Rectal Cancer: Comparing Less Invasive Local Excision With Radiation Versus Standard Total Mesorectal Excision Surgery

Table of Contents

• Key Points
• Why This Research Matters
• How the Research Was Conducted
• The Studies Included in This Analysis
• Recovery After Surgery: What the Data Show
• Cancer Control: Recurrence and Margin Results
• Survival Rates: Overall and Disease-Free
• What These Results Mean for Patients
• Study Limitations: What This Analysis Could Not Prove
• Recommendations for Patients
• Frequently Asked Questions
• Source Information

Key Points

• In six prospective studies of 679 selected patients, local excision plus radiation was linked to shorter operations, fewer overall complications, and shorter hospital stays than standard TME surgery.
• Cancer control and survival were statistically comparable between the two approaches, though trends toward slightly higher positive margins and local recurrence after local excision were not significant.
• Local excision removes the tumour but not surrounding lymph nodes, so it is reserved for patients whose tumours are at low risk of lymph node spread or who responded well to radiation.
• The findings apply mainly to small (under 3–4 cm), early-stage tumours up to cT3; more advanced tumours were included only if patients had a complete or near-complete response to chemoradiotherapy.
• This analysis could not compare quality-of-life or functional outcomes, and the size of recovery benefits varied between studies, so results should be interpreted with caution.

Why This Research Matters

Rectal cancer treatment has long centered on total mesorectal excision (TME), a major operation that removes the rectum along with surrounding fatty tissue and lymph nodes. For tumors in the middle or lower rectum, TME is the standard of care, sometimes combined with radiation and chemotherapy before surgery. However, the procedure comes at a cost.

Early or late complications are reported in 25 to 50% of patients — in other words, about 1 in 4 to 1 in 2 patients experience a complication. Even among patients who survive their cancer, long-term bowel, bladder, and sexual problems after TME often damage quality of life.

Because of these concerns, doctors have been exploring less invasive options. One emerging strategy is the "watch-and-wait" (WW) approach, in which patients who achieve a complete or near-complete response to radiation are monitored closely instead of undergoing surgery. But WW has its own problems. It is difficult to reliably distinguish between a complete response, a near-complete response, and an incomplete response. Moreover, tumors can regrow during surveillance at a relatively high rate, even in patients initially thought to have responded completely.

This review examined another less invasive alternative: local excision (LE), most often performed as transanal endoscopic microsurgery (TEM), a procedure that removes the tumor through the anus without removing the whole rectum. When LE is combined with radiation therapy (RT) before surgery — either long-course chemoradiotherapy or short-course radiation — it may allow doctors to evaluate the response to radiation through direct tissue examination, improve local control, and preserve the rectum.

The research team set out to answer a focused question: In selected rectal cancer patients, does LE plus RT produce results comparable to standard TME, both for short-term recovery and long-term cancer outcomes?

How the Research Was Conducted

Literature Search

This is a systematic review and meta-analysis, a type of study that pools the results of multiple clinical trials to reach more reliable conclusions. The researchers followed the PRISMA guidelines, an internationally recognized standard for reporting such reviews, and registered their protocol in advance with PROSPERO (registration number CRD420251048717).

The team searched PubMed, Embase, and the Cochrane Library using a core search combining the terms "rectal neoplasms," "local excision," and "total mesorectal excision." The search was limited to human studies published in English, with the final search completed by April 2025. An updated search in May 2025 captured additional long-term follow-up reports from two of the included trials.

Which Studies Were Eligible?

To be included, studies had to meet strict criteria:

• They had to be prospective comparative trials — either randomized controlled trials (RCTs) or non-randomized prospective studies. Retrospective studies were excluded.
• Patients had to have rectal cancer staged up to cT3 (tumor growing through the bowel wall but not into nearby organs) and/or have shown a favorable response to neoadjuvant (pre-surgical) therapy.
• Patients in the local excision group had to have received neoadjuvant radiation, either long-course chemoradiotherapy or short-course radiation.
• Studies had to report at least one postoperative or oncological outcome with enough data to calculate risk ratios and mean differences.

Excluded were study protocols, unpublished studies, letters, comments, abstracts, corrections, replies, retrospective studies, and review articles.

Outcomes Measured

Postoperative (short-term) outcomes included operative time, blood loss during surgery, overall complications (every severity grade), severe complications (defined as Clavien–Dindo grade 3 or higher — complications requiring surgical, endoscopic, or radiological intervention), length of hospital stay, and permanent stoma rate.

