The relationship of lymph node evaluation and colorectal cancer survival after curative resection: a multi-institutional study

Comparison of Therapeutic Effects Between Conventional 2D Laparoscopy and 3D Laparoscopy in the Treatment of Colorectal Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

This study aimed to evaluate the effectiveness and safety of 2D laparoscopy vs 3D laparoscopy for the treatment of colorectal cancer.

METHODS

A literature search was conducted through PubMed, Web of Science, and Embase from their inception to January 2024. Studies investigating different outcomes of colorectal surgery were included. Results are presented as odds ratios (ORs) or mean differences (MDs) with 95% confidence intervals (CIs). The protocol for this review has been registered on PROSPERO (CRD42024504902).

RESULTS

A total of 10 publications were retrieved in this article. The 3D group is associated with a significant improvement in intraoperative blood loss (MD = -8.04, 95% CI = -14.18 to -1.89, P = 0.01, I2 = 55%), operative time (MD = -17.33, 95% CI = -29.15 to -5.51, P = 0.004, I2 = 90%), and postoperative hospital stay (MD = -0.23, 95% CI = -0.43 to -0.04, P = 0.02, I2 = 48%) compared to that of patients treated in the 2D group, particularly for rectal cancer patients above three results (MD = -10.36, 95% CI = -15.00 to -5.73, P < 0.001, I2 = 0%), (MD = -18.85, 95% CI = -34.88 to -2.82, P = 0.02, I2 = 57%), and (MD = -0.93, 95% CI = -1.53 to -0.34, P = 0.002, I2 = 0%), respectively. There was no significant statistical difference in the time of pass flatus (MD = -0.14, 95% CI = -0.49 to  0.21, P = 0.44, I2 = 79%) and the number of dissected lymph nodes (MD = 0.36, 95% CI = -0.49 to 1.21, P = 0.41, I2 = 45%), but the 3D group had an earlier postoperative pass flatus for rectal cancer patients (MD = -0.46, 95% CI = -0.66 to -0.27, P<0.001, I2 = 0%) and the more number of dissected lymph nodes for colon cancer patients (MD = 1.54, 95% CI = 0.05 to 3.03, P = 0.04, I2 = 69%) than the 2D group. There was no significant difference in postoperative overall complication (OR = 0.94, 95% CI = 0.67 to 1.31, P = 0.71, I2 = 0%) and anastomotic leakage (OR = 0.93, 95% CI = 0.48 to 1.80, P = 0.83, I2 = 0%) in the two groups, regardless of rectal cancer and colon surgery patients.

CONCLUSION

This meta-analysis demonstrates that 3D laparoscopy could reduce the amount of blood loss, accelerate postoperative pass flatus, and shorten the operation time and postoperative hospital stay over 2D for radical rectal cancer surgery, without obvious advantage for radical colon cancer surgery. Moreover, 3D laparoscopy increases the number of dissected lymph nodes for radical colon cancer surgery but may not be observed in rectal cancer surgery.

Use of Carbon Nanoparticles to Improve the Efficiency of Harvesting Lymph Nodes in Rectal Cancer

BACKGROUND

The accurate determination of lymph node status in patients with rectal cancer requires harvesting a certain number of lymph nodes. This study investigated whether using carbon nanoparticles (CNs) could improve the efficiency of harvesting lymph nodes in rectal cancer patients.

MATERIALS AND METHODS

Data from patients with rectal cancer treated with radical resection were collected from Nanfang Hospital between January 2014 and June 2021. Patients in the CN group received a CN suspension 1 day before surgery, which was endoscopically injected around the tumor. A 1:1 case-matched study was performed using the propensity score. The efficiency of harvesting lymph nodes was investigated by comparing the number of total nodes, total time, and percentage of nodes <5 mm in size between the CN and non-CN groups.

