Impact of preoperative radiation for rectal cancer on subsequent lymph node evaluation: a population-based analysis

Effect of neoadjuvant therapy regimens on lymph nodes yield in rectal cancer

BACKGROUND AND OBJECTIVES

Pathological nodal staging is relevant to postoperative decision-making and a prognostic marker of cancer survival. This study aimed to assess the effect of different total neoadjuvant therapy (TNT) regimens on lymph node status following total mesorectal excision (TME) for locally advanced rectal cancer (LARC).

METHODS

A retrospective cohort study of patients treated for node-positive clinical stage 3 LARC with TNT between January 2015 and August 2022. Patients were stratified into induction therapy and consolidation therapy groups. Variables collated included patient demographics, clinical and radiological characteristics of the tumor, and pathology of the resected specimen. Primary outcome was total harvested lymph nodes.

RESULTS

Ninety-seven patients were included (57 [58.8%] males; mean age of 58.5 ± 11.4 years). The induction therapy group included 85 (87.6%) patients while 12 (12.4%) patients received consolidation therapy. A median interquartile range value of 22.00 (5.00-72.00) harvested lymph nodes was recorded for the induction therapy group in comparison to 16.00 (16.00-47.00) in the consolidation therapy arm (p = 0.487). Overall pathological complete response rate was 34%.

CONCLUSION

Total harvested nodes from resected specimens were marginally lower in the consolidation therapy group. Induction therapy may be preferrable to optimize postoperative specimen staging.

INFLUENCE OF NEOADJUVANT THERAPY ON THE RATIO OF LYMPH NODES

BACKGROUND

To evaluate the relationship between the ratio of affected lymph nodes (LNR) and clinical and anatomopathological variables in patients with rectal adenocarcinoma submitted or not to neoadjuvant chemoradiotherapy.

METHODS

The LNR was determined by dividing the number of compromised LNR by the total number of LNR dissected in the surgical specimen. Patients were divided into two groups: with QRT and without QRT. In each group, the relationship between LNR and the following variables was evaluated: degree of cell differentiation, depth of invasion in the rectal wall, angiolymphatic /perineural invasion, degree of tumor regression and occurrence of metastases. The LNR was evaluated in patients with more than 1, LNR (LNR >12) or less (LNR<12) in the surgical specimen with overall survival (OS) and disease-free survival (DFS). The results were expressed as the mean with the respective standard deviation. Qualitative variables were analyzed using Fisher's exact test, while quantitative variables were analyzed using the Kruskal -Wallis and Mann-Whitney tests. The significance level was 5%.

RESULTS

We evaluated 282 patients with QRT and 114 without QRT, between 1995-2011. In the QRT Group, LNR showed a significant association with mucinous tumors (P=0.007) and degree of tumor regression (P=0.003). In both groups, LNR was associated with poorly differentiated tumors (P=0.001, P=0.02), presence of angiolymphatic invasion (P<0.0001 and P=0.01), perineural (P=0.0007, P=0.02), degree of rectal wall invasion (T3>T2; P<0.0001, P=0.02); Compromised LNR (P<0.0001, P<0.01), metastases (P<0.0001, P<0.01). In patients with QRT, LNR<12 was associated with DFS (5.889; 95%CI1.935-19.687; P=0.018) and LNR>12 with DFS and OS (17.984; 95%CI5.931-54.351; P<0.001 and 10.286; 95%CI 2.654-39.854; P=0.007, respectively).

CONCLUSION

LNR was associated with histological aspects of poor prognosis, regardless of the use of QRT. In the occurrence of less than 12 evaluated LNR, the LNR was associated only with the DFS.

BACKGROUND

• Assessment of the lymph nodes during pathological analysis of the surgical specimen is crucial to determine treatment and prognosis.

BACKGROUND

• Neoadjuvance therapy reduces the number of lymph nodes, being lower than recommended, therefore the lymph node ratio can be an alternative analysis for a better prognosis.

Sequential Lateral Lymphatic Metastasis Shows Similar Oncologic Outcomes to Upward Spread in Advanced Rectal Cancer After Preoperative Chemoradiotherapy

BACKGROUND

Whether lateral pelvic node metastasis should be considered as a regional or systemic disease is a long-standing debate. Although previous Japanese studies have considered it to be locoregional disease, Western countries consider it a systemic disease and do not perform lateral pelvic node dissection after preoperative chemoradiotherapy.

OBJECTIVE

To evaluate whether lateral pelvic node metastasis is a systemic or regional disease that is amenable to curative resection.

DESIGN

Retrospective analysis of a prospectively collected database.

SETTING

This study was conducted at a tertiary cancer center.

PATIENTS

There were 616 consecutive patients who underwent curative total mesorectal excision alone or with lateral pelvic node dissection after preoperative chemoradiotherapy for locally advanced rectal cancer between 2011 and 2019.

MAIN OUTCOME MEASURES

Three-year disease-free and overall survival.

RESULTS

A total of 360 patients underwent total mesorectal excision, and 160 patients underwent total mesorectal excision with lateral pelvic node dissection. There was no difference in the 3-year disease-free survival (DFS; p = 0.844) or overall survival rates ( p = 0.921) between the groups. Patients with lateral pelvic node metastasis showed DFS similar to those with perirectal lymph node metastasis in the total mesorectal excision group. In a subgroup analysis, patients with internal iliac pelvic node metastasis showed a disease-free survival comparable to those with perirectal node involvement, and patients with other lateral pelvic node metastasis showed a DFS similar to those with intermediate node involvement. In the lateral pelvic node dissection group, the lateral pelvic node metastatic rate was 32.5%. On multivariate analysis, fewer than 8 of the unilateral harvested lateral pelvic nodes and advanced ypT stage were significantly associated with poor disease-free survival.

LIMITATION

The retrospective design.

CONCLUSIONS

Lateral lymphatic metastasis showed oncologic outcomes similar to those of upward spread, especially perirectal lymph nodes metastasis. Large cohort studies with long-term follow-up are required to confirm these results. See Video Abstract .

LAS METSTASIS LINFTICAS SECUENCIALES LATERALES MUESTRAN RESULTADOS ONCOLGICOS SIMILARES EN LA PROPAGACIN ASCENDENTE DEL CNCER RECTAL AVANZADO DESPUS DE LA RADIOQUIMIOTERAPIA PREOPERATORIA

