Lymph node yield in rectal cancer surgery: effect of preoperative chemoradiotherapy

Pathologic Outcomes of Short-Course and Long-Course Radiotherapy for Locally Advanced Rectal Cancers Treated With Total Neoadjuvant Therapy

INTRODUCTION

Total neoadjuvant therapy (TNT) for patients with locally advanced rectal cancer (LARC) is now the standard of care. Randomized trials suggest the use of short-course radiotherapy (SCRT) and long-course radiotherapy (LCRT) are oncologically equivalent.

OBJECTIVE

To describe pathologic outcomes after surgical resections of patients receiving SCRT versus LCRT as part of TNT for LARC.

PARTICIPANTS

All patients with LARC treated at a single tertiary hospital who underwent proctectomy after completing TNT were included. Patients were excluded if adequate details of TNT were not available in the electronic medical record.

RESULTS

A total of 53 patients with LARC were included. Thirty-nine patients (73.5%) received LCRT and 14 (26.4%) received SCRT. Forty-nine patients (92.5%) were clinical stage III (cN1-2) prior to treatment. The average lymph node yield after proctectomy was 20.9 for SCRT and 17.0 for LCRT (P = .075). Of the 49 patients with clinically positive nodes before treatment, 76.9% of those who received SCRT and 72.2% of those who received LCRT achieved pN0 disease after TNT. Additionally, there were no significant differences in rates of pathologic complete response between patients who received SCRT and LCRT, 7.1% and 12.8%, respectively (P = .565).

CONCLUSION

Pathologic outcomes of patients with LARC treated with SCRT or LCRT, as part of TNT, may be similar. Further prospective trials are needed to assess long-term clinical outcomes and to determine best treatment protocols.

Impact of neoadjuvant therapy on nodal harvest in clinical stage III rectal cancer: Establishing optimum cut-offs by disease response

INTRODUCTION

A minimum lymph node harvest (LNH) of 12 is the current standard for appropriate nodal staging in resectable rectal cancer. However, the rise of neoadjuvant chemoradiation (NCRT) and total neoadjuvant therapy (TNT) has been associated with decreasing number of LNH. We hypothesize that as tumor response to neoadjuvant therapy increases, the optimum for LNH to achieve appropriate nodal staging should decrease.

METHODS

Patients with clinical stage III rectal adenocarcinoma who underwent NCRT/TNT followed by resection were identified from the National Cancer Database. A JoinPoint regression analysis was used to determine the LNH for each tumor regression grade (TRG) category beyond which the rate of positive nodes does not significantly change.

RESULTS

Thirteen thousand four hundred and twenty-six patients met inclusion criteria. Of these, 2406 (17.9%) achieved TRG 0 or ypT0 and 8210 (61.2%) achieved ypN0. Collectively, 2043 patients (15.2%) were reported to have a pathologic complete response (ypT0 ypN0). Positive pathologic nodes were found in 15%, 23%, 31%, 54%, and 53% as ypT stage increased from ypT0 to ypT4, respectively. Similarly, ypN+ rates were 15%, 36%, 41%, and 55% in TRG 0-3. No JoinPoint was identified for TRG 0, whereas inflection points were found at 6-10 nodes for TRG1 (p = 0.002) and TRG 2 (p = 0.016), and at 11-15 nodes for TRG 3.

CONCLUSION

The benchmark of retrieving 12 nodes in resectable stage III rectal cancer is not consistently achieved after NCRT/TNT. We demonstrate that the LNH requirement to establish accurate pathologic nodal staging can vary depending on the tumor response to neoadjuvant therapies.

Comparison of conventional unstained lymph nodal harvesting vs methylene blue-stained lymph nodal harvesting in colorectal specimen in staging left-sided colorectal carcinoma: a randomized controlled trial

BACKGROUND

The management and prognosis of colorectal carcinomas (CRCs) are related to the stage of the disease, which, in turn, relies on the lymph node harvest from the surgical specimen. The guidelines recommend that at least 12 lymph nodes are required, which is not achieved in most resections. In this study, we propose a method to improve the lymph node yield in such cases. This study aimed to determine whether ex vivo injection of methylene blue into the inferior mesenteric artery or its branches improves lymph node retrieval in left-sided CRCs.

METHODS

This study was conducted as a single-center, double-blinded, superiority randomized controlled trial. Patients who underwent elective surgery for left-sided CRCs with curative intent were randomized into 2 groups: stained and unstained. The sample size was calculated as 66. In all patients, details of disease stage, history of neoadjuvant therapy, and number of isolated lymph nodes were recorded.

RESULTS

The mean number of lymph nodes extracted from the stained group was significantly higher than that from the unstained group (15.9 ± 5.2 vs 9.1 ± 5.7, respectively; P < .001). Among the patients who had received neoadjuvant therapy, the yield was higher in the stained group (P < .001). The yield was found to be greater in patients who had undergone upfront surgery than in those who had undergone neoadjuvant therapy, even in the stained group (100% vs 66.7%, respectively).

CONCLUSION

The use of methylene blue injection into resected specimens of left-sided CRCs significantly improved the lymph node yield.

Essentials of macroscopic evaluation of specimens from gastrointestinal tract

An astute macroscopic examination, coupled with correlating the gross findings with clinical indication and operative notes along with judicious, yet all pertinent sectioning for pathological examination is crucial for an accurate histopathological diagnosis, eventually leading to optimal patient care. This succinct review highlights the general concepts that lay the foundation of evaluating and grossing specimens from the luminal gastrointestinal (GI) tract. We also discuss the gross evaluation and sectioning of small therapeutic resections, along with a systematic approach and rationale when grossing and submitting histological sections from larger oncological resections from the luminal GI tract. Selected site-specific considerations, for example, grossing treated rectal and oesophageal cancers or taking sections from mucinous tumours of the appendix, among others, are also discussed.

Finding the minimum number of retrieved lymph nodes in node-negative colorectal cancer using Real-world Data and the SEER database

BACKGROUND

Current clinical guidelines recommend the removal of at least 12 lymph nodes (LNs) in resectable colorectal cancer (CRC). With advancements in lymphadenectomy technologies, the number of retrieved lymph nodes (rLNs) has markedly increased. This study aimed to investigate the lowest number of rLNs in node-negative patients.

MATERIALS AND METHODS

A total of 1103 N0 and 208 N1a stage patients were enrolled in our cohort, while 8503 N0 and 1276 N1a patients from the Surveillance, Epidemiology, and End Results CRC database were included. Propensity score matching and multivariate Cox regression analyses were performed to mitigate the influence of selection bias and control for potential confounding variables.

RESULTS

The median number of rLNs in N0 patients increased from 13.5 (interquartile range [IQR]: 9-18) in 2013 to 17 (IQR: 15-20) in 2019. The restrictive cubic spline illustrated a nonlinear relationship between rLNs and prognosis (nonlinearity, P =0.009), with a threshold ( N =16) influencing clinical outcomes. Patients at either N0 or N1a stage with sufficient rLNs (≥16) demonstrated superior prognoses to those with a limited rLNs (<16). After adjusting for clinical confounders, similar prognoses were observed in N0 limited and N1a adequate populations. Furthermore, Kaplan-Meier curves revealed that N0 limited patients who received chemotherapy exhibited better outcomes than those who did not.

CONCLUSIONS

Among patients with node-negative CRC, it is crucial to remove 16 or more LNs effectively. Fewer than 16 rLNs should be regarded as an independent risk factor, implying the need for adjuvant chemotherapy.

