Is the 1-cm rule of distal bowel resection margin in rectal cancer based on clinical evidence? A systematic review

Retrospective Evaluation of the Efficacy of Total Neoadjuvant Therapy and Chemoradiotherapy Neoadjuvant Treatment in Relation to Surgery in Patients with Rectal Cancer

Background and Objective: In the therapeutic strategy of rectal cancer, radiotherapy has consolidated its important position and frequent use in current practice due to its indications as neoadjuvant, adjuvant, definitive, or palliative treatment. In recent years, total neoadjuvant therapy (TNT) has been established as the preferred regimen compared to concurrent neoadjuvant chemoradiotherapy (CRT). In relation to better outcomes, the percentage of patients who achieved pathological complete response (pCR) after neoadjuvant treatment is higher in the case of TNT. This study aimed to analyze the response to TNT compared to neoadjuvant CRT regarding pCR rate and the change in staging after surgical intervention. Materials and Methods: We performed a retrospective study on 323 patients with rectal cancer and finally analyzed the data of 201 patients with neoadjuvant treatment, selected based on the inclusion and exclusion criteria. Patients received CRT neoadjuvant therapy or TNT neoadjuvant therapy with FOLFOX or CAPEOX. Results: Out of 157 patients who underwent TNT treatment, 19.74% had pathological complete response, whereas in the group with CRT (n = 44), those with pCR were 13.64%. After neoadjuvant treatment, the most frequent TNM classifications were ypT2 (40.30%) and ypN0 (79.10%). The statistical analysis of the postoperative disease stage, after neoadjuvant therapy, showed that the most frequent changes were downstaging (71.14%) and complete response (18.41%). Only four patients (1.99%) had an upstaging change. The majority of patients (88.56%) initially presented clinical evidence of nodal involvement whereas only 20.9% of the patients still presented regional disease at the time of surgical intervention. Conclusions: By using TNT, a higher rate of stage reduction is obtained compared to the neoadjuvant CRT treatment. The post-neoadjuvant-treatment imagistic evaluation fails to accurately evaluate the response. A better response to TNT was observed in young patients.

A comprehensive evaluation of 80 consecutive robotic low anterior resections: impact of not mobilizing the splenic flexure alongside low-tie vascular ligation as a standardized technique

Rectal cancer surgery represents challenges due to its location. To overcome them and minimize the risk of anastomosis-related complications, some technical maneuvers or even a diverting ileostomy may be required. One of these technical steps is the mobilization of the splenic flexure (SFM), especially in medium/low rectal cancer. High-tie vascular ligation may be another one. However, the need of these maneuvers may be controversial, as especially SFM may be time-consuming and increase the risk of iatrogenic. The objective is to present the short- and long-term outcomes of a low-tie ligation combined with no SFM in robotic low anterior resection (LAR) for mid- and low rectal cancer as a standardized technique. A retrospective observational single-cohort study was carried out at Reina Sofia University Hospital, Cordoba, Spain. 221 robotic rectal resections between Jul-18th-2018 and Jan-12th-2023 were initially considered. After case selection, 80 consecutive robotic LAR performed by a single surgeon were included. STROBE checklist assessed the methodological quality. Histopathological, morbidity and oncological outcomes were assessed. Anastomotic stricture occurrence and distance to anal verge were evaluated after LAR by rectosigmoidoscopy. Variables related to the ileostomy closure such as time to closure, post-operative complications or hospital stay were also considered. The majority of patients (81.2%) presented a mid-rectal cancer and the rest, lower location (18.8%). All patients had adequate perfusion of the anastomotic stump assessed by indocyanine green. Complete total mesorectal excision was performed in 98.8% of the patients with a lymph node ratio < 0.2 in 91.3%. The anastomotic leakage rate was 5%. One patient (1.5%) presented local recurrence. Anastomosis stricture occurred in 7.5% of the patients. The limitations were small cohort and retrospective design. The non-mobilization of the splenic flexure with a low-tie ligation in robotic LAR is a feasible and safe procedure that does not affect oncological outcomes.

Clinical efficacy and pathological outcomes of transanal endoscopic intersphincteric resection for low rectal cancer

BACKGROUND

Transanal endoscopic intersphincteric resection (ISR) surgery currently lacks sufficient clinical research and reporting.

AIM

To investigate the clinical effectiveness of transanal endoscopic ISR, in order to promote the clinical application and development of this technique.

METHODS

This study utilized a retrospective case series design. Clinical and pathological data of patients with lower rectal cancer who underwent transanal endoscopic ISR at the First Affiliated Hospital of Xiamen University between May 2018 and May 2023 were included. All patients underwent transanal endoscopic ISR as the surgical approach. We conducted this study to determine the perioperative recovery status, postoperative complications, and pathological specimen characteristics of this group of patients.

RESULTS

This study included 45 eligible patients, with no perioperative mortalities. The overall incidence of early complications was 22.22%, with a rate of 4.44% for Clavien-Dindo grade ≥ III events. Two patients (4.4%) developed anastomotic leakage after surgery, including one case of grade A and one case of grade B. Postoperative pathological examination confirmed negative circumferential resection margins and distal resection margins in all patients. The mean distance between the tumor lower margin and distal resection margin was found to be 2.30 ± 0.62 cm. The transanal endoscopic ISR procedure consistently yielded high quality pathological specimens.

CONCLUSION

Transanal endoscopic ISR is safe, feasible, and provides a clear anatomical view. It is associated with a low incidence of postoperative complications and favorable pathological outcomes, making it worth further research and application.

Close distal margin is associated with locoregional rectal cancer recurrence: A multicenter study

BACKGROUND AND OBJECTIVES

The importance of the radial margin for rectal cancer resection is well understood. However, surgeons have deemphasized the distal margin, accepting very close distal margins to perform sphincter-preserving surgery. We hypothesized that distal margins < 1 cm would be an independent risk factor for locoregional recurrence. The objective was to determine whether close distal margins are associated with increased locoregional recurrence risk.

METHODS

This was a multi-institutional retrospective cohort study conducted at six academic medical centers including patients who received low anterior resection surgery for primary rectal cancer between 2007 and 2018.

RESULTS

Of 556 low anterior resection patients, the rate of close distal margin was 12.8% (n = 71), and the locoregional recurrence rate was 5.0% (n = 28). The locoregional recurrence rate for close distal margin cases was 9.9% (n = 7) compared to 4.3% (n = 21) for distal margins ≥1.0 cm. In multivariable analysis, the only factor significantly associated with locoregional recurrence was close distal margin (adjusted odds ratio: 2.80, confidence interval: 1.08-7.25, p = 0.035).

CONCLUSIONS

Rectal cancer patients with close distal margins (<1 cm) following low anterior resection had a significantly higher risk for locoregional recurrence. Therefore, the decision to perform low anterior resection with margins < 1 cm should be taken with caution.

Low Rectal Cancers at Initial Staging MRI

Low rectal cancers, which are associated with increased risk of local recurrent disease and poorer prognosis, have unique anatomic considerations and issues for staging and treatment that do not apply to mid and high rectal cancers. Although tumor histology help drive the staging and treatment of all rectal cancers, it is of particular importance in low rectal cancers, which may involve the anal canal, to help establish whether a low rectal mass should be staged and treated as a rectal cancer (ie, adenocarcinoma) or an anal cancer (ie, squamous cell carcinoma). Optimal staging and treatment of rectal cancer are contingent on tumor location and local extent, which help guide management decisions including neoadjuvant therapy and curative surgical treatment strategies. Tumor location in the low rectum and local involvement of the anal canal, sphincter, and pelvic floor help determine whether a patient can undergo sphincter-preserving resection such as a low anterior resection versus abdominoperineal resection to achieve negative surgical margins. Issues exist related to the anatomy and patterns of disease spread that are unique to the low rectum and include how to determine and stage anal sphincter involvement, mesorectal fascia status at the pelvic floor, and nodal status of extramesorectal nodes such as the external iliac and inguinal lymph nodes. For these reasons, it is imperative that radiologists who interpret rectal cancer staging MRI examinations feel comfortable with the unique anatomy of the low rectum and anal canal, nuances of low rectal cancer local disease spread, and treatment paradigms for low rectal cancer. ©RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center. See the invited commentary by Gollub in this issue.

