Intra-arterial methylene blue injection into ex vivo colorectal cancer specimens improves lymph node staging accuracy: a randomized controlled trial

Feasibility of indocyanine green (ICG) fluorescence in ex vivo pathological dissection of colorectal lymph nodes-a pilot study

Accurate lymph node (LN) retrieval during colorectal carcinoma resection is pivotal for precise N-staging and the determination of adjuvant therapy. Current guidelines recommend the examination of at least 12 mesocolic or mesorectal lymph nodes for accurate staging. Traditional histological processing techniques, reliant on visual inspection and palpation, are time-consuming and heavily dependent on the examiner's expertise and availability. Various methods have been documented to enhance LN retrieval from colorectal specimens, including intra-arterial ex vivo methylene blue injection. Recent studies have explored the utility of indocyanine green (ICG) fluorescence imaging for visualizing pericolic lymph nodes and identifying sentinel lymph nodes in colorectal malignancies. This study included 10 patients who underwent colon resection for malignant tumors. During surgery, intravenous ICG dye and an endoscopic camera were employed to assess intestinal perfusion. Post-resection, ex vivo intra-arterial administration of ICG dye was performed on the specimens, followed by routine histological processing and an ICG-assisted lymph node dissection. The objective was to evaluate whether ICG imaging could identify additional lymph nodes compared to routine manual dissection and to assess the clinical relevance of these findings. For each patient, a minimum of 12 lymph nodes (median = 25.5, interquartile range = 12.25, maximum = 33) were examined. ICG imaging facilitated the detection of a median of three additional lymph nodes not identified during routine processing. Metastatic lymph nodes were found in four patients however no additional metastatic nodes were detected with ICG assistance. Our findings suggest that ex vivo intra-arterial administration of indocyanine green dye can augment lymph node dissection, particularly in cases where the number of lymph nodes retrieved is below the recommended threshold of 12.

The impact of methylene blue in colon cancer: a retrospective multicentric study

INTRODUCTION

Discussions about the optimal lymph node (LN) count and its therapeutic consequences have persisted over time. The final LN count in colorectal tissues is affected by a variety of variables (patient, tumor, operation, pathologist, immune response). Methylene blue (MB) intra-arterial injection is a simple and inexpensive procedure that can be used to enhance lymph node count.

AIM

Analyze whether there is a statistically significant difference between intra-arterial methylene blue injection and conventional dissection for the quantification of lymph nodes and determine if there is a variation in the quality of lymph node acquisition.

METHODS AND RESULTS

Between 2015 and 2022, we conducted a retrospective analysis of colon cancer specimens. Data on the tumor's features, the number of lymph nodes, the number of lymph nodes that were positive, and other factors had been collected. The number of identified lymph nodes was highly significantly improved in the study group (P < 0.05). There is not a significant statistical difference between groups regarding the metastatic lymph node harvest. The group with injection of intra-arterial methylene blue shows a significantly decreased (P < 0.05) of the of cases with less than 12 lymph nodes recovered comparing with the control group.

CONCLUSION

Colon cancer specimens can be easily evaluated concerning lymph nodes using the methylene blue method. Therefore, we strongly advise this approach as a standard procedure in the histological evaluation of colon cancer specimens in order to maximize the identification of lymph nodes. However, the detection of metastatic lymph nodes was unaffected significantly.

The impact of methylene blue in colorectal cancer: Systematic review and meta-analysis study

PURPOSE

In patients with colorectal cancer (CRC), the most important factor to decide the need of adjuvant chemotherapy is the histological lymph node (LN) evaluation. Our work aimed to give a broad view over the use of methylene blue and its consequences in the number of lymph node harvest.

METHODS

PUBMED, WEB OF SCIENCE and EMBASE databases were consulted, retrieving clinical trials, which mentioned the used of intra-arterial methylene blue in patients with colorectal cancer.

RESULTS

Eighteen clinical trials analyzing the use of intra-arterial methylene blue in specimens of colorectal cancer were selected. The articles show a statistical difference between the use of methylene blue and the classical dissection in both variable at study. The results of the statistical analysis of the lymph node harvest variable demonstrate a significant statistical difference between the group that received methylene blue injection and the group that underwent conventional dissection. There is a significant statistical difference between the experimental and control groups for the ideal lymph node harvest (lymph node harvest count greater than 12).

