Ch13: Surgical Oncology（外科肿瘤学）

Preparatory Mindset

Surgical oncology = the surgical management of cancer — tumor biology, staging, the role of surgery (prevention, diagnosis, cure, palliation), multimodal treatment, and the TNM/UICC staging system. The lecture (42.9KB — the longest S1 deck) covers the full spectrum; the prep PDFs add the tumor nomenclature and the surgical principles (根治术, 扩大根治, 姑息手术).

Exam mindset: know tumor classification (benign vs malignant), the TNM system, the surgical roles, the principles of oncologic resection (wide margins, lymphadenectomy, no-touch), and the multimodal team (surgery + chemo + radiation + targeted/immunotherapy). Know the classic numbers (UICC/AJCC staging, 5-year survival concept).

Core Concepts

1. Tumor biology & classification (MUST KNOW)

| Feature | Benign | Malignant (cancer) | |---|---|---| | Growth | Slow, expansive, encapsulated | Rapid, infiltrative, no capsule | | Differentiation | Well-differentiated | Poorly/undifferentiated (anaplasia) | | Metastasis | Never | Yes (lymphatic, hematogenous, seeding) | | Recurrence | Rare (after complete excision) | Common | | Systemic effects | Rare | Cachexia, paraneoplastic syndromes | | Nomenclature | -oma (lipoma, fibroma, adenoma) | Carcinoma (epithelial), sarcoma (mesenchymal), leukemia/lymphoma |

• Tumor (neoplasm): abnormal tissue growth; benign vs malignant
• Benign vs malignant:
• Carcinogenesis: initiation (mutation) → promotion → progression; oncogenes, tumor suppressor genes (p53, Rb), apoptosis evasion, angiogenesis, invasion, metastasis
• Metastasis routes: lymphatic (carcinomas), hematogenous (sarcomas, liver/lung), transcoelomic seeding (GI/ovarian)
• Paraneoplastic syndromes: hypercalcemia (PTHrP — lung SCC, breast, renal), SIADH (small cell lung), Cushing (small cell lung, adrenal), Lambert-Eaton (small cell lung), acanthosis nigricans (GI)

2. Staging — TNM & UICC/AJCC (MUST KNOW)

• T — primary tumor (Tis in situ, T1-4 size/invasion)
• N — regional lymph nodes (N0 no nodes, N1-3)
• M — distant metastasis (M0/M1)
• Stage grouping (I-IV) combines TNM → prognosis & treatment
• Other staging systems: Dukes (colorectal: A-D), FIGO (gynecologic), Ann Arbor (lymphoma), Breslow thickness/Clark level (melanoma), Gleason score (prostate)
• Staging workup: imaging (CT/MRI/PET-CT), biopsy (histology + molecular markers), tumor markers, sentinel lymph node biopsy (breast, melanoma)

3. Tumor markers (MUST KNOW)

• Markers are used for screening (PSA, AFP in high-risk), monitoring response & recurrence — NOT diagnostic alone

4. Roles of surgery in cancer (MUST KNOW)

1. Prevention (预防性手术): prophylactic mastectomy (BRCA), colectomy (FAP), thyroidectomy (MEN2)
2. Diagnosis (诊断性手术): biopsy (incisional, excisional, core needle, FNA), staging laparotomy
3. Cure (根治性手术): complete resection with negative margins (R0)
4. Debulking (减瘤手术): remove most tumor when cure impossible (ovarian cancer) — improves chemo response
5. Palliation (姑息手术): relieve symptoms (obstruction, bleeding, pain) — bypass, stenting, resection of bleeding tumor
6. Reconstruction (after resection)

• Resection margins: R0 = microscopically clear (curative intent); R1 = microscopic residual; R2 = macroscopic residual

5. Principles of oncologic resection (MUST KNOW)

• En bloc resection with wide margins (tumor + surrounding tissue)
• Lymphadenectomy: remove the draining lymph node basin (regional) — may be radical (all nodes) or sentinel-node-directed
• No-touch technique: ligate vessels early, avoid tumor spillage
• Multidisciplinary treatment (MDT): surgery + neoadjuvant (pre-op) or adjuvant (post-op) chemotherapy/radiotherapy/targeted/immunotherapy/hormonal therapy
• Radical vs modified: e (CM exam tested — NOT on PPT).g., breast cancer — radical mastectomy (Halsted) replaced by modified radical mastectomy & breast-conserving surgery (lumpectomy + SLNB + radiotherapy); rectal cancer — total mesorectal excision (TME) + neoadjuvant chemoradiation
• Cancer recurrence: local (margin/incomplete), regional (nodes), distant (metastasis)

