Less than 12 nodes in the surgical specimen after total mesorectal excision following neoadjuvant chemoradiation: it means more than you think!

Prognostic significance of lymph node yield on oncologic outcomes according to tumor response after preoperative chemoradiotherapy in rectal cancer patients

PURPOSE

This study aimed to evaluate the predictive value of lymph node yield (LNY) for survival outcomes according to tumor response after preoperative chemoradiotherapy (PCRT) in patients with rectal cancer.

METHODS

This study was a retrospective study conducted in a tertiary center. A total of 1,240 patients with clinical stage II or III rectal cancer who underwent curative resection after PCRT between 2007 and 2016 were included. Patients were categorized into the good response group (tumor regression grade [TRG], 0-1) or poor response group (TRG, 2-3). Propensity score matching was performed for age, sex, and pathologic stage between LNY of ≥12 and LNY of <12 within tumor response group. The primary outcome was 5-year disease-free survival (DFS) and overall survival (OS).

RESULTS

LNY and positive lymph nodes were inversely correlated with TRG. In good responders, 5-year DFS and 5-year OS of patients with LNY of <12 were better than those with LNY of ≥12, but there was no statistical significance. In poor responders, the LNY of <12 group had worse survival outcomes than the LNY of ≥12 group, but there was also no statistical significance. LNY of ≥12 was not associated with DFS and OS in multivariate analysis.

CONCLUSION

LNY of <12 showed contrasting outcomes between the good and poor responders in 5-year DFS and OS. LNY of 12 may not imply adequate oncologic surgery or proper staging in rectal cancer patients treated by PCRT. Furthermore, a decrease in LNY should be comprehended differently according to tumor response.

Robotic or transanal total mesorectal excision (TaTME) approach for rectal cancer, how about both? Feasibility and outcomes from a single institution

Laparoscopic surgery for rectal cancer is technically challenging. Robotic and transanal TME (TaTME) are both novel approaches developed to provide better visualization and dissection. We aim to combine both approaches in a hybrid procedure and evaluate the feasibility as well as patient and oncological outcomes in this study. A review of a prospectively maintained database of patients who underwent a hybrid abdominal robotic approach with TaTME for rectal cancer between January 2016 and October 2018 was undertaken. Patient demographics, tumor characteristics and surgical outcomes were recorded and analyzed. A total of 69 patients (43 males, 26 females) received this hybrid approach. Their median age was 58 years (range 35-87) with a mean BMI of 24.3 kg/m² (range 16.4-44.2). Median distance from anal verge was 5 cm (range 2-9). The patients had a median hospital length of stay of 7 days (range 5-28). Complication rate was 17.4% (12 patients) with 3 patients (4.3%) requiring a reoperation. TME quality was optimal with all of them either complete (81.2%) or almost complete (18.8%). 65 patients (94.2%) had an R0 resection with 4 patients (5.8%) with involved circumferential resection margins (≤ 1 mm). The median number of lymph nodes harvested was 20 (range 6-37). After a median follow-up of 27.7 months (range 7-42), local recurrence was identified in 2 patients (4%). Three patients (5.2%) had distant recurrence at the 3-year mark. Hybrid robotic abdominal dissection with transanal TME for rectal cancer appears to be feasible with comparable surgical outcomes to other traditional approaches.

Downstaged ypT0-2N0 rectal cancer after neoadjuvant chemoradiation therapy may not need adjuvant chemotherapy: a retrospective cohort study

PURPOSE

Current guidelines suggest that adjuvant chemotherapy (AC) be administered to all locally advanced (clinically T3-4 or N-positivity) rectal cancer patients undergoing neoadjuvant chemoradiotherapy (nCRT) and radical surgical resection regardless of the final pathological staging (yp staging). This study aimed to evaluate the necessity of AC for ypT0-2N0 rectal cancer.

METHODS

Patients with ypT0-2N0 rectal cancer, who received nCRT and radical surgical resection, were recruited retrospectively at a university hospital. The main outcome was to evaluate the 5-year overall survival (OS) and disease-free survival (DFS) between ypT0-2N0 rectal cancer patients with AC and those without AC. We also identified potential independent prognostic factors associated with poor outcomes.

RESULTS

One hundred and ten ypT0-2N0 rectal cancer patients (ypT0: n = 6; ypT1: n = 44; ypT2: n = 60) were followed up for a median of 60 months. No significant difference was observed in DFS and 5-year OS between patients with AC and those without AC. The risk of recurrence was associated with the postoperative pathological staging (0% with ypT0, 2.4% with ypT1, and 10% with ypT2). In the multivariate analysis, retrieval of < 12 lymph nodes was an independent favorable prognostic factor, which correlated with a higher OS (HR: 2.263; 95% CI: 1.093-4.687, P = 0.028). Intra-tumor lymphovascular and perineural invasion were poor prognostic markers for shorter DFS (HR: 5.940; 95% CI: 1.150-30.696, P = 0.033).

CONCLUSION

Postoperative AC is not required for patients with ypT0-2N0 rectal cancer downstaged by nCRT, especially in those without poor prognostic factors.

Impact factors of lymph node retrieval on survival in locally advanced rectal cancer with neoadjuvant therapy

BACKGROUND

Conventional clinical guidelines recommend that at least 12 lymph nodes should be removed during radical rectal cancer surgery to achieve accurate staging. The current application of neoadjuvant therapy has changed the number of lymph node dissection.

AIM

To investigate factors affecting the number of lymph nodes dissected after neoadjuvant chemoradiotherapy in locally advanced rectal cancer and to evaluate the relationship of the total number of retrieved lymph nodes (TLN) with disease-free survival (DFS) and overall survival (OS).

METHODS

A total of 231 patients with locally advanced rectal cancer from 2015 to 2017 were included in this study. According to the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) tumor-node-metastasis (TNM) classification system and the NCCN guidelines for rectal cancer, the patients were divided into two groups: group A (TLN ≥ 12, n = 177) and group B (TLN < 12, n = 54). Factors influencing lymph node retrieval were analyzed by univariate and binary logistic regression analysis. DFS and OS were evaluated by Kaplan-Meier curves and Cox regression models.

RESULTS

The median number of lymph nodes dissected was 18 (range, 12-45) in group A and 8 (range, 2-11) in group B. The lymph node ratio (number of positive lymph nodes/total number of lymph nodes) (P = 0.039) and the interval between neoadjuvant therapy and radical surgery (P = 0.002) were independent factors of the TLN. However,TLN was not associated with sex, age, ASA score, clinical T or N stage, pathological T stage, tumor response grade (Dworak), downstaging, pathological complete response, radiotherapy dose, preoperative concurrent chemotherapy regimen, tumor distance from anal verge, multivisceral resection, preoperative carcinoembryonic antigen level, perineural invasion, intravascular tumor embolus or degree of differentiation. The pathological T stage (P < 0.001) and TLN (P < 0.001) were independent factors of DFS, and pathological T stage (P = 0.011) and perineural invasion (P = 0.002) were independent factors of OS. In addition, the risk of distant recurrence was greater for TLN < 12 (P = 0.009).

CONCLUSION

A shorter interval to surgery after neoadjuvant chemoradiotherapy for rectal cancer under indications may cause increased number of lymph nodes harvested. Tumor shrinkage and more extensive lymph node retrieval may lead to a more favorable prognosis.

Prognostic impact of at least 12 lymph nodes after neoadjuvant therapy in rectal cancer: A meta-analysis

BACKGROUND

The number of dissected lymph nodes (LNs) in rectal cancer after neoadjuvant therapy has a controversial effect on the prognosis.

AIM

To investigate the prognostic impact of the number of LN dissected in rectal cancer patients after neoadjuvant therapy.

METHODS

We performed a systematic review and searched PubMed, Embase (Ovid), MEDLINE (Ovid), Web of Science, and Cochrane Library from January 1, 2000 until January 1, 2020. Two reviewers examined all the publications independently and extracted the relevant data. Articles were eligible for inclusion if they compared the number of LNs in rectal cancer specimens resected after neoadjuvant treatment (LNs ≥ 12 vs LNs < 12). The primary endpoints were the overall survival (OS) and disease-free survival (DFS).