Endoscopic ultrasound-guided injection of carbon nanoparticles suspension to label rectal cancer before neoadjuvant chemoradiotherapy: a retrospective cohort study

Background

Localization of the primary tumor and ensuring safe distal surgical margins (DSMs) following neoadjuvant chemoradiotherapy (nCRT) are challenging in locally advanced rectal cancers (LARCs). This study investigated the effectiveness of carbon nanoparticles suspension (CNS) for labeling the primary tumor and allowing precise tumor resection after nCRT.

Methods

Clinicopathological data of LARC patients who underwent nCRT followed by laparoscopic radical anal preservation surgery at our center between January 2018 and February 2023 were prospectively collected. The patients were divided into the CNS tattooed (CNS) and non-tattooed (control) groups. In the CNS group, CNS was injected in four quadrants on the anal side 1 cm away from the lower tumor margin. DSMs were determined through intraoperative distal rectal examination in the control group and observation of CNS tattoos in the CNS group. DSM lengths and positive DSM rates were compared between the two groups to analyse the feasibility and effectiveness of CNS for labeling LARCs before nCRT.

Results

There was no statistically significant difference in the basic demographic data, effectiveness of nCRT, or post-operative recovery rates between the two groups (all P > 0.05). In the CNS group, CNS tattoos were observed on the outside of the rectal wall, with an overall efficiency of 87.1% (27/31). The CNS group had fewer positive DSMs and safer DSM lengths (2.73 ± 0.88 vs 2.12 ± 1.15 cm, P = 0.012) than the control group (P < 0.05).

Conclusions

Endoscopic ultrasound-guided injection of CNS tattoos before nCRT could effectively label the LARCs, ensuring safe DSMs during anus-preserving surgeries (Chictr.org.cn No.: ChiCTR2300068991).

Mesorectal reconstruction with pedicled greater omental transplantation to relieve low anterior resection syndrome following total intersphincteric resection in patients with ultra-low rectal cancer

BACKGROUND

Total intersphincteric resection (ISR) is the ultimate anus-preserving surgery for patients with ultra-low rectal cancer (ULRC), which can result in various degrees of anorectal dysfunction. Known as low anterior resection syndrome (LARS), it seriously affects the postoperative quality of life of patients. The aim of this study was to discuss the value of mesorectal reconstruction with pedicled greater omental transplantation (PGOT) to relieve LARS following total ISR in patients with ULRC, hoping to provide new ideas and strategies for the prevention and improvement of LARS.

METHODS

We retrospectively analyzed hospitalization data and postoperative anorectal function of 26 ULRC patients, who were met inclusion and exclusion criteria in our center from January 2015 to February 2022. And combined with the results of anorectal manometry and rectal magnetic resonance imaging (MRI) defecography of some patients, we assessed comprehensively anorectal physiological and morphological changes of the patients after surgery, and their correlation with LARS.

RESULTS

In this study, 26 patients with ULRC were enrolled and divided into observation group (n = 15) and control group (n = 11) according to whether PGOT was performed. There were no significant differences in surgical results such as operative time, intraoperative blood loss and postoperative complications between the two groups (P > 0.05). Postoperative follow-up showed that patients in both groups showed severe LARS within 3 months after surgery, but from the 3rd month after surgery, LARS in both groups gradually began to decrease, especially in the observation group, which showed faster recovery and better recovery, with statistically significant difference (P < 0.001). Through anorectal manometry, the mean rectal resting pressure in the observation group was significantly lower than that in the control group (P = 0.010). In addition, the postoperative thickness of the posterior rectal mesenterium in the observation group was significantly higher than that in the control group (P = 0.001), and also higher than the preoperative level (P = 0.018). Moreover, rectal MRI defecography showed that the neo-rectum had good compliance under the matting of greater omentum, and its intestinal peristalsis was coordinated.

CONCLUSIONS

ULRC patients, with the help of greater omentum, coordinated their neo-rectum peristalsis after total ISR and recovery of LARS was faster and better. PGOT is expected to be an effective strategy for LARS prevention and treatment of ULRC patients after surgery and is worthy of clinical promotion.

Surgical treatment of rectal cancer: prospective cohort study about good oncologic results and low rates of abdominoperineal excision

OBJECTIVES

the purpose of this study was to evaluate the outcome of rectal cancer surgery, in a unit adopting the principles of total mesorectal excision (TME) with a high restorative procedure rate and with a low rate of abdominoperineal excision (APE).

METHODS

we enrolles patients with extraperitoneal rectal cancer undergoing TME or TME+APE. Patients with mid rectal tumors underwent TME, and patients with tumors of the lower rectum and no criteria for APE underwent TME and intersphincteric resection. Those in which the intersphincteric space was invaded and in those with a free distal margin less than 1cm or a tumor free radial margin were unattainable underwent APE or extralevator abdominoperineal excision (ELAPE). We assessed local recurrence rates, overall survival and involvement of the radial margin.

RESULTS

sixty (89.6%) patients underwent TME and seven (10.4%) TME + APE, of which five underwent ELAPE. The local recurrence, in pacientes undergoing TME+LAR, was 3.3% and in patients undergoing APE, 14.3%. The local recurrence rate (p=0.286) or the distant recurrence rate (p=1.000) was similar between groups. There was no involvement of radial margins. Survival after 120 months was similar (p=0.239).

CONCLUSION

rectal malignancies, including those located in the low rectum, may be surgically treated with a low rate of APE without compromising oncological principles and with a low local recurrence rates.

Real-time in vivo distal margin selection using confocal laser endomicroscopy in transanal total mesorectal excision for rectal cancer

BACKGROUND

Transanal total mesorectal excision (TaTME) allows patients with ultralow rectal cancer to be treated with sphincter-saving surgery. However, accurate delineation of the distal resection margin (DRM), which is essential to achieve R0 resection for low rectal cancer in TaTME, is technically demanding.

AIM

To assess the feasibility of optical biopsy using probe-based confocal laser endomicroscopy (pCLE) to select the DRM during TaTME for low rectal cancer.

METHODS

A total of 43 consecutive patients who were diagnosed with low rectal cancer and scheduled for TaTME were prospectively enrolled from January 2019 to January 2021. pCLE was used to determine the distal edge of the tumor as well as the DRM during surgery. The final pathological report was used as the gold standard. The diagnostic accuracy of pCLE examination was calculated.

RESULTS

A total of 86 pCLE videos of 43 patients were included in the analyses. The sensitivity, specificity and accuracy of real-time pCLE examination were 90.00% [95% confidence interval (CI): 76.34%-97.21%], 86.96% (95%CI: 73.74%-95.06%) and 88.37% (95%CI: 79.65%-94.28%), respectively. The accuracy of blinded pCLE reinterpretation was 86.05% (95%CI: 76.89%-92.58%). Furthermore, our results show satisfactory interobserver agreement (κ = 0.767, standard error = 0.069) for the detection of cancer tissue by pCLE. There were no positive DRMs (≤ 1 mm) in this study. The median DRM was 7 mm [interquartile range (IQR) = 5-10 mm]. The median Wexner score was 5 (IQR = 3-6) at 6 mo after stoma closure.

CONCLUSION

Real-time in vivo pCLE examination is feasible and safe for selecting the DRM during TaTME for low rectal cancer (clinical trial registration number: NCT04016948).