ANTECEDENTES:Es un debate muy antiguo si las metástasis en los ganglios pélvicos laterales deben considerarse una enfermedad regional o sistémica. Si bien estudios japoneses anteriores las consideran como una enfermedad locorregional, en los países de occidente se las considera como una enfermedad sistémica por la cual no se realiza disección de ganglios pélvicos laterales después de una radioquimioterapia preoperatoria.OBJETIVOS:Evaluar si la metástasis en los ganglios pélvicos laterales se consideran como enfermedad sistémica o enfermedad regional susceptible de resección curativa.DISEÑO:Análisis retrospectivo de una base de datos recopilada prospectivamente.AJUSTE:Este estudio se realizó en un centro oncológico terciario.PACIENTES:616 pacientes consecutivos se sometieron a excisión total del mesorrecto curativa sola o con disección de los ganglios pélvicos laterales después de radioquimioterapia preoperatoria en casos de cáncer de recto localmente avanzado entre 2011 y 2019.PRINCIPALES MEDIDAS DE RESULTADO:Sobrevida global y libre de enfermedad a 3 años.RESULTADOS:Un total de 360 pacientes se sometieron a excisión total del mesorrecto y 160 pacientes se sometieron a excisión total del mesorrecto con disección de ganglios pélvicos laterales.No hubo diferencias en la sobrevida libre de enfermedad a 3 años (p = 0,844) ni en las tasas de sobrevida general (p = 0,921) entre los grupos. Los pacientes con metástasis en los ganglios pélvicos laterales mostraron una sobrevida libre de enfermedad similar a aquellos con metástasis en los ganglios linfáticos perirrectales que se encontraban en el grupo de excisión total del mesorrecto.En el análisis de subgrupos, los pacientes con metástasis en los ganglios pélvicos ilíacos internos mostraron una sobrevida libre de enfermedad comparable a aquellos con afección de los ganglios perirrectales y los pacientes con otras metástasis en los ganglios pélvicos laterales mostraron una sobrevida libre de enfermedad similar a aquellos con afección de los ganglios intermedios.En el grupo de disección de los ganglios pélvicos laterales, la tasa de metástasis en dichos ganglios fué del 32,5%. En el análisis multivariado, < de 8 ganglios pélvicos laterales resecados unilateralmente y el estadio ypT avanzado se asociaron significativamente con una menor sobrevida libre de enfermedad.LIMITACIÓN:El diseño retrospectivo del estudio.CONCLUSIONES:Las metástasis linfáticas laterales mostraron resultados oncológicos similares a la diseminación ascendente, especialmente las metástasis en los ganglios linfáticos perirrectales. Se requieren grandes estudios de cohortes con seguimiento a largo plazo para confirmar estos resultados. (Traducción-Dr. Xavier Delgadillo ).

Does robotic TME bring difference in lymph node yield and quality of TME?

BACKGROUNDS

Oncological outcomes of the robotic low anterior rectal resection with total mesorectal excision (TME) are still under discussion. Few studies have proven that robotic TME (rTME) is a safe and equivalent method for treatment of rectal carcinoma. But there is almost no comparison between the rTME and conventional TME in terms of the number of lymph nodes obtained and the quality of the TME.

METHODS

A single institution retrospective study was designed in a cohort of 261 patients. Cohort was divided into two groups depending on the type of surgery (rTME versus TME) and within these two groups, patients were divided according to whether they underwent neoadjuvant chemoradiation (nCHRT) or did not. The primary objective of the study was to compare obtained number of the lymph nodes in specimen. Secondary objectives were comparison of the quality of the TME and the number of positive circumferential resection margins.

RESULTS

Results of the study have shown no significant difference in number of the lymph nodes obtained by the rTME and TME. There was no difference in the quality of the TME, neither in the group with the previous nCHRT nor in the group without a nCHRT.

CONCLUSION

With results from the study we consider the rTME to be non-inferior to the conventional TME. Therefore, at least identical oncological results can be expected in patients treated by the rTME.

Forecasting Individual Patients' Best Time for Surgery in Colon-Rectal Cancer by Tumor Regression during and after Neoadjuvant Radiochemotherapy

The standard treatment of locally advanced rectal cancer is neoadjuvant chemoradiotherapy before surgery. For those patients experiencing a complete clinical response after the treatment, a watch-and-wait strategy with close monitoring may be practicable. In this respect, the identification of biomarkers of the response to therapy is extremely important. Many mathematical models have been developed or used to describe tumor growth, such as Gompertz's Law and the Logistic Law. Here we show that the parameters of those macroscopic growth laws, obtained by fitting the tumor evolution during and immediately after therapy, are a useful tool for evaluating the best time for surgery in this type of cancer. A limited number of experimental observations of the tumor volume regression, during and after the neoadjuvant doses, permits a reliable evaluation of a specific patient response (partial or complete recovery) for a later time, and one can evaluate a modification of the scheduled treatment, following a watch-and-wait approach or an early or late surgery. Neoadjuvant chemoradiotherapy effects can be quantitatively described by applying Gompertz's Law and the Logistic Law to estimate tumor growth by monitoring patients at regular intervals. We show a quantitative difference in macroscopic parameters between partial and complete response patients, reliable for estimating the treatment effects and best time for surgery.

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.

Improved Accuracy of Lymph Node Staging and Long-Term Survival Benefit in Colorectal Cancer With Ex Vivo Arterial Methylene Blue Infiltration

Introduction:Ex vivo methylene blue (MB) injection into the main supplying arteries of the colorectal specimen after surgical removal is an uncomplicated technique to support lymph node harvest during pathological evaluation. The primary aim of this randomized, interventional, bicentric trial was to evaluate the impact of MB injection on lymph node yield, with secondary aims assessing the accuracy of lymph node staging and the effect on 5-year overall survival for patients undergoing resection of colorectal cancer.

Methods: In the study period between December 2013 and August 2015, 200 colorectal resections were performed at two independent onco-surgery centers of Hungary. Following surgical resection, each specimen was randomly assigned either to the control (standard pathological work-up) or to the MB staining group before formaldehyde fixation. Patient-level surgical and clinical data were retrieved from routinely collected clinical datasets. Survival status data were obtained from the National Health Insurance Fund of Hungary.

Results: A total of 162 specimens, 82 in the control and 80 in the MB groups, were included for analysis. Baseline characteristics were equally distributed among study groups, except for specimen length. Both the median of total number of lymph nodes retrieved (control 11 ± 8 [0–33] nodes vs. MB 14 ± 6 [0–42] nodes; p < 0.01), and the ratio of cases with at least 12 removed lymph nodes (36/82, 43.9% vs. 53/80, 66.3%; p < 0.01) were higher in the MB group. The rate of accurate lymph node staging was non-significantly improved. As for rectal cancer, nodal staging accuracy (16/31, 51.6% vs. 23/30, 76.7%; p = 0.04) and the proportion with minimum 12 lymph node retrieval (7/31, 22.6%, vs. 18/30, 60%; p < 0.01) was improved by MB injection. In Mantel–Cox regression, a statistically significant survival benefit with methylene blue injection at 5 years post-surgery was proven (51.2% vs. 68.8%; p = 0.04).

Conclusion: In our experience, postoperative ex vivo arterial methylene blue injection appears to be an uncomplicated technique, improving lymph node yield and decreasing the chance of insufficient nodal staging. The technique might also associate with a 5-year overall survival benefit.

Long-term outcomes after extra-levator versus conventional abdominoperineal excision for low rectal cancer

Purpose

Extralevator (ELAPE) and abdominoperineal excision (APE) are two major surgical approaches for low rectal cancer patients. Although excellent short-term efficacy is achieved in patients undergoing ELAPE, the long-term benefits have not been established. In this study we evaluated the safety, pathological and survival outcomes in rectal cancer patients who underwent ELAPE and APE.

Methods

One hundred fourteen patients were enrolled, including 68 in the ELAPE group and 46 in the APE group at the Beijing Chaoyang Hospital, Capital Medical University from January 2011 to November 2020. The baseline characteristics, overall survival (OS), progression-free survival (PFS), and local recurrence-free survival (LRFS) were calculated and compared between the two groups.

