A 62-year-old woman with a history of familial adenomatous polyposis (FAP) undergoes total proctocolectomy. Which single feature best distinguishes the surgical management of FAP from sporadic colorectal cancer in terms of the extent of resection?

Explanation

## Surgical Management: FAP vs Sporadic Colorectal Cancer **Key Point:** The surgical approach to FAP differs fundamentally from sporadic colorectal cancer because FAP involves the entire colon and rectum with hundreds to thousands of adenomatous polyps, whereas sporadic cancer is typically a single lesion. ### Comparison of Surgical Strategies | Feature | FAP | Sporadic CRC | |---------|-----|---------------| | **Number of polyps** | Hundreds to thousands | Single lesion (usually) | | **Risk of malignancy** | Nearly 100% by age 40–50 if untreated | Depends on stage and grade | | **Surgical extent** | Total proctocolectomy (entire colon + rectum) | Segmental resection based on location | | **Reconstruction** | IPAA or permanent ileostomy | Primary anastomosis (usually) | | **Indication for surgery** | Prophylactic (cancer prevention) | Therapeutic (cancer treatment) | | **Timing** | Elective, before cancer develops | Urgent/semi-urgent, after diagnosis | **High-Yield:** FAP patients who do not undergo prophylactic total proctocolectomy have a cumulative cancer risk approaching 100% by age 50. Therefore, the standard of care is total proctocolectomy with either IPAA (preserves continence) or permanent ileostomy (if IPAA not feasible or refused). **Clinical Pearl:** In sporadic colorectal cancer, the goal is to remove the tumour with adequate margins (typically 5 cm proximal and distal) and the draining lymph nodes. Segmental resection (e.g., left hemicolectomy for sigmoid cancer, right hemicolectomy for caecal cancer) is sufficient because the rest of the colon is normal. **Mnemonic:** **FAP = Full Abdomen Proctocolectomy** (total removal); **Sporadic = Segmental Surgery** (remove only the affected segment). ### Why Total Proctocolectomy in FAP? 1. **Polyp burden:** The entire colon and rectum are lined with adenomatous polyps; any remaining mucosa carries malignant potential. 2. **Synchronous cancer risk:** ~5% of FAP patients have synchronous colorectal cancers at diagnosis. 3. **Metachronous cancer risk:** Without total proctocolectomy, the remaining colon will develop cancer in nearly all untreated patients. 4. **Duodenal and gastric polyps:** FAP also causes polyps in the duodenum and stomach, requiring surveillance even after colectomy.