Proposed distal margin for resection of rectal cancer

Impact of Microscopically Positive (≤1 mm) Distal Margins on Disease Recurrence in Rectal Cancer Treated by Neoadjuvant Chemoradiotherapy

BACKGROUND

The adequate distal resection margin is still controversial in rectal cancer treated by neoadjuvant chemoradiotherapy (nCRT). The aim of this study was to assess the impact of a distal margin of ≤1 mm on locoregional recurrence-free survival (LRRFS).

METHODS

Among 255 patients treated with nCRT and surgery at the National Cancer Institute of Milan, 83 (32.5%) had a distal margin of ≤1 mm and 172 (67.5%) had a distal margin of >1 mm. Survival analyses were performed to assess the impact of distal margin on 5-year LRRFS, as well as Cox survival analysis. The role of distal margin on survival was analyzed according to different tumor regression grades (TRGs).

RESULTS

The overall 5-year LRRFS rate was 77.6% with a distal margin of ≤1 mm vs. 88.3% with a distal margin of >1 mm (Log-rank p = 0.09). Only stage ypT4 was an independent predictor of worse LRRFS (HR 15.14, p = 0.026). The 5-year LRRFS was significantly lower in TRG3-5 patients with a distal margin of ≤1 mm compared to those with a distal margin of >1 mm (68.5% vs. 84.2%, p = 0.027), while no difference was observed in case of TRG1-2 (p = 0.77).

CONCLUSIONS

Low-responder rectal cancers after nCRT still require a distal margin of >1 mm to reduce the high likelihood of local relapse.

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.

Long-term oncological outcomes of the sphincter preserving total mesorectal excision with varying distal resection margins

INTRODUCTION

A subcentimeter distal resection margin (DRM) appears to be acceptable for most patients, however, long-term follow up and specific subsets where DRM would influence recurrences have not been adequately investigated.

METHODS

A retrospective analysis of all sphincter-preserving resections for mid and low rectal cancers between July 2011 and May 2015 was performed. Extended total mesorectal excisions (TME) and patients with positive pathologic circumferential margins (CRM) were excluded.

RESULTS

Two hundred and thirty-six patients fit the inclusion criteria. DRM > 20 mm was obtained in 117 patients (49.6%), between 10 and 20 mm in 78 (33%) and <10 mm in 41 (17.4%) patients. Pathological DRM was positive in 4 patients (1.7%). Sixty-five recurrences occurred at a median follow up of 78.5 months. DRM did not influence any of the oncological outcomes. In a subset analysis of patients with poor pathological response to neoadjuvant radiation, that is, tumor regression grade > 3, DRM influenced disease-free survival (DFS) but not overall survival with a hazard ratio of 4.4 (p = 0.02). This was confirmed on multivariate regression analysis in this subgroup as well where pathological nodal status and DRM < 10 mm were independent predictors of DFS.

CONCLUSIONS

A subcentimeter DRM may be acceptable in most patients except those who have an inadequate response to neoadjuvant radiation.

The effect of pericolic lymph nodes metastasis beyond 10 cm proximal to the tumor on patients with rectal cancer

Background

This study aims to determine the real incidence of pericolic lymph nodes metastasis beyond 10 cm proximal to the tumor (pPCN) and its prognostic significance in rectal cancer patients.

Methods

Consecutive patients with rectal cancer underwent curative resection between 2015 and 2017 were included. Margin distance was marked and measured in vivo and lymph nodes were harvested on fresh specimens. Clinicopathological characteristics and oncological outcomes (3-year overall survival (OS) and disease-free survival (DFS)) were analyzed between patients with pPCN and patients without pPCN (nPCN).