RESULTS

A total of 768 patients were included, with 246 patients who underwent CN injection and 522 patients who did not. After matching, 246 pairs of patients were analyzed. After matching, the number of total nodes of each sample was significantly higher in the CN group than in the non-CN group ( P <0.001). The total time for node detection ( P <0.001) was significantly shorter in the CN group. The percentage of nodes <5 mm in size was increased significantly in the CN group ( P <0.001). Among patients with clinical staging I/II, the difference in positive LNs was significant (21.79% vs. 11.95%, P =0.029).

CONCLUSIONS

The application of CNs improved the efficiency of harvesting lymph nodes during rectal cancer surgery.

"Caudal to cranial" versus "medial to lateral" approach in laparoscopic right hemicolectomy with complete mesocolic excision for the treatment of stage II and III colon cancer: perioperative outcomes and 5-year prognosis

The purpose of this study was to compare the "caudal to cranial" (CC) versus "medial to lateral" (ML) approach for laparoscopic right hemicolectomy. Pertinent data from all patients with stage II and III between January 2015 and August 2017 were entered into a retrospective database. A total of 175 patients underwent the ML (N = 109) or CC approach (N = 66). Patient characteristics were equivalent between groups. The CC group showed a shorter surgical time 170.00 (145.00, 210.00) vs. (206.50 (178.75, 226.25) min) than the ML group (p < 0.001). The time to oral intake was shorter in the CC group than in the ML group ((3.00 (1.00, 4.00) vs. 3.00 (2.00, 5.00) days; p = 0.007). For the total harvested lymph nodes, there was no statistical significance between the CC group 16.50 (14.00, 21.25) and the ML group 18.00 (15.00, 22.00) (p = 0.327), and no difference was found in the positive harvested lymph nodes (0 (0, 2.00) vs. 0 (0, 1.50); p = 0.753). Meanwhile, no differences were found in other perioperative or pathological outcomes, including blood loss and complications. For 5-year prognosis, overall survival rates were 75.76% in the CC group and 82.57% in the ML group (HR 0.654, 95% CI 0.336-1.273, p = 0.207); disease-free survival rates were 80.30% in the CC group and 85.32% in the ML group (HR 0.683, 95% CI 0.328-1.422, p = 0.305). Both approaches were safe and feasible and resulted in excellent survival. The CC approach was beneficial in terms of the surgical time and time to oral intake.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Application of Carbon Nanoparticles in Tracing Lymph Nodes and Locating Tumors in Colorectal Cancer: A Concise Review

Background

Accurate lymph node (LN) staging has considerably prognostic and therapeutic value in patients with colorectal cancer (CRC). The purpose of this study is to evaluate the feasibility of applying carbon nanoparticles (CNPs) to track LN metastases in CRC.

Methods

Two researchers independently screened publications in PubMed, EMBASE, Cochrane and Ovid MEDLINE databases. The keywords were (carbon nanoparticles OR activated carbon nanoparticles) AND (colon cancer OR rectal cancer OR colorectal cancer). Titles and abstracts of the articles were meticulously read to rule out potential publications. Next, full texts of the ultimately obtained eligible publications were retrieved and analyzed in detail.

Results

The search produced 268 publications, and 140 abstracts were identified after a bibliographic review. Finally, 20 studies relevant to our subject were obtained; however, only 14 papers met our inclusion criteria and were included for final review. All studies included have compared the control group with carbon nanoparticles group (control group, defined as nontattooed group; and carbon nanoparticles group, defined as administering carbon nanoparticles during surgery) for their efficacy in intraoperative detecting and positioning. After analysis, appreciably less amount of bleeding (3/5 trials), shorter operation time (2/4 trials), and shorter time to detect lesions and dissect LNs (2/2 trials) were revealed in CNPs group compared to control group. Thirteen studies have recorded the numbers of the harvested LNs in both groups; meanwhile, CNPs group shows superiority to control group in LN retrieval as well (11/13 trials), which also could effectively aid in locating and harvesting more LNs with diameter below 5 mm.

Conclusion

The tracing technique for CNPs is a safe and useful strategy both in localizing tumor and tracing LNs in CRC surgery. But there is still a need for more randomized controlled trials to further establish its contribution to patient survival.

