The basics and principles of surgical oncology
DEFINITION AND GOALS
Surgical oncology is the use of surgery in cancer prevention, diagnosis, staging, cure, local control, palliation and reconstruction. The aims are complete oncological resection where possible, accurate staging, preservation of function and quality of life, and integration with systemic and radiation treatments.
BIOLOGY AND NATURAL HISTORY
Cancer develops through accumulation of genetic and epigenetic alterations, producing uncontrolled proliferation, invasion and potential metastasis. Tumour behaviour is described by histological type, grade, differentiation, molecular profile, depth of invasion, lymphovascular/perineural invasion and nodal/distant spread. The TNM system records primary tumour extent (T), regional nodes (N) and distant metastases (M); stage guides prognosis and treatment.
PREOPERATIVE ASSESSMENT AND STAGING
Confirm diagnosis by appropriate biopsy and pathology review. Complete staging with site-specific imaging and endoscopy; assess performance status, frailty, nutrition, comorbidities and organ function. Discuss the case in a multidisciplinary team (surgeon, medical/radiation oncologist, radiologist, pathologist, specialist nurses and allied health). Determine resectability, operability and whether neoadjuvant therapy is indicated. Consent includes intended procedure, margins, lymph-node surgery, stoma/reconstruction possibility and risks.
ONCOLOGICAL SURGICAL PRINCIPLES
Resection should remove the tumour intact with an adequate margin of normal tissue and avoid tumour violation/spillage. En-bloc resection is preferred when adjacent structures are directly invaded and an R0 resection is achievable. Regional lymph-node assessment or dissection is performed according to tumour site and staging requirements. R0 means microscopically clear margins; R1 indicates microscopic residual tumour; R2 indicates macroscopic residual disease. Specimens must be oriented and labelled for pathology. Preserve organs and function when oncologically safe, but do not compromise cancer clearance.
TREATMENT INTENT AND MULTIMODALITY
Curative surgery aims for durable eradication in localised disease. Cytoreductive/debulking surgery reduces tumour burden in selected cancers when evidence supports benefit and complete/optimal cytoreduction is feasible. Palliative surgery relieves obstruction, bleeding, perforation, pain or fistula when less invasive options are unsuitable. Neoadjuvant therapy is given before surgery to downstage disease or treat micrometastases; adjuvant therapy follows surgery to reduce recurrence risk. Targeted therapy and immunotherapy depend on molecular biomarkers.
POSTOPERATIVE CARE, COMPLICATIONS AND ETHICS
Enhanced recovery, nutrition, thromboprophylaxis, infection prevention, early mobilisation and rehabilitation reduce morbidity. Complications include bleeding, infection, anastomotic leak, organ dysfunction, thromboembolism, functional loss and recurrence. Follow-up detects recurrence, manages late effects and supports survivorship. Decisions should respect informed patient preferences, proportionality, equity and goals of care; when cure is not realistic, symptom control and palliative care remain active treatment.