Adequate length of the surgical Distal resection margin in rectal cancer: from the viewpoint of pathological findings

Partial mesorectal excision can be a primary option for middle rectal cancer: a propensity score-matched retrospective analysis

PURPOSE

Although partial mesorectal excision (PME) and total mesorectal excision (TME) is primarily indicated for the upper and lower rectal cancer, respectively, few studies have evaluated whether PME or TME is more optimal for middle rectal cancer.

METHODS

This study included 671 patients with middle and upper rectal cancer who underwent robot-assisted PME or TME. The 2 groups were optimized by propensity score matching of sex, age, clinical stage, tumor location, and neoadjuvant treatment.

RESULTS

Complete mesorectal excision was achieved in 617 of 671 patients (92.0%), without showing a difference between the PME and TME groups. Local recurrence rate (5.3% vs. 4.3%, P>0.999) and systemic recurrence rate (8.5% vs. 16.0%, P=0.181) also did not differ between the 2 groups, in patients with middle and upper rectal cancer. The 5-year disease-free survival (81.4% vs. 74.0%, P=0.537) and overall survival (88.0% vs. 81.1%, P=0.847) also did not differ between the PME and TME groups, confined to middle rectal cancer. Moreover, 5-year recurrence and survival rates were not affected by distal resection margins of 2 cm (P=0.112) to 4 cm (P>0.999), regardless of pathological stages. Postoperative complication rate was higher in the TME than in the PME group (21.4% vs. 14.5%, P=0.027). Incontinence was independently associated with TME (odds ratio [OR], 2.009; 95% confidence interval, 1.015-3.975; P=0.045), along with older age (OR, 4.366, P<0.001) and prolonged operation time (OR, 2.196; P=0.500).

CONCLUSION

PME can be primarily recommended for patients with middle rectal cancer with lower margin of >5 cm from the anal verge.

Required distal mesorectal resection margin in partial mesorectal excision: a systematic review on distal mesorectal spread

BACKGROUND

The required distal margin in partial mesorectal excision (PME) is controversial. The aim of this systematic review was to determine incidence and distance of distal mesorectal spread (DMS).

METHODS

A systematic search was performed using PubMed, Embase and Google Scholar databases. Articles eligible for inclusion were studies reporting on the presence of distal mesorectal spread in patients with rectal cancer who underwent radical resection.

RESULTS

Out of 2493 articles, 22 studies with a total of 1921 patients were included, of whom 340 underwent long-course neoadjuvant chemoradiotherapy (CRT). DMS was reported in 207 of 1921 (10.8%) specimens (1.2% in CRT group and 12.8% in non-CRT group), with specified distance of DMS relative to the tumor in 84 (40.6%) of the cases. Mean and median DMS were 20.2 and 20.0 mm, respectively. Distal margins of 40 mm and 30 mm would result in 10% and 32% residual tumor, respectively, which translates into 1% and 4% overall residual cancer risk given 11% incidence of DMS. The maximum reported DMS was 50 mm in 1 of 84 cases. In subgroup analysis, for T3, the mean DMS was 18.8 mm (range 8-40 mm) and 27.2 mm (range 10-40 mm) for T4 rectal cancer.

CONCLUSIONS

DMS occurred in 11% of cases, with a maximum of 50 mm in less than 1% of the DMS cases. For PME, substantial overtreatment is present if a distal margin of 5 cm is routinely utilized. Prospective studies evaluating more limited margins based on high-quality preoperative magnetic resonance imaging and pathological assessment are required.

CORRELATION BETWEEN THE LEVEL OF COLORECTAL ANASTOMOSIS AND ANORECTAL FUNCTION

Anterior rectal resection is a standard surgical procedure for treating carcinomas of rectum and distal sigmoid colon. In many cases of anterior rectal resection, postoperatively some level of fecal incontinence may occur. The aim of our study was to evaluate the impact of the colorectal anastomosis level on anorectal functional disorder. In our prospective study, the participants were patients diagnosed with carcinoma of rectum or distal sigmoid colon. All patients underwent standard open or laparoscopic anterior rectal resection. Six months after the surgery, the function of anorectum was evaluated in all participants. Finally, 38 patients were analyzed, including 13/38 (34.2%) patients with high rectal anastomosis, 11/38 (28.9%) with mid rectal anastomosis and 14/38 (36.8%) with low rectal anastomosis. Patients with a lower level of anastomosis had a statistically significantly greater number of stools, higher urgency and discrimination impairment, more pronounced solid, liquid and gas incontinence, and greater need for diapers (p<0.05 all). Therefore, patients with lower anastomosis had a statistically significant impairment of their quality of life and higher Wexner score (p<0.001 for both analyses). Our study results suggested reduced neorectal capacity to be the main pathophysiological factor for the development of postoperative anorectal function impairment.