The Impact of Narrow and Infiltrated Distal Margin After Proctectomy for Rectal Cancer on Patients' Outcomes: a Systematic Review and Meta-analysis

Rectal cancer is a common tumor within a difficult anatomic constraint. Total mesorectal excision with longitudinal and circumferential free margins is considered imperative for good prognosis. In this article, the authors systematically reviewed all published literature with specific Mesh terms until the end of year 2019. Thereafter, retrieved articles were assessed using the Newcastle-Ottawa Scale and meta-analysis was conducted comparing local recurrence among 1-cm, 5-mm, and narrow (< 1-mm)/infiltrated margins. Thirty-nine articles were included in the study. Macroscopic distal margin < 1 cm carried a higher incidence of recurrence for those who did not receive neoadjuvant radiation, without affecting neither estimated overall nor disease-free survival. Less than 5-mm margin after radiation therapy is accepted oncologically. Infiltrated margins and narrow margins (< 1 mm) microscopically are associated with higher incidence of local recurrence and shorter overall and disease-free survival. Surgeons should aim at 1-cm safety margin in radiotherapy-naïve patients and microscopic free margin > 1 mm for those who received neoadjuvant therapy. The cost/benefit of reoperation for patients with infiltrated margins is still inadequately studied.

Association of levels of metabolites with the safe margin of rectal cancer surgery: a metabolomics study

Background

Rectal cancer is one of the most lethal of gastrointestinal malignancies. Metabonomics has gradually developed as a convenient, inexpensive and non-destructive technique for the study of cancers.

Methods

A total of 150 tissue samples from 25 rectal cancer patients were analyzed by liquid chromatography–mass spectrometry (LC–MS), and 6 tissue samples were collected from each patient (group 1: tumor; group 2: 0.5 cm from tumor; group 3:1 cm from tumor; group 4:2 cm from tumor; group 5:3 cm from tumor and group 6:5 cm from tumor). The differential metabolites of tumor tissues and 5 cm from the tumor (normal tissues) were first selected. The differential metabolites between tumor tissues and normal tissues were regrouped by hierarchical clustering analysis, and further selected by discriminant analysis according to the regrouping of clustering results. The potential safe margin of clinical T(cT)1,cT2 stage rectal cancer and cT3,cT4 stage rectal cancer at the metabolomic level was further identified by observing the changes in the level of differential metabolites within the samples from group 1 to group 6.

Results

We found 22 specific metabolites to distinguish tumor tissue and normal tissue. The most significant changes in metabolite levels were observed at 0.5 cm (cT1, cT2) and 2.0 cm (cT3, cT4) from the tumor, while the changes in the tissues afterwards showed a stable trend.

Conclusions

There are differential metabolites between tumor tissues and normal tissues in rectal cancer. Based on our limited sample size, the safe distal incision margin for rectal cancer surgery in metabolites may be 0.5 cm in patients with cT1 and cT2 stage rectal cancer and 2.0 cm in patients with cT3 and cT4 stage rectal cancer.

Routine pathologic evaluation of circular stapler anastomotic rings is not useful after resection for colorectal cancer: retrospective study and systematic review with meta-analysis

BACKGROUND

Circular staplers are commonly used for reconstruction after radical resection for colorectal cancer. Pathological analysis of the anastomotic rings is common practice, although the benefits are unclear. The purpose of this study was to evaluate the usefulness of routine histopathological analysis of anastomotic rings in an original series and in a systematic review of the literature.

METHOD

The retrospective study was performed at two university-associated academic hospitals in Winnipeg, Canada, including patients investigated for colorectal cancers (within 30 cm of the anal verge) who underwent resection between 2007 and 2020. The systematic review involved Ovid MEDLINE, Embase, Scopus, and Web of Science databases, selecting for adult human studies involving analysis of anastomotic rings in elective colorectal cancer resections. The main outcome measure was the proportion of patients with cancer in the anastomotic ring specimens. The frequency of benign pathology findings and changes to patient management were also examined.

RESULTS

Out of 673 eligible patients, 487 were included in the retrospective analysis. No patients had cancer within the anastomotic ring specimens. Twenty-five patients (5.1 per cent) had benign pathological findings within the anastomotic ring specimens, and patient management was never affected. In the systematic review, 27 articles were included in the final analysis out of 5848 records reviewed. The rate of cancer within anastomotic ring specimens was 0.34 per cent, and the rate of change in patient management was 0.19 per cent.

CONCLUSION

The likelihood of finding cancer within anastomotic rings is rare and their histopathological examination seldom changes patient management.

Is a Distal Resection Margin of ≤ 1 cm Safe in Patients with Intermediate- to Low-Lying Rectal Cancer? A Systematic Review and Meta-Analysis

BACKGROUND

It is generally accepted that the distal resection margin of intermediate- to low-lying rectal cancer should be greater than 2 cm and at least 1 cm in special cases. This study intends to investigate whether a distal resection margin ≤ 1 cm affects tumor outcomes for patients with intermediate- to low-lying rectal cancer.

METHODS

A systematic review of the literature was conducted. Sixteen studies included data for distal resection margins ≤ 1 cm (1684 cases) and > 1 cm (5877 cases), and 5 studies included survival data. Meta-analysis was used to compare the local recurrence rate and long-term survival of patients with distal resection margins > or ≤ 1 cm.

RESULTS

The local recurrence rate in the ≤ 1-cm margin group (9.5%) was 2.3% higher than that in the > 1-cm margin group (7.2%) according to a fixed-effects model (RR [95% CI] 1.42 [1.18, 1.70], P < 0.001). The overall survival results of the five 1-cm margin studies showed an HR (95% CI) of 0.96 (0.75, 1.24) (P = 0.78). Subgroup analysis showed that the local recurrence rate in the subgroup with perioperative treatment was 1.2% lower in the ≤ 1-cm margin group (8.3%) than in the > 1-cm margin group (9.5%) (RR [95% CI] 0.97 [0.63, 1.49], P = 0.90). In the surgery alone subgroup, the local recurrence rate was 4.7% higher in the ≤ 1-cm margin group (12.4%) than in the > 1-cm group (7.7%) (RR [95% CI] 1.76 [1.09, 2.83], P = 0.02).

CONCLUSIONS

For patients with intermediate- to low-lying rectal cancer undergoing surgery alone, a distal resection margin ≤ 1 cm may be not safe.

Analysis of bowel function, urogenital function, and long-term follow-up outcomes associated with robotic and laparoscopic sphincter-preserving surgical approaches to total mesorectal excision in low rectal cancer: a retrospective cohort study

OBJECTIVE

The present study comparatively analyzed short-term clinical effectiveness and long-term follow-up endpoints associated with robotic-assisted sphincter-preserving surgery (RAS) and laparoscopic-assisted sphincter-preserving surgery (LAS) when used to treat low rectal cancer.

METHOD

Within such a single-center retrospective cohort analysis, low rectal cancer patients that underwent RAS (n=200) or LAS (n=486) between January 2015 and beginning of July 2018 were enrolled.

RESULTS

The mean operative durations in the RAS and LAS cohorts were 249±64 min and 203±47 min, respectively (P<0.001). Temporary ileostomy rates in the RAS and LAS cohorts were 64.5% and 51.6% (P = 0.002). In addition, major variations across such cohorts regarding catheter removal timing, time to liquid intake, time to first leaving bed, and length of hospitalization (all P<0.001). This distal resection margin distance within the RAS cohort was diminished in comparison to LAS cohort (P=0.004). For patients within the LAS cohort, the time required to recover from reduced urinary/female sexual function was > 6 months post-surgery (P<0.0001), whereas within the RAS cohort this interval was 3 months (P<0.0001). At 6 months post-surgery, male sexual function within RAS cohort was improved in comparison to LAS cohort (P<0.001). At 6 months post-surgery, Wexner scores revealed similar results (P<0.001). No major variations within overall or disease-free survival were identified across these cohorts at 3 or 5 years post-surgery.