A postsurgical prognostic nomogram for patients with lymph node positive rectosigmoid junction adenocarcinoma

OBJECTIVE

The definition of rectosigmoid junction (RSJ) is still in debate. The treatment and prognosis of patients with rectosigmoid junction cancer (RSJC) and positive lymph nodes (PLN-RSJCs) are mostly based on the American Joint Committee on Cancer (AJCC) staging system. Our study aims to assist clinicians in creating a more intuitive and accurate nomogram model for PLN-RSJCs for the prediction of patient overall survival (OS) after surgery.

METHODS

Based on the Surveillance, Epidemiology, and End Results (SEER) database, we extracted 3384 patients with PLN-RSJCs and randomly divided them into development (n = 2344) and validation (n = 1004) cohorts at a ratio of 7:3. Using univariate and multivariate COX regression analysis, we identified independent risk factors associated with OS in PLN-RSJCs in the development cohort, which were further used to establish a nomogram model. To verify the accuracy of the model, the concordance index (C-index), receiver operating characteristic (ROC) curves, calibration curves, and an internal validation cohort have been employed. Decision curve analysis (DCA) was used to assess the clinical applicability and benefits of the generated model. Survival curves of the low- and high-risk groups were calculated using the Kaplan-Meier method together with the log-rank test.

RESULTS

Age, marital, chemotherapy, AJCC stage, T and N stage of TNM system, tumor size, and regional lymph nodes were selected as independent risk factors and included in the nomogram model. The C-index of this nomogram in the development (0.751;0.737-0.765) and validation cohorts (0.750;0.764-0.736) were more significant than that of the AJCC 7th staging system (0.681; 0.665-0.697). The ROC curve with the calculated area under the curve (AUC) in the development cohort was 0.845,0.808 and 0.800 for 1-year, 3-year and 5-year OS, AUC in the validation cohort was 0.815,0.833 and 0.814 for 1-year, 3-year and 5-year, respectively. The calibration plots of both cohorts for 1-year,3-year and 5-year OS all demonstrated good agreement between actual clinical observations and predicted outcomes. In the development cohort, the DCA showed that the nomogram prediction model is more advantageous for clinical application than the AJCC 7th staging system. Kaplan-Meier curves in the low and high groups showed significant difference in patient OS.

CONCLUSIONS

We established an accurate nomogram model for PLN-RSJCs, intended to support clinicians in the treatment and follow-up of patients.

A systematic review and meta-analysis of the use of methylene blue to improve the lymph node harvest in rectal cancer surgery

BACKGROUND

Methylene blue staining of the resected specimen has been described as an alternative to the conventional palpation and visual inspection method to improve lymph node harvest. This meta-analysis evaluates the usefulness of this technique in surgery for rectal cancer, particularly after neoadjuvant therapy.

METHODS

Randomized controlled trials (RCTs) comparing lymph node harvest in methylene blue-stained rectal specimens to those of unstained specimens were identified from the Medline, Embase, and Cochrane databases. Non-randomized studies and those with only colonic resections were excluded. The quality of RCTs was assessed using Cochrane's risk of bias tool. A weighted mean difference (WMD) was calculated for overall harvest, harvest after neoadjuvant therapy, and metastatic nodal yield. In contrast, the risk difference (RD) was calculated to compare yields of less than 12 lymph nodes between the stained and unstained specimens.

RESULTS

Study selection comprised seven RCTs with 343 patients in the unstained group and 337 in the stained group. Overall lymph node harvest and harvest after neoadjuvant therapy were significantly higher in stained specimens with a WMD of 13.4 and 10.6 and a 95% confidence interval (CI) of 9.5-17.2 and 4.8-16.3, respectively. Harvest of metastatic lymph nodes was significantly higher in the stained group (WMD 1.0, 95% CI 0.6-1.4). The yield of less than 12 lymph nodes was significantly higher in the unstained group with RD of 0.292 and 95% CI of 0.182-0.403.

CONCLUSION

Despite a small number of patients, this meta-analysis confirms improved lymph node harvest in surgical specimens stained with methylene blue compared with unstained specimens.

Lymph node regression grading of locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy

Neoadjuvant chemoradiotherapy (nCRT) and total rectal mesenteric excision are the main standards of treatment for locally advanced rectal cancer (LARC). Lymph node regression grade (LRG) is an indicator of prognosis and response to preoperative nCRT based on postsurgical metastatic lymph node pathology. Common histopathological findings in metastatic lymph nodes after nCRT include necrosis, hemorrhage, nodular fibrosis, foamy histiocytes, cystic cell reactions, areas of hyalinosis, residual cancer cells, and pools of mucin. A number of LRG systems designed to classify the amount of lymph node regression after nCRT is mainly concerned with the relationship between residual cancer cells and regressive fibrosis and with estimating the number of lymph nodes existing with residual cancer cells. LRG offers significant prognostic information, and in most cases, LRG after nCRT correlates with patient outcomes. In this review, we describe the systematic classification of LRG after nCRT, patient prognosis, the correlation with tumor regression grade, and the typical histopathological findings of lymph nodes. This work may serve as a reference to help predict the clinical complete response and determine lymph node regression in patients based on preservation strategies, allowing for the formulation of more accurate treatment strategies for LARC patients, which has important clinical significance and scientific value.

A Preoperative Scoring System to Predict the Risk of Inadequate Lymph Node Count in Rectal Cancer

Purpose

The aim of this study was to develop and validate a preoperative scoring system to stratify rectal cancer (RC) patients with different risks of inadequate lymph node examination.

Methods

A total of 1,375 stage I–III RC patients between 2011 and 2020 from the Second Affiliated Hospital of Harbin Medical University were included in the retrospective study and randomly divided into a development set (n = 688) and a validation set (n = 687). The logistic regression model was used to determine independent factors contributing to lymph node count (LNC) < 12. A preoperative scoring system was constructed based on beta (β) coefficients. The area under the receiver operating curve (AUC) was used to test model discrimination.

Results

Preoperative significant indicators related to LNC < 12 included age, tumor size, tumor location, and CEA. The AUCs of the scoring system for development and validation sets were 0.694 (95% CI = 0.648–0.741) and 0.666 (95% CI = 0.615–0.716), respectively. Patients who scored 0–2, 3–4, and 5–6 were classified into the low-risk group, medium-risk group, and high-risk group, respectively.

Conclusions

The preoperative scoring system could identify RC patients with high risk of inadequate lymphadenectomy accurately and further provide a reference to perform preoperative lymph node staining in targeted patients to reduce the difficulty of meeting the 12-node standard, with the purpose of accurate tumor stage and favorable prognosis.

Prognostic value of lymph node ratio in resectable rectal cancer after preoperative short-course radiotherapy-results from randomized clinical trial

PURPOSE

The value of the lymph node ratio (LNR) in patients with rectal cancer has not yet been unequivocally established. This study aims to assess the effect of the lymph node ratio on the prognosis of rectal cancer in patients operated after short-course preoperative 25 Gy radiotherapy, at 10-year follow-up.

METHODS

This is a substudy based on data from a prospective randomized clinical trial. A total of 141 patients with resectable rectal cancer were included. Lymph node yield was compared in patients with short and long time intervals between radiotherapy and surgery. Survival curves were compared between patients with different ypN and LNR categories. Univariate and multivariate analyses were performed to identify independent prognostic factors for overall survival and disease-free survival.

RESULTS

Survival and recurrence data were available for a median follow-up of 11.6 years. The lymph node yield did not differ significantly between the patients in the short- and long-interval groups. A greater difference in 10-year survival was observed in patients with LNR ≤ 0.41 and > 0.41 when compared to the ypN categories. Separate prognostic factor analyses were performed for the entire population and for subgroups that had < 12 and 12 lymph nodes resected. LNR was identified as an independent prognostic factor for overall survival, in multivariate analyses, for all patients and those with less than 12 retrieved lymph nodes.