Results

Demographics and tumor stage were comparable between the two groups. The 5-year PFS (67.2% versus 38.6%, log-rank P = 0.008) were significantly improved in the ELAPE group compared to the APE group, and the survival advantage was especially reflected in patients with pT3 tumors, positive lymph nodes or even those who have not received neoadjuvant chemoradiotherapy. Multivariate analysis showed that APE was an independent risk factor for OS (hazard ratio 3.000, 95% confidence interval 1.171 to 4.970, P = 0.004) and PFS (hazard ratio 2.730, 95% confidence interval 1.506 to 4.984, P = 0.001).

Conclusion

 Compared with APE, ELAPE improved long-term outcomes for low rectal cancer patients, especially among patients with pT3 tumors, positive lymph nodes or those without neoadjuvant chemoradiotherapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-022-01692-y.

Lymph Node Yield in Gastrointestinal Cancer Surgery With or Without Prior Neoadjuvant Therapy: Protocol for a Systematic Review and Meta-analysis

BACKGROUND

Lymph node yield is the number of lymph nodes retrieved during oncological resection and histopathologically identified in the resection specimen. It is an important surrogate parameter for assessing the oncological radicality of the resection of gastrointestinal carcinomas, as well as a prognostic factor in these diseases. It remains unclear if and to what extent neoadjuvant chemotherapy, radiotherapy, or chemoradiotherapy, which have become established treatments for carcinoma of the esophagus, stomach, and rectum and are increasingly used in pancreatic carcinoma, affect the lymph node yield.

OBJECTIVE

This systematic review with meta-analysis is conducted with the aim of summarizing the available evidence regarding the lymph node yield, an oncological surrogate marker, in patients with gastrointestinal carcinomas undergoing surgery after neoadjuvant therapy compared to those undergoing surgery without neoadjuvant therapy.

METHODS

Randomized and nonrandomized studies comparing oncological resection of esophageal, stomach, pancreatic, and rectal carcinoma with and without prior neoadjuvant therapy are eligible for inclusion regardless of study design. Publications will be identified with a defined search strategy in 2 electronic databases: PubMed and Cochrane Library. The primary endpoint of the analysis is the number of lymph nodes identified in the resected specimen. Secondary endpoints include the number of harvested metastatic lymph nodes, operation time, postoperative complications, pathological TNM staging, and overall and recurrence-free survival time. Using suitable statistical methods, the endpoints between patients with and without neoadjuvant therapy, as well as in defined subgroups (neoadjuvant chemotherapy, radiotherapy, or chemoradiotherapy; and patients with esophageal, gastric, pancreatic, or rectal cancer), will be compared.

RESULTS

The literature search and data collection started in October 2021. Results are expected to be published in mid-2022.

CONCLUSIONS

This meta-analysis will provide the most up-to-date and complete summary of the evidence on an association between neoadjuvant therapy and lymph node yield in gastrointestinal cancer surgery. The underlying hypothesis is that neoadjuvant therapy decreases the number and size of lymph nodes through lymphocyte depletion and radiation-induced fibrosis, thus leading to a lower possible lymph node yield. The findings of the meta-analysis will show if this hypothesis is supported by evidence.

TRIAL REGISTRATION

PROSPERO CRD218459; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021218459.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/35243.

The Effect of Lymph Node Harvest on Prognosis in Locally Advanced Middle-Low Rectal Cancer After Neoadjuvant Chemoradiotherapy

OBJECTIVE

The purpose of this study was to investigate the relationship between lymph node harvest and the prognosis in locally advanced rectal cancer (LARC) patients after neoadjuvant chemoradiotherapy (nCRT).

METHODS

Patients who were diagnosed with clinical LARC and treated with nCRT and radical surgery between June 2008 and July 2017 were included in this study. The relationship between lymph node retrieval and prognosis was analyzed. Other lymph node-related indicators were explored.

RESULTS

A total of 837 patients with a median follow-up of 61 (7-139) months were included in the study. The five-year DFS and OS rates of all patients were 74.9% and 82.3%, respectively. Multivariate survival analysis suggested that dissection of ≥ 12 lymph nodes did not improve OS or DFS. 7 was selected as the best cutoff value for the total number of lymph nodes retrieved by Cox multivariate analysis (χ2 = 10.072, HR: 0.503, P=0.002). Dissection of ≥ 5 positive lymph nodes (PLNs) was an independent prognostic factor for poorer DFS (HR: 2.104, P=0.004) and OS (HR: 3.471, p<0.001). A positive lymph node ratio (LNR) of more than 0.29 was also an independent prognostic factor for poorer DFS (HR: 1.951, P=0.002) and OS (HR: 2.434, p<0.001).

CONCLUSION

The recommends that at least 7 harvested lymph nodes may be more appropriate for LARC patients with nCRT. PLN and LNR may be prognostic factors for LARC patients with ypN+ after nCRT.

Brazilian society of surgical oncology: Guidelines for the surgical treatment of mid-low rectal cancer

BACKGROUND

Colorectal cancer (CRC) is the third leading cause of cancer in North America, Western Europe, and Brazil, and represents an important public health problem. It is estimated that approximately 30% of all the CRC cases correspond to tumors located in the rectum, requiring complex multidisciplinary treatment. In an effort to provide surgeons who treat rectal cancer with the most current information based on the best evidence in the literature, the Brazilian Society of Surgical Oncology (SBCO) has produced the present guidelines for rectal cancer treatment that is focused on the main topics related to daily clinical practice.

OBJECTIVES

The SBCO developed the present guidelines to provide recommendations on the main topics related to the treatment of mid-low rectal cancer based on current scientific evidence.

METHODS

Between May and June 2021, 11 experts in CRC surgery met to develop the guidelines for the treatment of mid-low rectal cancer. A total of 22 relevant topics were disseminated among the participants. The methodological quality of a final list with 221 sources was evaluated, all the evidence was examined and revised, and the treatment guideline was formulated by the 11-expert committee. To reach a final consensus, all the topics were reviewed via a videoconference meeting that was attended by all 11 of the experts.

RESULTS

The prepared guidelines contained 22 topics considered to be highly relevant in the treatment of mid-low rectal cancer, covering subjects related to the tests required for staging, surgical technique-related aspects, recommended measures to reduce surgical complications, neoadjuvant strategies, and nonoperative treatments. In addition, a checklist was proposed to summarize the important information and offer an updated tool to assist surgeons who treat rectal cancer provide the best care to their patients.

CONCLUSION

These guidelines summarize concisely the recommendations based on the most current scientific evidence on the most relevant aspects of the treatment of mid-low rectal cancer and are a practical guide that can help surgeons who treat rectal cancer make the best therapeutic decision.

Evaluating disparities in delivery of neoadjuvant guideline-based chemoradiation for rectal cancer: A multicenter, propensity score-weighted cohort study

BACKGROUND

Despite guideline recommendations, some patients still receive care inappropriate for their clinical stage of disease. Identification of factors that contribute to variation in guideline base care may help eradicate disparities in the treatment of early and locally advanced rectal cancer.

METHODS

The American College of Surgeons National Cancer Database from 2010 to 2015 was analyzed with propensity score weighting to identify factors associated with delivery and omission of neoadjuvant guideline-based chemoradiation (GBC) for those with early and locally advanced rectal cancer.