Robotic Versus Laparoscopic Partial Mesorectal Excision for Cancer of the High Rectum: A Single-Center Study with Propensity Score Matching Analysis

BACKGROUND

The role of robotic surgery for partial mesorectal excision (PME) in patients with high rectal cancer (RC) remains unexplored. This study aimed to compare the operative and postoperative outcomes of robotic (R-PME) versus laparoscopic (L-PME) PME for high RC.

METHODS

This was a single-center propensity score cohort study of consecutive patients diagnosed with RC in the high rectum (>10 to 15 cm from the anal verge) who underwent surgery between September 2012 and May 2019.

RESULTS

Of 131 selected patients (50 R-PME and 81 L-PME), 88 were matched using propensity score (44 per group). Operative and postoperative variables were similar between R-PME and L-PME patients, except for operative time (220 min and 190 min, respectively; p < 0.0001). No conversion was needed. Overall morbidity was 15.9%; 4 patients (4.5%) developed anastomotic leakage. The mean hospital stay was 7.25 days for R-PME vs. 7.64 days for L-PME (p = 0.597). R0 resection was achieved in 100% of R-PME and 90.9% of L-PME (p = 0.116). Only 3 patients (1 R-PME, 2 L-PME) received a permanent stoma (p = 1). No group differences were observed for overall or disease-free survival rates at 5 years. The costs of R-PME were significantly higher than those of L-PME.

CONCLUSION

Minimally invasive surgery can be performed safely for PME in high RC. No difference can be detected between R-PME and L-PME for both short- and long-term outcomes, leaving the choice of the surgical approach to the surgeon's experience. Specific health economic studies are needed to evaluate the cost-effectiveness of robotic surgery for RC.

Effect of preoperative chemotherapy on distal spread of low rectal cancer located close to the anus

PURPOSE

This study aimed to clarify the frequency of distal spread and the optimal distal margin after preoperative chemotherapy for advanced low rectal cancer.

METHODS

The study included patients with advanced lower rectal cancer who received preoperative chemotherapy and underwent surgery during 2012-2015. We investigated the distal spread of tumor cells, defined as the distal distance from the intramucosal distal tumor edge to the farthest tumor cells located under the submucosal layer. Clinical characteristics were compared for distal spreads ≥ 10 and < 10 mm, and risk factors for distal spread ≥ 10 mm were investigated.

RESULTS

Of the 71 patients, 42 (59%) showed distal spread. Distal spreads of 1-9, 10-19, and ≥ 20 mm were observed in 27 (38%), 11 (15%), and 4 (6%) patients, respectively. Multivariate analysis revealed two independent risk factors for distal spread ≥ 10 mm after preoperative chemotherapy. The first risk factor is the presence of different therapeutic effects between the mucosal and deeper layers (meaning that superficial tumor shrinkage was evident on colonoscopy, but little tumor shrinkage was evident on magnetic resonance imaging) (odds ratio, 11.6; 95% CI, 2.22-61.3). The second risk factor is poorly differentiated or mucinous adenocarcinoma (odds ratio, 8.86; 95% CI, 1.58-49.9).

CONCLUSION

A distal margin of 20 mm is required (10 mm is insufficient) for advanced lower rectal cancer patients who receive preoperative chemotherapy followed by surgery. Independent risk factors for distal spread ≥ 10 mm include (1) the presence of different therapeutic effects between mucosal and deeper layers and (2) poorly differentiated or mucinous adenocarcinomas.