Oncological (cancer-related) outcomes included positive surgical margin rate (cancer cells found at the edge of the removed tissue), local recurrence rate (cancer returning in the same area), and overall recurrence rate (local plus distant recurrences). Survival outcomes included overall survival (OS) and disease-free survival (DFS).

Quality Assessment and Statistics

Randomized trials were assessed for bias using the Cochrane RoB 2 tool, while non-randomized studies used the ROBINS-I tool. When multiple publications reported on the same patients, only the most recent and complete dataset was used in the analysis to avoid double counting.

The researchers used random-effects statistical models, which account for differences between studies. Results were expressed as risk ratios (RRs) with 95% confidence intervals (CIs) for categorical outcomes, mean differences (MDs) for continuous outcomes, and hazard ratios (HRs) for survival outcomes. Heterogeneity (inconsistency between study results) was measured using the I² statistic; values above 50% were considered substantial.

The Studies Included in This Analysis

From 3,001 records identified in the initial database search (2,149 from PubMed, 590 from Embase, and 262 from the Cochrane Library), the researchers removed 852 duplicates, leaving 2,149 unique records. After excluding 1,895 records that were not clinical trials, 254 reports underwent title and abstract screening. Of those, 240 were deemed irrelevant, and 14 full-text reports were reviewed. Five were excluded as study protocols and three as duplicate follow-up reports from already-included trials.

Ultimately, six studies met the inclusion criteria: five randomized controlled trials and one prospective clinical trial. Together, they enrolled 679 patients: 366 patients received radiation followed by local excision (the LE + RT group), and 313 received TME surgery (some after chemoradiotherapy, others directly).

The studies came from the United Kingdom, Italy, China, France, and Spain. The two Italian trials (Lezoche 2008 and Lezoche 2012) were conducted by the same research group with partially overlapping patients; only the more recent dataset was used in the quantitative pooling to prevent double counting.

Patient selection criteria were fairly consistent across studies — most enrolled tumors up to cT3, node-negative (cN0), and under 3 to 4 cm in size, located in the middle or lower rectum. Two studies allowed more advanced tumors (cT4 or node-positive), but only if patients had achieved a complete or near-complete clinical response after chemoradiotherapy.

Treatment Details by Study

• Bach 2021 (UK): Included T1-2 N0 tumors up to 3 cm. The LE + RT group received short-course radiation (25 Gy) followed by TEM; the comparison group had upfront TME. Follow-up was about 51 months for the randomized portion and 49 months for the prospective portion.
• Lezoche 2008 and 2012 (Italy): Both included T2 N0, grade 1–2 tumors smaller than 3 cm, no more than 6 cm from the anal verge. Both groups received chemoradiotherapy (50.4 Gy); one group then had TEM, the other had TME. Follow-up was 84 months in the 2008 study and 115.2 months (about 9.6 years) in the 2012 study.
• Qiu 2025 (China): A prospective trial of T3-4 N0 or any-T node-positive tumors up to 10 cm from the anal verge, restricted to patients with a complete or near-complete clinical response. Both groups received 45–50 Gy chemoradiotherapy before surgery. Follow-up was 60 months.
• Rullier 2017/2020 (France): A 15-center RCT of T2-3 N0-1 tumors up to 4 cm, within 8 cm of the anal verge. Both groups received chemoradiotherapy (50 Gy and 50.4 Gy); one group had local excision, the other TME. Follow-up was 36 months in the primary report, with 5-year results later published.
• Serra-Aracil 2023/2025 (Spain): A 17-center RCT of T2-3 N0 tumors up to 4 cm. The LE + RT group received chemoradiotherapy (50.4 Gy) followed by TEM; the comparison group had upfront TME. Short-term results were reported at 63 months, with long-term results following in 2025.

Pathological Results After Treatment

The studies reported how often the tumor disappeared completely after treatment (pathological complete response, or ypT0). The rates in the LE + RT groups were notable:

• In Bach 2021, 31% of LE + RT patients had ypT0/pT0 tumors (no remaining cancer) versus 0% in the TME group.
• In Qiu 2025, 58% of LE + RT patients achieved ypT0 versus 51% of TME patients.
• In Serra-Aracil 2025, 44% of LE + RT patients had ypT0/pT0 versus 0% who had upfront TME.
• In Rullier 2017/2020, 40% of all patients (both groups combined) had ypT0 tumors.