RESULTS

Only 74% of patients with rectal cancer received stage-appropriate neoadjuvant chemoradiation; 4544 (88%) of those with early stage disease and 8675 (68%) in locally advanced disease. Chemotherapy and radiotherapy were not planned in 27% and 34% respectively, of those who did not receive GBC. Factors associated with receipt of non-guideline-based neoadjuvant chemoradiation were age >65 years, Medicare insurance, treatment at a community facility, West-South-Central geography, having locally advanced disease, and Charlson-Deyo score >3. Receipt of ideal guideline-based neoadjuvant chemoradiation conferred a survival benefit at 5 years.

CONCLUSION

Patient and non-patient factors contribute to disparities in guideline-based delivery of neoadjuvant chemoradiation in the treatment of rectal cancer. Identification of these risk factors are important to help standardize care and improve survival outcomes.

The assessment of risk factors for long-term survival outcome in ypN0 patients with rectal cancer after neoadjuvant therapy and radical anterior resection

BACKGROUND

The main negative prognostic factors in patients with rectal cancer after radical treatment include regional lymph node involvement, lymphovascular invasion, and perineural invasion. However, some patients still develop cancer recurrence despite the absence of the above risk factors. The aim of the study was to assess clinicopathological factors influencing long-term oncologic outcomes in ypN0M0 rectal cancer patients after neoadjuvant therapy and radical anterior resection.

METHODS

A retrospective survival analysis was performed on a group of 195 patients. We assessed clinicopathological factors which included tumor regression grade, number of lymph nodes in the specimen, Charlson comorbidity index (CCI), and colorectal anastomotic leakage (AL).

RESULTS

In the univariate analysis, AL and CCI > 3 had a significant negative impact on disease-free survival (DFS), disease-specific survival (DSS), and overall survival (OS). After the division of ALs into early and late ALs, it was found that only patients with late ALs had a significantly worse survival. The multivariate Cox regression analysis showed that CCI > 3 was a significant adverse risk factor for DFS (HR 5.78, 95% CI 2.15-15.51, p < 0.001), DSS (HR 7.25, 95% CI 2.25-23.39, p < 0.001), and OS (HR 3.9, 95% CI 1.72-8.85, p = 0.001). Similarly, late ALs had a significant negative impact on the risk of DFS (HR 5.05, 95% CI 1.97-12.93, p < 0.001), DSS (HR 10.84, 95% CI 3.44-34.18, p < 0.001), and OS (HR 4.3, 95% CI 1.94-9.53, p < 0.001).

CONCLUSIONS

Late AL and CCI > 3 are the factors that may have an impact on long-term oncologic outcomes. The impact of lymph node yield on understaging was not demonstrated.

Prognostic importance of lymph node count and ratio in rectal cancer after neoadjuvant chemoradiotherapy: Results from a cross-sectional study

BACKGROUND

The aim of this study was to determine the prognostic value of lymph node count (LNC) and lymph node ratio (LNR) in rectal cancer after neoadjuvant chemoradiotherapy (CRT).

METHODS

Patients who underwent neoadjuvant CRT and total mesorectal excision (TME) for Stage I-III rectal cancer were selected from a cross-sectional study including 71 Dutch centres. Primary outcome parameters were disease-free survival (DFS) and overall survival (OS). Prognostic significance of LNC and LNR (cut-off values 0.15, 0.20, 0.30) was tested for different (sub)groups.

RESULTS

From 2095 registered patients, 458 were included, of which 240 patients with LNC < 12 and 218 patients with LNC ≥ 12. LNC was not significantly associated with DFS (p = 0.35) and OS (p = 0.59). In univariable analysis, LNR was significantly associated with DFS and OS in the whole cohort and LNC subgroups, but not in multivariable analysis.

CONCLUSIONS

LNC was not associated with long-term oncological outcome in rectal cancer patients treated with CRT, nor was LNR when corrected for N-stage. However, LNR might be used to identify subgroups of node-positive patients with a favourable 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.

Margin negative resection and pathologic downstaging with multiagent chemotherapy with or without radiotherapy in patients with localized pancreas cancer: A national cancer database analysis

Purpose

Margin-negative (R0) resection is the only potentially curative treatment for patients with pancreatic ductal adenocarcinoma (PDAC). Pre-operative multi-agent chemotherapy alone (MAC) or MAC followed by pre-operative radiotherapy (MAC + RT) may be used to improve resectability and potentially survival. However, the optimal pre-operative regimen is unknown.

Methods

Patients with non-metastatic PDAC from 2006 to 2016 who received pre-operative MAC or MAC + RT before oncologic resection were identified in the National Cancer Database. Univariable and multivariable (MVA) associates with R0 resection were identified with logistic regression, and survival was analyzed secondarily with the Kaplan Meier method and Cox regression analysis.

Results

4,599 patients were identified (MAC: 3,109, MAC + RT: 1,490). Compared to those receiving MAC, patients receiving MAC + RT were more likely to have cT3-4 disease (76% vs 64%, p < 0.001) and cN + disease (33% vs 29%, p = 0.010), but were less likely to have ypT3-4 disease (59% vs 74%, p < 0.001) and ypN + disease (32% vs 55%, p < 0.001) and more likely to have a pathologic complete response (5% vs 2%, p < 0.001) and R0 resection (86% vs 80%, p < 0.001). On MVA, MAC + RT (OR 1.58, 95% CI 1.33-1.89, p < 0.001), evaluation at an academic center (OR 1.33, 95% CI 1.14-1.56, p < 0.001), and female sex (OR 1.43, 95% CI 1.23-1.67, p < 0.001) were associated with higher odds of R0 resection, while cT3-4 disease (OR 0.81, 95% CI 0.68-0.96, p = 0.013) was associated with lower odds of R0 resection.

Conclusion

For patients with localized PDAC who receive pre-operative MAC, the addition of pre-operative RT was associated with improved rates of R0 resection and pathologic response.

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.

Comparative Evaluation of the Short-Term Treatment Outcomes Between Open, Laparoscopic- and Robotic-Assisted Surgical Approaches for Rectal Cancer Treatment

The open surgeries and more recently minimal invasive surgeries aided by laparoscopic or robotic approaches are employed for rectal cancer treatment procedures. The open approach is the most commonly opted technique, but recent studies have also shown that laparoscopic total mesorectal excision (TME) has become the standard of care. There are certain shortcomings of laparoscopic surgery such as long learning curve, inadequate counter traction, limited dexterity, lack of tactile feedback and limited two-dimensional visions. Robotic surgery also offers several benefits to overcome the drawbacks of laparoscopic procedures, such as providing better dexterity and a more stable visualization. This study aims to analyse the surgical results in terms of completion of TME, short-term surgical outcomes and hospital stay in after open, laparoscopic- and robotic-assisted rectal resections respectively. A retrospective review of prospectively maintained database of patients operated for carcinoma rectum between January 2013 and August 2018 at Manipal Comprehensive Cancer Centre, Manipal-Vattikuti Institute of Robotic Surgery, Bangalore, was analysed in this study. The surgical parameters like completion of total mesorectal excision; proximal, distal and circumferential resection margins; number of nodes retrieved; and total post operative hospital stay were analysed in the open, laparoscopic-assisted and robotic-assisted groups. A total of 100 patients were included in the study consisting of 25, 25 and 50 patients each in the open, laparoscopic and robotic arms respectively. In case the desired results were not obtained using the advanced technique the procedure was converted and open technique was adopted. The conversion rate to open procedure was 8% (2of 25) in the laparoscopic-assisted group and 2% (1/50) in the robotic-assisted group. The average post operative hospital stay was 7.4, 7.36 and 6 days in the open, laparoscopic- and robotic-assisted group (p = 0.01) respectively. Robotic rectal resections show a trend towards better surgical results in the form of improved circumferential resection margins, completeness of TME and lower conversion rates.