CONCLUSION

Robotic sphincter-preserving surgery is a safe and effective surgical technique in low rectal patients in terms of postoperative oncological safety and long-term endpoints. And the RAS strategy provides certain additional benefits with respect to short-term urogenital/anorectal functional recovery in treated patients compared to LAS.

New Frontiers in Management of Early and Advanced Rectal Cancer

It is important to understand advances in treatment options for rectal cancer. We attempt to highlight advances in rectal cancer treatment in the form of a systematic review. Early-stage rectal cancer focuses on minimally invasive endoluminal surgery, with importance placed on patient selection as the driving factor for improved outcomes. To achieve a complete pathologic response, various neoadjuvant chemoradiation regimens have been employed. Short-course radiation therapy, total neoadjuvant chemotherapy, and others provide unique advantages with select patient populations best suited for each. With a clinical complete response, a "watch and wait" non-operative surveillance has been introduced with preliminary equivalency to radical resection. Various modalities for total mesorectal excision, such as robotic or transanal, have advantages and can be utilized in select patient populations. Tumors demonstrating solid organ or peritoneal spread, traditionally defined as unresectable lesions conveying a terminal diagnosis, have recently undergone advances in hepatic and pulmonary metastasectomy. Hepatic and pulmonary metastasectomy has demonstrated clear advantages in 5-year survival over standard chemotherapy. With the peritoneal spread of colorectal cancer, HIPEC with cytoreductive therapy has emerged as the preferred treatment. Understanding the various therapeutic interventions will pave the way for improved patient outcomes.

Oncological results in rectal cancer patients with a subcentimetre distal margin after laparoscopic-assisted sphincter-preserving surgery

Background

Distal resection margin (DRM) is closely associated with sphincter‐preserving surgery and oncological safety for patients with mid‐low rectal cancers. However, the optimal DRM has not been determined.

Methods

Data of 378 rectal cancer patients who underwent laparoscopic‐assisted sphincter‐preserving surgery from 2009 to 2015 were retrospectively analysed. Patients were divided into two groups based on DRM: ≤1 cm (n = 74) and >1 cm (n = 304). To minimize the differences between the two groups, propensity‐score matching on baseline features was performed.

Results

Before propensity‐score matching, no significant differences in 5‐year disease‐free survival (DFS) (92.8% versus 81.3%, P = 0.128) and 5‐year overall survival (OS) (83.7% versus 82.2%, P = 0.892) were observed in patients with DRMs of ≤1 cm (n = 74) and >1 cm (n = 304), respectively. After propensity‐score matching (1:1), there were also no significant differences in DFS (88.1% versus 78.2%, P = 0.162) and OS (84.5% versus 84.9%, P = 0.420) between the DRM of ≤1 cm group (n = 65) and >1 cm group (n = 65), respectively. A total of 44 patients received preoperative chemoradiotherapy (CRT). In this cohort, the 5‐year local recurrence (LR) rates (P = 0.118) and the 5‐year DFS rates (P = 0.298) were not significantly different between the two groups. A total of 334 patients received surgery without neoadjuvant CRT. There were also no significant differences in the 5‐year LR rates (P = 0.150) and 5‐year DFS rates (P = 0.172) between the two groups.

Conclusions

When aiming to achieve at least a 1–2 cm distal clinical resection margin, a histological resection margin of <1 cm on the DRM gave equivalent clinical outcomes to a DRM of >1 cm.

Functional outcomes after sphincter-preserving surgeries for low-lying rectal cancer: A review

Sphincter preservation and organ restoration during rectal cancer surgery avoids permanent stoma creation and diminishes psychosocial damages. However, decreased rectal volumes and sphincter dysfunction—including pelvic nerve damage—results in low anterior resection syndrome, as well as urinary and sexual dysfunction after rectal resection. Bowel habit changes such as fecal incontinence, fecal urgency, frequent bowel movements, clustered stools, and difficulties in bowel emptying can be treated using medications, pelvic floor rehabilitation, sacral neuromodulation, or neorectal reservoir reconstruction. Pelvic nerve damage resulting from superior and inferior hypogastric plexi during sphincter-preserving rectal cancer surgery can induce urologic and sexual dysfunctions. Preoperative voiding difficulty, perioperative blood loss, and autonomic nerve injury are considered independent risk factors for postoperative urinary dysfunction. Retrograde ejaculation and erectile dysfunction, female dyspareunia, and vaginal dryness are manifestations of sexual dysfunction resulting from autonomic nerve injury during rectal cancer surgery. Multifactorial causes for functional outcomes after sphincter- preserving surgeries are considered to improve patient’s quality of life with acceptable oncologic outcomes in the treatment of rectal cancer patients.

Distal spread and tumor regression patterns following preoperative chemoradiotherapy in rectal cancer patients

Background/aim/AIM

This study aimed to evaluate the regression pattern with the distal intramural spread (DIS) of rectum cancer after preoperative chemoradiation.

Materials and methods

Specimens from 56 patients who underwent radical resection after preoperative chemoradiation for rectal cancer were examined. The regression pattern (total, fragmented) of the tumor was recorded. DIS status was evaluated by creating sections 0.2 to 0.3 cm thick.

Results

A single macroscopic residual area was detected in all specimens. In 10 patients (17.8 %), pathologically complete responses were identified, and DIS was detected in 33 patients (58.9%). The average DIS distance was 0.56± 0.3 cm (range 0.2 – 1.8 cm); the spread was < 1 cm in 87.9% of the patients (29/33). The overall survival rates for 5 and 7 years were 76.8% and 73.2%, respectively. The survival rates between patients with and without DIS were not statistically different (94.6± 5.5 vs. 75.1 ± 10.2 months, respectively). In all of the patients, tumor regression pattern was total shrinkage of the tumor.

Conclusion

A sufficient distal resection margin for rectal cancer after preoperative chemoradiation is 1 cm in the vast majority of cases. However, DIS may exceed 1 cm in a small proportion of patients.

Impact of the distal resection margin on local recurrence after neoadjuvant chemoradiation and rectal excision for locally advanced rectal cancer

We aimed to evaluate whether a short distal resection margin (< 1 cm) was associated with local recurrence in patients with locally advanced rectal cancer who underwent preoperative chemoradiotherapy. Patients with rectal cancer who underwent preoperative chemoradiotherapy followed by curative surgery were divided into two groups based on the distal resection margin (≥ 1 cm and < 1 cm). In total, 507 patients were analyzed. The median follow-up duration was 48.9 months. The 3-year local recurrence rates were 2% and 8% in the ≥ 1 cm and < 1 cm groups, respectively (P < 0.001). Multivariable analysis revealed that a distal resection margin of < 1 cm was a significant risk factor for local recurrence (P = 0.008). Subgroup analysis revealed that a distal resection margin of < 1 cm was not an independent risk factor for local recurrence in the ypT0-1 group. However, among patients with tumor stages ypT2-4, the cumulative 3-year incidences of local recurrence were 2.3% and 9.8% in the ≥ 1 cm and < 1 cm groups, respectively (P = 0.01). A distal resection margin of < 1 cm might influence local recurrence rates in patients with locally advanced rectal cancer undergoing preoperative chemoradiotherapy, especially in patients with tumor stages ypT2-4.

