Future role

328.3.2.4 Liquid Biopsy

  • Detection of metastatic clonal evolution
  • Monitoring resistance
  • Anatomic vs molecular metastasis

328.3.2.5 IO + Local Therapy Combinations

  • Pembrolizumab + SABR
  • Synergistic effects
  • Trials ongoing

328.3.3 High-Yield Specialist Points

328.3.3.1 Solitary Pulmonary Metastasis vs Primary

  • History critical
  • Multiple lesions → likely mets
  • Solitary: tissue biopsy + IHC + molecular
  • Cancer registries
  • Multidisciplinary discussion

328.3.3.2 Wedge Resection vs Lobectomy

  • Wedge: limited mets, multiple wedges if needed
  • Lobectomy: large/central or anatomic
  • VATS preferred

328.3.3.3 Repeat Metastasectomy

  • Feasible in select
  • Each procedure with marginal benefit
  • Long disease-free interval encourages
  • Multidisciplinary

328.3.3.4 Endobronchial Metastasis Management

  • Bronchoscopic resection + stenting
  • Laser, electrocautery, cryotherapy
  • Radiation if needed
  • Palliative role

328.3.3.5 Symptomatic Bronchial Obstruction

  • Cough, dyspnea, hemoptysis, post-obstructive pneumonia
  • Bronchoscopic intervention
  • Radiation for tumor regression

328.3.3.6 Adjuvant Therapy After Metastasectomy

  • Variable
  • Chemo for some cancers
  • IO emerging
  • Trials ongoing

328.3.3.7 Trousseau Syndrome Treatment

  • LMWH (Caravaggio trial, Hokusai-Cancer for DOAC)
  • Some prefer LMWH (especially GI cancers)
  • Indefinite while cancer active

328.3.3.8 Choriocarcinoma + Pulmonary Tumor Embolism

  • β-hCG elevated
  • Rapid presentation
  • Chemo-sensitive (MTX, EMA-CO)

328.3.4 Pearls

  • Lung = #1 metastasis site in most cancers
  • Common primaries: breast, colon, kidney, testicular, head/neck, melanoma, sarcoma
  • Patterns: multiple bilateral (most), miliary (thyroid/renal/melanoma/sarcoma), lymphangitic (poor prognosis), endobronchial, pleural
  • Metastasectomy criteria + outcomes vary by primary
  • SABR-COMET 2019: oligometastatic + aggressive local therapy ↑ OS
  • Lymphangitic carcinomatosis: rapid + poor prognosis
  • HPOA: clubbing + periostitis (adenocarcinoma)
  • Trousseau: migratory thrombophlebitis (cancer-associated)
  • Pulmonary tumor embolism: choriocarcinoma classic