Lymph node status was reported mainly for TME patients, since local excision does not remove lymph nodes. In the TME groups, node-positive disease was found in 3 to 21% of patients depending on the study.

Recovery After Surgery: What the Data Show

Operative time, overall complication rates, and hospital stay were each analyzed using data from three studies totaling 341 patients (169 in the LE + RT group and 172 in the TME group). The pattern was consistent across all three measures.

Operative time was much shorter with LE + RT. The pooled mean difference was -112.33 minutes (95% CI: -223.06 to -1.61; p = 0.05). In plain terms, surgery lasted about 1 hour and 52 minutes less on average in the LE + RT group. The result sat exactly at the border of statistical significance, meaning there is about a 5% chance the finding could be due to random chance. Substantial heterogeneity was present (p < 0.01, I² = 96%), so this estimate should be interpreted cautiously.

Overall complications were roughly half as common after LE + RT. The pooled risk ratio was 0.46 (95% CI: 0.26–0.81; p = 0.03), meaning patients in the LE + RT group had a 54% lower relative risk of any complication compared with TME patients. In absolute terms, given that TME complications occur in roughly 25–50% of patients, this represents a substantial difference. There was no evidence of heterogeneity between studies (p = 0.58, I² = 0%), strengthening confidence in this finding.

Hospital stays were shorter by an average of nearly 5 days. The pooled mean difference was -4.95 days (95% CI: -9.34 to -0.56; p = 0.04). However, heterogeneity was substantial (p < 0.01, I² = 93%), so the exact size of this benefit likely varies from center to center.

Several other outcomes showed no significant difference between the groups:

• Severe (major) complications, defined as Clavien–Dindo grade 3 or higher
• Blood loss during surgery
• The rate of permanent stoma (a colostomy or ileostomy that cannot be reversed)

The similar permanent stoma rates are worth noting: one of the main hopes for LE + RT is avoiding a permanent stoma, and while this analysis did not find a statistically significant difference, it is an outcome many patients weigh heavily when choosing treatment.

Cancer Control: Recurrence and Margin Results

One of the most important questions for patients is whether the less invasive approach compromises cancer control. The average median follow-up across the six studies was 65.5 months (roughly 5.5 years), which is long enough to capture most recurrences of rectal cancer.

Recurrence outcomes were analyzed using data from five studies totaling 609 patients (331 in the LE + RT group and 278 in the TME group).

Positive surgical margins (cancer cells found at the edge of the removed tissue) tended to be more frequent in the LE + RT group, but this difference was not statistically significant. Individual study rates were:

• Bach 2021: 6% (5 of 88) in LE + RT versus 6% (2 of 35) in TME
• Qiu 2025: 8% (3 of 38) versus 0%
• Serra-Aracil 2025: 5% (4 of 81) versus 2% (2 of 81)

Two studies (Lezoche 2012 and Rullier) reported no margin data or no positive margins in either group. No substantial heterogeneity was found among studies.

Local recurrence (cancer returning in the pelvis) also tended to be higher in the LE + RT group, but again the difference was not statistically significant. Individual study local recurrence rates were:

• Bach 2021: 10% (about 1 in 10 patients) in LE + RT versus 0% in TME
• Lezoche 2008: 6% versus 3%
• Lezoche 2012: 8% versus 6%
• Qiu 2025: 5% versus 0%
• Rullier 2020: 7% versus 7%
• Serra-Aracil 2025: 7% versus 6%

Overall recurrence (local plus distant) showed no significant difference between groups. Distant recurrence rates reported in individual studies were similar — for example, 21% versus 17% in Qiu 2025, and 18% versus 19% in Rullier 2020.

Importantly, none of the pooled analyses for local or overall recurrence showed substantial heterogeneity, meaning the studies were consistent with one another.

Survival Rates: Overall and Disease-Free

Survival data were pooled from four studies comparing LE + RT with TME. The results were very close between the two groups.

For overall survival, the pooled hazard ratio was 0.93 (95% CI: 0.57–1.52; p = 0.66). Since a hazard ratio of 1 would mean identical survival, a value of 0.93 indicates a slight, non-significant advantage for LE + RT. Heterogeneity was low (p = 0.75, I² = 0%).

For disease-free survival (living without any cancer recurrence), the pooled hazard ratio was 1.02 (95% CI: 0.52–2.00; p = 0.92) — essentially no difference. Heterogeneity was low (p = 0.46, I² = 0%).