CONCLUSION

The use of intra-arterial methylene blue revealed a high potential for the quantification of lymph nodes, considering the increase of lymph node harvest and the higher percentage of cases with more than 12 lymph nodes count, albeit the high heterogeneity between the studies in terms of reported results. Future investigations with controlled double blinded studies obtaining better categorized results should be conducted in order to better evaluate this technique and compare it to the current paradigm.

Predictive value of circulating tumor cell counts during the treatment of cancer: interactions with the blood microenvironment

OBJECTIVE

This study aimed to evaluate the prognostic value of circulating tumor cell (CTC) in tumor patients during treatment.

METHODS

This study retrospectively analyzed clinical data obtained from 174 cancer patients during treatment. The relationship between the CTC counts and clinicopathological variables was analyzed. A ROC curve was applied to determine the optimal cut-off values and assess the predictive ability of the prognostic indicators. The overall survival (OS) for different prognostic factors was calculated using the Kaplan-Meier method, and the difference between the survival curves was then compared using the log-rank test. Cox regression model was used to investigate the effect of independent factors on patients' survival.

RESULTS

The CTC-positive rate was positively correlated with the clinicopathological variables of TNM stage, tumor differentiation, serum CEA level, and ki-67%. In the differential analysis of hematological microenvironment parameters in CTC-positive and CTC-negative samples, the complete blood count, blood biological chemistry, tumor markers (CEA, CA19-9, CA72-4), and lymphocyte subpopulation were statistically significant. The results of the ROC curve analysis indicated that the serum CEA level was the best diagnostic indicator to discriminate the CTC count in tumor patients. Additionally, the results of the univariate and multivariate analyses of OS in relation to clinical variables revealed that the CTC counts were an independent prognostic factor for unfavorable OS.

CONCLUSION

The CTC counts in patients with tumors undergoing treatment were significantly correlated with hematological microenvironment parameters. The detection of CTCs may therefore be used as an indicator of tumor prognosis.

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.

Methylene blue can increase the number of lymph nodes harvested in colorectal cancer: a meta-analysis

AIM

The lymph node (LN) status plays an important role in colorectal cancer (CRC), which depends on adequate LN harvest. In some studies, methylene blue has been used to increase the number of LNs harvested in vitro. The purpose was to evaluate the effect of methylene blue staining on LN harvest during radical resection of CRC.

METHODS

The Cochrane Library, MEDLINE, Embase, PubMed, and Web of Science were searched from the dates of inception until 15 October 2022. Studies were included if they were randomized controlled trials or nonrandomized controlled trials for radical resection of rectal cancer according to the principle of total mesorectal excision that compared the use of methylene blue with blank control in LN harvest. The primary outcomes were the number of LNs harvested and the incidence of fewer than 12 LNs harvested.

RESULT

Of 328 articles found, a meta-analysis was conducted of 15 studies (2 randomized controlled trials and 13 non-randomized controlled trials) composed of 3104 patients. Meta-analysis showed that methylene blue could not only significantly increase the number of LNs harvested in CRC specimens (stained group 28.23 vs unstained group 16.15; weighted mean difference 12.08; 95% CI, 8.03-16.12; p < 0.001; I² = 95%), but also reduce the incidence of fewer than 12 LNs harvested (methylene blue-stained group 7.91% vs unstained group 30.90%; OR 0.12; 95% CI, 0.05-0.26; p < 0.001; I² = 78%).

CONCLUSION

Methylene blue can increase the number of LNs harvested in CRC, reduce the incidence of fewer than 12 LNs harvested, and ensure the accuracy of LN staging.

Mapping Lymph Node during Indocyanine Green Fluorescence-Imaging Guided Gastric Oncologic Surgery: Current Applications and Future Directions

Huge strides have been made in the navigation of gastric cancer surgery thanks to the improvement of intraoperative techniques. For now, the use of indocyanine green (ICG) enhanced fluorescence imaging has received promising results in detecting sentinel lymph nodes (SLNs) and tracing lymphatic drainages, which make it applicable for limited and precise lymphadenectomy. Nevertheless, issues of the lack of specificity and unpredictable false-negative lymph nodes were encountered in gastric oncologic surgery practice using ICG-enhanced fluorescence imaging (ICG-FI), which restrict its application. Here, we reviewed the current application of ICG-FI and assessed potential approaches to improving ICG-FI.