Cost Effectiveness of Intraoperative Gross Examination in Colorectal Resections: A Retrospective Review of 200 Consecutive Cases

CONTEXT.—

Intraoperative pathology consultation is an important tool for many surgical procedures and is deemed appropriate when the pathology result immediately alters surgical management.

OBJECTIVE.—

To evaluate the utility of intraoperative gross examinations of colorectal resections and to better understand the associated costs.

DESIGN.—

The pathology database of our institution was searched for colorectal resections for primary disease, and those cases were separated into 3 categories: frozen section performed, intraoperative gross examination performed, and no intraoperative consultation. We reviewed 270 cases during a 15-month period.

RESULTS.—

Of the 270 cases, 200 (74.1%) had an intraoperative gross examination. In 34 of the 200 cases (17%), additional specimens were taken and, therefore, required operative note review to ascertain whether the additional specimens taken were based on the findings from the intraoperative gross examination. After reviewing the operative notes for those 34 cases, none (0%) were a result of the gross findings reported. The average associated time for intraoperative gross examinations was 27.67 minutes (including transport). The billable costs exceeded $7000 during the study period, and the cost of the pathology assistant's time per case was $22.10.

CONCLUSIONS.—

Our study demonstrates that no change in surgical management was a result of gross examination of colorectal resection specimens and that the associated costs were significant. Decreasing unnecessary consultations will directly save the health care system money by eliminating billable services and will also increase the efficiency of the pathology department by reducing the opportunity costs for the time of the pathologist and the pathology staff.

Preoperative chemoradiotherapy creates an opportunity to perform sphincter preserving resection for low-lying locally advanced rectal cancer based on an oncologic outcome study

Low-lying locally advanced rectal cancer (LARC) after preoperative chemoradiotherapy (CRT) can be surgically removed by either abdominperineal resection (APR) or sphincter preserving resection (SPR). This retrospective cohort study of 251 consecutive patients with low lying LARC who underwent CRT followed by radical surgery in a single institute, between March 2003 and November 2012, aimed to compare the oncological benefits between the two groups. 3-year disease free survival (DFS), overall survival (OS), cumulative incidence of recurrence and postoperative complications were compared between the two approaches. With median follow-up of 48.6 months, SPR group had higher 3-year DFS rate (86.4% vs 73.6%, P=0.023) and lower incidence of distant recurrence (12.0% vs 23.7%, P=0.026). The postoperative complications, incidence of local recurrence and the 3-year OS were comparable between the two groups. Pathologic T and N stage were the independent predictors for 3-year DFS (P=0.020 and P<0.001). In conclusion, our study suggest that low-lying LARC patients with a significant response to preoperative CRT can benefit from the advantage of SPR in preserving the anal sphincter function without compromising their oncologic outcome.

A Distal Resection Margin of ≤1 mm and Rectal Cancer Recurrence After Sphincter-Preserving Surgery: The Role of a Positive Distal Margin in Rectal Cancer Surgery

BACKGROUND

There is little information about the prognostic value of a microscopically positive distal margin in patients who have rectal cancer.

OBJECTIVE

We aimed to investigate the influence of a distal margin of ≤1 mm on oncologic outcomes after sphincter-preserving resection for rectal cancer.

DESIGN

This is a retrospective cohort study.

SETTINGS

The study was conducted at 2 hospitals.

PATIENTS

A total of 6574 patients underwent anterior resection for rectal cancer from January 1999 to December 2014; 97 (1.5%) patients with a distal margin of ≤1 mm were included in this study. For comparative analyses, patients were matched with 194 patients with a negative distal margin (>1 mm) according to sex, age, BMI, ASA score, neoadjuvant treatment, tumor location, and stage.

MAIN OUTCOME MEASURES

The oncologic outcomes of the 2 groups were compared.

RESULTS

Perineural and lymphovascular invasion rates were significantly higher in patients with a positive distal margin (54.6% vs 28.9%; 67.0% vs 42.8%; both p < 0.001) compared with to patients with negative distal margin. Comparison between microscopically positive and negative distal margin showed worse oncologic outcomes in patients with a microscopically positive distal margin, including 5-year local recurrence rate (24.1% vs 12.0%, p = 0.005); 5-year distant recurrence rate (35.5% vs 20.2%, p = 0.011); 5-year disease-free survival (45.5% vs 69.5%, p < 0.001); and 5-year OS (69.2% vs 79.7%, p = 0.004). Among the 97 patients with a microscopically positive distal margin, the 5-year disease-free survival rate was higher in patients who received adjuvant therapy (52.0% vs 30.7%, p = 0.089).