RESULTS

Nine articles were included in the meta-analyses. Statistical analysis revealed a statistically significant difference in OS [hazard ratio (HR) = 0.76, 95% confidence interval (CI): 0.66-0.88, I² = 12.2%, P = 0.336], DFS (HR = 0.76, 95%CI: 0.63-0.92, I² = 68.4%, P = 0.013), and distant recurrence (DR) (HR = 0.63, 95%CI: 0.48-0.93, I² = 30.5%, P = 0.237) between the LNs ≥ 12 and LNs < 12 groups, but local recurrence (HR = 0.67, 95%CI: 0.38-1.16, I² = 0%, P = 0.348) showed no statistical difference. Moreover, subgroup analysis of LN negative patients revealed a statistically significant difference in DFS (HR = 0.67, 95%CI: 0.52-0.88, I² = 0%, P = 0.565) between the LNs ≥ 12 and LNs < 12 groups.

CONCLUSION

Although neoadjuvant therapy reduces LN production in rectal cancer, our data indicate that dissecting at least 12 LNs after neoadjuvant therapy may improve the patients’ OS, DFS, and DR.

Influence of tumor location on short- and long-term outcomes after laparoscopic surgery for rectal cancer: a propensity score matched cohort study

BACKGROUND

This study aimed to evaluate the short- and long-term outcomes after laparoscopic resection for low rectal cancer (LRC) compared with mid/high rectal cancer (M/HRC).

METHODS

Patients with rectal cancer undergoing laparoscopic resection with curative intent were retrospectively reviewed between 2009 and 2015. After matched 1:1 by using propensity score analysis, perioperative and oncological outcomes were compared between LRC and M/HRC groups. Multivariate analysis was performed to identify independent factors of overall survival (OS) and disease-free survival (DFS).

RESULTS

Of 373 patients who met the criteria for inclusion, 198 patients were matched for the analysis. Laparoscopic surgery for LRC required longer operative time (P<0.001) and more blood loss volume (P = 0.015) compared with M/HRC, and the LRC group tended to have a higher incidence of postoperative complications (16.2% vs. 8.1%, P = 0.082). There was no significant difference in local recurrence between the two groups (9.1% vs. 4.0%, P = 0.251), whereas distant metastasis was inclined to be more frequent in LRC patients compared with M/HRC (21.2% vs. 12.1%, P = 0.086). The LRC group showed significantly inferior 5-year OS (77.0% vs. 86.4%, P = 0.033) and DFS (71.2% vs. 86.2%, P = 0.017) compared with the M/HRC group. Multivariate analysis indicated that tumor location was an independent predictor of DFS (HR = 2.305, 95% CI 1.203-4.417, P = 0.012).

CONCLUSION

Tumor location of the rectal cancer significantly affected the clinical and oncological outcomes after laparoscopic surgery, and it was an independent predictor of DFS.

Preoperative endoscopic tattooing technique improved lymph node retrieval in rectal cancer patients receiving neoadjuvant concurrent chemoradiotherapy

Aims

To describe the clinical utility of lymph node retrieval and prognostic value of tattooing in rectal cancer (RC) patients undergoing neoadjuvant concurrent chemoradiotherapy (CCRT).

Methods

A total 97 RC patients underwent preoperative CCRT, and 38 patients had preoperative endoscopic tattooing. Surgical intervention was performed after CCRT and the specimens were sampled as standard protocol in all patients. Other clinicopathological parameters correlated with lymph node retrieval status were also analysed.

Results

Fifteen patients (39.5%) of 38 RC patients in the tattooing group (TG) had adequate lymph node retrieval (>12) compared with 12 (20.3%) of 59 in the non-tattooing group. Higher lymph node retrieval rate was noted in the TG (p=0.04). In multivariable analysis, it showed tattooing was an independent predictive factor for higher lymph node retrieval in RC patients after CCRT (p=0.024) by logistic regression modelling. Besides histological grade, positive lymphovascular invasion, presence of lymph node metastasis, poor CCRT response and advanced pathological stage, inadequate lymph node retrieval was significantly associated with poor survival (all p<0.05) by Kaplan-Meier analysis. In multivariable analyses, the results revealed that lymph node retrieval (p=0.005), pathological stage (p=0.001) and tumour progression grade (p=0.02) were independent prognostic markers in RC patients receiving CCRT.

Conclusion

Preoperative endoscopic tattooing is a useful technique for RC patient receiving neoadjuvant CCRT. It can improve lymph node retrieval and provide an adequate diagnosis for proper treatment and prognosis.

Hybrid abdominal robotic approach with conventional transanal total mesorectal excision (TaTME) for rectal cancer: feasibility and outcomes from a single institution

Total mesorectal excision (TME) is currently recognised as the standard of care for patients with rectal cancer. Complete TME is known to be associated with lower rates of recurrence. Robotic and endoscopic TaTME approaches are reported to offer excellent proximal and distal rectal dissection into the TME plane, however, combining both approaches in a hybrid procedure could potentially optimise visualisation of the dissection plane and confer improved circumferential and distal margin rates. The aim of this study was to analyse the feasibility of a hybrid robotic abdominal approach with conventional TaTME for rectal cancer. Furthermore, pathological and patient outcomes were assessed. A review of prospectively maintained databases was undertaken to assess all patients undergoing robotic TME surgery for rectal tumours from August 2016 to October 2017. Patient demographics, tumour characteristics and outcomes were collated from patient charts and hospital databases. All patients underwent a modified Cecil approach after multidisciplinary team discussion. Eight patients (7 male, 1 female) underwent a combined hybrid approach with a median age of 60 years (range 47-73) and BMI of 29.5 (range 20-39.1) kg/m². Median distance from the anorectal junction (ARJ) was 7.5 (range 4-13) cm. Six patients underwent neoadjuvant treatment with chemoradiotherapy. Patients had a median length of stay (LOS) of 9 (range 4-33) days. There were no intra-operative complications encountered and no patients required a conversion to an open procedure. Complications included one anastomotic leak and one presacral collection. All patients had a complete TME with RO resection with a median number of lymph nodes harvested was 22 (range 6-37) lymph nodes. This hybrid technique is a feasible, practical and operatively favourable approach to rectal cancer surgery with initial pathological outcomes and complication profile equivalent to other approaches.

Increased lymph node yield indicates improved survival in locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy

PURPOSE

It is recommended for colorectal cancer to harvest at least 12 lymph nodes (LNs) during surgery to avoid understaging of the disease. However, it is still controversial whether it is necessary to harvest from locally advanced rectal cancer (LARC) patients who underwent neoadjuvant chemoradiotherapy (neo-CRT). The impact of lymph node yield (LNY) on prognosis in LARC patients was analyzed.

MATERIALS/METHODS

In total, 495 LARC patients who underwent neo-CRT in 2006-2015 were analyzed. After examining clinicopathological distribution differences between the LNY subgroups (with the threshold of 12), univariate and multivariate Cox survival analyses were performed. Survival plots were obtained from Kaplan-Meier analyses. Similar subgroup analyses were performed according to the tumor regression grade (TRG) and metastatic status of post-operational LNs.

RESULTS

Of the 495 patients, 287 (57.98%) had an LNY of less than 12. Nearly no significant clinicopathological difference was found between the LNY subgroups, including the TRG scores. Multivariate survival analysis demonstrated that at least 12 LNs examined was an independent prognostic feature of good overall survival (OS), disease-free survival (DFS), and distant metastasis free survival (DMFS), but not local recurrence free survival (LRFS). However, in the subgroup analyses, no association was found between LNY and prognosis in patients with good TRG scores (0-1) or negative LNs.

CONCLUSIONS

For LARC patients treated with neo-CRT, an LNY of at least 12 indicated an improved survival. Decreased LNY was not related to better tumor regression. It suggests that a sufficiently high LNY is still required, especially in those with a potentially poor tumor response.

The relationship between mesorectal grading and oncological outcome in rectal adenocarcinoma

AIM

The prognostic association between mesorectal grading and oncological outcome in patients undergoing resection for rectal adenocarcinoma is controversial. The aim of this retrospective chart review was to determine the individual impact of mesorectal grading on rectal cancer outcomes.

METHOD

We compared oncological outcomes in patients with complete, near-complete and incomplete mesorectum who underwent rectal excision with curative intent from 2009 to 2014 for Stage cI-III rectal adenocarcinoma. We also assessed the independent association of mesorectal grading and oncological outcome using multivariate models including other relevant variables.