The 5-year survival figures reported in individual studies reinforce this picture:

• Qiu 2025: overall survival 93.2% (LE + RT) versus 88.2% (TME); disease-free survival 75.6% versus 80.9%
• Rullier 2020: overall survival 66% versus 53%; disease-free survival 54% versus 49%
• Serra-Aracil 2025: overall survival 82.7% versus 85.2%; disease-free survival 88.9% versus 88.9%
• Bach 2021 (3-year data from the randomized cohort): overall survival 88% versus 93%; disease-free survival 76% versus 85%

The wide confidence intervals around the pooled survival estimates mean the data are compatible with a range of possibilities, but the most likely interpretation is that LE + RT does not meaningfully compromise survival in properly selected patients.

What These Results Mean for Patients

The big picture from this meta-analysis is encouraging for patients hoping to avoid major rectal surgery. The LE + RT approach was associated with a shorter operation, a roughly 54% lower relative risk of any postoperative complication, and a hospital stay about 5 days shorter — all while cancer outcomes and survival remained statistically comparable to TME.

These findings align with shifting expert opinion. The 2017 European Society for Medical Oncology (ESMO) guidelines recommended local excision only for very early cT1N0 tumors with low-grade features, and considered radiation followed by LE for small cT2 tumors mainly for elderly or frail patients at high surgical risk. The 2025 ESMO guidelines, however, now list neoadjuvant radiation followed by local excision as one of the standard management options when organ preservation is the goal, particularly for patients with cT2 or cT3aN0 tumors who achieve a good response to radiation.

The authors of this review emphasize that careful patient selection appears to be the key to success. In the studies analyzed, most patients had favorable tumor characteristics — small size, early stage, or a strong response to radiation — and that is exactly the population in which organ preservation appears safest.

It is also worth understanding what this treatment is not. Local excision removes the tumor but does not remove the lymph nodes in the surrounding tissue, unlike TME. This is why the approach is reserved for patients whose tumors are at low risk of having already spread to lymph nodes, or who have shown such a good response to radiation that the risk is considered acceptably low.

Study Limitations: What This Analysis Could Not Prove

As with any research, there are important limitations to keep in mind. First, only six studies met the inclusion criteria, and total patient numbers were modest (679 patients). This limits the statistical power of the analysis, especially for detecting small differences in survival.

Second, blinding and allocation concealment were difficult or impossible in these surgical trials — patients and doctors obviously know which surgery was performed. In two of the five randomized trials, bias related to deviations from the intended treatment was rated as high risk. The overall risk of bias across the trials ranged from low to high.

Third, two of the included studies had non-randomized prospective cohorts, and in those, bias due to confounding factors and patient selection was judged to be serious. The researchers note, however, that in both studies the design made it impossible to select patients based on their response to radiation.

Fourth, several key findings — operative time and hospital stay — showed substantial heterogeneity (I² of 96% and 93%, respectively). In plain language, the size of the benefit varied considerably between studies, so the average figures should be viewed as rough estimates rather than precise predictions for any individual hospital.

Fifth, the observed trends toward higher positive margin rates and higher local recurrence in the LE + RT group, while not statistically significant, should not be dismissed. A larger study might find a real difference. The surveillance and follow-up protocols in these trials were rigorous; whether similar results would occur in less specialized centers is unknown.

Finally, this analysis could not directly compare quality-of-life outcomes or functional results between the two approaches, even though avoiding long-term bowel, bladder, and sexual dysfunction is a primary reason patients choose organ preservation.

Recommendations for Patients

Based on this evidence, here is what patients facing a rectal cancer diagnosis should consider discussing with their care team:

1. Ask about tumor staging and predicted response. LE + RT appears most appropriate for tumors up to cT3 that are small (under 3–4 cm), node-negative, and likely to respond well to radiation. Patients with more advanced disease were only included in these trials if they achieved a complete or near-complete response after chemoradiotherapy.
2. Discuss organ preservation as a goal. If avoiding a permanent stoma or preserving rectal function is important to you, ask whether a course of radiation followed by restaging and possible local excision is an option at your center.
3. Understand the trade-off. LE + RT offers faster recovery and fewer complications, but it leaves lymph nodes in place. The pooled recurrence and survival data are reassuring, but the trends toward slightly higher local recurrence and positive margin rates mean you should understand the need for close follow-up.
4. Insist on expert multidisciplinary care. The trials in this analysis were conducted at specialized centers with experience in transanal endoscopic microsurgery and careful patient selection. Outcomes in lower-volume centers may differ.
5. Ask about follow-up surveillance. Because local regrowth is a known risk of organ-preserving approaches, ask what your surveillance schedule would look like — including how often you would have endoscopy and imaging.
6. Consider fitness for surgery. The authors note that LE + RT may be particularly valuable for patients who are not fit for major TME surgery, as well as for those who strongly prioritize organ preservation.