Prospective analysis of tumor spread to the small bowel mesentery in cases of right-sided colon cancer

PURPOSE

Guidelines advocate minimal ileal resection when right hemicolectomy is performed for right-sided colon cancer. The practice, thought to prevent malabsorption syndrome, does not appear to foster local recurrence. Little evidence based on rigorous study exists, however. To understand the pattern of lymphatic spread of right-sided colon cancer toward the small bowel and thus determine the appropriate margin size, we prospectively investigated anatomical distribution of lymph nodes (LNs) in the small bowel mesentery and of metastasis to these nodes in patients with right-sided colon cancer treated by such surgery.

METHODS

In each case, the mesenteric specimen, which had been dissected along the ileocolic vessels and included intermediate LNs, was divided into 2 areas: that 0-3 cm from the vessel pedicle (area 1) and that 3-5 cm from the pedicle (area 2). The peri-intestinal mesentery was cut into 9 segments.

RESULTS

Ninety-one patients were included in the study. Overall, 3366 LNs were dissected. Four hundred fifty-three of these LNs were located in area 1 (90 cases), and 15 (3.3%) were metastatic. Only 63 LNs were located in area 2 (34 cases; average of 0.69 per patient); none was metastatic. Overall, 269 LNs were found in the small bowel mesentery (in 56 of the 91 patients). Only 4 were positive (3 cases), and all were within 5 cm of the ileocecal valve.

CONCLUSION

Our data indicate that a surgical margin 3 cm from the ileocecal pedicle and a short (5 cm) ileal margin are oncologically reasonable for effective right hemicolectomy.

The re-evaluation of optimal lymph node yield in stage II right-sided colon cancer: is a minimum of 12 lymph nodes adequate?

PURPOSE

Adequate lymphadenectomy is critical for accurate nodal staging and planning adjuvant therapy in colon cancer. However, the optimal lymph node (LN) yield for stage II right-sided colon cancer (RSCC) is still unclear. This population-based study aimed to determine the optimal LN yield associated with survival and LN positivity in patients with stage II RSCC.

METHODS

All patients with stage II-III RSCC were identified from the Surveillance, Epidemiology, and End Results database over a 10-year interval (2006-2015). The optimal threshold for LN yield was explored using an outcome-oriented approach based on survival and LN positivity.

RESULTS

The median number of LNs examined for all 17,385 patients with stage II RSCC was 17 (IQR 12-23). Nineteen LNs were determined as the optimal cut-off point to maximize survival benefit from lymphadenectomy. Increased LN yield was associated with a gradual increase in the risk of node positivity, with no change after 19 nodes. Compared with patients with 19 or more LNs examined, the group with fewer LNs had a significantly poor cancer-specific survival (< 12 nodes: hazard ratio (HR) 2.26, P < 0.001; 12-18 nodes: HR 1.58, P < 0.001) and overall survival (< 12 nodes: HR 1.80, P < 0.001; 12-18 nodes: HR 1.31, P < 0.001). Similar survival results were found in the validation cohort. Patients with older age, small tumor size, and appendix and transverse colon cancer were more likely to receive inadequate LN harvest.

CONCLUSION

A minimum of 19 LNs is needed to be examined for optimal survival and adequate node staging in lymph node-negative RSCC.

Factors affecting the number of lymph nodes retrieved after colo-rectal cancer surgery: A prospective single-centre study

BACKGROUND

The number of harvested lymph nodes (LNs) in colorectal cancer surgery relates to oncologic radicality and accuracy of staging. In addition, it affects the choice of adjuvant therapy, as well as prognosis. The American Joint Committee on Cancer defines at least 12 LNs harvested as adequate in colorectal cancer resections. Despite the importance of the topic, even in high-volume colorectal centres the rate of adequacy never reaches 100%. The aim of this study was to identify factors that affect the number of harvested LNs in oncologic colorectal surgery.

MATERIALS AND METHODS

We prospectively collected all consecutive patients who underwent colorectal cancer resection from January 1st 2013 to December 31st 2017 at Emergency Surgery Unit St Orsola University Hospital of Bologna.