LIMITATIONS

This is a retrospective study; bias may exist.

CONCLUSIONS

A distal margin of 1 mm is associated with worse oncologic results. Our data indicate the importance of achieving a clear distal margin in the surgical treatment of rectal cancer. Adjuvant therapy should be used in these patients to reduce recurrence. See Video Abstract at http://links.lww.com/DCR/A408.

Continuous Effect of Radial Resection Margin on Recurrence and Survival in Rectal Cancer Patients Who Receive Preoperative Chemoradiation and Curative Surgery: A Multicenter Retrospective Analysis

PURPOSE

To elucidate the proper length and prognostic value of resection margins in rectal cancer patients who received preoperative chemoradiotherapy (CRT) followed by curative total mesorectal excision (TME).

METHODS AND MATERIALS

A total of 1476 rectal cancer patients staging cT3-4N0-2M0 were analyzed. All patients received radiation dose of 50.4 Gy in 28 fractions with concurrent 5-fluorouracil or capecitabine. Total mesorectal excision was performed 4 to 8 weeks after radiation therapy.

RESULTS

The recurrence-free survival (RFS) at 5 years showed a significant difference between 3 groups: patients with circumferential resection margin (CRM) ≤1 mm, CRM 1.1 to 5 mm, and CRM >5 mm (46.2% vs 68.6% vs 77.5%, P<.001). Patients with CRM ≤1 mm showed a significantly higher cumulative incidence of locoregional recurrence (P<.001) and distant metastasis (P<.001) at 5 years compared with the other 2 groups. Patients with CRM 1.1 to 5 mm showed a significantly higher cumulative incidence of distant metastasis (P<.001), but not locoregional recurrence (P=.192), compared with those with CRM >5 mm. Distal resection margin (≤5 vs >5 mm) did not show any significant difference in cumulative incidence of locoregional recurrence (P=.310) and distant metastasis (P=.926).

CONCLUSION

Rectal cancer patients with CRM ≤1 mm are a high-risk group, with the lowest RFS. Patients with CRM 1.1 to 5 mm may be at intermediate risk, with moderately increased distant recurrence. Distal resection margin was not significantly associated with RFS in rectal cancer after neoadjuvant CRT and total mesorectal excision.

Objective measurement of the distal resection margin by MRI of the fresh and fixed specimen after partial mesorectal excision for rectal cancer: 5 cm is not just 5 cm and depends on when measured

BACKGROUND

Most studies have directly established the optimal perioperative in situ clearance margin in surgery for rectal cancer from the histologically observed extent of distal spread, neglecting the tissue variability that occurs after resection and fixation of the rectal specimen.

PURPOSE

To measure the length of the distal resection margin in the fresh and fixed specimen following partial mesorectal excision for rectal cancer using magnetic resonance imaging (MRI) to document tissue shrinkage after surgical removal and fixation.

MATERIAL AND METHODS

The length of the distal resection margin was measured by MRI of the fresh and fixed specimen and at histopathological examination of the fixed specimen in 10 patients who underwent surgery for upper rectal cancer. In addition, tissue shrinkage was estimated by measuring the total length of the fresh and fixed specimen and distance from the peritoneal reflection anteriorly to the distal cut edge of the specimen.

RESULTS

Measured by MRI, the distal resection margin was in the range of 0.6-10.2 cm (mean, 4.6 cm) in the fresh specimen, and 0.5-6.2 cm (mean, 3.2 cm) in the fixed specimen. The tissue shrinkage ratio was a mean of 69% (interquartile range, 61-77%). Taking all ratios from MRI and histopathological examination of tissue shrinkage into account, the collective tissue shrinkage ratio was 70% (95% confidence interval, 67-73%)

CONCLUSION

The length of the distal resection margin was reduced by 30% after surgical removal and fixation of the specimen.