Every patient's situation is different. These findings provide evidence that LE + RT is a legitimate option for carefully selected patients — but the final decision should always be made together with your surgical and oncology team, based on your specific tumor characteristics, overall health, and personal priorities.

Frequently Asked Questions

Who might be eligible for local excision plus radiation instead of standard surgery?

In the six studies reviewed, most patients had small tumours (under 3–4 cm), early-stage disease up to cT3, and no lymph node involvement. Some studies also included more advanced tumours, but only when patients had achieved a complete or near-complete response to chemoradiotherapy. Local excision leaves lymph nodes in place, so it is reserved for patients whose tumours are at low risk of having already spread there.

What does it mean if my tumour shows a complete response after radiation?

A complete response means no remaining cancer cells are found when the treated tissue is examined. In the studies reviewed, complete response rates in the local excision plus radiation groups ranged from 31% to 58%, depending on the study. Achieving this response was one of the criteria used to select patients for the less invasive approach, because it suggests the radiation worked well against the tumour.

How does recovery compare between local excision plus radiation and standard TME surgery?

Across three studies of 341 patients, local excision plus radiation was linked to a much shorter operation (about 1 hour 52 minutes less on average), roughly half as many overall complications, and a hospital stay nearly 5 days shorter. However, the size of the benefit for operative time and hospital stay varied considerably between studies, so these are rough averages rather than exact predictions for any one hospital.

Does the less invasive approach affect cancer control or survival?

In this analysis, cancer control and survival were statistically comparable between local excision plus radiation and standard surgery. Pooled results showed no significant difference in overall recurrence, overall survival, or disease-free survival. There were non-significant trends toward slightly higher positive margin rates and local recurrence in the local excision group, so close follow-up remains important.

What is a positive surgical margin, and why does it matter?

A positive surgical margin means cancer cells were found at the edge of the removed tissue. In the studies reviewed, positive margins tended to be more frequent after local excision plus radiation than after standard surgery, but the difference was not statistically significant. Individual study rates ranged from 5% to 8% in the local excision groups. A positive margin may indicate a higher risk of the cancer returning locally.

Will I need a permanent stoma if I choose local excision plus radiation?

In this analysis, the rate of permanent stoma was not significantly different between local excision plus radiation and standard surgery. Avoiding a permanent stoma is one of the main reasons patients consider organ preservation, and while this review did not find a statistical difference, it is an outcome many patients weigh heavily when choosing treatment. Discuss your individual risk with your surgical team.

I have rectal cancer and was told I need total mesorectal excision — when should I seek a second opinion about local excision plus radiation instead?

A second opinion is worth seeking when organ preservation matters to you or when major surgery is a concern. Local excision plus radiation suits tumors up to cT3 that are small (under 3–4 cm), node-negative, and likely to respond to radiation; more advanced tumors qualified only after a complete or near-complete response to chemoradiotherapy. Because local excision leaves lymph nodes in place, selection and multidisciplinary experience matter. A second opinion can clarify whether you fit that group and what surveillance would involve. Diagnostic Detectives Network provides independent expert second opinions.

Source Information

This patient-friendly article is based on the following peer-reviewed research:

Original title: "Systematic review and meta-analysis comparing postoperative and oncological outcomes between local excision plus radiotherapy versus total mesorectal excision for rectal cancer."

Authors: Kitaguchi D, Forgione A, Innocenzi C, Yang Y, Espínola F, Giménez M, Oda T, Marescaux J.

Journal: World Journal of Surgical Oncology (2026) 24:203. Published as an open-access article under the Creative Commons Attribution 4.0 International License. DOI: https://doi.org/10.1186/s12957-026-04304-8

Registration: The systematic review protocol was registered with PROSPERO (International Prospective Register of Systematic Reviews) under registration number CRD420251048717.

Note: This article is a translation of the original scientific paper into plain language for patients and caregivers. It does not replace individualized medical advice. Patients should discuss their specific diagnosis and treatment options with qualified healthcare professionals.