The Safety and Feasibility of Laparoscopic Surgery for Very Low Rectal Cancer: A Retrospective Analysis Based on a Single Center's Experience

In this work we intend to validate the long-term oncologic outcomes for very low rectal cancer over the past 20 years and to determine whether laparoscopic procedures are useful options for very low rectal cancer. A total of 327 patients, who electively underwent laparoscopic rectal cancer surgery for a lesion within 5 cm from the anal verge, were enrolled in this study and their long-term outcomes were reviewed retrospectively. Of 327 patients, 70 patients underwent laparoscopic low anterior resection (LAR), 164 underwent laparoscopic abdominal transanal proctosigmoidocolectomy with coloanal anastomosis (LATA), and 93 underwent laparoscopic abdominoperineal resection (APR). The conversion rate was 1.22% (4/327). The overall postoperative morbidity rate was 26.30% (86/327). The 5-year disease free survival (DFS), 5-year overall survival (OS), and 3-year local recurrence (LR) were 64.3%, 79.7%, and 9.2%, respectively. The CRM involvement was a significant independent factor for DFS (p = 0.018) and OS (p = 0.042) in multivariate analysis. Laparoscopic APR showed poorer 5-year DFS (47.8%), 5-year OS (64.0%), and 3-year LR (17.6%) than laparoscopic LAR (74.1%, 86.4%, 1.9%) and laparoscopic LATA (69.2%, 83.6%, 9.2%). Laparoscopic procedures for very low rectal cancer including LAR, LATA, and APR could be good surgical options in selective patients with very low rectal cancer.

Treatment outcomes of patients with involved resection margin after rectal cancer surgery: A nationwide population-based cohort study in South Korea

BACKGROUND

The involvement of resection margins after rectal cancer surgery by malignant tumors is a negative prognostic factor. Therefore, it is important to analyze treatment outcomes and establish adjuvant therapy.

METHODS

The Health Insurance Review and Assessment Service collects data from medical institutions in South Korea. We reviewed the database of this prospectively collected cohort for patients who underwent curative resection for rectal cancer.

RESULTS

Of the 5,620 patients, 113 (2.0%) were diagnosed with resection margin involvement after surgery. The resection margins of patients with mid-rectal cancer, pathologic stage III, mucinous/signet ring cell carcinoma, and undergoing emergency surgery were more frequently involved. Neoadjuvant chemoradiotherapy was a significant preventive factor for resection margin involvement (odds ratio = 0.53; 95% confidence interval [CI], 0.32-0.87; p = 0.012). The OS of patients with adjuvant treatment was better than that of patients without adjuvant treatment (5-year overall survival [OS]: 62.8% vs. 46.3%, p = 0.02). The administration of chemoradiotherapy was also significantly associated with better OS (hazard ratio = 0.36; 95% CI, 0.17-0.77; p = 0.009).

CONCLUSION

Efforts to acquire wider resection margins are necessary for patients with mid-rectal cancer, pathologic stage III, mucinous/signet ring cell carcinoma, and emergency surgery. Neoadjuvant chemoradiotherapy was a significant preventive factor for involved resection margin. Patients with resection margin involvement showed better OS after adjuvant treatment than those without adjuvant treatment. The adjuvant chemoradiotherapy was helpful to prevent the worse prognosis of these patients.

Distal resection margins in rectal cancer specimens: differences in assessment between surgeons and pathologists and the influence of neoadjuvant chemoradiation

To investigate the discrepancy between the distal resection margin (DRM) assessed by surgeons and pathologists, and the impact of neoadjuvant chemoradiotherapy (nCRT) on DRM. This study included 67 rectal cancer patients undergoing elective surgery. DRMs were assessed through four different techniques: in vivo subjective estimative, made by the surgeon before the rectal resection (by palpation and visual estimative); in vivo objective, measured with a ruler before the rectal transection; ex vivo objective, measured right after resection of the specimen; post-fixation objective measurement, conducted by the pathologist. The DRMs subjectively and objectively assessed by the surgeons were not significantly different (3.40 cm vs. 3.45 cm). There was a mean reduction in the length of DRMs of 35.6%, from 3.45 cm objectively measured by the surgeon to 2.20 cm measured by the pathologist. This difference was significant among patients that did not receive nCRT (3.90 cm vs. 2.30 cm, P < 0.001), but not among those who received nCRT (2.30 vs. 2.05 cm). Surgeons are accurate in assessing rectal cancer DRMs. There are significant differences between intraoperative measurements of DRMs and the final pathologic results. However, these differences are not seen when nCRT is used, a finding that may be useful when sphincter preservation is being considered.

The extent of distal intramural spread of colorectal cancer cell study of it's relationship with histological grading, stage of disease and CEA level

BACKGROUND

The free margin of distal resection is an attempt to prevent local recurrence of the tumor and prolong survival. The recommended length of distal resection margin are varied among the researchers. This study was done to know the correlation between extents of distal intramural spread (DIS) and histology grading, stage and CEA levels of colorectal cancer.

METHODS

The design of the study was a cross sectional. Sample was patients diagnosed with colon or rectal adenocarcinoma in the period of September 2017-March 2018 and underwent resection at Dr.Kariadi Hospital. Resected fresh tissue tumors were directly measured for the distal resection margin and histopathologic examination done by anatomical pathologists. This study has been approved by the ethics committee of Dr.Kariadi Hospital/Faculty of Medicine Diponegoro University. The relationship between DIS length to histology grading, tumor stage and CEA level were analyzed using Spearman's correlation test.

RESULTS

The subjects of this study were 26 patients with colorectal cancer consisted of 15 men and 11 women. The average age of the patients was 53,04 years. The locations of the tumor were 17 in the rectum and 9 in the colon. The length DIS were between 1,07 and 11,49 mm. The longer DIS were occurred when the grading histology worsens, the tumor stage increases and the higher CEA levels with correlation coefficient were r = 0,77 (p < 0,001); r = 0,66 (p < 0,001) and r = 0,44 (p = 0,024) respectively. For the rectal location, the DIS length range were 0,28-10,36 mm. The longer DIS when grading histology worsens r = 0,59 (p = 0,012) and an increased tumor stage r = 0,73 (p = 0,001). The DIS length of the rectum was not proven to correlate with elevated CEA levels r = 0,14 (p = 0,588).

CONCLUSION

Histological grading, tumor stage and CEA levels can be predictors of distal intramural spread (DIS) colorectal cancer. The strongest correlation were between DIS and histologic grading. Thus, in mid and lower third of the rectal cancer, the histologic grade examination is strongly recommended. Based on this study, it is recommended that in rectal cancer undergoing sphincter preserving surgery distal resection sould be more than 2 cm from the tumor margin.

Functional outcome and quality of life following treatment for rectal cancer

Introduction Over the last decades, treatment for rectal cancer has substantially improved with development of new surgical options and treatment modalities. With the improvement of survival, functional outcome and quality of life are getting more attention.

Study objective To provide an overview of current modalities in rectal cancer treatment, with particular emphasis on functional outcomes and quality of life.

Results Functional outcomes after rectal cancer treatment are influenced by patient and tumor characteristics, surgical technique, the use of preoperative radiotherapy and the method and level of anastomosis. Sphincter preserving surgery for low rectal cancer often results in poor functional outcomes that impair quality of life, referred to as low anterior resection syndrome. Abdominoperineal resection imposes the need for a permanent stoma but avoids the risk of this syndrome. Contrary to general belief, long-term quality of life in patients with a permanent stoma is similar to those after sphincter preserving surgery for low rectal cancer.

Conclusion All patients should be informed about the risks of treatment modalities. Decision on rectal cancer treatment should be individualized since not all patients may benefit from a sphincter preserving surgery “at any price”. Non-resection treatment should be the future focus to avoid the need of a permanent stoma and bowel dysfunction.