The Influence of the Distal Resection Margin Length on Local Recurrence and long- term Survival in Patients with Rectal Cancer after Chemoradiotherapy and Sphincter- Preserving Rectal Resection

Background

Low recurrence rates and long term survival are the main therapeutic goals of rectal cancer surgery. Complete, margin- negative resection confers the greatest chance for a cure. The aim of our study was to determine whether the length of the distal resection margin was associated with local recurrence rate and long- term survival.

Patients and methods

One hundred and nine patients, who underwent sphincter-preserving resection for locally advanced rectal cancer after preoperative chemoradiotherapy between 2006 and 2010 in two tertiary referral centres were included in the study. Distal resection margin lengths were measured on formalin-fixed, pinned specimens. Characteristics of patients with distal resection margin < 8 mm (Group I, n = 27), 8–20 mm (Group II, n = 31) and > 20 mm (Group III, n = 51) were retrospectively analysed and compared. Median (range) follow-up time in Group I was 89 (51–111), in Group II 83 (57–111) and in Group III 80 (45–116) months (p = 0.326), respectively.

Results

Univariate survival analysis showed that distal resection margin length was not statistically significantly associated with overall survival or local recurrence rate (p > 0.05). In a multiple Cox regression analysis, after adjusting for pathologic T and N stage (yT, yN), distal resection margin length was still not statistically significantly associated with overall survival.

Conclusions

Our study shows that close distal resection margins can be accepted as oncologically safe for sphincter-preserving rectal resections after preoperative chemoradiotherapy.

The adequacy of the distal resection margin after preoperative chemoradiotherapy for rectal cancer

AIM

The study aimed to determine the adequacy of the distal margin in patients having preoperative chemoradiotherapy (CRT) followed by restorative surgery for rectal cancer.

METHOD

A total of 368 patients with locally advanced rectal cancer treated for cure at our institution between July 1999 and March 2009 were included in the study. All underwent preoperative CRT and sphincter-sparing surgery. The distal margin and other factors were examined for their effect on recurrence and survival. The median duration of follow-up was 48 months.

RESULTS

The length of distal margin ranged from 0 to 9.0 cm (median 1.5 cm). The pelvic control and disease-free survival rates at 5 years for patients with a margin of ≤ 3 mm were no different from those in whom it was > 3 mm (P = 0.6 and 0.8). The 5-year pelvic control rates between the ≤ 3 mm and > 3 mm groups were 66.7 and 86.2% in patients with a ypT3-4 tumour (P = 0.049) and 70.0 and 89.1% in patients who showed no response to CRT (P = 0.039).

CONCLUSION

The results suggest that a distal margin of < 3 mm in the surgical specimen after preoperative CRT is associated with a lower rate of pelvic tumour control at 5 years in patients with Stage ypT3-4 tumours or in those who do not respond to CRT.

Extent and completeness of mesorectal excision evaluated by postoperative magnetic resonance imaging

BACKGROUND

The major advance in rectal cancer management over the past 20 years has been the standardization of mesorectal excision. The aim of this study was to determine the prevalence and localization of inadvertent residual mesorectum detected on magnetic resonance imaging (MRI) after rectal cancer surgery.

METHODS

Postoperative T2-weighted MRI of the pelvis was performed on patients following mesorectal excision. A multidisciplinary team radiologist evaluated the images with regard to residual mesorectum and distal margin. Only mesorectum above the level of the anastomosis perpendicular to the bowel was regarded as inadvertent residual mesorectum after partial mesorectal excision. Histopathological records, standardized photographs and clinical records were assessed. The pathology and MRI findings were evaluated independently in a blinded fashion.

RESULTS

MRI-detected residual mesorectum was identified in 54 (39·7 per cent) of 136 patients. There was agreement with the pathology findings in 88 patients (64·7 per cent). Residual mesorectum was more frequent in patients treated with partial mesorectal excision (63 per cent) than those who had total mesorectal excision (36 per cent) or abdominoperineal resection (13 per cent) (P < 0·001). Pathology and MRI findings both showed that the distal resection margin after partial mesorectal excision was less than 5 cm in more than three-quarters of patients, and less than 3 cm in more than one-third.

CONCLUSION

Inadvertent residual mesorectum was commonly found on postoperative MRI, especially after partial mesorectal excision.