RESULTS

Out of 505 patients (339 men, median age of 60 years), 347 (69%) underwent a restorative procedure. There were 452 (89.5%), 33 (6.5%) and 20 (4%) patients with a complete, near-complete and incomplete mesorectum, respectively. Local recurrence was seen in 2.4% (n = 12) patients after a mean follow-up of 3.1 ± 1.7 years. Unadjusted 3-year Kaplan-Meier analysis by mesorectal grade showed decreased rates of overall, disease-free and cancer-specific survival and increased rates of overall and distant recurrence with a near-complete mesorectum, while local recurrence was increased in cases of an incomplete mesorectum (all P < 0.05). On multivariate analyses, a near-complete mesorectum was independently associated with decreased cancer-specific survival (hazard ratio 0.26, 95% CI 0.1-0.7; P = 0.007). There were no associations between mesorectal grading and overall survival, disease-free survival, overall recurrence or distant recurrence (all P > 0.05).

CONCLUSION

Mesorectal grading is independently associated with oncological outcome. It provides unique information for optimizing surgical quality in rectal cancer.

A Review of Current Challenges in Colorectal Cancer Reporting

Context.—

Pathologic assessment of colorectal cancer resection specimens plays an important role in postsurgical management and prognostication in patients with colorectal cancer. Challenges exist in the evaluation and reporting of these specimens, either because of difficulties in applying existing guidelines or related to newer concepts.

Objective.—

To address challenging areas in colorectal cancer pathology and to provide an overview of the literature, current guidelines, and expert recommendations for the handling of colorectal cancer resection specimens in everyday practice.

Data Sources.—

PubMed (US National Library of Medicine, Bethesda, Maryland) literature review; reporting protocols of the College of American Pathologists, the Royal College of Pathologists of the United Kingdom, and the Japanese Society for Cancer of the Colon and Rectum; and classification manuals of the American Joint Committee on Cancer and the Union for International Cancer Control.

Conclusions.—

This review has addressed issues and challenges affecting quality of colorectal cancer pathology reporting. High-quality pathology reporting is essential for prognostication and management of patients with colorectal cancer.

Pathological nodal staging score for rectal cancer patients treated with radical surgery with or without neoadjuvant therapy: a postoperative decision tool

Background

Lymph node status can predict the prognosis of patients with rectal cancer treated with surgery. Thus, we sought to establish a standard for the minimum number of lymph nodes (LNs) examined in patients with rectal cancer by evaluating the probability that pathologically negative LNs prove positive during surgery.

Patients and methods

We extracted information of 31,853 patients with stage I–III rectal carcinoma registered between 2004 and 2013 from the Surveillance, Epidemiology, and End Results database and divided them into two groups: the first group was SURG, including patients receiving surgery directly and the other group was NEO, encompassing those underwent neo-adjuvant therapy. Using a beta-binomial model, we developed nodal staging score (NSS) based on pT/ypT stage and the number of LNs retrieved.

Results

In both cohorts, the false-negative rate was estimated to be 16% when 12 LNs were examined, but it dropped to 10% when 20 LNs were evaluated. In the SURG cohort, to rule out 90% possibility of false staging, 3, 7, 28, and 32 LNs would be necessarily examined in patients with pT1–4 disease, respectively. While in the NEO cohort, 4, 7, 12, and 16 LNs would be included for examination in patients with ypT1–4 disease to guarantee an NSS of 90%.

Conclusion

By determining whether a rectal cancer patient with negative LNs was appropriately staged, the NSS model we developed in this study may assist in tailoring postoperative management.

Role of lymph node yield and lymph node ratio in predicting outcomes in non-metastatic colorectal cancer

Background

Lymph node yield (LNY) of 12 or more in resection of colorectal cancer is recommended in current international guidelines. Although a low LNY (less than 12) is associated with poorer outcome in some studies, its prognostic value is unclear in patients with early‐stage colorectal or rectal cancer with a complete pathological response following neoadjuvant therapy. Lymph node ratio (LNR), which reflects the proportion of positive to total nodes obtained, may be more accurate in predicting outcome in stage III colorectal cancer. This study aimed to identify factors correlating with LNY and evaluate the prognostic role of LNY and LNR in colorectal cancer.

Methods

An observational study was performed on patients with colorectal cancer treated at three hospitals in Melbourne, Australia, from January 2010 to March 2016. Association of LNY and LNR with clinical variables was analysed using linear regression. Disease‐free (DFS) and overall (OS) survival were investigated with Cox regression and Kaplan–Meier survival analyses.

Results

Some 1585 resections were analysed. Median follow‐up was 27·1 (range 0·1–71) months. Median LNY was 16 (range 0–86), and was lower for rectal cancers, decreased with increasing age, and increased with increasing stage. High LNY (12 or more) was associated with better DFS in colorectal cancer. Subgroup analysis indicated that low LNY was associated with poorer DFS and OS in stage III colonic cancer, but had no effect on DFS and OS in rectal cancer (stages I–III). Higher LNR was predictive of poorer DFS and OS.

Conclusion

Low LNY (less than 12) was predictive of poor DFS in stage III colonic cancer, but was not a factor for stage I or II colonic disease or any rectal cancer. LNR was a predictive factor in DFS and OS in stage III colonic cancer, but influenced DFS only in rectal cancer.

Lymph Node Yield After Neoadjuvant Chemoradiotherapy in Rectal Cancer Specimens: A Randomized Trial Comparing Two Fixatives

BACKGROUND

It is widely reported that neoadjuvant chemoradiation reduces lymph node yield in rectal cancer specimens. Some have questioned the adequacy of finding ≥12 lymph nodes for accurate staging, and fewer nodes were correlated with good response. Others reported that low lymph node count raises the chance for understaging and correlates with worse survival. In addition, a few studies demonstrated that diligent specimen analysis increases lymph node count.

OBJECTIVE

The aim of this study was to compare Carnoy's solution and formalin concerning lymph node yield in specimens of patients with rectal cancer after neoadjuvant chemoradiation.

DESIGN

This is a prospective randomized trial that was conducted from 2012 to 2015.

SETTINGS

This study was performed in a reference cancer center in Brazil.

PATIENTS

Patients who underwent low anterior resection with total mesorectal excision after neoadjuvant chemoradiation for rectal adenocarcinoma were included.

INTERVENTION

Rectosigmoid specimens were randomized for fixation with Carnoy's solution or formalin.

MAIN OUTCOME MEASURES

A total of 130 specimens were randomized. After dissection, the residual fat from the formalin group was immersed in Carnoy's solution in search for missed lymph nodes (Revision).

RESULTS

The Carnoy's solution group had superior lymph node count (24.0 vs 16.3, p < 0.01) and fewer cases with <12 lymph nodes (6 vs 22, p = 0.001). The Revision group found lymph nodes in all cases (mean, 11.1), retrieving metastatic lymph nodes in 6 patients. It reduced the formalin cases with <12 lymph nodes from 33.8% to 4.6% and upstaged 2 patients. Tumor response to neoadjuvant chemoradiotherapy was not associated with lymph node count.

LIMITATIONS

This was a unicentric study.

CONCLUSIONS

Compared with formalin, the Carnoy's solution increases lymph node count and reduces the cases with <12 lymph nodes. Harvested lymph nodes are missed following routine analysis and this is clinically relevant. Finding <12 lymph nodes is not a sign of good response to neoadjuvant chemoradiation (www.clinicaltrials.gov. Unique identifier: NCT02629315). See Video Abstract at http://links.lww.com/DCR/A694.

A statistical tool for risk assessment as a function of the number of lymph nodes retrieved from rectal cancer patients

AIM

Although a minimum of 12 lymph nodes (LNs) has been recommended for examination in colorectal cancer patients there remains considerable debate with regard to rectal cancer. Inadequacy of examined LNs could lead to understaging and inappropriate treatment as a consequence. We describe a statistical tool that allows an estimate of the probability of false-negative nodes.

METHOD

A total of 26 778 patients diagnosed between 2004 and 2013 with rectal adenocarcinoma [tumour stage (T stage) 1-3] who did not receive neoadjuvant therapies and had at least one histologically assessed LN were extracted from the Surveillance, Epidemiology and End Results (SEER) database. A statistical tool using beta-binomial distribution was developed to estimate the probability of missing a positive node as a function of the total number of LNs examined and T stage.

RESULTS

The probability of falsely identifying a patient as node-negative decreased with increasing number of nodes examined for each stage. It was estimated to be 72%, 66% and 52% for T1, T2 and T3 patients, respectively, with a single node examined. To confirm an occult nodal disease with 90% confidence, 5, 9 and 29 nodes need to be examined for patients from stages T1, T2 and T3, respectively.

CONCLUSION

The false-negative rate of the examined LNs in rectal cancer was verified to be dependent preoperatively on the clinical T stage. A more accurate nodal staging score was developed to recommend a threshold for the minimum number of examined nodes with regard to the favoured level of confidence.