Retrospective study of the functional and oncological outcomes of conformal sphincter preservation operation in the treatment of very low rectal cancer

BACKGROUND

Conformal sphincter preservation operation (CSPO) is a new surgical procedure for very low rectal cancers (within 4-5 cm from the anal verge). CSPO preserves more of the dentate line and distal rectal wall and also avoids injuring nerves in the intersphincteric space, resulting in satisfactory anal function after resection. The aim of this study was to analyze the short-term surgical results and long-term oncological and functional outcomes of CSPO.

METHODS

Consecutive patients with very low rectal cancer, who had CSPO between January 2011 and October 2018 at Changhai Hospital, Shanghai were included. Patient demographics, clinicopathological features, oncological outcomes and anal function were analyzed.

RESULTS

A total of 102 patients (67 men) with a mean age of 56.9 ± 10.8 years were included. The median distance of the tumor from the anal verge was 3 (IQR, 3-4) cm. Thirty-five patients received neoadjuvant chemoradiation (nCRT). The median distal resection margin (DRM) was 0.5 (IQR, 0.3-0.8) cm. One patient had a positive DRM. All circumferential margins were negative. There was no perioperative mortality. The postoperative complication rate was 19.6%. The median duration of follow-up was 28 (IQR, 12-45.5) months. The local recurrence rate was 2% and distant metastasis rate was 10.8%. The 3-year overall survival and disease-free survival rates were 100% and 83.9%, respectively. The mean Wexner incontinence and low anterior resection syndrome scores 12 months after ileostomy reversal were 5.9 ± 4.3, and 29.2 ± 6.9, respectively.

CONCLUSIONS

For patients with very low rectal cancers, fecal continence can be preserved with CSPO without compromising oncological results.

Precision functional sphincter-preserving surgery (PPS) for ultralow rectal cancer: a natural orifice specimen extraction (NOSE) surgery technique

BACKGROUND

In patients with ultralow rectal cancer, surgical resection of the tumor without impairing sphincter function remains a technical challenge. The purpose of this study was to describe a new technique of transanal natural orifice specimen extraction (NOSE) surgery using our independently developed devices, aiming to achieve precise cancer resection and preserve sphincter function in patients with ultralow rectal cancer.

METHODS

Precision functional sphincter-preserving surgery (PPS) was performed on nineteen patients with ultralow rectal cancer between June 2019 and April 2020. With the help of our independently developed devices, surgeons directly and accurately removed the lower edge of the tumor and retained healthy rectal tissue on the nontumorous side. Hand-sewn anastomosis with a mattress suture was used to achieve sturdy anastomosis. Preoperative baseline characteristics, operative details, 90-day postoperative complications, costs, and anal function score at 6 months after surgery were documented.

RESULTS

Nineteen ultralow rectal cancer patients with a median distance to the dentate line of 2.0 cm successfully underwent PPS without serious postoperative complications. Six out of nineteen patients (31.6%) received a prophylactic stoma. The average cost was 62164.1 yuan. At 6 months after surgery, the average Wexner anal function score and the average Vaizey score were both 3 points.

CONCLUSIONS

PPS can be employed to precisely resect rectal tumors and preserve sphincter function in ultralow rectal cancer patients. The use of our devices enhanced surgical efficiency, reduced the need for prophylactic stoma, reduced surgery-related costs, and prevented abdominal surgical incisions.

Latest Advances in Intersphincteric Resection for Low Rectal Cancer

Background

Intersphincteric resection (ISR) has been a preferable alternative to abdominoperineal resection (APR) for anal preservation in patients with low rectal cancer. Laparoscopic ISR and robotic ISR have been widely used with the proposal of 2 cm or even 1 cm rule of distal free margin and the development of minimally invasive technology. The aim of this review was to describe the newest advancements of ISR.

Methods

A comprehensive literature review was performed to identify studies on ISR techniques, preoperative chemoradiotherapy (PCRT), complications, oncological outcomes, and functional outcomes and thereby to summarize relevant information and controversies involved in ISR.

Results

Although PCRT is employed to avoid positive circumferential resection margin (CRM) and decrease local recurrence, it tends to engender damage of anorectal function and patients' quality of life (QoL). Common complications after ISR include anastomotic leakage (AL), anastomotic stricture (AS), urinary retention, fistula, pelvic sepsis, and prolapse. CRM involvement is the most important predictor for local recurrence. Preoperative assessment and particularly rectal endosonography are essential for selecting suitable patients. Anal dysfunction is associated with age, PCRT, location and growth of anastomotic stoma, tumour stage, and resection of internal sphincter.

Conclusions

The ISR technique seems feasible for selected patients with low rectal cancer. However, the postoperative QoL as a result of functional disorder should be fully discussed with patients before surgery.

Development of the 'PREDICT' score through a systematic review and meta-analysis of the predictive parameters for locoregional recurrence after total mesorectal excision

BACKGROUND

Despite robust management techniques, locoregional recurrence rates of rectal cancer are still significant. Although offering intensive follow-up has been shown to be beneficial in the early detection, it can be resource consuming. Having a robust knowledge of risk factors of locoregional recurrence will help in identification of patients who actually need intensive follow-up programs. This review aimed to identify the factors that can predict locoregional recurrence after Total mesorectal excision (TME).

METHODS

We systematically reviewed PubMed, Scopus and Cochrane for relevant articles with no date restrictions while language was restricted to English. We only included articles that had either provided Hazards ratio (HR)/odds ratio (OR) or provided enough data that allowed calculation of HR/OR specifically for rectal cancer. Articles were deemed eligible if they included patients undergoing (TME).

RESULTS

Seventeen studies (18,605 patients) published between 2002 and 2019 were included. A total of 699 patients developed locoregional recurrence at a median time of 25.2 months after surgery. There were eight significant predictors evaluated by more than one study; T3-T4 stage, circumferential resection margin, lymphovascular invasion, mucinous histology, N1-N2 stage, positive distal resection margin, Tumor < 5 cm from anal verge, and lack of neoadjuvant radiotherapy. A scoring system was developed based on the weight and pooled OR/HR of each predictor.

CONCLUSION

Using predictive factors identified in our review in context of scoring system may help in the early detection of locoregional recurrence after TME. This may help in tailoring the application of intensive follow-up programs.

Predictive Factors of Positive Circumferential and Longitudinal Margins in Early T3 Colorectal Cancer Resection

Background

Malignant involvement of circumferential resection margin (CRM) and longitudinal resection margin (LRM) after surgical resection of colorectal cancer (CRC) are associated with higher rates of recurrence and development of distant metastasis. This can influence the overall patient's prognosis. The aim of the current study was to identify pathological factors as predictors for the involvement of resection margins in early T3 CRC. Patients and Methods. Fifty patients radiologically diagnosed to have cT3a/b (CRC) were included in the study. After resection, the pathological examination was performed to identify patients with positive CRM and/or LRM. Relations between the different pathological parameters and the CMR and LRM involvements were assessed.

Results

Positive CRM was present in 17 cases (34%), while positive LRM was found in 6 cases (12%). The involvement of both margins was significantly associated with rectal tumors and tumors with infiltrative gross appearance, grade III, deeper invasion, and positive lymph node metastases. Also, there was a significant association between both margins' positivity and other pathological parameters as signet ring carcinoma, tumor budding, perineural and vascular invasion, high microvessel density (MVD), and sinusoidal vascular pattern, while the presence of necrosis and infiltrative advancing tumor front was significantly associated with CRM involvement only. The depth of tumor invasion and signet ring carcinoma were identified as independent predictor factors for positive CRM and LRM, respectively.

Conclusion

Preoperative identification of these pathological parameters can be a guide to tailor the management plan accordingly.

Direct intraoperative assessment of total mesorectal excision specimens by expert pathologists in patients with very low rectal cancer prevents unnecessary abdominoperineal resections

PURPOSE

In patients with low rectal cancer, the intraoperative assessment of sufficient distal resection margins can be challenging. The assessment determines whether reconstruction can be performed or whether permanent colostomy is required. The goal of the present study was to evaluate intraoperative assessment of the total mesorectal excision (TME) specimen during an interruption of the operation.