CONCLUSION

The lymph node yield is comparable in patients with different time intervals between radiation therapy and surgery. LNR better discriminates patients in terms of overall survival than ypN categories.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier: NCT01444495, date of registration: September 30, 2011.

Optimal Lymph Node Yield for Survival Prediction in Rectal Cancer Patients After Neoadjuvant Therapy

Purpose

A lymph node (LN) yield ≥12 is required to for accurate determination of nodal status for colorectal cancer but cannot always be achieved after neoadjuvant therapy. This study aims to determine the difference in LN yield from rectal cancer patients treated with and without neoadjuvant therapy and the effects of specific LN yields on survival.

Patients and Methods

The study cohort included a total of 4344 rectal cancer patients treated between January 2007 and December 2015, 2260 (52.03%) of whom received neoadjuvant therapy. Data were retrieved from the Taiwan nationwide cancer registry database. The minimum acceptable LN yield below 12 was investigated using the maximum area under the ROC curve.

Results

The median LN yield was 12 (8-17) for patients who received neoadjuvant therapy and 17 (13-24) for those who did not. The recommended LN yield ≥12 was achieved in 82.73% of patients without and 57.96% of those with neoadjuvant therapy (p < 0.0001). Patients with LN yield ≥12 had a higher OS probability than did those with LN <12 (OR, 1.33; 95% CI, 1.06-1.66; p = 0.0124). However, the predictive accuracy for survival was greater for LN yield ≥10 (AUC, 0.7767) than cut-offs of 12, 8, or 6, especially in patients with pathologically-negative nodes (AUC, 0.7660).

Conclusion

Neoadjuvant therapy significantly reduces the LN yield in subsequent surgery. A lower yield (LN ≥ 10) may be adequate for nodal evaluation in rectal cancer patients after neoadjuvant therapy.

Stage II colon cancer staging using the number of retrieved lymph nodes may be superior to current TNM staging for prognosis stratification: the Japanese study group for postoperative follow-up of colorectal cancer

PURPOSE

The purpose of the study was to compare staging of stage II colon cancer using the number of retrieved lymph nodes (RN) to current TNM staging for stratification of prognosis.

METHODS

The subjects were 6307 patients with stage II colon cancer who underwent curative resection at 24 Japanese institutions. The cutoff for the number of RN was established using Akaike information criterion (AIC) values for relapse-free survival (RFS) and overall survival (OS). Comparison of survival using TNM and T + RN (TRN) staging was performed using a Cox proportional hazards regression model.

RESULTS

AIC was lowest for 14 retrieved lymph nodes for RFS and OS. This number was used as the cutoff. In multivariate analysis, age (≥ 69), male gender, V1, CEA (> 5), pT (T4a, T4b), and RN-L were independent factors associated with RFS and OS. Six combinations of pT and RN categories were used to establish three subgroups: TRN stages IIA, IIB, and IIC. The 5-year RFS was 83.9%, 72.3%, and 71.8% in TNM stages IIA, IIB, and IIC; and 86.0%, 76.9%, and 60.3% in TRN stages IIA, IIB, and IIC. The 5-year OS was 90.0%, 81.3%, and 82.6% for the TNM stages; and 91.6%, 85.0%, and 71.9% for the TRN stages. The AIC for RFS was lower for TRN (22,318.2) than for TNM (22,390.6), and that for OS was also lower for TRN (16,285.3) than for TNM (16,355.1).

CONCLUSION

Stage II colon cancer staging using the number of retrieved lymph nodes may be superior to current TNM staging for prognosis stratification.

Prognostic Impact of Extranodal Extension in Rectal Cancer Patients Undergoing Radical Resection After Preoperative Chemoradiotherapy

BACKGROUND

Extranodal extension (ENE) of nodal metastasis has emerged as an important prognostic factor in many malignancies, including rectal cancer. However, its significance in patients with rectal cancer receiving preoperative chemoradiotherapy (PCRT) has not been extensively investigated. We therefore assessed ENE and its prognostic impact in a large series of consecutive rectal cancer patients with lymph node metastasis after PCRT and curative resection.

PATIENTS AND METHODS

Between January 2000 and December 2014, a total of 1925 patients with rectal cancer underwent surgical resection after PCRT. Medical records of 469 patients with pathologic node positivity were retrospectively reviewed.

RESULTS

Of the 469 patients, 118 (25.2%) presented with ENE. ENE was observed more frequently in those with advanced tumor stage (higher ypT, ypN, and ypStage), lymphovascular invasion, and perineural invasion. Five-year disease-free survival rate was lower in patients with ENE-positive tumors than those with ENE-negative tumors (36.1% vs. 52.3%, P = .003). Similarly, 5-year overall survival rate was lower in patients with ENE-positive tumors than those with ENE-negative tumors (60.2% vs. 70.6%, P < .001). Multivariate analysis revealed that the presence of ENE was an independent poor prognostic factor for disease-free survival (hazard ratio = 1.412; 95% confidence interval, 1.074-1.857; P = .013) and overall survival (hazard ratio = 1.531; 95% confidence interval 1.149-2.039; P = .004).

CONCLUSION

The presence of ENE in patients with rectal cancer undergoing PCRT is a negative prognostic factor, reflecting poor survival outcome.

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.

A retrospective study on the impact of the number of resected lymph nodes on the survival outcome of stage IV rectal cancer patients after preoperative therapy

Background

There is no consensus on the optimal number of examined LNs for stage IV rectal cancer patients after preoperative therapy. We aimed to explore the impact of the number of resected lymph nodes (LNs) on the survival outcomes of stage IV rectal cancer patients after preoperative therapy.

Methods

Clinicopathologic data of 556 patients diagnosed with stage IV rectal cancer between 1st January, 2010 and 31st December, 2015 from the Surveillance, Epidemiology, and End Results (SEER) database after preoperative therapy were reviewed. The patients were further divided into two groups: the ≥15 resected LNs group and <15 resected LNs group based on the X-tile software analysis results of the number of resected LNs.

Results

Both univariate and multivariate regression analyses revealed that the number of resected LNs and N status were significantly positively correlated with the survival outcome of the patients. Patients in the ≥15 resected LNs group had a significant better cancer-specific survival (CSS) (P=0.003) than those in the <15 resected LNs group. The 3-year CSS rate was 63.2% for patients with ≥15 resected LNs compared with 55.7% for those with <15 resected LNs. The 5-year CSS rate was 50.2% and 30.5% for patients in the ≥15 resected LNs group and those in the <15 resected LNs group, respectively.

Conclusions

The number of resected LNs is an important independent prognostic factor that influences the survival outcome of stage IV rectal cancer patients after receiving preoperative therapy.

The quality of lymph node harvests in extralevator abdominoperineal excisions

Background

Lymph node (LN) harvest in colorectal cancer resections is a well-recognised prognostic factor for disease staging and determining survival, particularly for node-negative (N0) diseases. Extralevator abdominoperineal excisions (ELAPE) aim to prevent “waisting” that occurs during conventional abdominoperineal resections (APR) for low rectal cancers, and reducing circumferential resection margin (CRM) infiltration rate. Our study investigates whether ELAPE may also improve the quality of LN harvests, addressing gaps in the literature.

Methods

This retrospective observational study reviewed 2 sets of 30 consecutive APRs before and after the adoption of ELAPE in our unit. The primary outcomes are the total LN counts and rates of meeting the standard of 12-minimum, particularly for those with node-negative disease. The secondary outcomes are the CRM involvement rates. Baseline characteristics including age, sex, laparoscopic or open surgery and the use of neoadjuvant chemoradiotherapy were accounted for in our analyses.

