Long-Term Outcomes of Local Full-Thickness Resection for Sessile Adenomas and Early Rectal Cancer

Overview

This prospective study evaluated perioperative morbidity and long-term oncological outcomes of transanal endoscopic microsurgery (TEM) for sessile rectal adenomas and early-stage rectal cancer. The findings support TEM as a curative option for benign and low-risk malignant rectal lesions with acceptable morbidity and favorable survival.

Background

Rectal adenomas are premalignant lesions whose excision reduces carcinoma incidence and symptoms. While snare polypectomy is preferred, some lesions require surgery. Local excision for early rectal cancer gained interest after Morson's 1977 report and was enhanced by the introduction of TEM in 1983, which improved access and reduced recurrence. This study analyzes long-term outcomes of TEM performed at a high-volume academic center following a standardized protocol.

Data Highlights

The study included adult patients with benign adenomas unsuitable for endoscopic resection and stage I low-risk rectal cancers. Patients with high-risk pT1 or pT2 cancers were offered adjuvant radiotherapy or salvage surgery. Follow-up included physical exams, rigid proctosigmoidoscopy, ERUS, and serum CEA monitoring. Surgical excision was considered complete with full-thickness resection and ≥1 mm negative margins. The protocol stratified patients into Group A (benign/pT1 low-risk) treated with TEM alone and Group B (pT1 high-risk/pT2 low-risk) offered additional therapy.

Key Findings

• TEM achieved full-thickness excision with negative margins in all cases, ensuring complete local resection.
• Group A patients (benign and pT1 low-risk cancers) required no further treatment post-TEM, demonstrating TEM's curative potential in these lesions.
• Group B patients (pT1 high-risk and pT2 low-risk) were offered salvage surgery or adjuvant radiotherapy, reflecting tailored management based on pathological risk factors.
• Perioperative morbidity was low, with no routine defect suturing after early experience, indicating a safe surgical profile.
• Long-term follow-up with endoscopic and imaging surveillance allowed early detection of recurrences, supporting the protocol's effectiveness.

Clinical Implications

TEM is a viable curative option for benign and low-risk early rectal cancers, offering organ preservation with low morbidity. Careful preoperative staging and pathological risk assessment are essential to guide adjuvant treatment decisions. Multidisciplinary evaluation and patient counseling facilitate shared decision-making and optimize outcomes.

Conclusion

This long-term analysis confirms that localized full-thickness resection via TEM provides effective treatment for sessile adenomas and selected early rectal cancers with favorable perioperative safety and oncological outcomes. The protocol supports individualized management balancing cure and function preservation.

References

1. Morson et al. 1977 -- Experience with conventional transanal approach for local excision
2. Buess et al. 1983 -- Introduction of transanal endoscopic microsurgery (TEM)
3. TEM pioneers 1990s -- Early results demonstrating superiority of TEM over conventional approaches
4. Authors' previous reports 1997-2006 -- Initial oncological results of TEM protocol