Pathologic complete response implies a fewer number of lymph nodes in specimen of rectal cancer patients treated by neoadjuvant therapy and total mesorectal excision

Studies have suggested that the use of neoadjuvant chemoradiation results in a lower lymph nodes yield in rectal cancer patients.

OBJECTIVE

To evaluate factors associated with less than 12 lymph nodes harvested on patients with rectal cancer treated with preoperative chemoradiotherapy followed by total mesorectal excision.

PATIENTS

This was a cohort/retrospective single cancer center study. Low and mid locally advanced rectal cancer or T2N0 under risk of sphincter resection underwent chemoradiotherapy followed by total mesorectal excision with curative intent. Chemotherapy consisted of 5-FU and leucovorin IV. Total dose of pelvic radiation was 5040 Gys. All patients were staged and restaged by digital rectal examination, proctoscopy, colonoscopy, CT of abdomen and chest, and MRI of the pelvis. Patients were stratified in two groups: ≥12 and < 12 L N retrieved. The possible factors affecting number of LN were analyzed.

RESULTS

95 patients met the inclusion criteria. Mean LN harvest was 23.2 (3-67). 81 patients (85%) had ≥12 L N. Gender, age, tumor size, tumor stage, tumor location, length of specimen, presence of LN involvement, type of surgery, and surgical access showed no association with number of LN retrieved. Only pathological complete response showed a statistically significant association with <12 L N on univariate (p = 0.004) and multivariate analyses (p = 0.002).

LIMITATIONS

Data were collected retrospectively. The number of patients disparity between the two groups.

CONCLUSIONS

Complete pathologic response is associated with <12 L N harvested. Thus, the number of lymph nodes should not be used as a surrogate for oncologic adequacy of resection in patients with pathologic complete response.

Therapeutic effects of oxaliplatin-based neoadjuvant chemotherapy and chemoradiotherapy in patients with locally advanced rectal cancer: a single-center, retrospective cohort study

BACKGROUND

Neoadjuvant chemoradiotherapy (NACRT) has now become the standard treatment for locally advanced rectal cancer (LARC). NACRT has decreased local relapse (LR) rate in patients with LARC; however, distant relapse has recently attracted much attention. This study aimed to assess the feasibility and efficiency of neoadjuvant chemotherapy (NAC) for LARC.

METHODS

Data on patients with cT3/4 and N+ rectal cancer who were treated in our institution from April 2010 to February 2016 were reviewed retrospectively. Twenty-seven patients who received 2-9 cycles of oxaliplatin-based NAC and 28 patients who received NACRT (45 Gy delivered in 25 fractions and 5-fluorouracil-based oral chemotherapy) were analyzed. The primary and secondary endpoints of the present study were the 3-year relapse-free survival (RFS) and the local and distant relapse rates, respectively.

RESULTS

Regardless of the kind of neoadjuvant therapy, no patient experienced any grade 3-4 therapy-related adverse events. The frequent toxic events were grade 1 diarrhea in patients with NACRT and neutropenia in patients with NAC. A significantly higher proportion of patients with NAC underwent laparoscopic surgery and anterior resection (p = 0.037 and p = 0.003, respectively). The percentages of patients with lymph node yield less than 12 in the NAC group, and those in the NACRT group were 26 and 68%, respectively (p = 0.002). Comparing the NAC with the NACRT groups, the local relapse and distant relapse rates were 7.4 and 7.1% and 7.4 and 18%, respectively. There were no significant differences in 3-year RFS and 4-year overall survival (OS) between NAC and NACRT (3-year RFS 85.2 vs. 70.4%, p = 0.279; 4-year OS 96.3 vs. 89.1%, p = 0.145, respectively). With an analysis excluding patients who received postoperative adjuvant chemotherapy, no patients who received NAC had a distant relapse, and there was a significant difference in 3-year RFS compared with the NACRT groups (94.4 vs. 63.2%, p = 0.043).

CONCLUSION

These outcomes suggest that the therapeutic effect of oxaliplatin-based NAC is at least equal to that of NACRT and that NAC is a feasible and promising option for LARC.

Oncologic Outcome of ypT1-2N0 Rectal Cancer After Neoadjuvant Chemoradiotherapy Compared With pT1-2N0 Rectal Cancer

OBJECTIVE

To investigate the oncologic outcome of ypT1-2N0 mid and lower rectal cancer after chemoradiotherapy (CRT) compared with pT1-2N0 rectal cancer.

METHODS

We compared the oncologic outcome of patients with mid and lower rectal cancer who underwent preoperative CRT and who did not, between February 2005 and August 2012.

RESULTS

Compared with patients who did not receive preoperative CRT, patients who received preoperative CRT did not have significantly different clinicopathologic features except clinical stage and distal resection margin. The 5-year disease-free survival (DFS) rates were lower in patients who received preoperative CRT than those who did not (84.4% vs. 95.5%, P=0.029). Preoperative CRT was a prognostic factor affecting 5-year DFS in patients with pathologically proven stage T1N0 mid and lower rectal cancer (HR, 11.157; 95% CI, 1.735-71.762; P=0.011) CONCLUSIONS:: ypT2N0 rectal cancer after neoadjuvant CRT showed shorter DFS compared with pT2N0 rectal cancer.

Low-tie IMA and selective D3 lymph node sampling in laparoscopic rectal resection for carcinoma rectum: comparison of surgical and oncological outcomes with the open technique

Background

Level of proximal lymphovascular ligation remains controversial in carcinoma rectum. High-tie inferior mesenteric artery (IMA) claims better lymph node clearance; low-tie IMA minimizes autonomic nerve injury (ANI) and ensures vascularity to anastomosis. Objective of this study is to compare postsurgical complications and oncological clearance in laparoscopic rectal resection (LRR) and open rectal resection (ORR) for carcinoma rectum, with low-tie IMA and selective D3 lymphadenectomy.

Methods

Retrospective analysis was done comparing LRR and ORR done with low-tie IMA for carcinoma rectum/rectosigmoid for significant differences (P<0.05) regarding postsurgical complications and histopathology parameters.

Results

A total of 118 patients; 48 in LRR group and 70 in ORR group were studied. They were comparable in age, site of lesion and clinical TNM (cTNM) stage. Comorbidities and symptoms requiring upfront surgery were more among ORR. 75% LRR and 55.3% ORR had neoadjuvant chemoradiation (NACRT). Duration of surgery was longer in LRR. Clavien-Dindo grade >3 was similar in two groups. Histopathology characteristics were also comparable; including specimen length, lymph node yield, length of distal margin and pathologic TNM (pTNM) stage. Selective D3 lymphadenectomy was done in 37.5% LRR and 37.14% ORR. And 4.16% in LRR and 4.28% in ORR were had positive IMA root lymph nodes.

Conclusions

The post-surgical complications and oncological clearance of LRR done with low-tie IMA and selective D3 lymphadenectomy were found equivalent to ORR. Low-tie IMA without routine splenic flexure mobilisation had no technical issues regarding the anastomosis.

Treatment strategies for rectal cancer with synchronous liver metastases: surgical and oncological outcomes with propensity-score analysis

BACKGROUND

The optimal sequence of surgery for rectal cancer (RC) with synchronous liver metastases (SLM) is controversial.

OBJECTIVES

The primary objective was to explore differences between the rectum first (RF) and the liver first strategy (LF) to achieve the complete resection (CR) of both tumors.

METHODS

Patients diagnosed of RC with resectable or potentially resectable SLM were included. Data collected prospectively were analyzed with an intention-to-treat perspective, adjusting for between-sample differences (propensity score). The complete resection rate (CRR) was the main outcome variable.

RESULTS

During a 5-year period, 23 patients underwent the LF strategy and 24 patients the RF strategy. Median overall survival (OS) was 32 months in the LF group and 41 months in the RF group (p = 0.499), and was 51 and 17 months, respectively, for patients achieving or not achieving CR of both tumors (p < 0.001). CRR's were 65% in liver first group and 63% in rectum first group, (p = 0.846). No between-strategy differences in morbidity or duration of treatment were observed.

CONCLUSIONS

This study supports the notion that the achievement of CR of RC and SLM should be the goal of oncological treatment. Both RF and LF strategies are feasible and safe, but no between-strategy differences have been found in the CRR.

Considering Value in Rectal Cancer Surgery: An Analysis of Costs and Outcomes Based on the Open, Laparoscopic, and Robotic Approach for Proctectomy

OBJECTIVE

The aim of the study was to compare value (outcomes/costs) of proctectomy in patients with rectal cancer by 3 approaches: open, laparoscopic, and robotic.