Results

There were 298 patients in the nPCN group and 14 patients (4.5%) in pPCN group. Baseline characteristics were balanced except more patients received preoperative or postoperative chemoradiotherapy in pPCN group. Preoperative more advanced cTNM stage (log-rank p = 0.005) and intraoperative more pericolic lymph nodes beyond 10 cm proximal to the tumor (PCNs) (log-rank p = 0.002) were independent risk factors for pPCN. The maximum short-axis diameter of mesenteric lymph nodes ≥8 mm was also contributed to predicting the pPCN. pPCN was an independent prognostic indicator and associated with worse 3-year OS (66% vs 91%, Cox p = 0.033) and DFS (58% vs 92%, Cox p = 0.012).

Conclusion

The incidence of pPCN was higher than expected. Patients with high-risk factors (cTNM stage III or more PCNs) might get benefits from an extended proximal bowel resection to avoid residual positive PCNs.

Impact of Length of Distal Margin on Outcomes Following Sphincter Preserving Surgery for Middle and Lower Third Rectal Cancers

Outcomes of sphincter preserving surgery for distal rectal cancers improve with clear circumferential resection and distal resection margin. However, the extent of distal resection margin after a complete mesorectal excision is often a cause for debate. We evaluated the outcome of middle and lower third rectal cancer patients undergoing sphincter preservation with variable distal resection margin at our center. Patients with biopsy-proven rectal adenocarcinoma within 10 cm from anal verge undergoing sphincter preserving resections were included. Patients with positive circumferential resection margin were excluded. Patients were divided into three groups based on the extent of distal resection margin (< 6 mm, 6-10 mm, > 10 mm) and oncological outcomes were compared. The median age of 242 patients was 50 years and 44 (18.2%) were high-grade tumors. Preoperative chemoradiation was used in 185 (75.2%) patients. Median distal resection margin was 20 mm. Patients in < 10 mm group had a significantly higher proportion of lower third (68.3% vs 39.8%, p = 0.004) and chemoradiation-treated tumors (85.4 vs 74.6%, p = 0.001). A significantly higher percentage required an intersphincteric resection in the < 10 mm group (53.7% vs 14.4%, p = 0.0001). Significantly higher percentage tumors were pT3 in > 10 mm group (45.3% vs. 31.7%) (p = 0.05). The median follow-up was 23 months. There was no difference in the overall, loco-regional, and distant recurrence rates between the three groups. A subcentimeter distal resection margin does not influence loco-regional or distant recurrence rates following sphincter preserving surgery for middle and lower third rectal adenocarcinoma.

Changes in disease pattern and treatment outcome of colorectal cancer: a review of 5,474 cases in 20 years

BACKGROUND AND AIMS

Colorectal cancer (CRC) is the third most common cause of cancer-related death in Taiwan. During the past 20 years, several advances have improved the treatment outcome and quality of life of CRC patients. The purpose of this study was to identify the changes in the clinicopathological features and outcome of CRC over this period.

MATERIALS AND METHODS

Based on the computerized database of the Taipei Veterans General Hospital, between January 1981 and December 2000, 5,474 CRC patients were identified and divided into 2 groups based on the date of treatment (1981-1990 and 1991-2000). The clinicopathological features, outcome, and prognostic factors were analyzed and compared.

RESULTS/FINDINGS

The age at onset of cancer was 61 years in the 1980s group and 66 years in the 1990s group. The frequency of rectal tumors decreased from 50% in the 1980s group to 44% in the 1990s group. Tumor, nodes, metastasis (TNM) stage distribution, surgical mortality, and anastomosis leakage were similar in the two groups. However, the 5-year overall survival rate was better in the 1990s group (56%) than that in the 1980s group (50%, P = 0.001). For rectal cancer patients, the local recurrence rate was lower in the 1990s group (6%) than that in the 1980s group (10%, P < 0.01). In stage III CRC, the 5-year overall survival rate was significantly higher in the 1990s group (54%) than that in the 1980s group (48%, P = 0.011). TNM stage was the most important independent prognostic factor for overall and disease-free survivals, followed by differentiation grade, CEA level, and treatment period.

INTERPRETATION/CONCLUSION

Advances in surgical technique and more standard use of chemotherapy have improved CRC outcome.