Results

Median LN counts were slightly higher in the ELAPE group (16.5 vs. 15). Specimens failing the minimum 12-LN requirements were almost significantly fewer in the ELAPE group (OR 0.456, P = 0.085). Among node-negative rectal cancers, significantly fewer resections failed the 12-LN standard in the ELAPE group than APR group (OR 0.211, P = 0.044). ELAPE led to a near-significant decrease in CRM involvement (OR 0.365, P = 0.088). These improvements were persistently observed after taking into account baselines and potential confounders in regression analyses.

Conclusion

ELAPE provides higher quality of LN harvests that meet the 12-minimal requirements than conventional APR, particularly in node-negative rectal cancers. The superiority is independent of potential confounding factors, and may implicate better clinical outcomes.

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.

Pathologic Complete Response Despite Nodal Yield Has Best Survival in Locally Advanced Rectal Cancer

BACKGROUND

Controversy exists regarding the ability of neoadjuvant chemoradiation (nCR) to diminish lymph node yield (LNY) and how that relationship is influenced by tumor response in patients undergoing proctectomy for locally advanced rectal cancer.

MATERIALS AND METHODS

The National Cancer Database was used to identify patients with rectal adenocarcinomas from 2004 to 2014. Patients that received nCR were compared with those that underwent surgery alone. LNY was stratified into <12 and ≥12 groups to determine their differences in stage specific overall survival.

RESULTS

Of 56,812 patients 46.5% underwent surgery alone and 53.5% were administered nCR. There were more patients with LNY<12 in the nCR group compared to surgery alone, across all stages (44.1% versus 36.5%, P < 0.001). nCR improved OS regardless of LNY (P < 0.001). Although patients with LNY≥12 had improved overall survival, patients who had a pathologic complete response (pCR) achieved the greatest survival. In patients that did not achieve a pCR, LNY≥12 was a marker of improved OS but LNY did not impact OS in patients that attained pCR (P < 0.001).

CONCLUSIONS

Although nCR diminished LNY, LNY≥12 improved OS demonstrating the importance of quality total mesorectal excision. However, LNY did not impact patients that achieved pCR. These patients, who achieved the best OS, demonstrated that tumors' biologic response to nCR had the greatest impact on patient outcomes.

Can better surgical outcomes be obtained in the learning process of robotic rectal cancer surgery? A propensity score-matched comparison between learning phases

BACKGROUND

Although studies of robotic rectal cancer surgery have demonstrated the effects of learning on operation time, comparisons have failed to demonstrate differences in clinicopathological outcomes between unadjusted learning phases. This study aimed to investigate the learning curve of robotic rectal cancer surgery for clinicopathological outcomes and compare surgical outcomes between adjusted learning phases. Study design We enrolled 506 consecutive patients with rectal adenocarcinoma who underwent robotic resection by a single surgeon between 2007 and 2018. Risk-adjusted cumulative sum (RA-CUSUM) for surgical failure was used to analyze the learning curve. Surgical failure was defined as the occurrence of any of the following: conversion to open surgery, severe complications (Clavien-Dindo grade ≥ 3a), insufficient number of harvested lymph nodes (LNs), or R1 resection. Comparisons between learning phases analyzed by RA-CUSUM were performed before and after propensity score matching.

RESULTS

In RA-CUSUM analysis, the learning curve was divided into two learning phases: phase 1 (1st-177th cases, n = 177) and phase 2 (178th-506th cases, n = 329). Before matching, patients in phase 2 had deeper tumor invasion and higher rates of positive LNs on pretreatment images and preoperative chemoradiotherapy. After matching, phase 1 (n = 150) and phase 2 (n = 150) patients exhibited similar clinical characteristics. Phase 2 patients had lower rates of surgical failure overall and these components: conversion to open surgery, severe complications, and insufficient harvested LNs.

CONCLUSIONS

For robotic rectal cancer surgery, surgical outcomes improved after the 177th case. Further studies by other robotic surgeons are required to validate our results.

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.

Effect of pathologist's dedication on lymph node detection rate and postoperative survival in colorectal cancer

AIM

As adjuvant chemotherapy in colorectal cancer relies on the identification of lymph node metastases, the pathologist's dedication may have a considerable influence on postoperative survival.

METHOD

The aim of this retrospective study was to assess the impact of the pathologist's dedication on lymph node detection rate and postoperative survival in patients operated on by a single experienced colorectal surgeon within a 5-year period. We assessed 229 patients undergoing total mesorectal excision or complete mesocolic excision by the senior author between 1 January 2009 and 31 December 2013. Pathologists were grouped as 'general pathologist' or 'dedicated pathologist' depending on their dedication/specialization.

RESULTS

Dedicated pathologists found statistically significantly more lymph nodes in colorectal specimens than general pathologists [23 (interquartile range 24) vs 14 (interquartile range 11), respectively; P < 0.001]. The detection rate of ≥ 12 lymph nodes per specimen was significantly higher in the dedicated pathologist group [65/74 (87.8%) vs 105/155 (67.7%); P = 0.016]. However, postoperative survival did not differ in the respective subgroups. In the multivariable analysis by Cox proportional hazard model, International Union against Cancer Stage IV was the only factor associated with decreased disease-specific survival (hazard ratio 28.257; 95% CI 3.850-207.386; P = 0.001).

CONCLUSION

In our centre, the pathologist's dedication has an impact on lymph node detection rate but does not influence postoperative disease-specific survival.

Role of "Second Look" Lymph Node Search in Harvesting Optimal Number of Lymph Nodes for Staging of Colorectal Carcinoma

As with other malignancies, lymph node metastasis is an important staging element and prognostic factor in colorectal carcinomas. The number of involved lymph nodes is directly related to decreased 5-year overall survival for all pT stages according to United States Surveillance, Epidemiology, and End Results (SEER) cancer registry database. The National Quality Forum specifies that the presence of at least 12 lymph nodes in a surgical resection is one of the key quality measures for the evaluation of colorectal cancer. Therefore, the harvesting of a minimum of twelve lymph nodes is the most widely accepted standard for evaluating colorectal cancer. Since this is an accepted quality standard, a second attempt at lymph node dissection in the gross specimen is often performed when the initial lymph node count is less than 12, incurring a delay in reporting and additional expense. However, this is an arbitrary number and not based on any hard scientific evidence. We decided to investigate whether the additional effort and expense of submitting additional lymph nodes had any effect on pathologic lymph node staging (pN). We identified a total of 99 colectomies for colorectal cancer in which the prosector subsequently submitted additional lymph nodes following initial review. The mean lymph node count increased from 8.3 ± 7.5 on initial search to 14.6 ± 8.0 following submission of additional sections. The number of cases meeting the target of 12 lymph nodes increased from 14 to 69. Examination of the additional lymph nodes resulted in pathologic upstaging (pN) of five cases. Gross reexamination and submission of additional lymph nodes may provide more accurate staging in a limited number of cases. Whether exhaustive submission of mesenteric fat or fat-clearing methods is justified will need to be further investigated.

Distribution of Lymph Nodes in Stage III Patients With Mid and Low Rectal Cancer: Preliminary Study

Purpose

Most patients with rectal cancer undergo a total mesorectal excision and a partial resection of the sigmoid colon to improve oncologic outcomes. The aim of this study was to assess the distribution of lymph nodes (LNs) in rectal cancer.

Methods

The records of 54 patients with mid and low rectal cancer between April 2015 and March 2017 were reviewed, and 49 patients were enrolled in this study. All harvested LNs were analyzed according to the harvested area: the mesorectum area (MA), the vascular pedicle area (VA), and the sigmoid area (SA).

