Analysis of risk factors for lymph nodal involvement in early stages of rectal cancer: when can local excision be considered an appropriate treatment? Systematic review and meta-analysis of the literature

Endoscopic and trans-anal local excision vs. radical resection in the treatment of early rectal cancer: A systematic review and network meta-analysis

PURPOSE

The management of early-stage rectal cancer in clinical practice is controversial. The aim of this network meta-analysis was to compare oncological and postoperative outcomes for T1T2N0M0 rectal cancers managed with local excision in comparison to conventional radical resection.

METHODS

A systematic review of Medline, Embase and Cochrane electronic databases was performed. Relevant studies were selected using PRISMA guidelines. The primary outcomes measured were 5-year local recurrence and overall survival. Secondary outcomes included rates of postoperative complication, 30-day mortality, positive margin and permanent stoma formation.

RESULTS

Three randomized controlled trials and 27 observational studies contributed 8570 patients for analysis. Radical resection was associated with reduced 5-year local recurrence in comparison to local excision. This was statistically significant in comparison to trans-anal local excision (odds ratio (OR) 0.23; 95% confidence interval 0.16-0.30) and favourable in comparison to endoscopic techniques (OR 0.40; 95% confidence interval 0.13-1.23) although this did not reach clinical significance. Positive margin rates were lowest for radical resection. However, 30-day mortality rates, perioperative complications and permanent stoma rates all favoured local excision with no statistically significant difference between endoscopic and trans-anal techniques.

CONCLUSION

Radical resection of early rectal cancer is associated with the lowest 5-year local recurrence rates and the lowest rate of positive margins. However, this must be balanced with its higher 30-day mortality and complication rates as well as the increased risk of permanent stoma. The emerging potential role of neoadjuvant therapy prior to local resection, and the heterogeneity of its use, as an alternative treatment for early rectal cancer further complicates the treatment paradigm and adds to controversy in this field.

Differences in Factors Predicting Lymph Node Metastasis Between pT1 Rectal Cancer and pT1 Colon Cancer: A Retrospective Study

BACKGROUND

Studies have demonstrated conflicting results regarding factors that predict lymph node metastasis (LNM) in pT1 colorectal cancers. We hypothesized that these discrepancies could be related to different factors predicting LNM between rectal and colon cancer. This study aimed to compare predicting factors for LNM between pT1 rectal and colon cancer.

METHODS

This retrospective study evaluated a prospectively maintained database that included 380 patients with pT1 colorectal cancer from January 2010 to December 2020. Patients were grouped according to whether they had rectal or colon cancer, with or without LNM, and factors predicting LNM were analyzed.

RESULTS

In pT1 rectal cancer, LNM was associated with deeper submucosal (SM) invasion (P = .024) and a higher proportion of poorly differentiated tumors (P = .006). In pT1 colon cancer, LNM was associated with a higher proportion of moderately/poorly differentiated tumors (P = .002) and lymphatic invasion (P = .004). In the multivariate analysis for rectal cancer, depth of SM invasion (≥3000 μm) was an independent predictive factor for LNM (95% confidence interval [CI], 1.48-27.94; P = .013), whereas for colon cancer, moderately/poorly differentiated tumors (95% CI, 1.38-8.13; P = .008) and lymphatic invasion (95% CI, 1.44-11.78; P = .008) were independent predictive factors for LNM.

DISCUSSION

There were distinct differences in the factors predicting LNM between pT1 rectal cancer and colon cancer. These results suggest the necessity in differentiating between rectal and colon cancer when performing studies on LNM in pT1 colorectal cancer.

Excision of malignant and pre-malignant rectal lesions by transanal endoscopic microsurgery in patients under 50 years of age

BACKGROUND

The most common technique for treating benign and early malignant rectal lesions is transanal endoscopic microsurgery (TEM). Local excision is an acceptable technique for high-risk and elderly patients, but there are hardly any data regarding young patients.

AIM

To describe TEM outcomes in patients under 50 years of age.

METHODS

We collected demographic, clinical, and pathological data from all patients under the age of 50 years who underwent the TEM procedure at Hasharon Rabin Medical Center from January 2005 to December 2018.

RESULTS

During the study period, a total of 26 patients under the age of 50 years underwent TEM procedures. Their mean age was 43.3 years. Eleven (42.0%) were male. The mean operative time was 67 min, and the mean tumor size was 2.39 cm, with a mean anal verge distance of 8.50 cm. No major intraoperative or postoperative complications were recorded. The median length of stay was 2 d. Seven (26.9%) lesions were adenomas with low-grade dysplasia, four (15.4%) were high-grade dysplasia adenomas, two were T1 carcinomas (7.8%), and three were T2 carcinomas (11.5%). No residual disease was found following endoscopic polypectomy in two patients (7.8%), but four (15.4%) had other pathologies. Surgical margins were negative in all cases. Local recurrence was detected in one patient 33 mo following surgery.

