Oncological outcomes of local excision versus radical surgery for early rectal cancer in the context of staging and surveillance: A systematic review and meta-analysis

BACKGROUND

Local resection (LR) methods for rectal cancer are generally considered in the palliative setting or for patients deemed a high anaesthetic risk. This systematic review and meta-analysis aimed to compare oncological outcomes of LR and radical resection (RR) for early rectal cancer in the context of staging and surveillance assessment.

METHODS

A literature search of MEDLINE, Embase and Emcare databases was performed for studies that reported data on clinical outcomes for both LR and RR for early rectal cancer from January 1995 to April 2023. Meta-analysis was performed using random-effect models and between-study heterogeneity was assessed. The quality of assessment was assessed using the Newcastle-Ottawa Scale for observational studies and the Cochrane Risk of Bias 2.0 tool for randomised controlled trials.

RESULTS

Twenty studies with 12,022 patients were included: 6,476 patients had LR and 5,546 patients underwent RR. RR led to an improvement in 5-year overall survival (OR 1.84; 95 % CI 1.54-2.20; p < 0.0001; I2 20 %) and local recurrence (OR 3.06; 95 % CI 2.02-4.64; p < 0.0001; I2 39 %) when compared to LR. However, when staging and surveillance methods were clearly adopted in LR cases, there was an improvement in R0 rates (96.7 % vs 85.6 %), 5-year disease-free survival (93.0 % vs 77.9 %) and overall survival (81.6 % vs 79.0 %) compared to when staging and surveillance was not reported/performed.

CONCLUSIONS

LR may be appropriate for selected patients without poor prognostic factors in early rectal cancer. This study also highlights that there is currently no single standardised staging or surveillance approach being adopted in the management of early rectal cancer. A more specified and standardised preoperative staging for patient selection as well as clinical and image-based surveillance protocols is needed.

Deep Submucosal Invasion Is Not an Independent Risk Factor for Lymph Node Metastasis in T1 Colorectal Cancer: A Meta-Analysis

BACKGROUND & AIMS

Deep submucosal invasion (DSI) is considered a key risk factor for lymph node metastasis (LNM) and important criterion to recommend surgery in T1 colorectal cancer. However, metastatic risk for DSI is shown to be low in the absence of other histologic risk factors. This meta-analysis determines the independent risk of DSI for LNM.

METHODS

Suitable studies were included to establish LNM risk for DSI in univariable analysis. To assess DSI as independent risk factor, studies were eligible if risk factors (eg, DSI, poor differentiation, lymphovascular invasion, and high-grade tumor budding) were simultaneously included in multivariable analysis or LNM rate of DSI was described in absence of poor differentiation, lymphovascular invasion, and high-grade tumor budding. Odds ratios (OR) and 95% CIs were calculated.

RESULTS

Sixty-seven studies (21,238 patients) were included. Overall LNM rate was 11.2% and significantly higher for DSI-positive cancers (OR, 2.58; 95% CI, 2.10-3.18). Eight studies (3621 patients) were included in multivariable meta-analysis and did not weigh DSI as a significant predictor for LNM (OR, 1.73; 95% CI, 0.96-3.12). As opposed to a significant association between LNM and poor differentiation (OR, 2.14; 95% CI, 1.39-3.28), high-grade tumor budding (OR, 2.83; 95% CI, 2.06-3.88), and lymphovascular invasion (OR, 3.16; 95% CI, 1.88-5.33). Eight studies (1146 patients) analyzed DSI as solitary risk factor; absolute risk of LNM was 2.6% and pooled incidence rate was 2.83 (95% CI, 1.66-4.78).

CONCLUSIONS

DSI is not a strong independent predictor for LNM and should be reconsidered as a sole indicator for oncologic surgery. The expanding armamentarium for local excision as first-line treatment prompts serious consideration in amenable cases to tailor T1 colorectal cancer management.