Results

Finally, 865 LNs were harvested from all patients, and of these, 71 (8.2%) showed metastases. In stage III patients, 343 LNs were harvested, and of these, 52 (15.2%) showed metastases. Significant differences were found in the total numbers of harvested LNs by area (P < 0.001) and in the numbers of harvested positive LNs by area (P < 0.001). In stage III patients, LNs from the MA were more frequently to be positive than were those from the VA (P < 0.001) or the SA (P < 0.001).

Conclusion

LN metastasis in the SA was rare. Therefore, resecting the mesorectum and the vascular pedicle may be more important than resecting the sigmoid mesentery due to concerns about LN metastases.

Propensity score analysis of recurrence for neutrophil-to-lymphocyte ratio in colorectal cancer

BACKGROUND

The perioperative serum neutrophil-to-lymphocyte ratio (NLR) has been proposed to predict adverse prognosis in colorectal cancer (CRC). However, its interpretation remains unclear. The present study aimed to clarify the prognostic value of NLR in predicting survival among CRC patients.

MATERIALS AND METHODS

A single-centre, retrospective, propensity score-matched study of adenocarcinoma patients who underwent D3 lymphadenectomy via laparoscopic or open surgery between 2010 and 2016 was conducted. A cutoff of 3.5 was used based on the receiver operating characteristic curve. To overcome selection biases, we performed a 1:1 match using six covariates.

RESULTS

The high-preoperative NLR group had a higher recurrence rate than the low group (P < 0.001). Univariate analysis showed that increased NLR (P < 0.001), N1 (P = 0.016), and N2 (P < 0.001) were associated with worse recurrence-free survival (RFS). Multivariate analysis showed that N2 (hazard ratio [HR], 2.492; P = 0.008) was an adverse prognostic factor for RFS. Univariate analysis for overall survival (OS) revealed that high perioperative NLR (P = 0.001), N1 (P = 0.01), N2 (P < 0.001), and distant metastasis (P < 0.001) were adverse prognostic factors. Subsequent multivariate analysis showed that M1 (HR, 3.973; P < 0.001) and N2 (HR, 2.381; P = 0.013) were highly adverse factors for OS. Clinical assessments performed during a 21.14 (±16.20)-mo follow-up revealed that OS (P = 0.001) and RFS (P < 0.001) were worse in the high-perioperative group than in the low group between the matched groups.

CONCLUSIONS

An elevated preoperative NLR is a strong predictor of worse RFS and OS in CRC patients.

Resected irradiated rectal cancers: Are twelve lymph nodes really necessary in the era of neoadjuvant therapy?

BACKGROUND

Our study aims to identify the minimum number of lymph nodes (LN) associated with improved survival in patients who underwent NRT for stage II-III rectal cancer.

METHODS

Adults with clinical stage II and III rectal adenocarcinoma in the National Cancer Data Base were stratified by NRT. Multivariable Cox regression modeling with restricted cubic splines was used to determine the minimum number of LNs associated with improved survival.

RESULTS

Of 38,363 patients, 76% received NRT. After adjustment, a LNY≥12 was associated with improved survival among patients receiving NRT (HR 0.79, p < 0.0001) and those without NRT (HR 0.88, p = 0.04). Among patients receiving NRT, factors independently associated with LNY≥12 were younger age, private insurance, low comorbidity score, a recent year of diagnosis, higher T stage and grade, APR resection, and academic institution.

CONCLUSIONS

A minimum LNY of 12 confers a survival benefit for rectal cancer patients regardless of receiving neoadjuvant radiation therapy.

Understanding the factors associated with reduction in the number of lymph nodes in rectal cancer patients treated by neoadjuvant treatment

INTRODUCTION

Rectal cancer patients frequently present with locally advanced disease for which the standard of care includes neoadjuvant chemoradiotherapy followed by total mesorectal excision. Positive lymph nodes are one of the most powerful risk factors for recurrence and survival in colorectal cancer. In the absence of specific rectal guidelines, the literature recommends to the pathologist to optimize the number of rectal lymph nodes (LN) retrieved. We made a literature review in order to identify factors that could potentially affect the number of LN retrieved in specimens of patients with rectal cancer treated by chemoradiotherapy (CRT) followed by total mesorectal excision (TME).

RESULTS

Age did not have a significant effect on LN yield. The effect of sex on LN number is not consistent in the literature. Most of the papers did not find a relationship between lower LN obtained and gender. Laparoscopy for primary rectal cancer is associated with a greater number of LN as well as short-term benefits. Tumors in the upper rectum are associated with a higher number of LN than those in the mid and lower rectum. The type of surgery had no effect on lymph node yield either. Tumors with complete or almost complete pathologic regression were exactly the ones with lower number of lymph nodes detected. Approximately one-third of patients with neoadjuvant treatment had less than 12 LN yield.

CONCLUSION

The tumor regression grade is the most important factor for the decrease in the number of lymph nodes.

Effect of Neoadjuvant Chemoradiotherapy on Locally Advanced Rectal Mucinous Adenocarcinoma: A Propensity Score-Matched Study

Aims. To compare the surgical and oncological outcomes of rectal mucinous adenocarcinomas treated with neoadjuvant chemoradiotherapy versus surgery alone. Methods. A total of 167 locally advanced rectal mucinous adenocarcinoma patients treated with neoadjuvant chemoradiotherapy and surgery alone between 2008 and 2014 were matched using propensity score; the surgical and oncological outcomes were compared. Results. Ninety-six patients were matched. Postoperative morbidity was similar between groups. Sphincter preservation rate was higher in patients receiving neoadjuvant chemoradiotherapy (79.2% versus 60.4%, P = 0.045), especially for tumors ≥ 3 cm but ≤5 cm from the anal verge (75.0% versus 44.0%, P = 0.036). With a median follow-up of 54.8 months, the 5-year overall survival rate (neoadjuvant chemoradiotherapy versus surgery alone: 79.6% versus 67.1%; P = 0.599) and disease-free survival rate (75.6% versus 64.2%; P = 0.888) were similar. The 5-year local recurrence rate was lower in patients receiving neoadjuvant chemoradiotherapy (7.7% versus 26.0%, P = 0.036), while no difference was observed in distant metastasis. A poor response to chemoradiation was associated with higher local recurrence (P = 0.037). Conclusions. Compared with surgery alone, neoadjuvant chemoradiotherapy was found to increase the sphincter preservation rate and reduce local recurrence, thus being beneficial for locally advanced rectal mucinous adenocarcinoma patients.

Lymph node yield after rectal resection in patients treated with neoadjuvant radiation for rectal cancer: A systematic review and meta-analysis

BACKGROUND

The lymph node status represents a major prognostic factor in colorectal cancer. However, it was demonstrated that neoadjuvant chemoradiotherapy (CRT) decreases the numbers of lymph nodes in the specimen. Several studies describe less than 12 lymph nodes in the resected specimen of rectal cancer patients after neoadjuvant radiation. This meta-analysis quantifies the influence of neoadjuvant CRT or radiotherapy (RT) only on the lymph node yield in rectal cancer patients.

METHODS

We performed a systematic review and searched PubMed, EMBASE and the Cochrane Library without any language restriction from 1st of January 1980 until 31st March 2015. Two reviewers examined all publications independently and extracted the relevant data if the study assessed lymph node counts or positive lymph node yields of patients who received neoadjuvant treatment compared with patients who did not receive neoadjuvant treatment. Meta-analyses were conducted to quantify the mean difference in lymph node yield.