6. Multimodal therapy (MUST KNOW)

• Chemotherapy: systemic cytotoxic — adjuvant, neoadjuvant, palliative; side effects (myelosuppression, mucositis, neuropathy, cardiotoxicity)
• Radiotherapy: local — preop (downstage), postop (sterilize margins), definitive (larynx, cervix), palliative (bone mets); side effects (dermatitis, mucositis, fibrosis)
• Hormonal therapy: breast (tamoxifen/aromatase inhibitors), prostate (ADT)
• Targeted therapy: trastuzumab (HER2+ breast), imatinib (GIST, CML), EGFR inhibitors, anti-VEGF
• Immunotherapy: checkpoint inhibitors (PD-1/PD-L1, CTLA-4), CAR-T
• Palliative care: symptom control, quality of life — NOT just end-of-life

7. Common surgical cancers overview (details in Y4S2 chapters)

• Colorectal: most common GI cancer; left-sided (change in bowel habit, blood) vs right-sided (anemia, mass); CEA; Dukes/TNM; surgery + adjuvant chemo for node-positive
• Breast: screening mammography; lumpectomy + SLNB + radiation vs mastectomy; ER/PR/HER2-driven therapy
• Gastric: gastric cancer (HP, diet); subtotal/total gastrectomy + lymphadenectomy (D2)
• Liver/HCC: cirrhosis/ HBV; AFP; resection/transplant/ablation/TACE
• Pancreatic: pancreatic head cancer → Whipple (pancreaticoduodenectomy); poor prognosis
• Lung: NSCLC vs SCLC; lobectomy; staging (mediastinoscopy, PET)
• Thyroid: papillary (most common, good prognosis), follicular, medullary (calcitonin, MEN2), anaplastic; thyroidectomy
• Esophageal: SCC (Asia/China) vs adenocarcinoma (Barrett); esophagectomy
• GIST: imatinib; melanoma: Breslow thickness, SLNB; renal: RCC — nephrectomy

High-Yield Points

• Benign = -oma, encapsulated, no mets; Malignant = carcinoma (epithelial)/sarcoma (mesenchymal), infiltrative, mets
• TNM: T tumor, N nodes, M metastasis → stage I-IV
• R0 = clear margins (curative); R1/R2 = residual
• Surgical roles: prevention, diagnosis, cure, debulking, palliation, reconstruction
• Tumor markers: AFP (HCC), CEA (colorectal), CA19-9 (pancreas), PSA (prostate), CA125 (ovary), calcitonin (medullary thyroid)
• Multimodal: surgery + chemo/radio/targeted/immuno/hormonal; neoadjuvant = preop, adjuvant = postop
• Breast: lumpectomy + SLNB + RT vs mastectomy; ER/PR/HER2 driven
• Colorectal: CEA, TNM/Dukes, TME for rectal
• Lymphatic mets = carcinomas; hematogenous = sarcomas
• Paraneoplastic: PTHrP hypercalcemia (SCC lung), SIADH/Cushing (small cell)

Topic Summary

Surgical oncology: tumors are benign (encapsulated, -oma, no mets) or malignant (carcinoma/sarcoma, infiltrative, metastatic — lymphatic for carcinomas, hematogenous for sarcomas). Staging uses TNM → stage groups (UICC/AJCC) with organ-specific systems (Dukes, Breslow, Gleason). Tumor markers (AFP, CEA, CA19-9, PSA, CA125, calcitonin) aid screening/monitoring. Surgery has six roles: prevention, diagnosis, cure (R0 margins), debulking, palliation, reconstruction. Principles: en bloc resection, lymphadenectomy, no-touch, MDT with neoadjuvant/adjuvant chemotherapy, radiotherapy, hormonal/targeted/immunotherapy. Common cancers (colorectal, breast, gastric, HCC, pancreatic, lung, thyroid, esophageal) are detailed in the Y4S2 organ chapters.