BACKGROUND

The role of minimally invasive proctectomy in rectal cancer is controversial. In the era of value-based medicine, costs must be considered along with outcomes.

METHODS

Primary rectal cancer patients undergoing curative intent proctectomy at our institution between 2010 and 2014 were included. Patients were grouped by approach [open surgery, laparoscopic surgery, and robotic surgery (RS)] on an intent-to-treat basis. Groups were compared by direct costs of hospitalization for the primary resection, 30-day readmissions, and ileostomy closure and for short-term outcomes.

RESULTS

A total of 488 patients were evaluated; 327 were men (67%), median age was 59 (27-93) years, and restorative procedures were performed in 333 (68.2%). Groups were similar in demographics, tumor characteristics, and treatment details. Significant outcome differences between groups were found in operative and anesthesia times (longer in the RS group), and in estimated blood loss, intraoperative transfusion, length of stay, and postoperative complications (all higher in the open surgery group). No significant differences were found in short-term oncologic outcomes. Direct cost of the hospitalization for primary resection and total direct cost (including readmission/ileostomy closure hospitalizations) were significantly greater in the RS group.

CONCLUSIONS

The laparoscopic and open approaches to proctectomy in patients with rectal cancer provide similar value. If robotic proctectomy is to be widely applied in the future, the costs of the procedure must be reduced.

Patterns of recurrence in patients achieving pathologic complete response after neoadjuvant chemoradiotherapy for rectal cancer

PURPOSE

The aim of this study was to characterize the patterns of recurrence in patients achieving pathologic complete response (pCR) after neoadjuvant chemoradiotherapy (CRT) for locally advanced rectal cancer.

METHODS

Patients with locally advanced rectal cancer treated with neoadjuvant CRT and who achieved pCR from January 2004 to December 2012 were collected. The primary outcome measurement was the patterns of recurrence.

RESULTS

Among 195 patients who achieved pCR, 18 developed recurrence. Furthermore, local recurrence occurred in 1.5% of patients (3/195), while distant metastases occurred in 7.7% of patients (15/195), which included 7 lung metastases, 1 liver metastasis, and 8 metastases in other locations.

CONCLUSIONS

Our study indicated that patients achieving pCR following neoadjuvant CRT have a favorable prognosis, with distant metastases predominating in all recurrences. Among patients with distant metastases, non-liver metastases were the predominant pattern.

A single institution's long-term follow-up of patients with pathological complete response in locally advanced rectal adenocarcinoma following neoadjuvant chemoradiotherapy

PURPOSE

This paper aimed to study the long term follow-up of patients with primary rectal adenocarcinoma receiving neoadjuvant chemoradiotherapy who obtained a pathological complete response (pCR) and identify factors predicting complete response.

METHODS

Retrospective review of notes, histology, pre-operative full blood count and imaging of patients with primary rectal adenocarcinoma diagnosed in our institute from 2000 to 2012 from a prospectively maintained database were used. SPSS version 22.0 was used for statistical analysis.

RESULTS

Three hundred eighty patients diagnosed with primary rectal adenocarcinoma were identified, 277 received neoadjuvant chemoradiotherapy followed by curative resection. Forty-six patients obtained a pCR (ypT0N0) with no local recurrence and two metastatic recurrences on follow-up. Patients with a pCR have a significantly improved overall survival and disease-free survival compared to a non-pCR (150.0 and 136.1 vs 77.5 and 84.7 months, p = 0.001). On univariate analysis, increased tumour height above anal verge, low lymph node yield, high pre-operative haemoglobin and a low neutrophil-lymphocyte ratio are significant factors identifying a pCR. Multivariable analysis of the above factors confirmed tumour height above anal verge as significant in obtaining a pCR.

CONCLUSION

Patients with rectal adenocarcinoma who develop a pCR following neoadjuvant chemoradiotherapy have improved overall and disease-free survival. We have identified distance from anal verge, low lymph node yield, high pre-operative haemoglobin and low neutrophil-lymphocyte ratio as significant predictors of developing a pCR.

Lymph node yield is an independent predictor of survival in rectal cancer regardless of receipt of neoadjuvant therapy

AIMS

Lymph node yield (LNY) is used as a marker of adequate oncological resection. The American Joint Committee on Cancer (AJCC) currently recommends that at least 12 nodes are necessary to confirm node-negative disease for rectal cancer. A LNY of 12 is not always achieved, particularly in patients who have undergone neoadjuvant treatment. This study attempts to examine factors associated with LNY and its prognostic impact following neoadjuvant chemoradiation in rectal cancer.

METHODS

The 2006-2011 National Cancer Data Base was queried for patients with clinical stage I-III rectal cancer who underwent a proctectomy. Suboptimal LNY was defined as <12 lymph nodes examined. A mixed-effects multinomial logistic regression model was used to identify independent factors associated with LNY. Mixed-effects Cox proportional hazards models were used to estimate the adjusted effect of LNY on 5-year overall survival.

RESULTS

25 447 patients met inclusion criteria. Overall, 62% of the cohort received neoadjuvant chemoradiation and 32% had suboptimal LNY. The median LNY for patients who received neoadjuvant therapy was 13 (IQR: 9-18) and for patients who did not receive neoadjuvant therapy was 15 (IQR: 12-21). After risk adjustment, there was a 3.5-fold difference in the rate of suboptimal LNY among individual hospitals (27%-95%). Suboptimal LNY was independently associated with an 18% increased hazard of death among patients who did not receive neoadjuvant treatment and a 20% increased hazard of death among those who did receive neoadjuvant treatment when controlled for adjuvant treatment, staging, proximal/distal margins and other patient factors.

CONCLUSIONS

Suboptimal LNY is independently associated with worse overall survival regardless of neoadjuvant therapy, pathological staging and patient factors in rectal cancer. This finding underlies the importance and challenge of an optimal lymph node evaluation for prognostication, especially for patients receiving neoadjuvant therapy.

Less than 12 lymph nodes in the surgical specimen after neoadjuvant chemo-radiotherapy: an indicator of tumor regression in locally advanced rectal cancer?

BACKGROUND

The number of lymph node retrieved in the surgical specimen is important for tumor staging and has paramount impact on prognosis in colorectal cancer and imitates the adequacy of lymph node surgical clearance. The paucity of lymph node yields in patients undergoing resection after preoperative chemo radiotherapy (CRT) in rectal cancer has seen. Lower total number of lymph nodes in the total mesoractal excision (TME) specimen after CRT, could a marker of better tumor response.

METHODS

We retrospectively reviewed the prospectively managed data of patients underwent excision for rectal cancer, who treated by neoadjuvant radiotherapy with or without chemotherapy in locally advanced rectal cancer. From 2010 to 2014, 364 patients underwent rectal cancer surgery, of which ninety-one treated with neoadjuvant treatment. Standard surgical and pathological protocols were followed. Patients were categorized into two groups based on the number of total harvested lymph nodes with group 1, having 12 or more nodes harvested, and group 2 including patients who had <12 lymph nodes harvested. The total number of lymph nodes retrieved from the surgical specimen was correlated with grade of tumor regression with neoadjuvant treatment.

RESULTS

Out of 91 patients, 38 patients (42%) had less than 12 lymph nodes examined in specimen. The difference in median number of lymph nodes was observed significantly as 9 (range, 2-11) versus 16 (range, 12-32), in group 2 and 1, respectively (P<0.01). Patients with fewer lymph node group were comparable with respect to age, BMI, pre-operative staging, neoadjuvant treatment. Pathological complete response in tumor pCR was seen with significantly higher rate (40% vs. 26%, P<0.05) in group 2. As per Mandard criteria, there was significant difference in tumor regression grade (TRG) between both the groups (P<0.05). Among patients with metastatic lymph nodes, median LNR was lower in <12 lymph nodes group at 0.167 (range, 0.09-0.45) versus 0.187 (range, 0.05-0.54), difference was not statistically significant (P=0.81).

CONCLUSIONS

Retrieval of fewer than 12 lymph nodes in surgical specimen of rectal cancer who had received neo-adjuvant radiotherapy with or without chemotherapy should be considered as a good indicator of tumor response with better local disease control, and a good prognostic factor, rather than as a pointer of poor diligence of the surgical and pathological assessment.

Prognostic significance of lymph node yield in ypN0 rectal cancer

BACKGROUND

Neoadjuvant radiation therapy for locally advanced rectal adenocarcinoma decreases lymph node yield. This study investigated the association between survival and number of lymph nodes evaluated in patients with pathologically negative nodes after neoadjuvant therapy.