Nomogram Predicting Overall Survival of Resected Locally Advanced Rectal Cancer Patients with Neoadjuvant Chemoradiotherapy

PURPOSE

The overall survival (OS) of resected locally advanced rectal cancer patients who underwent neoadjuvant chemoradiotherapy (nCRT) was significantly different, even among patients with the same tumor stage. The nomogram was designed to predict OS of rectal cancer with nCRT and divide the patients into different risk groups.

MATERIALS AND METHODS

Based on materials from 911 rectal cancer patients with nCRT, the multivariable Cox regression model was carried out to select the significant prognostic factors for overall survival. And then, the nomogram was formulated using these independent prognostic factors. The discrimination of the nomogram was assessed by concordance index (C-index), calibration curves and time-dependent area under curve (AUC). The patients respective risk scores were calculated through the nomogram. The best cut-off risk score was calculated to stratify the patients. The survival curves of the two different risk cohorts were performed, which assessed the predictive ability of the nomogram.

RESULTS

Age, cT stage, pretreatment CEA, pretreatment CA19-9, surgery, posttreatment CEA, posttreatment CA19-9, pT stage, pN stage and adjuvant chemotherapy were selected for the construction of the nomogram. And then the nomogram was constructed with independent prognostic factors. The C-index of the nomogram was 0.724, which showed the nomogram provided good discernment. The acceptable agreement between the predictions of nomogram and actual observations was illustrated by calibration plots for 3-, 5- and 10-year OS in the cohort. Time-dependent AUC with 6-fold cross-validation also showed consistent results of the nomogram. Risk group stratification confirmed that the nomogram had great capacity for distinguishing the prognosis.

CONCLUSION

The nomogram was developed and validated to predict overall survival of resected locally advanced rectal cancer patients with nCRT. The proposed nomogram might help clinicians to develop individualized treatment strategies. However, further studies are warranted to optimize the nomogram by finding out other unknown prognostic factors, and more external validation is still required.

Lymph Node Harvest After Neoadjuvant Treatment for Rectal Cancer and Its Impact on Oncological Outcomes

The aim of this study was to analyze the influence of neoadjuvant treatment on nodal harvest after rectal cancer surgery and its impact on long-term oncological outcomes. A retrospective analysis of patients with rectal cancer who received curative intent treatment from 2002 to 2012 in our institution was performed. Data on various clinic-pathological and treatment details were recovered from the records. The number of nodes harvested after surgery was analyzed. The influence of number of nodes harvested on overall survival and disease free survival was analyzed. Among the 459 patients included in this study, 326 underwent surgery after neoadjuvant treatment (NAT). The mean number of nodes harvested was significantly lower in patients who received NAT compared with those who did not (8.9 ± 5.77 vs 14 ± 9.84, p < 0.001). However, the mean number of pathologically positive nodes was not significantly different. A minimum of 12 nodes were harvested in only 27.9% of patients who received NAT. No lymph nodes were identified in the specimen in 15 patients (4.6%) who underwent surgery after NAT. The only independent factors influencing harvest of a minimum of 12 nodes were patient age and NAT. The 5-year overall survival was not significantly different in patients in whom < 12 or ≥ 12 nodes were harvested (64% vs 69% respectively, p = 0.5). Neoadjuvant chemoradiation significantly reduces nodal harvest in patients undergoing treatment for rectal cancer. However, this reduced nodal harvest did not adversely impact survival in patients. However, every effort must be made by the surgeon and the pathologist to maximize the nodal harvest.

A lower cut-off for lymph node harvest predicts for poorer overall survival after rectal surgery post neoadjuvant chemoradiotherapy

Background

A lymph node harvest (LNH) of < 12 is a predictor for poor prognosis in rectal cancer patients. However, neoadjuvant chemoradiotherapy (NACRT) is known to decrease LNH; hence, a cut-off of 12 is inappropriate in such patients. This paper aims to establish a LNH cut-off predictive for disease-free and overall survival in NACRT patients.

Methods

A retrospective review of patients who underwent elective surgery for rectal cancer from 2006 to 2013 was performed. All patients with R1/2 resections and presence of metastases and those operated on for recurrence were excluded. Patient demographics, clinical features, operative details, LNH, 30-day mortality and disease-free and overall survival were recorded. P values of < 0.05 were considered significant.

Results

A total of 257 patients were studied, with 174 (68%) males and a median age of 66 years. Ninety-four (37%) patients received long-course NACRT, and 122 (48%) patients were stage 2 and below. Median LNH was 17, which was reduced in the NACRT group (14 versus 23, P < 0.01). Average length of stay was 9 ± 8 days, with a major post-operative complication rate of 4%. Using hazard ratio plots for the NACRT subgroup, LNH cut-offs of 16.5 and 8.5 were obtained for disease-free survival (DFS) and overall survival (OS) respectively. Survival analysis showed that a LNH cut-off of 8.5 was a significant predictor of OS (P < 0.001).

Conclusion

LNH is reduced in patients receiving NACRT before rectal cancer surgery. A LNH of 9 and above is associated with improved overall survival. We propose that this can be used as a tool for prognosis.

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.

Antiproliferative and pro‑apoptotic effects of Cyclocarya paliurus polysaccharide and X‑ray irradiation combination on SW480 colorectal cancer cells

The anti-hyperglycemic effects of Cyclocarya paliurus polysaccharide (CPP) have attracted increasing attention; however, limited research has been conducted on the potential effects of CPP on inhibiting tumor growth. The present study aimed to investigate the functions of CPP in combination with X-ray irradiation on colorectal cancer cells and the underlying mechanisms. SW480 cells were treated with various concentrations of CPP for 24, 48 and 72 h to determine cell viability using a Cell Counting Kit-8 assay. Then, the cells were divided into four groups as follows: Control, CPP (100 µmol/l), 8 Gy and CPP + 8 Gy. The proliferation and apoptosis, and colony formation of cells were detected using flow cytometry and plate clone formation assays, respectively. Reverse transcription-quantitative PCR and western blot analyses were conducted to determine the expression of proliferation and apoptosis-associated, and PI3K/Akt signaling-associated genes. Treatment with 75 µmol/l CPP for 48 h significantly decreased cell viability compared with untreated cells. CPP in combination with 8 Gy X-ray treatment significantly promoted the induction of apoptosis, and suppressed cell proliferation and clone formation compared with the control, CPP and 8 Gy groups. The detection of mRNA and protein expression levels by reverse transcription-PCR and western blotting demonstrated that CPP in combination with 8 Gy not only significantly decreased the expression of proliferation marker protein Ki-67, p53 and Bcl-2, but also upregulated the expression of cleaved caspase-3 and Bax, compared with the control. In addition, CPP and 8 Gy combined significantly attenuated the phosphorylation of PI3K and Akt. The present study demonstrated that the combination of CPP with X-ray irradiation suppressed SW480 cell proliferation and promoted cell apoptosis compared with the control, CPP and 8 Gy groups. The underlying mechanisms may involve inhibition of PI3K/Akt signaling.