METHODS

The intraoperative strategy of eight patients with low rectal cancer was evaluated. In all cases, intraoperative pathological assessment of the TME specimen by an expert pathologist together with the surgeon was performed. Assessment of the distance of the tumor to the resection margin was measured macroscopically as well as microscopically.

RESULTS

All patients underwent neoadjuvant chemoradiation. The tumor was located at an average 4.8 ± 1.4 cm from the anal verge. In all cases, preoperative MRI revealed mrT3 tumors. The intraoperative assessment showed a median distal resection margin of 10 mm (2-15 mm). In six patients, sufficient margins allowed for reconstruction while in two patients APR was needed. In three patients (37.5%), the pathological assessment changed the operative strategy: In one patient APR could be avoided while two patients required APR instead of the anticipated TME.

CONCLUSION

The intraoperative assessment of the TME specimen by an expert pathologist together with the surgeon is a valuable tool to avoid unnecessary APR or R1 resections. We therefore suggest routine intraoperative pathological assessment in all operations for borderline low rectal cancers.

Can Ex Vivo Magnetic Resonance Imaging of Rectal Cancer Specimens Improve the Mesorectal Lymph Node Yield for Pathological Examination?

Supplemental digital content is available in the text.

The aim of this study was to use 7 T ex vivo magnetic resonance imaging (MRI) scans to determine the size of lymph nodes (LNs) in total mesorectal excision (TME) specimens and to increase the pathological yield of LNs with MR-guided pathology.

Anal function and quality of life analysis after laparoscopic modified Parks for ultra-low rectal cancer patients

Background

To assess postoperative anal function and quality of life of ultra-low rectal cancer patients treated by laparoscopic modified Parks surgery.

Methods

From February 2017 to March 2019, 114 patients with ultra-low rectal cancer above T2 were treated respectively with ultra-low anterior resection (Dixon), modified coloanal anastomosis (modified Parks), and Miles according to the preoperative stage and anastomotic position. The postoperative anal function and Fecal Incontinence Quality of Life Scale (FIQL) of each patient were collected and synthetically analyzed.

Results

Compared with the Dixon group, the postoperative anal function and FIQL in the Parks group were poor at the early stage. However, from 6 to 12 months after surgery, the scores of anal function and FIQL in the Parks group were similar to those in the Dixon group (P > 0.05). Compared with the Miles group, the FIQL of the two groups were similar in the early postoperative stage. However, with the passage of time, from 3 to 9 months after surgery, the four domains of FIQL in the Parks group were higher than those in the Miles group successively (P < 0.05).

Conclusions

Laparoscopic modified Parks is a safe, effective, and economical anus-preserving surgery. Although its early anal function and FIQL were poor, it could gradually recover to the similar level as Dixon. Moreover, it can save the anus and obtain a better postoperative quality of life for some patients who previously could only undergo Miles.

"Watch and Wait" for complete clinical response after neoadjuvant chemoradiotherapy for rectal cancer

The management of rectal cancer has evolved substantially over recent decades, becoming increasingly complex. This was once a disease associated with high mortality and limited treatment options that typically necessitated a permanent colostomy, has now become a model for multidisciplinary evaluation, treatment and surgical advancement. Despite advances in the rates of total mesorectal excision, decreased local recurrence and increased 5-year survival rates, the multimodal treatment of rectal cancer is associated with a significant impact on long-term functional and quality of life outcomes including risks of bowel, bladder and sexual dysfunction, and potential need for a permanent stoma. There is great interest in strategies to decrease the toxicity of treatment, including selective use of radiation, chemotherapy or even surgery. The modern concept of selective use of surgery for patients with rectal cancer are based on the observed pathological complete response in approximately 10-20% of patients following long-course chemoradiation therapy. While definitive surgical resection remains the standard of care for all patients with non-metastatic rectal cancer, a growing number of studies are providing supportive evidence for a watch-and-wait, organ preserving approach in highly selected patients with rectal cancer. However, questions regarding the heterogeneity of patient selection, optimal method for inducing pathological complete response, methods and intervals for assessing treatment response and adequacy of follow-up remain unanswered. The aim of this review is to provide an up-to-date summary of the current evidence for the watch-and-wait management of rectal cancer following a complete clinical response after neoadjuvant chemoradiation.

[Intersphincteric resection for stage I-III low rectal cancer is an oncologically safe alternative to extralevator abdomino-perineal rectal resection]

AIM

To compare oncologic efficiency of intersphincteric resections and extralevator abdominoperineal excisions in surgical treatment of low rectal cancer.

METHODS

Between 2006 and 2015 in Department of colorectal and pelvic floor surgery (Russian scientific center of surgery n.a. acad. B.V. Petrovsky) and in Clinic of Colorectal and Minimally invasive surgery (Sechenov First Moscow State Medical University) 40 consecutive patients underwent intersphincteric resection (ISR) and 31 underwent extralevator abdominoperineal excision (EAPE). All patients had low rectal cancer staged I-III within 5 cm from the anal verge.

RESULTS

Circular resection margin >1 mm was achieved in 95% and 84% of patients after ISR and EAPR correspondingly (p=0.002), negative distal resection margin was achieved in 95% of ISR patients. In ISR group mean distance from the lower tumor edge to the distal resection margin was 1,17±0,78 cm. Colo-anal anastomosis leak rate was 17%. The 3-year disease-free survival in ISR group was 97%, 5-year disease-free survival was 93%. The 5-year disease-free survival in stage III for ISR group was 71,4%. In 98% of ISR patients complete restoration of bowel continuity was performed.

Oncologic outcomes for low rectal adenocarcinoma following low anterior resection with coloanal anastomosis versus abdominoperineal resection: a National Cancer Database propensity matched analysis

PURPOSE

Low anterior resection with coloanal anastomosis (CAA) for low rectal cancer is a technically difficult operation with limited data available on oncologic outcomes. We aim to investigate overall survival and operative oncologic outcomes in patients who underwent CAA compared to abdominoperineal resection (APR).

METHODS

The National Cancer Database (2004-2013) was used to identify patients with non-metastatic rectal adenocarcinoma who underwent CAA or APR. Patients were 1:1 matched on age, gender, Charlson score, tumor size, tumor grade, pathologic stage, and radiation treatment with propensity scores. The primary outcome was overall survival. Secondary outcomes included 30-day mortality and resection margins.

RESULTS

Following matching, 3536 patients remained in each group. No significant differences in matched demographic, treatment, or tumor variables were seen between groups. There was no significant difference in 30-day mortality (1.24% vs. 1.39%, p = 0.60). Following resection, margins were more likely to be negative after CAA compared with APR (5.26% vs. 8.14%, p < 0.001). When stratified by pathologic stage, there was a significant survival advantage for individuals undergoing CAA compared to APR (stage 1 HR 0.72, [95% CI 0.62-0.85], p < 0.001; stage 2 HR 0.76, [95% CI 0.65-0.88], p < 0.001; stage 3 HR 0.76, [95% CI 0.67-0.85], p < 0.001).

CONCLUSIONS

Patients undergoing CAA compared with APR for rectal cancer have better overall survival and are less likely to have positive margins despite the technically challenging operation.