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.

Advanced Lymph Node Staging With Ex Vivo Intra-arterial Indigo Carmine Injection After Transanal Total Mesorectal Excision for Rectal Cancer: A Retrospective Cohort Study

BACKGROUND

Exact lymph node staging is essential in rectal cancer therapy.

OBJECTIVE

The aim of the study was to assess the impact of intra-arterial indigo carmine injection after transanal total mesorectal excision on the number of retrieved lymph nodes.

DESIGN

This was a retrospective, nonrandomized study.

SETTINGS

The study was conducted at a tertiary hospital by a multidisciplinary team.

PATIENTS

Patients who underwent transanal total mesorectal excision for suspected rectal cancer between 2013 and 2019 were included.

INTERVENTIONS

Rectal cancer specimens received ex vivo intra-arterial indigo carmine injection to stain lymph nodes.

MAIN OUTCOME MEASURES

Outcome measures included the number of retrieved lymph nodes with or without staining.

RESULTS

Specimens of 189 patients were analyzed, of which 108 (57.1%) were stained with indigo carmine. A mean of 19.8 ± 6.1 lymph nodes was identified in stained samples compared to 16.0 ± 4.9 without staining ( p < 0.001). Multivariable analysis showed that 3.2 additional lymph nodes were found in stained specimens (95% CI: 1.0 to 5.3; p = 0.02). In stained specimens the adequate lymph node count (≥12) was increased in univariable (odds ratio: 3.24, 95% CI: 1.13 to 10.65; p = 0.03) but not in multivariable analysis. Indigo carmine injection had no effect on the number of positive lymph nodes or the nodal stage. Chemoradiotherapy reduced the lymph node count by 2.5 ( p = 0.008). After staining, 95.0% of patients with chemoradiotherapy had ≥12 lymph nodes retrieved. The median follow-up of patients was 24.2 months with a local recurrence rate of 3.3%.

LIMITATIONS

The study is limited by its retrospective design and the nonrandomized allocation.

CONCLUSIONS

Ex vivo intra-arterial indigo carmine injection increases the number of isolated lymph nodes after transanal total mesorectal excision regardless of neoadjuvant chemoradiotherapy. Indigo carmine injection is not associated with nodal upstaging or an increased number of tumor-positive lymph nodes. See Video Abstract at http://links.lww.com/DCR/B839 .

ESTADIFICACIN AVANZADA DE LOS GANGLIOS LINFTICOS CON INYECCIN INTRAARTERIAL EX VIVO,DE NDIGO CARMN,DESPUS DE LA ESCISIN TOTAL DEL MESORRECTO POR VA TRANSANAL PARA CNCER DE RECTO UN ESTUDIO DE COHORTE RETROSPECTIVO

ANTECEDENTES:La estadificación exacta de los ganglios linfáticos es esencial en la tratamiento del cáncer de recto.OBJETIVO:El objetivo del estudio fue evaluar el impacto de la inyección intraarterial de índigo carmín después de la escisión total del mesorrecto por vía transanal con relación al número de ganglios linfáticos recuperados en el espécimen quirúrgico..DISEÑO:Estudio retrospectivo no aleatorizado.AJUSTE:El estudio se llevó a cabo en un hospital de tercer nivel por un equipo multidisciplinario.PACIENTES:Pacientes a quienes se les practicó escisión total del mesorrecto por vía transanal por sospecha de cáncer de recto entre 2013 y 2019.INTERVENCIONES:Al espécimen quirúrgico que se obtuvo, se le practicó inyección intraarterial ex vivo, de índigo carmín para teñir los ganglios linfáticos.PRINCIPALES MEDIDAS DE RESULTADO:El número de ganglios linfáticos recuperados con o sin tinción.RESULTADOS:Se analizaron muestras de 189 pacientes, de los cuales 108 (57,1%) fueron teñidos con índigo carmín. Se identificó una media de 19,8 ± 6,1 ganglios linfáticos en las muestras teñidas en comparación con 16,0 ± 4,9 sin tinción ( p < 0,001). El análisis multivariado mostró que se encontraron 3.2 ganglios linfáticos adicionales en las muestras teñidas (intervalo de confianza del 95%: 1,0 a 5,3; p = 0,02). En las muestras teñidas, el recuento adecuado de ganglios linfáticos (≥12) aumentó en el análisis univariado (razón de posibilidades: 3,24, intervalo de confianza del 95%: 1,13 a 10,65; p = 0,03) pero no en el multivariado. La inyección de índigo carmín no tuvo ningún efecto sobre el número de ganglios linfáticos positivos o el estadio ganglionar. La quimiorradioterapia redujo el recuento de ganglios linfáticos en 2,5 ( p = 0,008). Después de la tinción, en el 95,0% de los pacientes con quimiorradioterapia se recuperaron ≥12 ganglios linfáticos. La mediana de seguimiento de los pacientes fue de 24,2 meses con una tasa de recurrencia local del 3,3%.LIMITACIONES:El estudio está limitado por su diseño retrospectivo y la asignación no aleatoria.CONCLUSIONES:La inyección ex vivo de índigo carmín intraarterial aumenta el número de ganglios linfáticos aislados después de la escisión total del mesorrectal por vía transanal a pesar de la quimiorradioterapia neoadyuvante. La inyección de índigo carmín no se asocia con un aumento del estadio de los ganglios ni con un mayor número de ganglios linfáticos positivos para tumor. Consulte Video Resumen en http://links.lww.com/DCR/B839 . (Traducción-Eduardo Londoño-Schimmer ).

