Methylene blue intra-arterial staining of resected colorectal cancer specimens improves accuracy of nodal staging: A randomized controlled trial

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.

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.

Lymph node stain after radical resection of rectal cancer mainly increased the harvest of mini lymph node: A randomized controlled trial

AIM

The lymph node status plays an important role in rectal cancer, which depends on adequate lymph node harvest. Lymph node stain techniques increase the lymph node harvest. The aim of this prospective study is to investigate which subgroups of lymph nodes harvested were increased mostly.

METHODS

From May 2020 to May 2022, 172 stage II-III rectal cancer patients were randomized to methylene blue (MB) stained group or unstained group to retrieve the lymph nodes. Methylene blue solution was injected into the inferior mesenteric artery, we dissected lymph nodes by palpation and sight. The lymph nodes were divided into 3 groups depending on the anatomy (main lymph nodes, superior rectal and perirectal lymph nodes (SPLNs), and pericolic lymph nodes located beyond 10 cm proximal to the tumor), and 3 groups depending on the short diameter of the nodes (big: ≥ 5 mm, small: 5-2 mm, mini: ≤ 2 mm).

RESULTS

The number of lymph nodes harvested with MB was significantly higher (22.0 (14.8, 32.0) vs 14.5 (11.0, 22.0); p < 0.001) without difference in positive patients or number of positive nodes. The positive rate of the big node was 3.5%, the small node was 1.9%, and the mini node was 0.2%. In the subgroup analysis, the median number of mini lymph nodes in the MB-stained group was significantly more than that of the unstained group (median (IQR): 9.0 (6.0, 14.0) vs 4.0 (2.0,6.0), p < 0.001); and the median number of SPLNs in the MB-stained group were significantly more than that of the unstained group (median (IQR): 15.0 (9.0, 19.0) vs 10.0 (6.0, 13.3), p < 0.001); these differences were existing in both patients with and without neoadjuvant treatments.

CONCLUSION

Intra-arterial injection of MB can significantly increase the number of lymph nodes harvested in rectal cancers, especially those mini lymph nodes. However, methylene blue staining did not significantly increase the number of positive lymph nodes and the proportion of patients with more than 12 lymph nodes, or affect lymph node staging accuracy after radical resection of rectal cancer.

Dietary inclusion of nitrite-containing frankfurter exacerbates colorectal cancer pathology and alters metabolism in APCmin mice

Colorectal cancer (CRC) is the second most prevelant malignancy in Europe and diet is an important modifiable risk factor. Processed meat consumption, including meats with preservative salts such as sodium nitrite, have been implicated in CRC pathogenesis. This study investigated how the CRC pathology and metabolic status of adenomatous polyposis coli (APC) multiple intestinal neoplasia (min) mice was perturbed following 8 weeks of pork meat consumption. Dietary inclusions (15%) of either nitrite-free pork, nitrite-free sausage, or nitrite-containing sausage (frankfurter) were compared against a parallel control group (100% chow). Comprehensive studies investigated: gastrointestinal tract histology (tumours), aberrant crypt foci (ACF), mucin deplin foci (MDF), lipid peroxidation (urine and serum), faecal microbiota, and serum metabolomics (599 metabolites). After 8 weeks mice consuming the frankfurter diet had 53% more (P = 0.014) gastrointestinal tumours than control, although ACF and MDF did not differ. Urine and serum lipid peroxidation markers were 59% (P = 0.001) and 108% (P = 0.001) higher, respectively in the frankfurter group. Gut dysbiosis was evident in these mice with comparably fewer Bacteriodes and more Firmicutes. Fasting serum levels of trimethylamine N-oxide (TMAO) and numerous triglycerides were elevated. Various serum phosphotidylcholine species were decreased. These results demonstrate that nitrite-containing sausages may exaccerbate the development of CRC pathology in APC^Min mice to a greater extent than nitrite-free sausages, and this is associated with greater lipid peroxidation, wide-ranging metabolic alternation and gut dysbiosis.

Efficacy and Safety of Modified Seamless Endoscopic Dacryocystorhinostomy in Patients with Chronic Dacryocystitis

Objective

To evaluate the efficacy and safety of a modified seamless endoscopic dacryocystorhinostomy (EN-DCR) with chronic dacryocystitis.

Methods

This study included 54 patients (54 eyes) with chronic dacryocystitis treated in our hospital from 2019 to 2021, including 32 patients (32 eyes) who underwent modified and 22 patients (22 eyes) who underwent routine EN-DCR. In the modified EN-DCR, the nasal cavity was filled 30 min before the operation by injection of 1 mg/ml adrenaline hydrochloride and application of ephedrine hydrochloride and nitrofurazone nasal drops. Before the operation, the lacrimal passages were rinsed with a 1 : 2 mixture of dilute methylene blue and normal saline. The “I”-shaped incision was replaced by a ^“C^“-shaped incision near the lateral bone window. In place of suturing, a gelatin sponge was applied at the confluence of the lacrimal sac and nasal mucosa. After the end of the operation, the lacrimal sac was filled with tapered expansion sponge for 1 week. In routine EN-DCR, the nasal cavity was filled with 1 mg/ml epinephrine hydrochloride, and nitrofurazone nasal drops were provided for 5 minutes after the beginning of the operation; and a “I”-shaped incision was made in the nasal mucosa, with one stitch for each anterior and posterior flap. Operation time, intraoperative bleeding, and postoperative lacrimal duct irrigation were compared, with the curative effect evaluated after a follow-up of 6 months.

