Local Excision: Some Reality Testing

Completion Total Mesorectal Excision After Transanal Local Excision of Early Rectal Cancer: A Systematic Review and Meta-analysis

BACKGROUND

Completion total mesorectal excision is recommended when local excision of early rectal cancers demonstrates high-risk histopathological features. Concerns regarding the quality of completion resections and the impact on oncological safety remain unanswered.

OBJECTIVE

This study aims to summarize and analyze the outcomes associated with completion surgery and undertake a comparative analysis with primary rectal resections.

DATA SOURCES

Data sources included PubMed, Cochrane library, MEDLINE, and Embase databases up to April 2021.

STUDY SELECTION

All studies reporting any outcome of completion surgery after transanal local excision of an early rectal cancer were selected. Case reports, studies of benign lesions, and studies using flexible endoscopic techniques were not included.

INTERVENTION

The intervention was completion total mesorectal excision after transanal local excision of early rectal cancers.

MAIN OUTCOME MEASURES

Primary outcome measures included histopathological and long-term oncological outcomes of completion total mesorectal excision. Secondary outcome measures included short-term perioperative outcomes.

RESULTS

Twenty-three studies including 646 patients met the eligibility criteria, and 8 studies were included in the meta-analyses. Patients undergoing completion surgery have longer operative times (standardized mean difference, 0.49; 95% CI, 0.23-0.75; p = 0.0002) and higher intraoperative blood loss (standardized mean difference, 0.25; 95% CI, 0.01-0.5; p = 0.04) compared with primary resections, but perioperative morbidity is comparable (risk ratio, 1.26; 95% CI, 0.98-1.62; p = 0.08). Completion surgery is associated with higher rates of incomplete mesorectal specimens (risk ratio, 3.06; 95% CI, 1.41-6.62; p = 0.005) and lower lymph node yields (standardized mean difference, -0.26; 95% CI, -0.47 to 0.06; p = 0.01). Comparative analysis on long-term outcomes is limited, but no evidence of inferior recurrence or survival rates is found.

LIMITATIONS

Only small retrospective cohort and case-control studies are published on this topic, with considerable heterogeneity limiting the effectiveness of meta-analysis.

CONCLUSIONS

This review provides the strongest evidence to date that completion surgery is associated with an inferior histopathological grade of the mesorectum and finds insufficient long-term results to satisfy concerns regarding oncological safety. International collaborative research is required to demonstrate noninferiority.

REGISTRATION NO

CRD42021245101.

Transanal endoscopic microsurgery versus standard transanal excision for the removal of rectal neoplasms: a systematic review and meta-analysis

BACKGROUND

Transanal endoscopic microsurgery is the intraluminal excision of rectal lesions with the use of instrumentation to maintain a stable pneumorectum, enabling a magnified view of the target lesion. Despite suggested benefits over traditional transanal excision, there is no consensus on which technique is superior.

OBJECTIVE

The aim of the current study is to use meta-analytical techniques to compare transanal endoscopic microsurgery with transanal excision.

DATA SOURCES

A comprehensive literature search of PubMed, Embase, and The Cochrane Library was performed.

STUDY SELECTION

All studies comparing transanal endoscopic microsurgery with transanal excision were included.

INTERVENTIONS

Transanal endoscopic microsurgery was compared with transanal excision by using random-effects methods to combine data. Data are presented as ORs with 95% CIs.

MAIN OUTCOME MEASURES

The main outcomes measured were postoperative complication rate, negative microscopic margin rate, specimen fragmentation rate, and lesion recurrence.

RESULTS

Six comparative series comparing outcomes following 927 local excisions were identified. There was no difference between techniques in postoperative complication rate (OR, 1.018; 95% CI, 0.658-1.575; p = 0.937). Transanal endoscopic microsurgery had a higher rate of negative microscopic margins in comparison with transanal excision (OR, 5.281; 95% CI, 3.201-8.712; p < 0.001). Transanal endoscopic microsurgery had a reduced rate of specimen fragmentation (OR, 0.096; 95% CI, 0.044-0.209; p < 0.001) and lesion recurrence (OR, 0.248; 95% CI, 0.154-0.401; p < 0.001) compared with transanal excision. There was no across-study heterogeneity for any end point.