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.

Prognostic Impact of Perineural Invasion in Rectal Cancer After Neoadjuvant Chemoradiotherapy

BACKGROUND

Perineural invasion (PNI) has emerged as an important factor related to colorectal cancer spread; however, the impact of neoadjuvant chemoradiotherapy (nCRT) on PNI remains unclear. Herein, we investigated the prognostic value of PNI, along with lymphovascular invasion (LVI), in rectal cancer patients treated with nCRT.

METHODS

This single-center observational study of pathologic variables, including PNI and LVI, analyzed 1411 invasive rectal cancer patients (965 and 446 patients treated with primary resection and nCRT, respectively).

RESULTS

The overall detection rates of LVI and PNI were 16.7 and 28.8%, respectively. The incidence of LVI was significantly lower in patients treated with nCRT (8.1 vs. 20.6%, P < .001); this was confirmed by multivariate analysis. However, PNI was not affected by nCRT (with nCRT 28.3% vs. without nCRT 29.1%, P = .786). In the 446 patients with nCRT, multivariate analysis revealed that PNI was an independent prognostic factor for both disease-free survival (DFS) and overall survival (OS). For the prediction of both 5-year DFS and OS, the C-index for the combinations of T-stage with the PNI (TPNI) system showed favorable result, especially in patients with a total number of harvested lymph nodes <8.

CONCLUSION

PNI is a meaningful prognostic factor for rectal cancer patients treated with nCRT, especially when <8 lymph nodes are harvested. The lack of influence of nCRT on the PNI incidence suggests that residual tumor cells with PNI are more radioresistant or biologically aggressive than those without.

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.

Neoadjuvant chemoradiation and rectal cancer

Neoadjuvant chemoradiation (NACR) is now standard of care in stage II and III rectal cancer. The advent of this modality of treatment has impacted on the way the pathological evaluation of resection specimens that have been subjected to preoperative chemoradiation is conducted. The gross description, sectioning and microscopic examination have had to be adapted to accommodate the changes induced by NACR. Attempts at introducing a uniform approach to the gross triaging and reporting of these specimens have been met with muted response. There still exists much variation in approach. The purpose of this overview is to highlight some of the newer developments and issues around NACR-treated rectal cancers from a pathological point of view. The NACR-treated resection specimens should be handled in a consistent manner, at least within individual institutions, if not universally. There should be generous sampling with multiple sections taken as tumour is often sequestered deep in the bowel wall. Microscopic examination should be extra vigilant as residual cancer can be present as single cells or small clusters, often deep in the muscularis propria or serosa. Acellular pools of mucin or non-viable tumour cells in mucin within the bowel wall or lymph nodes are not regarded as positive and do not upstage the tumour. The issue of grading of regression has been the subject of much debate, and several approaches have been published. It is recommended that a system that has clinical meaning and use to oncologists be used. Lymph node counts will be reduced after NACR, but reasonable attempts to accrue 12 nodes should be made.

Impact of adjuvant chemotherapy on patients with ypT0-2 ypN0 rectal cancer after neoadjuvant chemoradiation: a cohort study from a tertiary referral hospital

Background

To investigate the importance of adjuvant chemotherapy in locally advanced rectal cancer (≥ cT3 or N+) staged ypT0–2 ypN0 on final histological work-up after neoadjuvant chemoradiation and radical resection.

Methods

The clinical course of patients with rectal cancer and ypT0–2 ypN0 stages after neoadjuvant chemoradiation and radical resection was analyzed from 1999 to 2012. Patients were divided into two groups depending on whether adjuvant chemotherapy was administered or not. Overall survival, distant metastases, and local recurrence were compared between both groups.

Results

Fifty-four patients with adjuvant (ACT) and 50 patients without adjuvant chemotherapy (NACT) after neoadjuvant chemoradiation followed by radical resection for rectal cancer were included in the analysis. Mean follow-up was 68 ± 33.7 months. One patient without adjuvant chemotherapy and none in the ACT group developed a local recurrence. Five patients in the NACT group and three patients in the ACT group had distant recurrences. Median disease-free survival for all patients was 65.5 ± 34.5 months. Multivariate analysis showed adjuvant chemotherapy to be the most relevant factor for disease-free and overall survival. Patients staged ypT2 ypN0 showed a significantly better disease-free survival after application of adjuvant chemotherapy. Disease-free survival in ypT0–1 ypN0 patients showed no correlation to the administration of adjuvant chemotherapy.

Conclusion

Administration of adjuvant chemotherapy after neoadjuvant chemoradiation and radical resection in rectal cancer improved disease-free and overall survival of patients with ypT0–2 ypN0 tumor stages in our study. In particular, ypT2 ypN0 patients seem to profit from adjuvant treatment.

Lymph node ratio is an independent prognostic factor for rectal cancer after neoadjuvant therapy: A meta-analysis

OBJECTIVE

With neoadjuvant therapy increasingly used in advanced rectal cancer, the lymph node ratio (LNR) has been strongly considered to indicate cancer-specific survival in recent years, and a comprehensive evaluation of a large number of studies is deficient. The objective of our study is to pool enough eligible studies to assess the relationship between LNR and prognosis of advanced rectal cancer after neoadjuvant therapy.

METHODS

A systematic search was done in the PubMed and EmBase databases (through 1 March 2017) that reported LNR in colorectal cancer after neoadjuvant therapy. The first two authors independently conducted the study selection and data extraction. All statistical analyses were conducted using STATA 13.0 (College Station, Texas).

RESULTS

Thirteen studies with 4023 participants were included in the meta-analysis, and all were published after 2011. A high LNR was assessed to be a predictor of poor overall survival in rectal cancer after neoadjuvant therapy (HR: 2.94, 95% CI:1.97 to 3.91, P < 0.001). Similarly, a high LNR was related to poor disease-free survival (HR: 2.83, 95% CI: 1.82 to 3.85, P < 0.001). With respect to recurrence, the HRs of 3.25, 1.93, and 2.11 also showed a strong relationship between high LNR and poor local, distant, and total recurrences.

CONCLUSIONS

Our present study demonstrates that a high LNR can predict poor survival in advanced rectal cancer. We suggest well-designed clinical trials to prospectively assess LNR as an independent predictor of rectal cancer survival.

Prognostic accuracy of different lymph node staging systems in rectal adenocarcinoma with or without preoperative radiation therapy

Background and objective

A variety of different lymph node (LN) staging systems have been developed to describe the lymph node status accurately. We aim to compare the prognostic accuracy of American Joint Committee on Cancer seventh N stage relative to negative number of lymph node (nLN), lymph node ratio (LNR) and log odds of metastatic lymph nodes (LODDS) in rectal adenocarcinoma (RC).

Methods

A total of 19 167 Stage II-III rectal cancer patients who underwent surgical resection of rectal adenocarcinoma were identified from Surveillance, Epidemiology and End Results database. Akaike's Information Criterion (AIC) and the Harrell's concordance index (c statistic) were used to evaluate the relative discriminative power of the different LN staging systems.