CONCLUSION

Among young adult patients, TEM for benign rectal lesions has excellent outcomes. It may also offer a balance between the efficacy of complete oncologic resection and postoperative quality of life in the treatment of rectal cancer. In some cases, it may be considered an alternative to radical surgery.

Multidisciplinary Treatment Strategy for Early Colon Cancer: A Review-An English Version

Treatment for early colon cancer has progressed rapidly, with endoscopic resection and minimally invasive surgery. It is important to select patients without risk of lymph node metastasis before deciding on endoscopic resection for early colon cancer treatment. Pathological risk factors include histologic grade of cancer cell differentiation, lymphovascular invasion, perineural invasion, tumor budding, and deep submucosal invasion. These risk factors for predicting lymph node metastasis are crucial for determining the treatment strategy of endoscopic excision and radical resection for early colon cancer. A multidisciplinary approach is emphasized to establish a treatment strategy for early colon cancer to minimize the risk of complications and obtain excellent oncologic outcomes by selecting an appropriate treatment optimized for the patient's stage and condition. Therefore, we aimed to review the optimal multidisciplinary treatment strategies, including endoscopy and surgery, for early colon cancer.

Improving the management of early colorectal cancers (eCRC) by using quantitative markers to predict lymph node involvement and thus the need for major resection of pT1 cancers

BACKGROUND

Since implementing the NHS bowel cancer screening programme, the rate of early colorectal cancer (eCRC; pT1) has increased threefold to 17%, but how these lesions should be managed is currently unclear.

AIM

To improve risk stratification of eCRC by developing reproducible quantitative markers to build a multivariate model to predict lymph node metastasis (LNM).

METHODS

Our retrospective cohort of 207 symptomatic pT1 eCRC was assessed for quantitative markers. Associations between categorical data and LNM were performed using χ2 test and Fisher's exact test. Multivariable modelling was performed using logistic regression. Youden's rule gave the cut-point for LNM.

RESULTS

All significant parameters in the univariate analysis were included in a multivariate model; tumour stroma (95% CI 2.3 to 41.0; p=0.002), area of submucosal invasion (95% CI 2.1 to 284.6; p=0.011), poor tumour differentiation (95% CI 2.0 to 358.3; p=0.003) and lymphatic invasion (95% CI 1.3 to 192.6; p=0.028) were predictive of LNM. Youden's rule gave a cut-off of p>5%, capturing 18/19 LNM (94.7%) cases and leading to a resection recommendation for 34% of cases. The model that only included quantitative factors were also significant, capturing 17/19 LNM cases (90%) and leading to resection rate of 35% of cases (72/206).

CONCLUSIONS

In this study, we were able to reduce the potential resection rate of pT1 with the multivariate qualitative and/or quantitative model to 34% or 35% while detecting 95% or 90% of all LNM cases, respectively. While these findings need to be validated, this model could lead to a reduction of the major resection rate in eCRC.

Clinical practice guidelines for the surgical treatment of rectal cancer: a consensus statement of the Hellenic Society of Medical Oncologists (HeSMO)

In rectal cancer management, accurate staging by magnetic resonance imaging, neo-adjuvant treatment with the use of radiotherapy, and total mesorectal excision have resulted in remarkable improvement in the oncological outcomes. However, there is substantial discrepancy in the therapeutic approach and failure to adhere to international guidelines among different Greek-Cypriot hospitals. The present guidelines aim to aid the multidisciplinary management of rectal cancer, considering both the local special characteristics of our healthcare system and the international relevant agreements (ESMO, EURECCA). Following background discussion and online communication sessions for feedback among the members of an executive team, a consensus rectal cancer management was obtained. Statements were subjected to the Delphi methodology voting system on two rounds to achieve further consensus by invited multidisciplinary international experts on colorectal cancer. Statements were considered of high, moderate or low consensus if they were voted by ≥80%, 60-80%, or <60%, respectively; those obtaining a low consensus level after both voting rounds were rejected. One hundred and two statements were developed and voted by 100 experts. The mean rate of abstention per statement was 12.5% (range: 2-45%). In the end of the process, all statements achieved a high consensus. Guidelines and algorithms of diagnosis and treatment were proposed. The importance of centralization, care by a multidisciplinary team, adherence to guidelines, and personalization is emphasized.

Small carcinomas involving less than one-quarter of the rectal circumference: local excision is still associated with a high risk of nodal positivity

AIM

A study was carried out to determine the relationship between mesorectal lymph nodal involvement and T stage in a group of patients with a rectal cancer involving less than one-quarter of the rectal circumference, such as might be selected for local excision.

METHOD

The data of patients having rectal resection between 2010 and 2014 were prospectively entered in a rectal carcinoma registry. A model for describing tumours involving less than one quadrant of the rectal circumference was created to facilitate the evaluation process.