Augmented CD133 expression in distal margin correlates with poor prognosis in colorectal cancer

Pathological assessment of excised tumour and surgical margins in colorectal cancer (CRC) play crucial role in prognosis after surgery. Molecular assessment of margins could be more sensitive and informative than conventional histopathological analysis. Considering this view, we evaluated the distal surgical margins for expression of cancer stem cell (CSC) markers. Cellular and molecular assessment of normal, tumour and distal margin tissues were performed by flow cytometry, real-time q-PCR and immuno-histochemical analysis for CRC patients after tumour excision. CRC patients were evaluated for expression of CSC markers in their normal, tumour and distal tissues. Flow cytometry assay revealed CD133 and CD44 enriched cells in distal margin and tumour compared to normal colorectal tissues, which was further confirmed by immunohistochemistry. Most importantly, immunohistochemistry also revealed the enrichment of CSC markers expression in pathologically negative distal margins. Patients with distal margin enriched for CD133 expression showed an increased recurrence rate and decreased disease-free survival. This study proposes that although distal margin seems to be tumour free in conventional histopathological analysis, it could harbour cells enriched for CSC markers. Further CD133 could be a promising molecule to be used in molecular pathology for disease prognosis after surgery in CRC patients.

Meta-analysis of histopathological outcomes of laparoscopic assisted rectal resection (LARR) vs open rectal resection (ORR) for carcinoma

BACKGROUND

We conducted a meta-analysis of the randomized evidence to determine the relative merits of histopathological outcomes of laparoscopic assisted (LARR) versus open rectal resection (ORR) for rectal cancer.

DATA SOURCES

A search of PubMed and other electronic databases comparing LARR and ORR between Jan 2000 and June 2016 was performed. Histopathological variables analyzed included; location of rectal tumors; complete and incomplete TME; positive and negative circumferential resection margins (+/-CRM); positive distal resected margins (+DRM); distance of tumor from DRM; number of lymph nodes harvested; resected specimen length; tumor size and perforated rectum.

RESULTS

Fourteen RCTs totaling 3843 patients (LARR = 2096, ORR = 1747) were analyzed. Comparable effects were noted for all these histopathological variables except for the variable perforated rectum which favored ORR.

CONCLUSIONS

LARR compares favorably to ORR for rectal cancer treatment. However, there is significantly higher risk of rectal perforation during LARR compared to ORR.

The influence of endorectal filling on rectal cancer staging with MRI

OBJECTIVE

To assess the influence of endorectal filling (EF) on rectal cancer staging.

METHODS

47 patients who underwent a staging MRI of rectal cancer in the period from 2011 to 2014 were included. The MRI protocol included T₂ weighted fast spin echo sequences without and with EF at 3 T (EF-MRI). Images were scored by two readers for T-stage, distance of the lower pole of the tumour to the anorectal junction, distance to the mesorectal fascia (MRF), and number of (suspicious) lymph nodes. Agreement in T-staging was calculated using the Cohen's κ value. Comparison of continuous variables was performed using Wilcoxon matched pairs signed-rank test.

RESULTS

The interobserver agreement for T-staging with and without EF-MRI showed a poor agreement between both readers (weighted κ = 0.156, weighted κ = 0.037, respectively). Tumours tended to be overstaged more prominently with EF-MRI. The accuracy of predicting the pathological T-stage slightly improved from 55% with EF to 64% without EF for Reader 1 and from 59 to 68% for Reader 2, respectively. The distance of the tumour to the anorectal junction increased from 33.9 to 49.3 mm (p < 0.001) after EF for Reader 2. EF-MRI did not significantly influence the number of (suspicious) lymph nodes and distance to the mesorectal fascia.

CONCLUSION

EF-MRI did not lead to an improved tumour staging and it has the potential to influence the distance to a key anatomical landmark. EF-MRI is therefore not recommended in primary staging rectal cancer. Advances in knowledge: EF-MRI may not be used as an additional tool to stage rectal cancer patients, as it does not seem to facilitate in locoregionally staging the disease.

Identification and Quantification of Drug-Resistant Cells in Colorectal Tumor and Distal Margin

Cancer stem cells are cellular subpopulations in tumor, which are highly tumorigenic and drug resistant due to their adaptive molecular mechanism. In the recent years, these cells have attracted researchers' focus because of their unique properties which makes them biologically well evolved than other proliferating tumor cells. We have studied the presence of cancer stem cells in colorectal cancer (CRC) and its surgical margins. We report for the first time the presence of drug-resistant cells in distal resection margins in CRC and showed that a closer distal margin of less than 2 cm could have higher possibility of drug-resistant cells to spread.

The fate of preserved sphincter in rectal cancer patients

PURPOSE

Sphincter-saving surgery is widely accepted operative modality to treat rectal cancer. It often requires temporary diverting stoma to avoid the complications of anastomotic failure. This study investigates the cumulative failure rate in sphincter preservation for rectal cancer and the risk factors associated with the permanent stoma.

METHODS

A retrospective study on 358 patients diagnosed with primary rectal cancer from 2009 to 2013 was conducted at a single institute. Three hundred and thirty-one out of 358 patients with rectal cancer located within 12 cm from the anal verge, who underwent sphincter-preserving surgery, were included in this study. The cumulative rate for permanent stoma was calculated. Univariate and multivariate analysis were performed, comparing the patients with stoma to the ones without.

RESULTS

Temporary diverting stoma was created in 223 (82%) patients. After median follow-up of 42 months, 18 patients (6.6%) persistently used temporary stoma or required re-creation of stoma. Univariate analysis revealed that BMI, tumor location below 4 cm from the anal verge, coloanal anastomosis, anastomotic leakage, and local recurrence were significantly associated with persistent use or re-formation of stoma. Multivariate analysis showed that anastomotic leakage (OR 50.3; 95% CI, 10.1-250.1; p < 0.0001) and local recurrence (OR 11.3; 95% CI, 1.61-78.5; p = 0.015) were the independent risk factors.

CONCLUSION

Patients with anastomotic leakage and local recurrence are at high risk for permanent stoma. Not only should patients be fully informed of possible failure in sphincter preservation preoperatively, but also patient-oriented decision should be made on patient-tailored surgical plan.

A Prospective Study of Distal Microscopic Spread in Rectal Cancer After Neoadjuvant Chemoradiation in Pinned and Unpinned Specimen

The most important margin in determining the prognosis of rectal cancer is circumferential resection margin (CRM). But, the type of surgery is determined by distal rectal margin (DRM), whether sphincter saving procedure is possible or patient needs an abdominoperineal resection. There are no standardized uniform guidelines for measurement of DRM. The purpose of this study is to assess the distal microscopic spread beyond gross margin after neoadjuvant concurrent chemoradiation (CCRT) in rectal cancers, the factors influencing the distal microscopic spread, the shrinkage of the distal margin in pinned and unpinned fresh and fixed specimen, and to find out the best method of measurement of distal rectal margin. A prospective analytical study was conducted from May 2013 through February 2015 in 47 cases of carcinoma rectum (both AR and APR) who had received neoadjuvant CCRT. Fresh specimen was collected within 30 min of specimen retrieval and a longitudinal cut was made in the distal margin of all specimens. One side of the specimen was pinned onto a cork board and the other side was left unpinned. Measurements were made from the distal end of clinical gross tumor. DRM was determined in both pinned and unpinned sides in fresh and fixed specimen. Of the 47 patients, 2 patients (4.2%) had small focus of tumor beyond gross margins, 1 at 6 mm and another at 3.5 mm on the unpinned side. The average margin for fresh and fixed pinned specimens was 3.67 and 3.47 cm, respectively, with percentage shrinkage of 5.4% for the pinned specimens. The average margin for fresh and fixed unpinned specimens was 3.32 and 2.84 cm, respectively, with percentage shrinkage of 14.4% for the unpinned specimens. Six patients (12.7%) had complete pathological response. Correlation of distal margin was better in pinned specimen. A correction factor of 15% for shrinkage needs to be taken into account while assessing unpinned specimen. Only in 4.2% of patients, there was distal submucosal spread beyond gross margin. Long-term follow up is required for assessing adequacy of DRM post neoadjuvant CCRT.