Results

Of the 19 167 patients, 10 958 received preoperative radiotherapy (pre-RT cohort) and 8209 patients were treated with surgical resection directly (SURG cohort). When assessed using categorical cutoff values, LNR has a somewhat better prognostic accuracy both in pre-RT (c-index: 0.62; AIC: 2988.6) and SURG groups (c-index: 0.60; AIC: 3359.8). Further analysis based on different total number of lymph node (TNLN) suggested that when less than 10 lymph nodes were retrieved, LNR exhibited significant superiority (pre-RT: c-index: 0.597, AIC: 1006.8; SURG: c-index: 0.560, AIC: 810.5). When analyzed as a continuous variable, the LODDS system performed the best and was not impacted by TNLN.

Conclusion

When assessed as a categorical variable, LNR was the most powerful method to predict survival for Stage II-III RC patients with limited TNLN. Rather, LODDS was the most accurate staging system regardless of the TNLN when LN status was modeled as continuous variable.

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.

What Is the Minimum Number of Examined Lymph Nodes After Neoadjuvant Therapy in Rectal Cancer?

BACKGROUND

To date, no guidelines have standardized the number of examined lymph nodes (eLNs) after neoadjuvant treatment. This study investigated the minimum number of eLNs required for patients with rectal cancer (RC) who received neoadjuvant treatment.

MATERIAL AND METHODS

This study was based on data from the Surveillance, Epidemiology, and End Results (SEER)-Medicare-linked database. We included 2173 patients with RC who received neoadjuvant therapy. Restricted cubic spline was used to analyze the association between eLNs and lymph node metastasis (LNM).

RESULTS

The number of eLNs was an independent predictive factor for the presence of LNM (odds ratio 1.033; 95% confidence interval 1.020-1.046; P < 0.001). When the number of eLN ≤ 16, 10 and 11 eLNs had the highest rates of positive LNM. Analysis of the restricted cubic spline method found that when number of eLNs was < 10, the LNM rate increased rapidly, but this increase was not so obviously when there were > 10 eLNs.

CONCLUSIONS

Among RC patients who receive neoadjuvant therapy, the minimum number of eLNs may be 10 to ensure pathological quality.

Preoperative radiation therapy in the surgical management of gastric and junctional adenocarcinoma: Should lymph node retrieval guidelines be altered?

BACKGROUND

Although surgery remains the cornerstone of gastric cancer therapy, the use of radiation therapy (RT) is increasingly being employed to optimize outcomes. We sought to assess outcomes following use of RT for the treatment of gastric adenocarcinoma.

METHODS

Using the National Cancer Data Base (NCDB) from 1998 to 2012, all patients with resected gastric adenocarcinoma were identified. Patients were stratified into four groups based on preoperative therapy: RT alone, chemotherapy only, chemoradiotherapy (CRT), and no preoperative therapy. Overall survival was estimated using multivariate Cox proportional hazards model. Adjusted secondary outcomes include margin positivity, lymph node harvest, LOS, 30-day readmission and mortality.

RESULTS

A total of 10 019 patients met study criteria. In the unadjusted analysis, patients undergoing CRT compared to chemotherapy alone had fewer positive margins (7.9% vs 15.9%; P < 0.001), increased negative LNs (54.6% vs 37.7%; P < 0.001) with reduced LN retrieval (mean: 13.5 vs 19.6; P < 0.01). After multivariate adjustment, there was no survival benefit to any preoperative therapy; however, preoperative RT/CRT remained associated with decreased LN retrieval.

CONCLUSIONS

The results support previous reports on preoperative RT resulting in decreased margin positivity. This study highlights the need to reconsider practice guidelines regarding appropriate lymphadenectomy in the setting of preoperative RT given reduced LN retrieval.

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.

Comparison of two novel staging systems with the TNM system in predicting stage III colon cancer survival

BACKGROUND AND OBJECTIVES

Adaptations of the TNM staging system that incorporate the Lymph Node Ratio (LNR) have been proposed for stage III colon cancer. This study compared the concordance of two novel staging systems and the TNM system with observed survival outcomes in stage III patients.

METHODS

A review of patients who underwent surgery for stage III colon cancer between January 2002 and April 2015 at a tertiary care centre was performed. The Kaplan-Meier method was used to estimate the 5-year overall (OS) and disease free survival (DFS) rates, and the concordance probability was calculated to evaluate the discriminatory power of the staging systems.

RESULTS

Two hundred and sixty-one patients were identified. For TNM stages IIIA, IIIB, and IIIC, 5-year OS was 83.4%, 67.6%, and 38.3%, respectively (P < 0.001). All three staging systems were independently predictive of OS and DFS (P < 0.001). However, the novel staging system by Sugimoto et al¹⁸ was the most favourable prognostic tool, with a concordance of 0.646 for DFS and 0.659 for OS.

CONCLUSIONS

The novel staging system by Sugimoto et al¹⁸ was superior to the TNM system. Incorporating LNR into staging models for node positive colon cancers may improve survival information available to patients and potentially aid treatment decisions.

10-Year Oncologic Outcomes After Laparoscopic or Open Total Mesorectal Excision for Rectal Cancer

BACKGROUND

Only few studies have compared laparoscopic total mesorectal excision (LTME) and open total mesorectal excision (OTME) for rectal cancer with follow-up longer than 5 years. The aim of this study was to compare 10-year oncologic outcomes after LTME and OTME for nonmetastatic rectal cancer.

METHODS

We conducted a retrospective analysis of a prospective database of rectal cancer patients undergoing LTME or OTME. Statistical analyses were performed on an ''intention-to-treat'' basis and by actual treatment. Overall survival (OS) and disease-free survival (DFS) were compared by using the Kaplan-Meier method. A multivariable analysis was performed to identify predictors of poor survival.

RESULTS

Between April 1994 and August 2005, a total of 153 LTME patients and 154 OTME patients were included. Similarly, 10-year OS and DFS after LTME and OTME were observed: 76.8 versus 70.6 % (P = 0.138) and 69.1 versus 67.6 % (P = 0.508), respectively. Conversion to OTME did not adversely affect OS and DFS. Stage-by-stage comparison showed no significant differences between LTME and OTME. No significant differences were observed in local recurrence rates after LTME and OTME (6.5 vs. 7.8 %, P = 0.837). Median time until local recurrence was 24.5 (range, 12-56) months after LTME and 22 (6-64) months after OTME (P = 0.777). Poor tumor differentiation, lymphovascular invasion, and a lymph node ratio of 0.25 or more were the independent predictors of poorer OS and DFS.

CONCLUSION

This retrospective study with long follow-up did not show significant differences between the two groups in OS and DFS.

Neoadjuvant Therapy for Rectal Cancer Affects Lymph Node Yield and Status Without Clear Implications on Outcome: The Case for Eliminating a Metric and Using Preoperative Staging to Guide Therapy

BACKGROUND

Nodal status has long been considered pivotal to oncologic care, staging, and management. This has resulted in the establishment of rudimentary metrics regarding adequate lymph node yield in colon and rectal cancers for accurate cancer staging. In the era of neoadjuvant treatment, the implications of lymph node yield and status on patient outcomes remains unclear.

PATIENT AND METHODS

This study included 1,680 patients with locally advanced rectal cancer from the NCCN prospective oncology database stratified into 3 groups based on preoperative therapy received: no neoadjuvant therapy, neoadjuvant chemoradiation, and neoadjuvant chemotherapy. Clinicopathologic characteristics and survival were compared between the groups, with univariate and multivariate analyses undertaken.