RESULTS

A total of 34 articles (including 37 datasets) were included in the meta-analyses. Neoadjuvant CRT resulted in a mean reduction of 3.9 lymph nodes (95% confidence interval [CI] 3.7-4.1) and an average reduction in harvested positive lymph nodes of 0.7 (95% CI 0.2-1.2) compared with patients who received no neoadjuvant therapy. Individuals who received neoadjuvant RT had, in average, 2.1 lymph node less (95% CI 1.7-2.5) resected compared with their counterparts who received no neoadjuvant treatment.

CONCLUSIONS

Neoadjuvant CRT or RT only in rectal cancer patients leads to a decrease in lymph node harvest of approximately four and two lymph nodes, respectively. We therefore stress the importance of intensifying all efforts from involved subspecialities (i.e. surgeons and pathologists) to reach the benchmark harvest of 12 resected lymph nodes according to current guidelines.

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.

Do demographics and tumour-related factors affect nodal yield at neck dissection? A retrospective cohort study

Background:

Nodal metastasis is an important prognostic factor in head and neck squamous cell carcinoma. This study aimed to determine the average nodal basin yield per level of neck dissection, and to investigate if age, gender, body mass index, tumour size, depth of tumour invasion and p16 status influence nodal yield.

Method:

A retrospective review of 185 patients with head and neck squamous cell carcinoma generated 240 neck dissection specimens.

Results:

The respective mean nodal yields for levels I, II, III, IV and V were 5.27, 9.43, 8.49, 7.43 and 9.02 in non-cutaneous squamous cell carcinoma patients, and 4.2, 7.57, 9.65, 4.33 and 12.29 in cutaneous squamous cell carcinoma patients. Multiple regression analysis revealed that p16-positive patients with mucosal squamous cell carcinoma yielded, on average, 2.4 more nodes than their p16-negative peers (p = 0.04, 95 per cent confidence interval = 0.116 to 4.693). This figure was 3.84 (p = 0.008, 95 per cent confidence interval = 1.070 to 6.605) for p16-positive patients with oral cavity squamous cell carcinoma.

Conclusion:

In mucosal squamous cell carcinoma, p16-positive status significantly influenced nodal yield, with the impact being more pronounced in oral cavity squamous cell carcinoma patients.

Prognostic significance of tumor regression in lymph nodes after neoadjuvant therapy for rectal carcinoma

Neoadjuvant therapy (NAT) is mainly indicated for locally advanced rectal carcinoma. Many reports have shown that regression of the primary tumor is a prognostic factor. However, few reports to date have analyzed the potential prognostic significance of lymph node regression in rectal carcinoma. The aim of the present study is to describe the pattern of tumor regression in lymph nodes after NAT for rectal carcinoma and its potential prognostic significance. We have retrospectively reviewed 106 cases of rectal carcinoma treated at a single institution. We have retrieved data from the patients and reviewed the histopathological slides to evaluate tumor regression both of the primary tumor and of LN metastases. Prognosis has been defined both in terms of disease-free survival (DFS) and disease-specific survival (DSS). Of the patients, 16% showed complete response of the primary tumor, while 24% showed poor response, according to the CAP regression grading system. Absence of lymph node involvement after therapy was found in 80% of the patients (ypN0 cases), while 20% were ypN+. We reviewed 639 LN; 85 were involved by tumor, and 170 showed histological signs of tumor regression. The main pattern of tumor regression in lymph nodes was fibrosis (66.3%), followed by hystiocytosis (29.1%) and mucin pools (4.6%). We found histological signs of regression in 57% of ypN0 cases and 76% of ypN+ cases. We found a significant association between regression grade of the primary tumor and of lymph node metastases. For ypN0 patients with persistence of the primary tumor after NAT, the median DFS was significantly shorter in patients showing tumor regression in the LN. In a Cox multivariate survival model for DFS, this prognostic influence was independent of the regression grade of the primary tumor and also of the ypTNM stage. We found no significant association between any factor and DSS. The pattern of tumor regression in lymph nodes was not significantly associated with prognosis. Tumor regression in lymph nodes is an important prognostic factor in rectal carcinoma after NAT and should be specifically looked for and included in pathology reports.

Prognostic Value of Lymph Node Ratio in Locally Advanced Rectal Cancer Patients After Preoperative Chemoradiotherapy Followed by Total Mesorectal Excision

Although the absolute number of positive lymph nodes (LNs) has been established as 1 of the most important prognostic factors in rectal cancers, many researchers have proposed that the lymph node ratio (LNR) may have better predicted outcomes. We conducted a retrospective study to compare the predictive ability of LNR and ypN category in rectal cancer. A total of 264 locally advanced rectal cancer (LARC) patients who underwent preoperative chemoradiotherapy (CRT) followed by total mesorectal excision (TME) between 2005 and 2012 were reviewed. All patients were categorized into 3 groups or patients with metastatic LNs were categorized into 2 groups according to the LNR. The prognostic effect on overall survival (OS) and disease-free survival (DFS) was evaluated. With a median follow-up of 45 months, the OS and DFS were 68.4% and 59.3% for the entire cohort, respectively. The respective 5-year OS and DFS rates for the 3 groups (LNR = 0, 0 < LNR ≤ 0.20, and 0.20 < LNR ≤ 1.0) were as follows: 83.2%, 72.6%, and 49.4% (P < 0.001) and 79.5%, 57.3%, and 33.5% (P < 0.001), respectively. Multivariate analysis revealed that LNR and differentiation, but not the number of positive LNs, had independent prognostic value for OS (hazard ratio [HR] = 2.328, 95% confidence interval [CI]: 1.850-4.526, P < 0.001) and DFS (HR = 3.004, 95% CI: 1.616-5.980, P < 0.001). As for patients with positive LNs, the respective 5-year OS and DFS rates for the 2 groups (0 < LNR ≤ 0.20, and 0.20 < LNR ≤ 1.0) were 72.6% and 49.4% (P < 0.001) and 57.3% and 33.5% (P < 0.001), respectively. Multivariate analysis revealed that only LNR was an independent factor for OS (HR = 3.214, 95% CI: 1.726-5.986, P < 0.001) and DFS (HR = 4.230, 95% CI: 1.825-6.458, P < 0.001). Subgroups analysis demonstrated that the ypN category had no impact on survival whereas increased LNR was a significantly prognostic indicator for worse survival in the LNs < 12 subgroup. LNR is an independent prognostic factor in LARC patients treated with preoperative CRT followed by TME. It may be a better independent staging method than the number of metastatic LNs when <12 LNs are harvested after preoperative CRT.

Adjuvant chemotherapy for rectal cancer: Is it needed?

Adjuvant chemotherapy has become a standard treatment of advanced rectal cancer in the West. The benefits of adjuvant chemotherapy after surgery alone have been well established. However, controversy surrounds the use adjuvant chemotherapy in patients who received preoperative chemoradiotherapy, despite it being recommended by a number of international guidelines. Results of recent multicentre randomised control trials showed no benefit of adjuvant chemotherapy in terms of survival and rates of distant metastases. However, concerns exist regarding the quality of the studies including inadequate staging modalities, out-dated chemotherapeutic regimens and surgical approaches and small sample sizes. It has become evident that not all the patients respond to adjuvant chemotherapy and more personalised approach should be employed when considering the benefits of adjuvant chemotherapy. The present review discusses the strengths and weaknesses of the current evidence-base and suggests improvements for future studies.