LIMITATIONS

Most studies were retrospectively designed, and there were variations in patient populations and duration of follow-up.

CONCLUSIONS

Available data are limited because of a lack of randomized controlled trials. However, based on current evidence, transanal endoscopic microsurgery is oncologically superior to transanal excision for the excision of rectal neoplasms.

Completion surgery following transanal endoscopic microsurgery: assessment of quality and short- and long-term outcome

AIM

Patients with unfavourable pathology after transanal endoscopic microsurgery (TEM) should be offered completion surgery (CS) if appropriate. The aim of this retrospective cohort study was to assess the short-term outcome and long-term oncological results of CS and identify factors compromising the quality of resection specimens.

METHOD

Data were retrieved and analysed on patients who underwent CS from a comprehensive national TEM database (1992-2008) and the institutional prospective database from the Oxford University Hospitals (2008-2011).

RESULTS

There were 36 patients eligible for analysis. Postoperative complications occurred in 19 and were minor (grade I-II) in 13 and major (grade III-V) in six patients. The quality of the resected specimen was graded as good in 23 (64%), moderate in six (16.6%) and poor in seven (19.4%). Full-thickness excision by TEM (P = 0.03), an interval to CS greater than 7 weeks (P = 0.05) and distally located lesions (P = 0.04) were associated with increased risk for an inferior surgical specimen. Overall survival after CS was 91% at 1 year and 83% at 5 years. Patients with a 'good' TME specimen had significantly improved disease-free survival compared with patients with an 'inferior' specimen (100 vs 51%, P = 0.001).

CONCLUSION

Patients having full-thickness TEM excision, distally placed lesions and a long interval (> 7 weeks) to CS were likely to have an inferior TME specimen. The results confirm that CS after TEM does not negatively influence local recurrence and survival, but the reduced disease-free survival in patients with an inferior specimen is of concern.

Endocavitary contact radiation therapy for ultrasonographically staged T1 N0 and T2 N0 rectal cancer

Background

The purpose of this study was to determine the long-term outcomes of patients undergoing endocavitary contact radiation therapy (ECR) for stage I rectal cancer.

Methods

A database of patients treated with ECR for biopsy-proven rectal adenocarcinoma from July 1986 to June 2006 was reviewed retrospectively. Only patients with primary, non-metastatic, ultrasonographically staged T1 N0 and T2 N0 cancer who had no adjuvant treatment were included. Patients received a median of 90 (range 60–190) Gy contact radiation, delivered transanally by a 50-kV X-ray tube in two to five fractions.

Results

Of 149 patients, 77 (40 T1, 37 T2) met the inclusion criteria. Median age was 74 (range 38–104) years, and median follow-up 69 (range 10–219) months. ECR failed in 21 patients (27 per cent) (persistent disease, four; recurrence, 17), of whom ten remained disease free after salvage therapy. The estimated 5-year disease-free survival rate was 74 (95 per cent confidence interval 63 to 83) per cent after ECR alone, and 87 (76 to 93) per cent when survival after salvage therapy for recurrence was included.

Conclusion

ECR is a minimally invasive treatment option for early-stage rectal cancer. However, similar to other local therapies, ECR has a worse oncological outcome than radical surgery.

Local excision of distal rectal cancer: an update of cancer and leukemia group B 8984

PURPOSE

The efficacy of local excision in the treatment of some early-stage distal rectal cancers is still being debated, because few high-quality, long-term prospective data on outcomes are available.

METHODS

Fifty-nine patients with T1 lesions were treated with local excision alone, whereas 51 patients with T2 lesions received external beam irradiation (5,400 cGY) and 5-fluorouracil (500 mg/m(2) intravenously Days 1-3, Days 29-31) after local excision. Kaplan-Meier curves were used to estimate the primary outcomes. The log-rank test and Cox's proportional hazards model were used to compare subgroups relative to these outcomes.