RESULTS

The clinicopathologic characteristics demonstrated statistically significant differences and heterogeneity among the 3 groups. The neoadjuvant chemoradiation group demonstrated the statistically lowest median lymph node yield (n=15) compared with 17 and 18 for no-neoadjuvant and neoadjuvant chemotherapy, respectively (P<.0001). Neoadjuvant treatment did impact survival, with chemoradiation demonstrating increased median overall survival of 42.7 compared with 37.3 and 26.6 months for neoadjuvant chemotherapy and no-neoadjuvant therapy, respectively (P<.0001). Patients with a yield of fewer than 12 lymph nodes had improved median overall survival of 43.3 months compared with 36.6 months in patients with 12 or more lymph nodes (P=.009). Multivariate analysis demonstrated that neither node yield nor status were predictors for overall survival.

DISCUSSION

This analysis reiterates that nodal yield in rectal cancer is multifactorial, with neoadjuvant therapy being a significant factor. Node yield and status were not significant predictors of overall survival. A nodal metric may not be clinically relevant in the era of neoadjuvant therapy, and guidelines for perioperative therapy may need reconsideration.

Tattooing improves the detection of small lymph nodes and increases the number of retrieved lymph nodes in patients with rectal cancer who receive preoperative chemoradiotherapy: A randomized controlled clinical trial

BACKGROUND

In rectal cancer who received chemoradiotherapy, the number of Lymph nodes (LNs) required remains unclear. We conducted a randomized controlled trial to determine whether preoperative tattooing increases the number of LNs and enhances the detection rate of metastatic LNs.

METHODS

Eighty patients with rectal cancer who received chemoradiotherapy were randomly assigned to receive no tattooing (C group) or to receive tattooing (T group).

RESULTS

The number of LNs was significantly higher in the T group (13.3 ± 7.4, mean ± SD) than in the C group (8.8 ± 5.9, p < 0.001), however, the number of positive LNs did not differ (0.5 ± 1.3 vs. 0.5 ± 1.1, p = 0.882). The long-axis diameter of LNs was significantly smaller in the T group than in the C group (3.4 ± 1.8 vs. 3.9 ± 2.3 mm, p < 0.001), however, the long-axis diameter of positive LNs did not differ.

CONCLUSIONS

Tattooing increased the number of retrieved LNs by 51%, however, there was no increase in the number of positive LNs.

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.

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.

The number of retrieved lymph nodes needed for accurate staging differs based on the presence of preoperative chemoradiation for rectal cancer

The aim of this study is to investigate if retrieval of 12 lymph nodes (LNs) is sufficient to avoid stage migration as well as to evaluate the prognostic impact of insufficient LN retrieval in different treatment settings of rectal cancer, particularly in the case of preoperative chemoradiotherapy (pCRT).The data of all patients with biopsy proven rectal adenocarcinoma who underwent curative surgery between January 2005 and December 2012 were analyzed. Univariate and multivariate analyses for oncologic outcomes were performed in LN metastasis or no LN metastasis (LN-) group. Subgroup analyses were performed according to whether a patient had received pCRT.A total of 1825 patients were enrolled into the study. The maximal Chi-square method revealed the minimum number of harvested LNs required to be 12. Univariate and multivariate analyses found LNs ≥ 12 to be an independent prognostic factor for both overall survival (OS) (hazard ratio [HR] = 0.5, 95% confidence intervals [CIs]: 0.3-0.8; P = 0.002) and disease-free survival (DFS) (HR = 0.6, 95% CI: 0.4-0.7; P < 0.001) in the LN- group. In the LN- group, LNs ≥ 12 continued to be a significant prognostic factor both for OS and DFS in the subgroup of patients who did not undergo pCRT. However, in the subgroup of the LN- patients who underwent pCRT, LN ≥ 8 was significant for DFS and OS.Retrieval of LNs ≥ 12 and LNs ≥ 8 should be achieved to obtain accurate staging and optimal treatment for the non-pCRT and pCRT groups in rectal cancer, respectively.

Techniques to increase lymph node harvest from gastrointestinal cancer specimens: a systematic review and meta-analysis

AIMS

This review aims to compare different histopathological techniques for lymph node harvest from ex-vivo gastrointestinal cancer specimens and to examine their influence on: (i) lymph node yield; (ii) positive lymph node detection; and (iii) cancer staging.

METHOD AND RESULTS

Systematic review of the English language literature to 10 October 2011, comparing manual nodal dissection to other techniques for lymph node harvest. The methodological quality of included studies was assessed. Twenty-seven studies, examining fat clearing, methylene blue staining, fat stretching and use of a dedicated pathology assistant, were assessed. The methodological quality of the majority of included studies was poor. Meta-analysis showed that fat clearing and methylene blue staining increased mean lymph node yield by 13 and 15 nodes, respectively, when compared to manual dissection. Of the 15 studies reporting positive lymph node count, two demonstrated a significant improvement for techniques other than manual dissection. Compared to manual dissection, other techniques were not shown to influence cancer staging.

CONCLUSION

This review has shown that fat clearing and methylene blue staining increases the mean lymph node yield from gastrointestinal cancer specimens. There is insufficient evidence to suggest that these techniques increase positive lymph node count or lead to upstaging.

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 prognostic value of lymph node ratio in a national cohort of rectal cancer patients

OBJECTIVE

To analyze the prognostic implications of the lymph node ratio (LNR) in curative resected rectal cancer.

SUMMARY BACKGROUND DATA

It has been proposed that the LNR has a high prognostic impact in colorectal cancer, but the lymph node ratio has not been evaluated exclusively for rectal cancer in a large national cohort study.

METHODS

All 6793 patients in Denmark diagnosed with stage I to III adenocarcinoma of the rectum, and so treated in the period from 2003 to 2011, were included in the analysis. The cohort was divided into two groups according to whether or not neo-adjuvant treatment had been given.

RESULTS

In a multivariate analysis the pN status, ypN status and lymph node yield were found to be independent prognostic factors for overall survival, irrespective of neo-adjuvant therapy. The LNR was also found to be a significant prognostic factor with a Hazard Ratio ranging from 1.154 (95% CI: 0.930-1.432) (LNR: 0.01-0.08) to 2.974 (95% CI: 2.452-3.606) (LNR > 0.5) in the group of patients who had surgery to begin with and from 1.381 (95% CI: 0.891-2.139) (LNR: 0.01-0.08) to 2.915 (95% CI: 2.244-3.787) (LNR > 0.5) in the group of patients who had neo-adjuvant treatment.

CONCLUSIONS

The LNR reflects the influence on survival from N-status and the lymph node yield and since LNR was shown to be a significant prognostic predictor for overall survival in patients with curatively resected stage III rectal cancer irrespective of neo-adjuvant therapy we recommend that the introduction of LNR should be considered for rectal cancer in a revised TNM classification.

Importance of Adequate Lymphadenectomy in Gastrointestinal Cancer

One of the most important factors influencing cancer-specific survival in the field GI oncology is the presence of positive lymph nodes. Although it remains controversial, adequate lymph node examination is required for accurate staging such that patients can receive correct adjuvant treatments and for stratification in clinical trials. Nevertheless, wide variation in the quality of lymph node examination exists in the US and many centers are not meeting guideline treatment recommendations.