RESULTS

In all, 304 patients were included in the study. In 68 (22.4%) a small tumour (< 1 quadrant involved) was found. Of these, 26.5% had positive mesorectal lymph nodes (N+). In lesions of Stage ypT0 cancer 12.5% patients were node positive, in Stage Tis and T1 tumours there was no case of node positivity, but in Stage T2 and Stage T3 cancers the incidence of node positivity was 27.5% and 64%.

CONCLUSION

The study demonstrated that, even for small tumours involving only one rectal quadrant, the risk of lymph nodal involvement was about 25%. Had the patients undergone local excision the treatment would have been incomplete.

Endoscopic Submucosal Dissection (ESD) in Colorectal Tumors

Background

Endoscopic submucosal dissection (ESD) – initially developed for the treatment of early gastric cancer in Japan – is an attractive option for en bloc resection of larger sessile or flat colorectal neoplasia.

Methods

A review of the current literature on colorectal ESD was carried out.

Results

In contrast to conventional endoscopic mucosal resection (EMR), ESD for larger colorectal neoplasia yields high en bloc resection rates and very low recurrence rates. The frequency of delayed bleeding is similar for EMR and ESD. Higher perforation rates during ESD are mostly due to microperforations identified and treated during the intervention, and are therefore of minor clinical relevance. A major disadvantage of ESD is the necessity for high-level endoscopic skills and long procedure times. ESD also has the potential to replace laparoscopic surgery or transanal endoscopic microsurgery mainly due to its lower complication rates.

Conclusion

ESD for the resection of larger flat or sessile colorectal lesions has potential advantages over conventional EMR or minimally invasive surgery. Due to the low incidence of early gastric cancer, experience with ESD will remain limited in Western countries. The spread of colorectal ESD will depend on adequate training opportunities and also on modifications yielding a reduction in procedure time.

A novel opportunity in minimally invasive colorectal cancer therapy: defining a role for endoscopic submucosal dissection in the United States

Colorectal cancer is the third most common cancer among both men and women in the United States and the second leading cause of cancer death. Endoscopic submucosal dissection (ESD) is an innovative advanced endoscopic therapy for superficial gastrointestinal neoplasms which is rapidly becoming standard of care particularly in Asia. ESD was first developed for the resection of early gastric cancers; yet ESD for colon tumors has gained increasing attention in recent years. The advantage of ESD over conventional endoscopic resection lies in its potential to achieve en bloc resection regardless of tumor size, leading to more precise histological evaluation and greater potential for cure. Selecting appropriate patients for this procedure involves identifying colorectal cancers with nul risk of lymph node spread. For colorectal ESD to engraft in the United States, the prevalence of such early stage lesions must be defined so that centers of excellence can be developed for high volume clinical practice to offer patients the safest and most efficacious outcomes. This review discusses the endoscopic staging of colorectal neoplasms, indications for colorectal ESD, and the epidemiology of early stage ESD-amenable colorectal cancer in America to better define an opportunity for this important minimally invasive therapy.

TransAnal Minimally Invasive Surgery (TAMIS) with SILS™ port versus Transanal Endoscopic Microsurgery (TEM): a comparative experimental study

BACKGROUND

TransAnal Minimally Invasive Surgery (TAMIS) has been proposed as an alternative to Transanal Endoscopic Microsurgery (TEM) for resection of benign polyps and early cancers of rectum. Since clinical application has begun in the absence of any experimental validation, we assessed its feasibility and efficacy ex vivo in a pilot study.

METHODS

In a dedicated trainer box for transanal procedures, 10 surgeons with no experience in transanal surgery were asked to perform a dissection/suture task using both TAMIS and TEM in randomly allocated order. Surgeons were asked to dissect two identically drawn lesions of ~3 cm in larger diameter. Precision of dissection was assessed using a quantitative photographic method, while the time needed for dissection and suturing was considered a measure of quantitative evaluation. Each participant expressed a subjective opinion regarding difficulty with dissection, difficulty with suturing, vision quality, and conflict between instruments on a scale from 1 to 5.

RESULTS

No difference was observed between the two techniques regarding the accuracy of dissection as the margin was interrupted along 4.1 % of the circumference in the TEM group compared with 2.48 % in the SILS group (P = 0.271). Dissection and suturing were significantly quicker in the TEM group [04:30 vs. 06:35 min (P = 0.049) and 14:34 versus 19:18 min (P = 0.003)]. In three cases in the SILS group, completing the suture was not considered possible, and the procedures were terminated by TEM. Subjective evaluation revealed a better appreciation of TEM in all proposed comparisons: dissection (2.6 vs. 3.5, P = 0.004), suturing difficulty (3.1 vs. 4.6, P < 0.001), quality of vision (2.3 vs. 2.8, P = 0.18), and instrument conflicts (3.1 vs. 4.0, P = 0.054).

CONCLUSIONS

In the ex vivo setting, both techniques were comparable for achieving a good dissection, although TAMIS failed to prove effective in suturing the rectal wall. Moreover, TEM was significantly quicker despite the small groups and was better appreciated by the surgeons.