A comparison of formalin and GEWF in fixation of colorectal carcinoma specimens: rates of lymph node retrieval and effect on TNM staging

AIMS

The Royal College of Pathologists recommend that a median of at least 12 lymph nodes should be harvested during pathological staging of colorectal cancer. It is not always easy to harvest the required number, especially in patients with rectal cancer receiving neoadjuvant therapy. Lymph node revealing solutions, for example, GEWF, may improve nodal yield. GEWF is safe, cheap and easy to use.

METHODS

In a controlled trial, lymph node yields were compared after secondary specimen dissection following either 24 h of further fixation in formalin (n=101) or GEWF immersion (n=99). The number, size and tumour status of additional lymph nodes identified were compared between groups. Twenty-seven cases that received long-course neoadjuvant therapy were also assessed.

RESULTS

Median lymph node yield at primary dissection met national standards overall (19) but also in the long-course neoadjuvant therapy group (13). Lymph nodes were smaller in neoadjuvant cases compared with non-neoadjuvant cases (mean size range 1.3-5.6 mm vs 1.5-8.9 mm). The use of further fixation and GEWF detected more nodes at secondary dissection. The mean number of additional nodes harvested was greater with formalin (8.3) than GEWF (7.3). There was no significant difference in the mean size of the additional lymph nodes detected between groups (point estimate 1.02; 95% CI -0.58 to 2.63; p=0.211). Upstaging triggering adjunct chemotherapy occurred in 1% (2/200) of cases.

CONCLUSIONS

The routine use of adjunct techniques to identify additional lymph nodes is unnecessary with underlying high-quality dissection practice. Emphasis should be placed upon education and training, spending appropriate time dissecting and ensuring specimens are sufficiently fixed beforehand.

Preoperative Submucosal Injection of Carbon Nanoparticles Improves Lymph Node Staging Accuracy in Rectal Cancer after Neoadjuvant Chemoradiotherapy

BACKGROUND

The aim of this study was to evaluate the association between the number of nodes harvested and the rate of node positivity, and to evaluate the effect of carbon nanoparticles (CNPs) in improving lymph node detection and staging accuracy in patients who received neoadjuvant chemoradiotherapy (NCRT) followed by curative resection.

STUDY DESIGN

Between September 2008 and June 2014, 152 consecutive rectal cancer patients treated with NCRT and curative resection were included. Forty-five patients underwent preoperative submucosal injection of CNPs (CNP group); the other patients underwent surgery only (control group). The relationship between the number of lymph nodes harvested and the rate of node positivity was investigated. A comparison of the number of harvested lymph nodes and the node positivity rate between the 2 groups was also performed. The lymph nodes in the CNP group were analyzed in detail.

RESULTS

The rate of node positivity increased gradually from 8.6% in patients with 1 to 5 nodes assessed to 37.8% in patients with 17 to 44 nodes assessed. The number of lymph nodes harvested was an independent risk factor for node positivity (p = 0.036). The mean number of lymph nodes retrieved in the CNP group was more than in the control group (21.1 vs 8.0, p = 0.000). The percentage of patients with positive lymph nodes was lower than in the control group (19.6% vs 35.6%, p = 0.037). In the CNP group, of 58 metastatic lymph nodes, 45 (77.6%) were dyed. Of 37 metastatic lymph nodes smaller than 5 mm, 33 (89.2%) were dyed.

CONCLUSIONS

More precise oncologic prognosis assessment was provided for patients with rectal cancer after NCRT by increasing the number of lymph nodes counted using a dye-tracing method, indicating that the use of CNPs is beneficial.

The effect of neoadjuvant therapy on the size, number, and distribution of mesorectal lymph nodes

The current therapeutic approach to patients with locally advanced rectal cancer is neoadjuvant radiotherapy or chemoradiotherapy followed by total mesorectal excision. We aimed to investigate the number, size, and distribution of metastatic and nonmetastatic lymph nodes within the mesorectum; whether neoadjuvant therapy has any impact on the number and size of the lymph nodes; and the impact of metastatic lymph node localization on overall and disease-free survival. Specimens from 50 consecutive patients with stage II/III rectal cancer receiving either neoadjuvant radiotherapy or chemoradiotherapy were investigated. Lymph node dissection was carried out by careful visual inspection and palpation. The localization of the each lymph node within the mesorectum and the relation with the tumor site were noted. The size and the number of lymph nodes retrieved decreased significantly with neoadjuvant therapy. Majority of the metastatic and nonmetastatic lymph nodes were located at or proximally to the tumor level and posterior side of the mesorectum. No relation was observed between the overall and disease-free survival, and the localization of the metastatic lymph nodes. Presence of lymph node metastases proximal to the tumor level has no impact on survival compared with the presence of lymph node metastasis only in the peritumoral region of the mesorectum. Although neoadjuvant therapy decreases the size and the number of lymph nodes, reaching an ideal number of lymph nodes for accurate staging is still possible with careful naked eye examination and dissection of perirectal fat. As the majority of metastatic and nonmetastatic lymph nodes are located in peritumoral and proximal compartment, and posterior side of the mesorectum, these regions should be the major interest of dissection.

Pathologic Assessment of Rectal Carcinoma after Neoadjuvant Radio(chemo)therapy: Prognostic Implications

Neoadjuvant radio(chemo)therapy is increasingly used in rectal cancer and induces a number of morphologic changes that affect prognostication after curative surgery, thereby creating new challenges for surgical pathologists, particularly in evaluating morphologic changes and tumour response to preoperative treatment. Surgical pathologists play an important role in determining the many facets of rectal carcinoma patient care after neoadjuvant treatment. These range from proper handling of macroscopic specimens to accurate microscopic evaluation of pathological features associated with patients' prognosis. This review presents the well-established pathological prognostic indicators and discusses challenging features in order to provide both surgical pathologists and treating physicians with a checklist that is useful in a neoadjuvant setting.

The new approach to the rectal cancer: 'down-to-up' double endolaparoscopic pelvic access. Preliminary evaluation of outcomes

Laparoscopic access in low anterior rectal resection is widely adopted, performing an 'up-to-down' dissection. The aim of this study is to present and analyze the outcomes of a novel surgical 'down-to-up' total mesorectal excision technique that could obviate to the well-known issues of the standard treatment. 18 suitable patients underwent double endolaparoscopic pelvic access (DEPA) 'down-to-up' technique. DEPA TME was completed in all patients, with intact mesorectum. Mean operative time was 365 min (range 280-510 min). The morbidity rate was 22%, including three radiologically detected leakage (grade A) and one pelvic abscess, requiring only a conservative management. Mortality rate at 30 and 90 days was 0%. Resection margins were negative in all patients. A median of 11 nodes (range 5-19) was retrieved per specimen. Mean length of hospital stay was 9 days (range 7-19 days). Patients were followed for an average of 14 months (range 0-42 months), with no recurrence. Despite exiguous patient's sample in this pilot study, transanal endoscopic TME with laparoscopic assistance seems to be feasible and safe, and is a promising alternative to open and laparoscopic TME. However, a conspicuous functional and oncologic long-term evaluation is required, before the widespread adoption could be recommended.

Ratio of metastatic lymph nodes is more important for rectal cancer patients treated with preoperative chemoradiotherapy

AIM

To evaluate the predictive value of the lymph node (LN) ratio (LNR, number of metastatic LNs/ examined LNs) for recurrence in patients with rectal cancer and to compare its applicability according to preoperative chemoradiotherapy (PCRT).

METHODS

From 2000 to 2009, 967 patients with metastatic LNs after curative resection for locally advanced rectal cancer were identified. Patients were categorized according to PCRT (PCRT vs No PCRT). The cut-off LNR was determined based on the pN1 vs pN2 when the recommended number of LNs was harvested. The 5-year recurrence-free survival (RFS) rates using the Kaplan-Meier method were compared according to p/yp N stage and the LNR in each group.