Changes in outcome with sphincter preserving surgery for rectal cancer in Korea, 1991-2000

AIM

To report the clinical and oncological data of patients operated on for rectal cancers 3-5 cm from the AV over a 10 year period, including the Sphincter preservation (SP) rate.

METHODS

We reviewed medical records of 304 patients with rectal cancers 3-5 cm from the AV who underwent surgical resection from January 1991 through December 2000. The 10 years were divided into three periods based on the introduction of new surgical techniques, specifically, ultralow anterior resection (ULAR) with double stapling in March 1994 and ULAR with coloanal anastomosis in April 1997. The rates of SP, complications and patient survival during these periods were compared.

RESULTS

The SP rate increased significantly over the 10 years, from 16.4% in period I (January 1991-February 1994), to 53.0% in period II (March 1994-March 1997), to 86.5% in period III (April 1997-December 2000) (p<0.001). Over time, the age of the patients increased (p=0.004), the length of the distal resection margin became shorter (p=0.005), and the rate of lymph node metastasis increased (p=0.016). The factors significantly influencing SP were the period (p<0.001) and the distance from the AV (p<0.001). Over time, morbidity did not increase, and overall and disease free survival rates did not decrease. In contrast, the overall survival of N2 cases significantly increased over time (p=0.0492).

CONCLUSION

Over 10 years, the SP rate in rectal cancers 3-5 cm from the AV was significantly increased by the introduction of the double stapling and coloanal anastomosis techniques. These surgical methods, however, had no effect on morbidity, disease free survival and overall survival rates.

Preoperative parameters expanding the indication of sphincter preserving surgery in patients with advanced low rectal cancer

OBJECTIVE

To clarify the preoperative parameters of the required distal margin that can be applied to the criteria of sphincter-preserving surgery in rectal cancer.

SUMMARY BACKGROUND DATA

Although aggressive sphincter-preserving surgery, including intersphincteric resection, is beginning to be applied to low rectal tumors, unexpected distal cancer spread might undermine local control in patients undergoing such a procedure. The 'two-centimeter rule' of distal clearance is predominant at present, whereas preoperative criteria to determine the individual required distal margin have not yet been established.

METHODS

First, by reviewing 556 rectal cancers, promising risk parameters of intramural distal spread (IM) were selected and, subsequently, such parameters were examined in regard to whether they could be evaluated preoperatively. Furthermore, 80 patients with lower rectal cancers located above the anal canal who were undergoing abdominoperineal resection were reviewed as to whether IM risk factors could be used as criteria to identify the low rectal cancer with or without anal canal involvement.

RESULTS

IM was observed in 10.6% (IM >or= 10 mm: 2.3%) of the patients examined, and the incidence was higher in tumors with certain unfavorable histologic characteristics, including tumor "budding," in their submucosal region at the distal edge (24.4%) than in those with no such histology (5.3%). Regarding such unfavorable histology as IM risk factor, together with 3/4 or more annularity and type 3 gross appearance, IM rates were 3.3% (IM >or= 10 mm: 0.5%) in the no-risk group, 9.1% (IM >or= 10 mm: 1.7%) in the one-risk group, and 29.1% (IM >or= 10mm: 7.8%) in the multiple-risks group. These results were reproduced well even if such risk factors were evaluated endoscopically or histologically on preoperative biopsy specimens. Furthermore, no anal canal involvement was observed in 32 tumors without IM risk; however, microscopic cancer spread down to the anal canal, including that into outside of the internal sphincter muscle, was observed in 9.1% of tumors with one IM risk and in 26.7% of multiple-risk tumors.

CONCLUSIONS

The preoperative evaluation of particular parameters related to IM enabled the accurate selection of rectal cancer to which the one-centimeter rule of distal clearance can be applied. This could allow us to expand the indication of sphincter preservation for very low rectal cancer patients.

Distal intramural spread is an independent prognostic factor for distant metastasis and poor outcome in patients with rectal cancer: a multivariate analysis

BACKGROUND

The aim of this study was to clarify the prognostic value of distal intramural spread of tumor for survival and recurrence in patients with rectal cancer.