Results

Operation time was significantly shorter (41.3 ± 12.1 min vs. 65.4 ± 11.6 min; χ² = 7.312, P < 0.05) and intraoperative bleeding was significantly lower (12.5 ± 5.2 ml vs. 60.3 ± 8.9 ml; χ² = 24.883, P < 0.05) in the modified group than in the routine EN-DCR group. After follow-up for 6 months, the effective cure rate was significantly higher in the modified group than in the routine group (96.9% vs. 68.2%; χ² = 6.383, P < 0.05).

Conclusion

Compared with routine EN-DCR, modified seamless EN-DCR can achieve better surgical outcomes, shorten operation time, and reduce intraoperative bleeding.

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 ).

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.

Changes in the quality of care of colorectal cancer in Estonia: a population-based high-resolution study

OBJECTIVES

Large disparities in colorectal cancer (CRC) management and survival have been observed across Europe. Despite recent increases, the survival deficit of Estonian patients with CRC persists, particularly for rectal cancer. The aim of this study was to examine diagnostic, staging and treatment patterns of CRC in Estonia, comparing clinical data from 1997 and 2011.

DESIGN

Nationwide population-based retrospective study.

SETTING

Estonia.

PARTICIPANTS

All incident cases of colon and rectal cancer diagnosed in 1997 and 2011 identified from the Estonian Cancer Registry. Clinical data gathered from medical records.

OUTCOME MEASURES

Differences in diagnostic, staging and treatment patterns; 5-year relative survival ratios.

RESULTS

The number of colon cancer cases was 337 in 1997 and 498 in 2011; for rectal cancer, the respective numbers were 209 and 349. From 1997 to 2011, large increases were seen in the use of colonoscopy and lung and liver imaging. Radical resection rate increased from 48% to 59%, but emergency surgeries showed a rise from 18% to 26% in colon and from 7% to 14% in rectal cancer. The proportion of radically operated patients with ≥12 lymph nodes examined pathologically increased from 2% to 58% in colon cancer and from 2% to 50% in rectal cancer. The use of neoadjuvant radiotherapy increased from 6% to 39% among stage II and from 20% to 50% among patients with stage III rectal cancer. The use of adjuvant chemotherapy in stage III colon cancer increased from 42% to 63%. The 5-year RSR increased from 50% to 58% in colon cancer and from 37% to 64% in patients with rectal cancer.

CONCLUSIONS

Major improvements were seen in the diagnostics, staging and treatment of CRC in Estonia contributing to better outcomes. Increase in emergency surgeries highlights possible shortcomings in timely diagnosis and treatment.

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.

Subsite- and stage-specific colorectal cancer trends in Estonia prior to implementation of screening

BACKGROUND

The occurrence of colorectal cancer (CRC) in Estonia has been characterised by increasing incidence, low survival and no screening. The study aimed to examine long-term incidence and survival trends of CRC in Estonia with specific focus on subsite and stage.

METHODS

We analysed CRC incidence and relative survival using Estonian Cancer Registry data on all cases of colorectal cancer (ICD-10 C18-21) diagnosed in 1995-2014. TNM classification was used to categorise stage.

RESULTS

Age-standardized incidence of colon cancer increased both in men and women at a rate of approximately 1% per year. Significant increase was seen for right-sided tumours, but not for left-sided tumours. Rectal cancer incidence increased significantly only in men and anal cancer incidence only in women. Age-standardized five-year relative survival for colon cancer increased from 50% in 1995-1999 to 59% in 2010-2014; for rectal cancer, from 38% to 56%. Colon cancer survival improved significantly for left-sided tumours (from 51% to 62%) and stage IV disease (from 6% to 15%). For rectal cancer, significant survival gain was seen for stage II (from 58% to 75%), stage III (from 34% to 70%) and stage IV (from 1% to 12%).

CONCLUSION

In the pre-screening era in Estonia, increase in colon cancer incidence was limited to right-sided tumours. Large stage-specific survival gain, particularly for rectal cancer, was probably due to better staging and advances in multimodality treatment. Nonetheless, more than one quarter of new CRC cases are diagnosed at stage IV, emphasising the need for an efficient screening program.

Lymph Node Metastasis in Colorectal Cancer

Pathologic examination of lymph nodes in patients with cancer remains crucial for postoperative treatment and prognosis prediction. In this article, the authors aim to review several important and challenging issues regarding lymph node metastasis in colorectal cancer using the AJCC staging manual, College of American Pathologists cancer protocol, as well as the literature. These topics include lymph node staging, the definition and controversies in tumor deposits, isolated tumor cells in lymph node and micrometastasis, lymph node ratio as a prognostic stratification factor, and neoadjuvant treatment effect in rectal cancer. Updates from the most recent AJCC 8th edition are included.