The Role of Transanal Endoscopic Surgery for Early Rectal Cancer

Transanal endoscopic surgery (TES), which is performed through a variety of transanal endoluminal multitasking surgical platforms, was developed to facilitate endoscopic en bloc excision of rectal lesions as a minimally invasive alternative to radical proctectomy. Although the oncologic safety of TES in the treatment of malignant rectal tumors has been an area of vigorous controversy over the past two decades, TES is currently accepted as an oncologically safe approach for the treatment of carefully selected early and superficial rectal cancers. TES can also serve as both a diagnostic and potentially curative treatment of partially resected unsuspected malignant polyps. In this article, indications and contraindications for transanal endoscopic excision of early rectal cancer lesions are reviewed, as well as selection criteria for the most appropriate transanal excisional approach. Preoperative preparation and surgical technique for complications of TES will be reviewed, as well as recommended surveillance and management of upstaged tumors.

Classic and Novel Histopathologic Risk Factors for Lymph Node Metastasis in T1 Colorectal Cancer: A Systematic Review and Meta-analysis

BACKGROUND

Treatment of endoscopically resected T1 colorectal cancers is based on the risk of lymph node metastasis. Risk is based on histopathologic features, although there is lack of consensus as to what constitutes high-risk features.

OBJECTIVE

The purpose of this study was to conduct a systematic review and meta-analysis of histopathologic risk factors for lymph node metastasis.

DATA SOURCES

A search of MEDLINE, Embase, Scopus, and Cochrane controlled register of trials for risk factors for lymph node metastasis was performed from inception until August 2018.

STUDY SELECTION

Included patients must have had an oncologic resection to confirm lymph node status and reported at least 1 histopathologic risk factor.

INTERVENTION

Rates of lymph node positivity were compared between patients with and without risk factors.

MAIN OUTCOME MEASURES

We report the results of the meta-analysis as ORs.

RESULTS

Of 8592 citations, 60 met inclusion criteria. Pooled analyses found that lymphovascular invasion, vascular invasion, neural invasion, and poorly differentiated histology were significantly associated with lymph node metastasis, as were depths of 1000 µm (OR = 2.76), 1500 µm (OR = 4.37), 2000 µm (OR = 2.37), submucosal level 3 depth (OR = 3.08), and submucosal level 2/3 (OR = 3.08) depth. Depth of 3000 µm, Haggitt level 4, and widths of 3000 µm and 4000 µm were not significantly associated with lymph node metastasis. Tumor budding (OR = 4.99) and poorly differentiated clusters (OR = 14.61) were also significantly associated with lymph node metastasis.

LIMITATIONS

Included studies reported risk factors independently, making it impossible to examine the additive metastasis risk in patients with numerous risk factors.

CONCLUSIONS

We identified 1500 μm as the depth most significantly associated with lymph node metastasis. Novel factors tumor budding and poorly differentiated clusters were also significantly associated with lymph node metastasis. These findings should help inform guidelines regarding risk stratification of T1 tumors and prompt additional investigation into the exact contribution of poorly differentiated clusters to lymph node metastasis.

Education and Training in Transanal Endoscopic Surgery and Transanal Total Mesorectal Excision

There is a paradigm shift in surgical training, and new tool and technology are being used to facilitate mastery of the content and technical skills. The transanal procedures for rectal cancer-transanal endoscopic surgery (TES) and transanal total mesorectal excision (TaTME)-have a distinct learning curve for competence in the procedures, and require special training for familiarity with the "bottom-up" anatomy, procedural risks, and managing complex cases. These procedures have been models for structured education and training, using multimodal tools, to ensure safe implementation of TES and TaTME into clinical practice. The goal of this work was to review the current state of surgical education, the introduction and learning curve of the TES and TaTME procedures, and the established and future models for education of the transanal procedures for rectal cancer.

Survival following rectal cancer surgery: does the age matter?

