6. Surgical Oncology: Basic Concepts, TNM Staging, Neoadjuvant and Adjuvant Treatment, Onco-Team
I. Basic Concepts
- Surgical oncology: Diagnosis, staging, surgical treatment and follow-up of solid tumors
- Main goals: Biopsy/staging, curative resection, reconstruction, debulking and palliation
- Cancer treatment is multimodal → Surgery + chemotherapy/radiotherapy/targeted/hormonal/immunotherapy when indicated
Indications
- Relative indications: Benign tumors, premalignant lesions, uncertain diagnosis, symptomatic mass
- Absolute indications: Malignant tumors when surgery gives diagnostic, curative or major palliative benefit
- Vital indications: Tumor causes life-threatening complication
- Examples: Obstruction, bleeding, perforation, vascular/biliary/airway compression
Contraindications
- Inoperable: Patient is not suitable for surgery/anesthesia
- Incurable: Tumor is not completely resectable or disease is disseminated
Resectability and Operability
- Resectability: Refers to the tumor → Can the cancer be removed completely?
- Depends on: Local invasion, metastases, vascular involvement, technical margins
- Operability: Refers to the patient → Can the patient tolerate the operation?
- Depends on: Age, comorbidities, frailty, cardiopulmonary reserve, nutrition, organ function
- Resectable tumor + inoperable patient → non-operative/less invasive treatment
- Operable patient + unresectable tumor → neoadjuvant, systemic or palliative strategy
Therapeutic Aim
- Curative surgery: Complete tumor removal → Aim for R0 resection
- Palliative surgery: Complete cure is not possible → Treat symptoms/complications
- Solve life-threatening condition: Bowel obstruction, bleeding, perforation
- Improve QOL: Pain relief, stoma/bypass, decompression, feeding access
- Improve effect/tolerance of oncological therapy
- R0: No microscopic residual tumor
- R1: Microscopic residual tumor
- R2: Macroscopic residual tumor
Principles of Surgical Technique
- No-touch technique: Do not press/manipulate the tumor directly → Reduce tumor cell spread
- Early vein/vascular ligation: When anatomically appropriate → Reduce hematogenous dissemination
- Wide resection margin: Tumor + healthy tissue margin → R0 goal
- En-bloc resection: Primary tumor + involved lymph nodes/organs/tissues removed in one block
- Lymph node management: Sentinel node biopsy or lymphadenectomy according to tumor type/stage
- Preserve organ function and QOL if oncological radicality is not compromised
- Minimally invasive/organ-sparing technique → Only if oncological safety is equivalent
II. TNM Staging
- TNM: Standardized anatomical cancer staging system
- Purpose: Classify tumor extent → Guide treatment, prognosis and outcome comparison
- Exact definitions are tumor-specific
Classification
- T = primary tumor
- Tx: Tumor cannot be assessed
- Tis: Carcinoma in situ
- T1, T2, T3, T4: Increasing size/depth/local extent of primary tumor
- N = regional lymph nodes
- Nx: Regional lymph nodes cannot be evaluated
- N0: No regional lymph node involvement
- N1, N2, N3: Increasing number/location/extent of involved nodes
- M = distant metastasis
- M0: No distant metastasis
- M1: Distant metastasis
- Mx: Distant metastasis cannot be evaluated; older/local usage
Stage Groups
- Stage 0: Carcinoma in situ
- Stage I: Cancer localized to its primary site
- Stage II: Locally advanced cancer
- Stage III: Regional lymph node involvement and/or surrounding tissue spread
- Stage IV: Distant metastasis
Importance
- Planning of therapy → Surgery first vs neoadjuvant vs palliative/systemic treatment
- Assessment of resectability and need for lymph node treatment
- Prognosis and survival estimate
- Evaluation of therapy → cTNM before treatment, pTNM after surgery, yTNM after neoadjuvant therapy
- Comparison of therapeutic modalities and clinical trial eligibility
- Clear communication inside the onco-team
III. Adjuvant and Neoadjuvant Therapy
- Treatment choice depends on TNM stage, histology, biomarkers, patient fitness and treatment aim
- Modalities: Chemotherapy, radiotherapy, chemoradiotherapy, targeted therapy, immunotherapy, hormonal therapy
Neoadjuvant Therapy
- Definition: Oncological treatment before surgery
- Goal: Shrink/downstage tumor → Permit resection or less radical operation
- Treat micrometastases early
- Assess tumor response → Prognostic information
- May improve R0 rate and organ/function preservation
- Examples: Rectal cancer chemoradiotherapy/TNT, locally advanced breast cancer systemic therapy, esophageal cancer chemoradiotherapy
Adjuvant Therapy
- Definition: Oncological treatment after curative-intent surgery
- Goal: Eliminate microscopic residual disease → Reduce recurrence risk
- Indications depend on pTNM, nodal status, margin status, tumor biology and patient fitness
- Examples: Chemotherapy, radiotherapy, trastuzumab for HER2+ breast cancer, hormonal therapy for ER+ breast cancer
- Benefit must be balanced against toxicity, comorbidities and patient preference
IV. Onco-Team
- Onco-team / multidisciplinary tumor board: Specialists who plan and coordinate comprehensive cancer care
- Decision is based on diagnosis, TNM stage, histology, biomarkers, resectability, operability and patient preference
Members
- Medical oncologist, surgical oncologist/surgeon, radiation oncologist
- Pathologist, radiologist/nuclear medicine specialist
- Organ specialist depending on tumor type
- Specialist nurse, dietitian/nutritionist, psychologist/psychiatrist, pharmacist
- Genetic counselor, palliative care and social worker when needed
Importance
- Comprehensive care → Different specialties bring different perspectives
- Improved decision-making → Evidence-based, consensus-driven plan
- Personalized treatment → Stage, biology, patient condition, QOL and preferences
- Correct treatment sequence → Neoadjuvant, surgery, adjuvant, palliation or follow-up
- Improved support and education → Medical, nutritional, psychological and social care
- Better outcomes and less under-/overtreatment