RESULTS

With a median follow-up of 7.1 (range, 2.1-11.4) years, ten-year rates of overall survival were 84 percent for patients with T1 and 66 percent for T2 rectal cancer. Disease-free survival was 75 percent for T1 and 64 percent for T2 disease. Local recurrence rates for patients with T1 and T2 lesions were 8 and 18 percent, respectively, and rates of distant metastases were 5 percent for T1 and 12 percent for T2 lesions. T stage was a statistically significant predictor of overall survival (P = 0.04) and approached statistical significance as a predictor of disease-free survival (P = 0.07).

CONCLUSIONS

Local excision alone for T1 rectal adenocarcinomas is associated with low recurrence and good survival rates that remain durable with long-term follow-up. T2 lesions treated via local excision and adjuvant therapy are associated with higher recurrence rates.

Population-based analyses of lymph node metastases in colorectal cancer

BACKGROUND & AIMS

The potential presence of lymph node metastases in patients with colorectal cancer (CRC) limits the application of minimally invasive techniques of resection. We used data from the National Cancer Institute's Surveillance, Epidemiology, and End Results registry to better understand the underlying risk of lymph node metastases and factors that influence this risk in a population-based fashion.

METHODS

In a cohort of 124,180 CRC patients diagnosed from 1988 through 2002 treated with radical surgery without neoadjuvant irradiation, we assessed the proportion of patients who were lymph node positive and determined factors that influenced the risk of lymph node metastases including patient characteristics, anatomic location, and histopathologic factors.

RESULTS

Among all patients, the proportion of lymph node metastases was 34.5%. The overall proportion of node positivity was 8% for T1 tumors, 18.5% for T2 tumors, 42% for T3 tumors, and 50% for T4 tumors. Nodal metastases were noted in 7% of proximal T1 colon tumors, 7.5% of distal T1 colon tumors, and 10.1% of T1 rectal tumors. Patients with poorly differentiated tumors were much more likely to be node positive (52%) than patients with well-differentiated tumors (20%) (P<.0001).

CONCLUSIONS

Even patients with superficial CRCs have a significant risk of nodal metastases. This risk should be considered when balancing the risks and benefits of minimally invasive techniques such as local excision or endoscopic resection for the treatment of CRC.

The influence of histopathologic criteria on the long-term prognosis of locally excised pT1 rectal carcinomas: results of local excision (transanal endoscopic microsurgery) and immediate reoperation

PURPOSE

Local excision of early rectal cancer is a controversial issue, which is in part because of differences in the evaluation of histopathologic criteria. This prospective study was designed to determine prognostic factors for recurrences and the need for reoperation.

METHODS

In 105 of 118 patients with pT1 carcinomas and local excision, results of recurrence rates and ten-year cancer-free survival were studied separately according to different histologic criteria (R0, R1, Rx, R < or = 1 mm, high-/low-risk situation), tumor localization (anterior, posterior, lateral wall and third of rectum), size, and degree of resection (full-thickness/partial wall). Patients were grouped into local excision (n = 89) and local excision followed by reoperation (n = 21). Risk classification was performed by division into "low-risk" carcinomas after local R0-resection (Group A) and unfavorable histologic results after local resection (R1, Rx, R < or = 1 mm, high-risk situation; Group B).

RESULTS

Local recurrence rates after local R0-resection of low-risk carcinomas were 6 percent, whereas patients in Group B with local resection were 39 percent. The recurrence risk in those patients was significantly reduced to 6 percent by reoperation (P = 0.015). In addition, ten-year, cancer-free survival was 93 percent in Group B after reoperation compared with 89 percent in patients of Group A after local excision alone.

CONCLUSIONS

Local R0-resection in cases with low-risk pT1 carcinomas represents an oncologically adequate therapy, which results in similar survival rates compared with primary radical surgery of pT1N0M0 rectal carcinomas. High recurrence rates are observed in tumors with unfavorable histologic result (Group B) requiring further treatment. In these cases immediate reoperation reduces the recurrence rate to 6 percent.