METHODS

Patients with locally advanced rectal adenocarcinoma who underwent neoadjuvant therapy and had pathologically negative lymph nodes were included from the Surveillance, Epidemiology, and End Results (SEER) database over a 7-year interval (January 2004 to December 2010). Systematic dichotomization for optimal cut-off point identification was performed using statistical modelling.

RESULTS

A total of 3995 patients met the inclusion criteria. The majority had T3 (66·7 per cent) and moderately differentiated (71·5 per cent) tumours. The median number of lymph nodes retrieved was 12 (i.q.r. 7-16). An optimal cut-off of nine lymph nodes was identified. Increasing age (P < 0·001), increasing T category (T4 versus T1, P < 0·001; T3 versus T1, P = 0·010), response to neoadjuvant therapy (P < 0·001) and number of nodes evaluated (P < 0·001) were significant factors for overall survival in univariable analysis. After adjustment in the multivariable model, the group with nine or more nodes examined had significantly better overall survival (hazard ratio (HR) 0·76, 95 per cent c.i. 0·65 to 0·88, P < 0·001; 5-year survival 83·2 versus 78·0 per cent) and cancer-specific survival (HR 0·76, 0·64 to 0·92, P = 0·004; 5-year survival 87·9 versus 85·1 per cent) than the group with one to eight nodes examined.

CONCLUSION

Overall and cancer-specific survival were worse where fewer than nine lymph nodes were identified after neoadjuvant therapy for locally advanced rectal cancer.

The role of lymph node revealing solution on the improvement of lymph node harvest in colorectal cancer specimens

AIM

The correct analysis of lymph node status is one of the most important parameters for the accurate pathological diagnosis of colorectal cancer. Our aim was to evaluate the number of lymph nodes among the specimens obtained from colorectal resections due to colorectal cancer, before and after the routine use of a lymph node revealing solution (LNRS).

METHOD

Data from 780 surgical specimens from patients of both genders with colorectal cancer were studied. The cases were divided chronologically into two groups: the conventional group included 497 specimens treated with conventional methods, i.e. without the use of the LNRS (January 2000 to July 2007), and the LNRS group included 283 specimens examined through the routine use of this solution (August 2007 to July 2012).

RESULTS

Most patients were female (57.4%) with a median age of 62 years. The median lymph node number was 18, and 75.9% of the cases (592) had 12 or more nodes dissected. Lymph node metastases were noted in 334 cases (42.8%). A median of 24 lymph nodes was dissected in the LNRS group compared to 15 in the conventional group (P < 0.001). The LNRS group had 9.2% of cases with fewer than 12 lymph nodes dissected compared with 32.6% in the conventional group (P < 0.001).

CONCLUSIONS

The use of the LNRS increases the number of lymph nodes obtained from colorectal cancer surgical specimens and can help to reduce the number of cases with < 12 lymph nodes.

Effect of Lymph Node Count on Pathological Stage III Rectal Cancer with Preoperative Radiotherapy

Lymph node (LN) status after surgery for rectal cancer is affected by preoperative radiotherapy. The purpose of this study was to perform a population-based evaluation of the impact of pathologic LN status after neoadjuvant radiotherapy on survival. A total of 1,650 patients receiving neoadjuvant chemotherapy in Surveillance, Epidemiology, and End Results Program (SEER)-registered ypIII stage rectal cancer was analyzed. We identified the optimal cutoff for retrieved LNs as 10 (χ2 = 14.006, P < 0.001), which was validated as an independent prognosis factors in a Cox regression model. Further analysis showed that the LN count was only a prognosis factor with the number from 8 to 16(except for 13).After the number 16, the 5-year survival rate decreased gradually. Collectively, our results confirmed that the number of LNs in yp III stage rectal patients was a prognosis factor only with the numbers from 8 to 16(except for 13). Using the total mesorectal excision technique with an adequate pathologic examination, a large number of LNs retrieved (≥17) might indicate worse tumor response grade and poorer survival.

Neoadjuvant chemoradiation for rectal cancer is not associated with higher rates of thromboembolism

AIM

Thromboembolism (TE) is a leading cause of death amongst cancer patients. The effect of neoadjuvant chemoradiotherapy (nCRT) on the risk of TE in rectal cancer patients is unknown. The aim of this study was to determine whether nCRT was associated with an increased risk of TE in patients with rectal cancer, either during therapy or with subsequent treatment.

METHOD

This was a retrospective study from a prospectively maintained database at a tertiary referral centre. Participants included patients with rectal cancer treated between January 2000 and December 2013. The primary outcome was the rate of TE in patients with rectal cancer who had nCRT compared with those who did not.

RESULTS

One hundred and seventy-one (7.8%) of 2181 rectal cancer patients developed TE. Patients who had nCRT did not have an increased incidence of TE compared with those who had surgery alone (81/946, 8.6% vs 94/1235, 7.6%, P = 0.42) after a median follow-up of 95 months. Ten (1.1%) of 946 patients who received nCRT developed TE during or immediately after nCRT. Most TE events occurred in the 30-day postoperative period (70 patients, 3.2%).

CONCLUSION

The prevalence of TE in patients with rectal cancer was 7.8%, with most events occurring in within 30 days of surgery. Neoadjuvant chemoradiation was not associated with an increased risk of TE.

Increased number of negative lymph nodes is associated with improved cancer specific survival in pathological IIIB and IIIC rectal cancer treated with preoperative radiotherapy

Preoperative radiation significantly decreases the number of retrieved lymph nodes (LNs) in rectal cancer, but little is known with respect to the prognostic significance of negative LN (NLN) counts under these circumstances. In this study, Surveillance, Epidemiology, and End Results Program (SEER)-registered ypIII stage rectal cancer patients, and patients from Fudan University Shanghai Cancer Center (FDSCC) were combined and analyzed. The results showed that the survival rate of patients with n (cutoff) or more NLNs increased gradually when n ranged from two to nine. After n reached 10 or greater, survival rates were approximately equivalent. Furthermore, the optimal cutoff value of 10 was validated as an independent prognostic factor in stage ypIIIB and ypIIIC patients by both univariate and multivariate analysis (P < 0.001); the number of NLNs could also stratify the prognosis of ypN(+) patients in more detail. Patients in the FDSCC set validated these findings and confirmed that NLN count was not decreased in the good tumor regression group relative to the poor tumor regression group. These results suggest that NLN count is an independent prognostic factor for ypIIIB and ypIIIC rectal cancer patients, and, together with the number of positive LNs, this will provide better prognostic information than the number of positive LNs alone.

Response to chemoradiotherapy and lymph node involvement in locally advanced rectal cancer

AIM: To establish the association between lymph node involvement and the response to neoadjuvant therapy in locally advanced rectal cancer.

METHODS: Data of 130 patients with mid and low locally advanced rectal adenocarcinoma treated with neoadjuvant chemoradiation followed by radical surgery over a 5-year period were reviewed. Tumor staging was done by endorectal ultrasound and/or magnetic resonance imaging. Tumor response to neoadjuvant therapy was determined by T-downstaging and tumor regression grading (TRG). Pathologic complete response (pCR) is defined as the absence of tumor cells in the surgical specimen (ypT0N0). The varying degrees TRG were classified according to Mandard’s scoring system. The evaluation of the response is based on the comparison between previous clinico-radiological staging and the results of pathological evaluation. χ² and Spearman’s correlation tests were used for the comparison of variables.

RESULTS: Pathologic complete response (pCR, ypT0N0, TRG1) was observed in 19 cases (14.6%), and other 18 (13.8%) had only very few residual malignant cells in the rectal wall (TRG2). T-downstaging was found in 63 (48.5%). Mean lymph node retrieval was 9.4 (range 0-38). In 37 cases (28.5%) more than 12 nodes were identified in the surgical specimen. Preoperative lymph node involvement was seen in 77 patients (59.2%), 71 N1 and 6 N2. Postoperative lymph node involvement was observed in 41 patients (31.5%), 29 N1 and 12 N2, while the remaining 89 were N0 (68.5%). In relation to ypT stage, we found nodal involvement of 9.4% in ypT0-1, 22.2% in ypT2 and 43.7% in ypT3-4. Of the 37 patients considered “responders” to neoadjuvant therapy (TRG1 and 2), there were only 4 N+ (10.8%) and the remainder N0 (89.2%). In the “non responders” group (TRG 3, 4 and 5), 37 cases were N+ (39.8%) and 56 (60.2%) were N0 (P < 0.001).