Circulating Lymphocytes Reflect the Local Immune Response in Patients with Colorectal Carcinoma

Tumor-infiltrating lymphocytes (TILs) correlate with the number and size of the surrounding lymph nodes in patients with colorectal carcinoma (CRC) and reflect the quality of the antitumor immune response. In this prospective study, we analyzed whether this response correlated with the circulating lymphocytes in peripheral blood (PB). In 47 patients with newly diagnosed CRC, flow cytometry was performed to analyze the B cells, T cells, NK cells, and a variety of their subsets in PB. The results were correlated with TILs in the resected tumor and with the number and size of the surrounding lymph nodes in nodal negative (N- patients (LN5: number of lymph nodes measuring ≥5 mm) and the metastasis-to-lymph node size ratio (MSR) in nodal positive patients (N+). Differences between the number of TILs could be seen between N+ and N- patients, dependent on the LN5 and MSR categories, with higher values in N- cases and in patients with a higher LN5 category or a lower MSR. Additionally, higher values of various circulating lymphocyte subgroups were observed in these patients. For the total PB lymphocytes, CD8 cells, and some of their subgroups, a positive correlation with the TILs was found. This study shows that circulating lymphocytes—in particular, cytotoxic T cells—correlate with the local antitumor immune response displayed by TILs and lymph node activation. Our findings indicate that local and generalized antitumor immune responses are concordant with their different components.

Comparative effectiveness of pathologic techniques to improve lymph node yield from colorectal cancer specimens. A systematic review and network meta-analysis

BACKGROUND

A number of randomized controlled trials (RCT) have compared different techniques to improve lymph node yield (LNY) in colorectal cancer specimens but data on comparative effectiveness are sparse. Our aim was to compare the relative effectiveness and rank all available techniques.

METHODS

A systematic search of Embase, Cochrane, PubMed and Scopus was performed for randomized trials. Pairwise meta-analysis performed if more than two homogeneous studies were available for each comparison. Network meta-analysis was used to rank and compare all available techniques.

RESULTS

Fifteen studies fulfilled the inclusion criteria. Techniques that were compared included methylene blue (MB), GEWF, Carnoy solution (CS), patent blue (PB), formalin, fat clearing (FC) and their combinations. The overall quality of studies was found to be fair. In pairwise meta-analysis MB had a higher lymph node yield weighted mean difference [WMD] 13.67 [4.83-22.51], P<0.01, lower number of specimens with less than 12 lymph nodes log Odds Ratio= -1.88(-2.8, -0.91), P<0.01 and higher LNY in patients with prior chemoradiotherapy (WMD 9.11 [3.15,15.08], p=0.02) as compared to formalin. Evaluation of the network plot revealed a well-connected network. In network meta-analysis MBFC had a higher LNY with [Mean Difference (MD) 13 and 95% credible interval (CI) (2.09- 23.91)] as compared to formalin. MBFC probability of being the best technique for LNY was 91.4%. In network meta-analysis MB did not have a statistically significant difference when compared to formalin.

CONCLUSIONS

MBFCS seems to be the most effective technique for LNY. Further studies are required to make safe conclusions for outcomes such positive lymph nodes and upstaging.

