Treatment for newly diagnosed cT1 rectal cancer

CT: computed tomography; MRI: magnetic resonance imaging; FDG-PET: fluorodeoxyglucose positron emission tomography; LAR: low anterior resection; APR: abdominoperineal resection.
* Endoscopic excision alone is not appropriate for malignant polyps with any of the following:

• For both pedunculated and nonpedunculated (sessile) polyps:
  • Piecemeal resection
  • Poorly differentiated histology
  • Lymphovascular or perineural invasion
  • Tumor budding (foci of isolated cancer cells or a cluster of five or fewer cancer cells at the invasive margin of the polyp)
  • Cancer at resection margin
  • Submucosal invasion depth ≥1 mm

¶ Transabdominal surgery remains an option for patients with tumors amenable to local excision and may be preferred in some cases, especially in younger patients who are fit for surgery. Cases with all of the following features are amenable to local excision:

• Superficial T1 cancer, limited to the submucosa
• No radiographic evidence of metastatic disease to regional nodes
• Tumor <3 cm in diameter
• Low risk of developing positive regional nodes (well-differentiated, no lymphovascular or neural invasion)
• Involves <30% of the circumference of the lumen
• Mobile, nonfixed
• Margins clear (>3 mm)
• Compliance with appropriate postoperative surveillance

Δ Pelvic MRI recommended for rectal primaries. CT is appropriate for all except those with clinical T1N0 cancers with favorable histologic factors.

• If pelvic MRI has been done, we perform CT of the chest and abdomen
• If pelvic MRI has not been done, we perform CT of the chest, abdomen, and pelvis