Surgical oncology: cancer prevention and diagnostics, classification of malignancies

1. Big picture

This topic is about how cancer is prevented, suspected, diagnosed, classified, and staged before surgical treatment. In the previous topic, the focus was cancer biology and precancerous lesions. Here the examiner wants a practical surgical-oncology workflow:

Risk factor / screening / symptoms
        ↓
Suspicion of malignancy
        ↓
Clinical examination + imaging
        ↓
Histological confirmation
        ↓
Classification: tumour type, grade, stage, molecular markers
        ↓
Multidisciplinary decision
        ↓
Curative, neoadjuvant, adjuvant, palliative, or preventive treatment

The surgical principle is simple:

**No oncologic operation should be p