Introduction: Information regarding rectal cancer surgery outcomes and survival benefits in the elderly is sparse. Radical rectal surgery can be associated with substantial morbidity and mortality. We investigated age-specific survival for patients undergoing radical rectal surgery to determine outcomes in elderly patients Methods: Over a 10-year period data on all patients who underwent rectal cancer surgery was performed. Patients were grouped according to age and eight other variables including cancer stage (Duke's/TNM). Data analysed using computer program R. Kaplan-Meier survival curves estimated for age groups and compared using a modified log-rank permutation test. Survival curves fitted using Cox proportional hazard models and hazard ratios obtained Results: About 374 patients underwent surgery. Survival percentages at 1 year by age group are 91.3% for age <50, and 75.5% for age >80. At 5 years these are 87.0% for age <50 and 57.1% for >80. Overall the variation among the survival curves for the age groups is significant (p < .001). The hazard ratio for over the 80+ with the age group <50 as the reference is 4.79 (95% CI: 1.44-15.92) and is significant (p = .011) Conclusion: Overall survival is significantly less in the elderly. There is a striking reduction in survival in >80 year olds in the first post-operative year. This study highlights that care must be taken in deciding whether radical surgery should be offered to those patients and careful consideration is given to allow the best overall survival and quality of life.

Neutrophil to lymphocyte ratio predicts risk of nodal involvement in T1 colorectal cancer patients

BACKGROUND

Risk of nodal involvement in T1 colorectal cancer is assessed by tumor histological features. In several tumors, the ratio between neutrophils and lymphocytes (NLR) or platelets and lymphocytes (PLR) have been applied to lymph-node metastases prediction. The aim of this study was to evaluate the role of NLR, derived NLR (dNLR) and PLR in predicting nodal involvement in T1 colorectal cancers.

METHODS

NLR, dNLR and PLR in surgical resected T1 colorectal cancers were retrospectively calculated and analysed in nodal positive and negative cases.

RESULTS

Data regarding 102 patients were considered. Nodal involvement rate was 10.8%. NLR values were higher in node positive patients (P=0.04). A trend toward significance (P=0.05) was found for higher dNLR values and positive nodal status. For NLR, ROC curve analysis allowed to choose a predictive cut-off value of 3.7 (AUC of 0.69; 95% CI: 0.48-0.89). Nodal positivity was reported in 71.5% of high NLR patients; only two N0 cases (28.5%) were registered in high NLR group (P<0.001). The logistic regression analysis aimed to evidence the predictive role of high NLR in node positivity resulted in a significant OR of 37.1 (P<0.0001; 95% CI: 0.48-0.89). NLR allowed to distinguish N0 from N1 patients in 99.4% of cases.

CONCLUSIONS

NLR<3.7 was associated with lower risk of lymph-node metastases in T1 colorectal cancer patients. NLR could be used with histopathological data to identify patients at lower risk of nodal metastases.

Is the assessment of submucosal invasion still useful in the management of early rectal cancer? A study of 91 consecutive patients

AIM

The only studies on the prognosis of T1 tumours are old and investigate colic and rectal cancers. Very few studies use Kikuchi's classification (of dividing submucosa into three strata) to evaluate the depth of the submucosal invasion. This study aimed to assess the pathological risk factors for lymph node metastasis (LNM), and the pathological and oncological results of patients with early rectal cancer (ERC, pT1 tumour).

METHOD

Between 2000 and 2014, 91 consecutive patients undergoing surgery [primary total mesorectal excision (TME) or local excision (LE) alone, or LE followed by TME] for ERC were included.

RESULTS

Eighteen patients underwent LE, 22 underwent LE followed by TME and 51 underwent primary total TME. After TME (n = 73), 16 (23%) patients had LNM. The LNM rate was 15% for Sm1 tumours, 14% for Sm2 tumours and 30% for Sm3 tumours. In multivariate analysis, lymphovascular invasion (P = 0.027) and high tumour budding (P = 0.037) were the only independent factors predictive of LNM. The depth of submucosal invasion was not associated with an increased risk of LNM. After a mean follow up of 56 ± 46 months, 5-year overall survival, specific survival and disease-free survival were, respectively, 82%, 93% and 75%. No significant difference of survival was found according to the depth of submucosal invasion or to the surgical management.