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.

Can Ex Vivo Magnetic Resonance Imaging of Rectal Cancer Specimens Improve the Mesorectal Lymph Node Yield for Pathological Examination?

Supplemental digital content is available in the text.

The aim of this study was to use 7 T ex vivo magnetic resonance imaging (MRI) scans to determine the size of lymph nodes (LNs) in total mesorectal excision (TME) specimens and to increase the pathological yield of LNs with MR-guided pathology.

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.

Circulating tumor cells as an independent prognostic factor in advanced colorectal cancer: a retrospective study in 121 patients

PURPOSE

This study aimed to evaluate the prognostic value of circulating tumor cells (CTCs) in advanced colorectal cancer (CRC) patients during chemotherapy course.

METHODS

From January 2016 to September 2017, the clinicopathological variables, such as gender, age, tumor location, tumor de-differentiation, depth of invasion, lymphatic invasion, distant metastasis, TNM stage, CTCs enumeration during 2-6 cycles of chemotherapy, and serum carcinoembryonic antigen (CEA) level during the same period, of 121 newly acquired and histopathologically confirmed CRC patients were collected from the Shanghai Ninth People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine. All patients were followed up for survival until the end of November 2018. Statistical analysis focused on the associations between CTCs counts and clinicopathological variables. Overall survival (OS) and progression-free survival (PFS) among different prognostic factors were calculated using the Kaplan-Meier method, and the differences between the survival curves were compared by using the log-rank test. Factors of prognostic significance were investigated with the multivariate Cox regression analysis.

RESULTS

Here, 71 of 121 patients were CTC-positive, in which CTC-positive rate was positively correlated with the depth of invasion, lymphatic invasion, distant metastasis, TNM stage, and serum CEA level (P < 0.05 for all). However, no significant difference was found between CTC-positive and other clinicopathological variables (P > 0.05 for all), such as gender, age, tumor location, and tumor de-differentiation. CTCs counts gradually increased with the advancement of depth of invasion (P = 0.002), lymphatic invasion (P = 0.004), distant metastasis (P = 0.007), TNM stage (P = 0.001), serum CEA level (P = 0.001), and decreased tumor de-differentiation (P = 0.011). Furthermore, the Kaplan-Meier survival curves showed that patients with CTC-positive had a significantly unfavorable PFS (14 vs. 23 months, P = 0.001) and OS (18 vs. 25 months, P = 0.003). The multivariate Cox regression analyses revealed that the presence of CTCs during chemotherapy was an independent factor for unfavorable PFS (hazard ratio (HR) 2.682, P = 0.017, 95% confidence interval (CI) 1.193-6.029) and OS (HR 2.790, P = 0.048, 95% CI 1.010-7.705) in advanced CRC patients.

CONCLUSIONS

This study provided an evidence that the presence of CTCs may be valuable for predicting survival outcome, and CTCs was associated with unfavorable survival in advanced CRC patients during chemotherapy.

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

BACKGROUND

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

OBJECTIVE

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

DESIGN

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

SETTINGS

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

PATIENTS

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

INTERVENTION

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

MAIN OUTCOME MEASURES

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

RESULTS

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

LIMITATIONS

This was a unicentric study.

CONCLUSIONS

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

Ex Vivo Intra-arterial Methylene Blue Injection in Rectal Cancer Specimens Increases the Lymph-Node Harvest, Especially After Preoperative Radiation

BACKGROUND

The examination of as large a number of lymph nodes as possible in rectal carcinoma resectates is important for exact staging. However, after neoadjuvant radiochemotherapy (RCT), it can be difficult to obtain a sufficient number of lymph nodes. We therefore investigated whether staining with methylene blue via the inferior mesenteric artery can lead to an increase in the yield of lymph nodes in rectal carcinoma tissue after neoadjuvant RCT.

METHODS

In a prospective, unicentric study rectal carcinoma resectates from three consecutive groups of patients were examined (Group I, no staining; Group II, staining with methylene blue; Group III, again no staining). The numbers of lymph nodes examined were compared (a) between the groups and (b) between patients who had not, or who had, received neoadjuvant RCT.