CONCLUSION: Response to neoadjuvant chemoradiation in rectal cancer is associated with lymph node involvement.

Oncologic Impact of Fewer Than 12 Lymph Nodes in Patients Who Underwent Neoadjuvant Chemoradiation Followed by Total Mesorectal Excision for Locally Advanced Rectal Cancer

A minimum of 12 harvested lymph nodes (hLNs) are recommended in colorectal cancer. However, a paucity of hLNs is frequently presented after preoperative chemoradiation (pCRT) in rectal cancer and the significance of this is still uncertain. The aim of this study is to analyze the impact of hLNs on long-term oncologic outcomes. A total of 302 patients with locally advanced rectal cancer who underwent pCRT and curative resection between 1989 and 2009 were reviewed. Patients were categorized into 2 groups according to the number of hLNs: <12 versus ≥12 LN. The 2 groups were compared with respect to 5-year disease-free and overall survival. The optimal number or ratio of hLNs was investigated in subgroup analysis according to LN status. The median follow-up was 57 months. Patient characteristics other than age did not differ between the 2 groups. The group with <12 LNs had more favorable ypTNM and ypN stage than those with ≥12 LNs. However, the long-term oncologic outcomes were not significantly different between the 2 groups. In subgroup analysis of ypN(-), the group with <5 hLNs had the most favorable oncologic outcomes. In ypN(+) cases, a higher LN ratio tended to be associated with poorer 5-year overall survival. The paucity of hLNs in locally advanced rectal cancer after chemoradiation did not imply poor oncologic outcomes in this study. In addition, <5 hLNs in ypN(-) patients could reflect a good tumor response rather than suboptimal radicality.

Impact of Total Lymph Node Count on Staging and Survival After Neoadjuvant Chemoradiation Therapy for Rectal Cancer

PURPOSE

Current guidelines recommend that a minimum of 12 lymph nodes (LNs) be dissected to accurately stage rectal cancer patients. Neoadjuvant chemoradiation therapy (CRT) decreases the number of LNs retrieved at surgery. The purpose of this study was to assess the impact of the number of LNs dissected on overall survival (OS) for localized rectal cancer patients treated with neoadjuvant CRT.

METHODS

Treatment data were obtained on all patients treated for rectal cancer (2000-2013) in the National Oncology Data Alliance™, a proprietary database of merged tumor registries. Eligible patients were treated with neoadjuvant CRT followed by surgery and had complete data on number of positive LNs, number of LNs examined, and treatment dates (n = 4565).

RESULTS

Hazard ratios for OS decreased sequentially with increasing number of LNs examined until a maximum benefit was achieved with examination of eight LNs. On multivariate analysis, age, sex, race, marital status, grade, ypT stage, ypN stage, type of surgery, margin status, presence of pathologically confirmed metastasis at surgery, and number of LNs examined were significant predictors of OS.

CONCLUSIONS

Examination of eight or more LNs in rectal cancer patients treated with neoadjuvant CRT resulted in accurate staging and assignment into prognostic groups with an ensuing improvement in OS by stage. This study suggests that eight LNs is the threshold for an adequate lymph node dissection after neoadjuvant CRT.

Intraoperative fluorescence imaging to localize tumors and sentinel lymph nodes in rectal cancer

Tumor involvement at the resection margin remains the most important predictor for local recurrence in patients with rectal cancer. A careful description of tumor localization is therefore essential. Currently, endoscopic tattooing with ink is customary, but visibility during laparoscopic resections is limited. Near-infrared (NIR) fluorescence imaging using indocyanine green (ICG) could be an improvement. In addition to localize tumors, ICG can also be used to identify sentinel lymph nodes (SLNs). The feasibility of this new technique was explored in five patients undergoing laparoscopic low anterior resection for rectal cancer. Intraoperative tumor visualization was possible in four out of five patients. Fluorescence signal could be detected 32 ± 18 minutes after incision, while ink could be detected 42 ± 21 minutes after incision (p = 0.53). No recurrence was diagnosed within three months after surgery. Ex vivo imaging identified a mean of 4.2 ± 2.7 fluorescent lymph nodes, which were appointed SLNs. One out of a total of 83 resected lymph nodes contained a micrometastasis. This node was not fluorescent. This technical note describes the feasibility of endoscopic tattooing of rectal cancer using ICG:nanocolloid and NIR fluorescence imaging during laparoscopic resection. Simultaneous SLN mapping was also feasible, but may be less reliable due to neoadjuvant therapy.

Implications of lymph node retrieval in locoregional rectal cancer treated with chemoradiotherapy: a California Cancer Registry Study

BACKGROUND

In contrast to colon cancer, the implications of reduced lymph node retrieval in rectal cancer are unclear.

METHODS

Using the California Cancer Registry, we performed a retrospective cohort study of 4790 patients with stage I - III rectal cancer diagnosed from 2000 to 2007 who underwent tri-modality therapy. Using multivariate Cox proportional hazards models adjusted for age, sex, race, socioeconomic status, T-stage, and lymph node numbers, we evaluated rectal cancer specific survival (RC-SS) in neoadjuvant and adjuvant cohorts in the overall population and amongst those without involved lymph nodes (pN0).

RESULTS

Sixty one percent of evaluable patients were treated with neoadjuvant chemoradiation. Although there was no difference in RC-SS between neoadjuvant and adjuvant chemoradiation cohorts, the median number of lymph nodes examined was reduced after neoadjuvant therapy (8 vs. 11, p < 0.0001). Positive lymph nodes were associated with worse RC-SS regardless of sequence, although the effect was numerically stronger for residual lymph nodes in the neoadjuvant cohort. Compared to at least 12, eight or fewer lymph nodes retrieved was associated with worse outcome in both neoadjuvant and adjuvant cohorts. However, no association between reduced lymph nodes examined and RC-SS was seen in the neoadjuvant cohort when the analysis was restricted to pN0 patients.

CONCLUSIONS

In this large cohort of rectal cancer patients treated with tri-modality therapy, reduced lymph node retrieval in node negative patients did not provide additional prognostic information in patients treated with neoadjuvant therapy.

Transanal total mesorectal excision (taTME) for cancer located in the lower rectum: short- and mid-term results

BACKGROUND

Laparoscopic trans-abdominal total mesorectal excision is technically demanding. Transanal Total Mesorectal Excision (taTME) is a new technique which seems to provide technical advantages. This study describes the results of taTME in a consecutive series of patients with low rectal cancer.

METHODS

From January 2012 to December 2013, a consecutive series of 26 patients with low rectal cancer underwent laparoscopic taTME with coloanal anastomosis. cT4 or Type II-III rectal cancer (according to Rullier's classification) were contraindications to taTME. After anal sleeve mucosectomy, the rectal wall was transected at the ano-rectal junction. A single-access multichannel port was inserted in the anal canal. taTME was performed from down to up until the sacral promontory posteriorly and the Pouch of Douglas anteriorly were reached. A laparoscopic trans-abdominal approach was used to complete the left colon mobilization.

RESULTS

Sixteen patients (61.5%) were male. The mean distance of the rectal cancer from the anal verge was 4.4 cm (range 3-6). Nineteen patients (73.1%) received long-course neoadjuvant radiotherapy. At final pathology, resection margins were negative in all the patients: the mean distal and radial resection margins were 19 mm and 11.2 mm, respectively. TME was complete in 23 patients (88.5%) and nearly complete in three. Postoperative mortality was 3.8%. The overall morbidity rate was 26.9% (7 patients): two patients (7.7%) had an anastomotic leakage (Dindo I-d). After a mean follow up of 23 months, no patients have developed a local recurrence.

CONCLUSIONS

laparoscopic taTME allow wide resection margins and good quality TME.