CONCLUSION

Histological features seem to be stronger risk factors for LNM than depth of submucosal invasion. Considering the LNM rate, TME should be discussed after LE in terms of one of these pathological criteria.

Transanal endoscopic operation for rectal cancer after neoadjuvant therapy

PURPOSE

In this paper we report the oncological outcomes from clinical series of patients with rectal cancer submitted to local excision after neoadjuvant therapy and discuss the indications for local excision in partial clinical responders.

METHODS

We analysed a prospective database of 39 patients submitted to a transanal endoscopic operation for rectal cancer after neoadjuvant chemoradiation between 2006 and 2015, comparing clinical and pathological variables, perioperative complications, recurrence rate and overall survival.

RESULTS

We obtained 15.4% ypT0, 17.9% ypT1, 35.9% ypT2 and 28.2% ypT3. After a median follow-up of 24 months, tumoral recurrence was observed in 4 patients, one of them with isolated pulmonary metastasis. R0 resection was achieved in 79.5%, and postoperative complications were observed in 30.2% patients and no perioperative mortality occur. Compromise surgical margins do not affect recurrence rate, and 94.9% of patients are alive nowadays.

CONCLUSION

Local excision could be associated with low recurrence rate and good overall survival. Short hospitalization time and low level of serious complications observed could be an interesting option for patients who would not tolerate a radical procedure or for those who declined a total mesorectal excision. A strict long-term follow-up must be warranted to detect early tumoral recurrence.

Management of colorectal T1 carcinoma treated by endoscopic resection from the Western perspective

Detection of early colorectal cancer is expected to rise in light of national colorectal cancer screening programs. This The present review article delineates current endoscopic risk assessments, differentiating invasive from non-invasive neoplasia, for high likelihood of lymph node metastasis in early colorectal cancer, also termed high-risk early colorectal cancer, and endoscopic and surgical resection methods from a Western hemisphere perspective.

Transanal Minimally Invasive Surgery: Review of Indications and Outcomes from 75 Consecutive Patients

BACKGROUND

Transanal minimally invasive surgery (TAMIS) is an advanced local excision platform that helps overcome technical limitations and morbidity associated with other resection methods. Our goal was to review the indications and outcomes of TAMIS in a large series.

STUDY DESIGN

A review of a prospective database identified patients who underwent TAMIS from 2010 to 2014. Demographic, perioperative, short-term outcomes, and recurrence data were analyzed.

RESULTS

There were 75 patients with 76 lesions analyzed. Mean age was 64.0 years (SD 11.6 years) and mean BMI was 27.4 kg/m(2) (SD 4.7 kg/m(2)). Median American Society of Anesthesiologists (ASA) score was 2 (range 1 to 4). There were 59 benign (77.3%) and 17 malignant (22.7%) lesions: 6 pT0, 6 pT1, 4 pT2, and 1 pT3. Median lesion distance from the anal verge was 10 cm (range 6 to 16 cm). Mean operative time was 76.0 minutes (SD 36.1 minutes). Three patients had intraperitoneal entry; all were closed transanally, but 2 had temporary diverting ileostomies fashioned to ensure healing. Median length of stay was 1 day (range 0 to 6). One patient had a fragmented lesion (1.3%). Five patients had positive margins: 2 in palliative pT2 resections, and 3 in pT1, pT2, and gastrointestinal stromal tumor (GIST) patients. They were managed with radical resection (pT1 and pT2 lesions) and surveillance/medical oncology (GIST). Postoperatively, 3 patients had complications (bleeding, rectal stricture, and recto-vaginal fistula), and all were managed nonoperatively. After median follow-up of 39.5 months (range 10.5 to 65.3 months), 1 pT1 patient with negative margins developed a local recurrence and underwent salvage APR.

CONCLUSIONS

Transanal minimally invasive surgery is a viable option for excision of benign or early stage rectal masses, with mid-term oncologic outcomes comparable to those of radical resection. Further, TAMIS minimizes the morbidity and can allow more patients to benefit from the minimally invasive approach.