RESULTS

Among patients with the same p/ypN stage, the 5-year RFS rate differed according to the LNR. In addition, the 5-year RFS rate was significantly different between pN and LNR groups in patients with No PCRT. In PCRT group, however, only LNR was associated with prognosis. On multivariate analysis, both pN and LNR were significant independent prognostic factors for 5-year RFS in the No PCRT group. In the PCRT group, only LNR category was found to be associated with RFS (HR = 2.36, 95%CI: 1.31-3.84, and P = 0.001).

CONCLUSION

The LNR is an important prognostic predictor of RFS in rectal cancer patients especially treated with PCRT. Current pN categories could not discriminate between prognostic groups of RFS after PCRT.

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.

Reduction in the size of enlarged pelvic lymph nodes after chemoradiation therapy is associated with fewer lymph node metastases in locally advanced rectal carcinoma

PURPOSE

We hypothesized that a reduction in the size of the lymph nodes after neoadjuvant therapy for locally advanced rectal carcinoma would be associated with decreased lymph node metastases and/or a better prognosis.

METHODS

Between March 2006 and April 2012, 71 patients with primary rectal cancer received neoadjuvant chemoradiation therapy (CRT). For all lymph nodes 5 mm or larger in size, the major and minor axes were measured on CT scan images, and the product was calculated. The lymph node size was determined before and after CRT. The patients were divided into three groups based on the lymph node size before and after treatment. Group A exhibited a reduction in size of 60% or more, Group B a reduction of less than 60% and Group C had no lymph node enlargement before treatment.

RESULTS

The incidence of lymph node metastases on pathological examination was 15% in Group A and 50% in Group B (p = 0.006). The five-year disease-free survival in Group A was 84% compared with 78% in Group B (log rank p = 0.34). The five-year overall survival in Group A was 92% compared with 74% in Group B (log rank p = 0.088).

CONCLUSIONS

A reduction in the size of enlarged lymph nodes after neoadjuvant therapy may be a useful prognostic factor for recurrence and survival.

Tumour stage and preoperative chemoradiotherapy influence the lymph node yield in stages I-III rectal cancer: results from a prospective nationwide cohort study

AIM

The study aimed to determine whether the lymph node yield (LNY) in rectal cancer is influenced by patient-related and histopathological factors and the use of preoperative chemoradiotherapy (CRT).

METHOD

An analysis was carried out of the LNY in a nationwide Danish cohort of 7950 patients, treated by curative resection of Stage I-III rectal cancer during the period 2001-2011. The impact of year of diagnosis, age, gender, pathological stage of the tumour (pT-stage) and preoperative CRT on LNY was analysed.

RESULTS

Twenty-nine per cent of the patients received preoperative CRT. The median LNY was 13 [interquartile range (IQR): 8-19]. A total of 43.4% of the patients had an LNY of < 12. The median LNY increased from 8 (IQR: 5-12) to 20 (IQR: 13-28) LNs over the years of the study period (P < 0.0001). Gender and body mass index (BMI) had no impact on the median LNY. Age had a minor impact, with a range of 12 (IQR: 8-18) to 13 (IQR: 9-20) (P < 0.0001). The LNY ranged from 9 (IQR: 6-14) to 16 (IQR: 10-26), according to pT-stage (pT0-pT4) (P < 0.0001). Median LNY, according to preoperative CRT or no preoperative CRT, was 10 (IQR: 6-16) and 14 (IQR: 8-18), respectively (P < 0.0001). The percentages of patients with an LNY of < 12, according to preoperative CRT or no preoperative CRT, were 58.7% and 37.1%, respectively (P < 0.0001).

CONCLUSION

An increase in the LNY over the period of the study was observed, probably reflecting improved quality of surgery and histopathology. A minor significant reduction of LNY was found with increasing age of the patient. LNY was significantly related to pT-stage and to the use of preoperative chemoradiotherapy. For these reasons the minimum harvest of 12 LNs as a surrogate marker for the oncological quality of surgery should be questioned.

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.

The effect of preoperative chemoradiotherapy on lymph nodes harvested in TME for rectal cancer

BACKGROUND

Adequate lymph nodes resection in rectal cancer is important for staging and local control. This retrospective analysis single center study evaluated the effect of neoadjuvant chemoradiation on the number of lymph nodes in rectal carcinoma, considering some clinicopathological parameters.

METHODS

A total of 111 patients undergone total mesorectal excision for rectal adenocarcinoma from July 2005 to May 2012 in our center were included. No patient underwent any prior pelvic surgery or radiotherapy. Chemoradiotherapy was indicated in patients with rectal cancer stage II or III before chemoradiation.

RESULTS

One-hundred and eleven patients were considered. The mean age was 67.6 yrs (range 36 - 84, SD 10.8). Fifty (45.0%) received neoadjuvant therapy before resection. The mean number of removed lymph nodes was 13.6 (range 0-39, SD 7.3). In the patients who received neoadjuvant therapy the number of nodes detected was lower (11.5, SD 6.5 vs. 15.3, SD 7.5, p = 0.006). 37.4% of patients with preoperative chemoradiotherapy had 12 or more lymph nodes in the specimen compared to the 63.6% of those who had surgery at the first step (p: 0.006).Other factors associated in univariate analysis with lower lymph nodes yield included stage (p 0.005) and grade (p 0.0003) of the tumour. Age, sex, tumor site, type of operation, surgeons and pathologists did not weight upon the number of the removed lymph nodes.

CONCLUSION

In TME surgery for rectal cancer, preoperative CRT results into a reduction of lymph nodes yield in univariate analisys and linear regression.

Clinical impact of fat clearing technique in nodal staging of rectal cancer after preoperative chemoradiotherapy

Purpose

This study was designed to evaluate the efficacy of a fat clearing technique for accurate nodal staging of rectal cancer patients after preoperative chemoradiotherapy (CRT).

Methods

A total of 19 patients with rectal cancer within 10 cm from anal verge were divided into two groups: non-CRT group (n = 10) and CRT group (n = 9). For pathologic assessment, lymph node (LN) harvest was performed using conventional manual dissection followed by a fat clearing technique.

Results

A median of 3.0 additional LNs in non-CRT group and 3.8 LNs in CRT group were identified by the fat clearing technique. When subanalysis was performed in patients with fewer than 12 retrieved LNs, a median of 4.0 extra LNs in non-CRT group and 3.5 extra LNs in CRT group were identified after the fat clearing technique. None of additionally identified nodes were metastatic. In both groups, the median size of retrieved LNs following the fat clearing technique was smaller than that obtained by manual dissection (2.0 mm vs. 3.0 mm, P < 0.001).

Conclusion

The fat clearing technique allowed detection of additional LNs that were missed by the manual method, but these detected LNs were not proven to be metastatic.

Lymph node evaluation for resected colorectal cancer

SUMMARY The negative impact of regional lymph node metastasis on survival from nonmetastatic colorectal cancers is proportional to the number of nodes harvested. A thorough lymph node examination by the pathologist is essential for accurate staging. Recommendations in the USA and Europe stipulate that a minimum of 12–15 lymph nodes must be examined to accurately predict regional node negativity. The prognostic separation for stage III colorectal cancer obtained by the lymph node ratio is superior to that of the absolute number of positive nodes. The extent of mesenteric resection, pathologic technique, age or tumor location may influence lymph node yield. In the future, biological significance and clinical impact on outcome of very small amounts of tumor in regional nodes could help in staging patients. The current data are considered insufficient to recommend either the routine examination of multiple tissue levels of paraffin blocks or the use of special/ancillary techniques.