Lymph node count after preoperative radiotherapy is an independently prognostic factor for pathologically lymph node-negative patients with rectal cancer

Recent studies indicated that preoperative radiotherapy significantly reduces the lymph nodes (LNs) harvest from patients with rectal cancer. This may weaken the prognostic value of current standard of LNs retrieval (≥12 LNs). This study investigates the prognostic impact of the LN counts on pathologically LN-negative (ypN0) after preoperative radiotherapy for patients with rectal cancer.Surveillance, Epidemiology and End Results (SEER) registered nonmetastatic rectal cancer patients diagnosed between 1998 and 2005 were included in this study. Optimal cutoff value for number of LNs retrieved was determined by X-tile program. Log-rank tests were adopted to compare the rectal cause specific survival (RCSS) for ypN0 patients using separated cutoff value of LN counting from 2 to 20. Correlation between LN count and tumor regression was investigated in an additional 221 patients from Fudan University Shanghai Cancer Center (FUSCC).The results showed that there were fewer number of LNs examined in patients with preoperative radiotherapy than those without (8.9 vs 10.9, P < 0.001). X-tile program identified the difference in survival was most significant (maximum of χ log-rank values) for the number 4. And 5-year RCSS increased accordingly with the cutoff values ranging from 4 to 15, which were confirmed as optimal cutoff and validated as independent prognostic factors in multivariate regression analysis (χ = 50.65, P < 0.001). Patients in FUSCC set were found to have fewer LNs retrieval in group of good tumor regression than in that of poor one (P = 0.01).These results confirmed the reduced number of LN retrieval in patients with rectal cancer treated with preop-RT. LN count is still an independently prognostic factor for ypN0 rectal cancer.

Serosal surfaces, mucin pools, and deposits, oh my: challenges in staging colorectal carcinoma

Colorectal carcinoma is the third most common cancer in the United States. Proper and standardized pathologic staging is vital for prognostic assessment and impacts therapeutic decisions. The Tumor Node Metastasis (TNM) staging system was developed by the American Joint Committee on Cancer (AJCC) to be a data-driven, evidence-based staging system providing an accurate prediction of outcome. The AJCC 7th edition (2010) included several changes clarifying some issues and leading to new controversies. We aim to address selected challenging issues in tumor T staging, neoadjuvant treatment effects in rectal cancer, and definition of lymph node vs tumor deposit. Serosal involvement in colorectal cancer is staged as T4, which is associated with decreased survival and may impact additional therapy decisions. Although careful sampling and sectioning are helpful, challenges remain in interpretation of tumor within 1 mm of serosal surface with a reaction. Elastic stain as a surrogate marker for serosal invasion has been studied, but its usefulness remains unclear. Some unique issues in rectal cancer include the presence of serosa in proximal but not in distal tumors and post-neoadjuvant effects. Tumor should be staged based on tumor cells rather than acellular mucin pools. Additionally, tumor response should be graded only in primary tumor but not in lymph nodes or metastatic sites. The distinction between tumor deposits and lymph nodes has been modified in AJCC TNM from using size in the 5th edition, to the round contour in the 6th edition, to only features of residual lymph node architecture in the 7th edition. Interobserver variability remains but tumor deposits should be documented when present. The number of deposits should not be added to the total number of positive lymph nodes, and the N1c designation should only be used in cases without any positive lymph nodes. Future clarification will likely evolve as more data become available.

Impact of lymph node ratio and number on survival in patients with rectal adenocarcinoma after preoperative chemo radiation

BACKGROUND

Retrieval of <12 lymph nodes after proctectomy and preoperative chemoradiation (C-XRT) may improve survival in good risk patients. The objective of this study was to determine impact of <12 retrieved lymph nodes and lymph node ratio (LNR) on survival in a population with certain poor prognostic features for rectal cancer.

METHODS

Patients who underwent surgery for rectal adenocarcinoma between 2005 and 2011 were divided them into <12 or >12 lymph node groups. The LNR groups were based on interquartile range. Clinicopathological and treatment outcomes were compared. Expected 5 year disease free and overall survival was calculated. Cox proportional hazard model was used to determine independent predictors.

RESULTS

More patients in <12 lymph nodes removed group had low tumors (<5 cm from anal verge) (75.5% versus 60.7%) (P=0.03) and underwent abdominoperineal resection (59.1% versus 42.9%) (P=0.02). Overall survival (OS) and disease free survival (DFS) was not different [(56% and 52% (P=0.7)] [(50% and 57% (P=0.5)]. LNR<0.15 was independent predictor of DFS while LNR ratio<0.12 for OS on multivariate analysis.

CONCLUSION

LNR and not number of retrieved nodes impacts survival in younger patients with predominance of anorectal tumors after C-XRT. A specific LNR cutoff remains to be defined.

Low Lymph Node Retrieval After Preoperative Chemoradiation for Rectal Cancer is Associated with Improved Prognosis in Patients with a Good Tumor Response

PURPOSE

To examine the association between the number of lymph nodes retrieved and oncologic outcome after preoperative chemoradiation for rectal cancer according to tumor regression grade.

METHODS

Patients with rectal cancer who underwent curative surgery between May 2004 and December 2012 were analyzed retrospectively. Using multivariate analysis, the correlation between clinicopathologic variables and the number of lymph nodes retrieved was evaluated. The associations between the oncologic outcome and number of lymph nodes retrieved were also investigated according to the tumor regression grade.

RESULTS

In total, 1,332 patients were identified, of whom 433 (32.8 %) received preoperative chemoradiation. Multivariate analysis revealed that preoperative chemoradiation was an independent predictor of the number of lymph nodes retrieved (P = 0.002). After chemoradiation, the number of total and positive lymph nodes retrieved was inversely correlated with tumor regression. Retrieval of ≥12 lymph nodes was not an independent prognostic factor for disease-free survival; however, among patients with a good tumor response, those with <12 lymph nodes retrieved had a significantly better 3-year disease-free survival (P = 0.030) than those with ≥12 lymph nodes retrieved.

CONCLUSIONS

Reduced lymph node yield after preoperative chemoradiation for rectal cancer does not indicate inadequate oncologic surgery. It may represent good treatment response and better prognosis, especially in patients with good pathologic tumor regression after chemoradiation.

The impact of pathologic nodal status on survival following neoadjuvant chemoradiation for locally advanced rectal cancer

PURPOSE

For patients with locally advanced rectal cancer, the accuracy rates of preneoadjuvant therapy nodal staging and potential nodal downstaging make the prognostic significance of nodal status unclear. We therefore sought to review our experience in order to better understand the impact of clinical and pathologic nodal status upon patient outcomes.

METHODS

174 patients were identified as having undergone neoadjuvant chemoradiation and resection for rectal cancer. For analytic purposes, patients were grouped into four nodal categories (uN( 0)· pN( 0), uN( 0)· pN( +), uN (+) · pN( 0), and uN (+) · pN( +)). Univariate and multivariate analyses were performed.

RESULTS

104 men and 70 women of median age 60 years (29-85 years) were followed for a median of 31 months (1-121 months). Nodal staging was available for 129 patients, with a median of 8 lymph nodes (range 0-39) evaluated. Disease recurred in 3 of 41 (7%) uN   (0) ·pN (  0), 10 of 52 (20%) uN (   +)·pN (  0), 7 of 18 (41%) uN (  0)·pN (   +), and 6 of 17 (35%) uN (  +)·pN (  +) patients. Those patients having nodal downstaging (uN (  +)·pN (  0)) experienced superior overall survival (p = 0.03). Only pathologic nodal status was a significant predictor of both disease-free and overall survival in multivariate modeling. Adjuvant chemotherapy did not impact disease-free or overall survival for patients with pN0.

CONCLUSIONS

Pathologic nodal status may represent a superior predictor of survival for patients with local advanced rectal cancers. Our findings may have potential implications for the application of adjuvant therapy.

Laparoscopic versus open surgery following neoadjuvant chemoradiotherapy for rectal cancer: a systematic review and meta-analysis

BACKGROUND

This meta-analysis aimed to evaluate the short-term and pathological outcomes of laparoscopic surgery (LS) versus open surgery (OS) following neoadjuvant chemoradiotherapy (NCRT) for rectal cancer.

METHODS

PubMed, Embase, Web of Science, Cochrane Library, and Chinese Biomedicine Literature databases were searched for eligible studies published up to July 2013. The rates of postoperative complication, positive circumferential resection margin (CRM), and the number of lymph nodes harvested were evaluated.

RESULTS

Three randomized controlled trials (RCTs) and five non-RCTs enrolling 953 patients were included. Compared to OS, LS had similar rate of postoperative complication [odds ratio (OR) 0.86; 95% confidence interval (CI), 0.60 to 1.22], comparable rate of positive CRM (OR 0.41; 95% CI, 0.16 to 1.02), and smaller number of lymph nodes (weighted mean difference -0.8; 95% CI, -1.1 to -0.5). LS also had significantly less blood loss, faster bowel movement recovery, and shorter postoperative hospitalization than those of OS.

CONCLUSION

LS is associated with favorable short-term benefits, similar postoperative complication rate, and comparable pathological outcomes for rectal cancer after NCRT compared to OS despite a slight difference in the number of lymph nodes. Additional high-quality studies are needed to validate long-term outcomes of LS following NCRT.