METHODS

Microscopic distal intramural spread was examined in 134 consecutive specimens of resected rectal cancer. Correlations among distal intramural spread, established clinicopathologic factors, and patients' prognoses were examined by univariate and multivariate analyses. American Joint Committee on Cancer classification and stage groupings were used for tumor assessment.

RESULTS

Thirty-three patients (24.6%) had distal intramural spread. Multivariate logistical regression analysis revealed that T3/T4 and M1 were independent predictive variables for the presence of distal intramural spread. Patients with distal intramural spread had a shorter disease-specific or disease-free survival time after curative surgery than those without distal intramural spread (P =.0003 and P =.0006, respectively). Most patients with distal intramural spread developed distant recurrence. Cox's regression with multiple covariates showed that distal intramural spread is an independent factor in predicting distant recurrence and worse outcomes after curative surgery in patients with rectal cancer.

CONCLUSIONS

Distal intramural spread is an independent risk factor for distant metastasis and poor prognosis in patients with rectal cancer.

Adequacy of 1-cm distal margin after restorative rectal cancer resection with sharp mesorectal excision and preoperative combined-modality therapy

BACKGROUND

Preoperative combined-modality therapy (CMT) for rectal cancer allows a sphincter-sparing procedure in some individuals who would otherwise require an abdominoperineal resection. To further define the subset of rectal cancer patients suitable for this approach, we determined the adequacy of a distal margin of < or = 1 cm in patients with locally advanced rectal cancer requiring preoperative CMT.

METHODS

Ninety-four consecutive patients, status post curative low anterior resection for rectal cancer after preoperative CMT, were identified from the prospective Colorectal Service Database. Distal margin length, tumor grade, tumor-node-metastasis stage, presence of lymphovascular and perineural invasion, and tumor distance from the anal verge were examined for their effect on recurrence and survival. Median follow-up was 44 months.

RESULTS

Distal margin length ranged from.1 to 9.5 cm (median, 2.0 cm) and did not correlate with local recurrence (hazard ratio, 1.1; P =.34) or recurrence-free survival (hazard ratio, 1.1; P =.29) by univariate analysis. Kaplan-Meier estimates of recurrence-free survival and local recurrence at 3 years for the < or = 1 cm versus >1 cm and the < ore = 2 cm versus > 2 cm groups were not significantly different. Groups were well matched for other clinicopathologic variables.

CONCLUSIONS

Our data suggest that for patients with locally advanced rectal cancer undergoing resection and preoperative CMT, distal margins < or = 1 cm do not seem to compromise oncological outcome.

Locally recurrent rectal cancer: role of composite resection of extensive pelvic tumors with strategies for minimizing risk of recurrence

Locally recurrent cancer of the rectum has been under-recognized as a complication, although it affects up to 40% of patients treated with surgery alone. Even in the best centers, rates average 25%. While radiotherapy may reduce recurrence, it is now apparent that total mesorectal excision is the most effective modality, with rates as low as 5%. The dramatic decrease in local recurrence can also be linked to increased survival in prospective studies, an effect more significant than any adjuvant therapy. The options, however, for patients with locally recurrent cancer are limited. Fifteen percent of patients with this complication die without systemic spread. Salvage by surgery offers potential cure. Other than anastomotic recurrences that can be locally resected, the best approach for long-term survival is an extensive surgical procedure requiring en bloc removal of adjacent organs and pelvic structures-so-called composite resection. With careful selection, 30% 5-year survival can be achieved and palliation is considerable, with 50% long-term local control. Intraoperative radiotherapy and brachytherapy, and/or preoperative chemoradiation may provide better results in future. Newer techniques of coloanal anastomosis, improved urinary diversion, and myocutaneous flaps for perineal reconstruction radically reduce the morbidity of these procedures. The approach to recurrent rectal cancer requires a sophisticated multidisciplinary team to obtain optimum results.