RESULTS

In all, 75 rectal carcinoma preparations were assessed. The yield of lymph nodes investigated before the use of staining (Group I) increased when staining was introduced (Group II), both for the patients without neoadjuvant RCT (20.9 vs. 31.3, p = 0.018) and for those who did receive this (15.0 vs. 35.1; p = 0.003). After withdrawal of the staining procedure (Group III), the lymph-node yield remained high for the patients without neoadjuvant RCT (31.3 vs. 30.4; p = 0.882), but it reverted to a lower value for those who did receive neoadjuvant RCT (35.1 vs. 24.2; p = 0.029). Before the introduction of staining (Group I), significantly fewer lymph nodes were examined for patients who received neoadjuvant RCT (15.0 vs. 20.9; p = 0.039). However, with staining (Group II), no difference was found associated with the use or non-use of neoadjuvant RCT (31.3 vs. 35.1; p = 0.520).

CONCLUSION

The use of methylene blue staining of rectal carcinoma preparations leads to a significant increase in the number of lymph nodes examined after neoadjuvant RCT. This can be expected to improve the accuracy of lymph-node staging of neoadjuvant-treated rectal carcinoma.

Assessment of lymph node involvement in colorectal cancer

Lymph node metastasis informs prognosis and is a key factor in deciding further management, particularly adjuvant chemotherapy. It is core to all contemporary staging systems, including the widely used tumor node metastasis staging system. Patients with node-negative disease have 5-year survival rates of 70%-80%, implying a significant minority of patients with occult lymph node metastases will succumb to disease recurrence. Enhanced staging techniques may help to identify this subset of patients, who might benefit from further treatment. Obtaining adequate numbers of lymph nodes is essential for accurate staging. Lymph node yields are affected by numerous factors, many inherent to the patient and the tumour, but others related to surgical and histopathological practice. Good lymph node recovery relies on close collaboration between surgeon and pathologist. The optimal extent of surgical resection remains a subject of debate. Extended lymphadenectomy, extra-mesenteric lymph node dissection, high arterial ligation and complete mesocolic excision are amongst the surgical techniques with plausible oncological bases, but which are not supported by the highest levels of evidence. With further development and refinement, intra-operative lymphatic mapping and sentinel lymph node biopsy may provide a guide to the optimum extent of lymphadenectomy, but in its present form, it is beset by false negatives, skip lesions and failures to identify a sentinel node. Once resected, histopathological assessment of the surgical specimen can be improved by thorough dissection techniques, step-sectioning of tissue blocks and immunohistochemistry. More recently, molecular methods have been employed. In this review, we consider the numerous factors that affect lymph node yields, including the impact of the surgical and histopathological techniques. Potential future strategies, including the use of evolving technologies, are also discussed.

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

AIM

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Stage migration vs immunology: The lymph node count story in colon cancer

Lymph node staging is of crucial importance for the therapy stratification and prognosis estimation in colon cancer. Beside the detection of metastases, the number of harvested lymph nodes itself has prognostic relevance in stage II/III cancers. A stage migration effect caused by missed lymph node metastases has been postulated as most likely explanation for that. In order to avoid false negative node staging reporting of at least 12 lymph nodes is recommended. However, this threshold is met only in a minority of cases in daily practice. Due to quality initiatives the situation has improved in the past. This, however, had no influence on staging in several studies. While the numbers of evaluated lymph nodes increased continuously during the last decades the rate of node positive cases remained relatively constant. This fact together with other indications raised doubts that understaging is indeed the correct explanation for the prognostic impact of lymph node harvest. Several authors assume that immune response could play a major role in this context influencing both the lymph node detectability and the tumor’s behavior. Further studies addressing this issue are need. Based on the findings the recommendations concerning minimal lymph node numbers and adjuvant chemotherapy should be reconsidered.

Current concepts of colorectal cancer resection pathology

The discussion of pathology results is one of the important items in the multidisciplinary meeting. These results describe not only the adequacy of earlier treatments (neoadjuvant therapy, surgery), but guide subsequent treatment decisions by providing staging information and additional prognostic and predictive factors. In the era of next-generation sequencing, every so often the emphasis is put on the molecular background of tumours, but the information that can be retrieved from the resection specimen remains essential for optimal patient care. In the current review the different surgical approaches will be described, together with the relevant macroscopic evaluations. Microscopic features will be addressed, giving an overview that is aimed at optimal information exchange in the multidisciplinary meeting. Finally, special requirements for reporting local excisions and specimen after neoadjuvant therapy will be discussed.