RESULTS

Six hundred and forty-three consecutive patients (382 elective, 261 emergency) met the study inclusion criteria. Emergency surgery and laparoscopic approach did not have a significant influence on the number of harvested LNs. The adequacy of lymphadenectomy was negatively affected by age >80 (OR 3.47, p < 0.001), ASA score ≥3 (OR 3.48, p < 0.001), Hartmann's or rectal resection (OR 3.6, p < 0.001) and R1-R2 resection margins (OR 3.9, p = 0.006), while it was positively affected by T-status ≥3 (OR 0.33 p < 0.001).

CONCLUSION

Both the surgical technique and procedure regimen did not affect the number of lymphnodes retrieved. Age >80 and ASA score ≥3 and Hartmann's procedure or rectal resection showed to be risk factors related to inadequate lymphadenectomy in colorectal cancer surgery.

Efficacy of preoperative colonoscopic tattooing with indocyanine green on lymph node harvest and factors associated with inadequate lymph node harvest in colorectal cancer

Objective: Adequate lymph node harvest (LNH) in colorectal cancer is closely related to survival. This study aimed to evaluate the effect of preoperative colonoscopic tattooing (PCT) with indocyanine green (ICG) on adequate LNH in colorectal cancer. Materials and methods: A total of 1079 patients who underwent surgical resection for colorectal cancer were divided into two groups: a tattooing group and a non-tattooing group. The patients were retrospectively analyzed for the number and adequacy of LNH according to tumor locations and stages. Univariate and multivariate analysis for factors associated with adequate LNH were done. Results: There was no significant difference between the two groups in the number and adequacy of LNH according to tumor locations. However, T1 colorectal cancer in the tattooing group had significantly higher adequate LNH (91.6% vs 82.1%, OR 2.370, p = .048) and T1 and N0 rectal cancer in the tattooing group also had higher adequate LNH although there was no statistical significance (100% vs 82.4%, OR 12.088, p = .095; 96.9% vs 84.8%, OR 5.570, p = .099) when compared to the non-tattooing group. Male sex and T1 stage were significantly associated with inadequate LNH in multivariate analysis (OR 0.556 (95% CI 0.340-0.909), p = .019; OR 0.555 (95% CI 0.339-0.910), p = .019, respectively). Conclusion: PCT with ICG did not improve adequate LNH in colorectal cancer but effectively improved adequate LNH in early colorectal cancer. Male sex and early cancer were risk factors for inadequate LNH in colorectal cancer, so PCT is needed for adequate LNH in these patients.

Effect of activated carbon nanoparticles on lymph node harvest in patients with colorectal cancer

AIM

The aim was to examine the effect of activated carbon nanoparticles (ACNs) on lymph node retrieval in colorectal cancer (CRC) patients.

METHODS

This prospective randomized study of 80 subjects was performed between March 2016 and December 2016. Eighty patients with CRC were randomly divided into two groups, the ACN group and a control group. The patients in the ACN group were subjected to 1 ml of ACN injection in the subserosa around the tumour before colectomy and D3 lymphadenectomy. The patients in the control group received the same procedure without the injection of ACNs. After surgery, lymph nodes were isolated, and the greatest dimensions were measured by the same pathologist.

RESULTS

The average number of lymph nodes harvested from each patient was markedly more in the ACN group (31.3 ± 8.1) than in the control group (21.9 ± 5.3; P < 0.001), and the average number of lymph nodes less than 5 mm in greatest dimension was significantly more in the ACN group (11.9 ± 4.9) than in the control group (4.1 ± 2.4; P < 0.001). The ACN group (15/40) had a higher rate of Stage III patients compared to the control group (6/39; P = 0.026). Besides, the greatest dimension of 32.8% metastatic lymph nodes was less than 5 mm.

CONCLUSION

There is significant upstaging following the use of ACNs, which could find more involved nodes. Therefore, ACNs can be used as a tracer to harvest more lymph nodes in CRC patients, with improvement in the accuracy of pathological staging.

A Gene-Related Nomogram for Preoperative Prediction of Lymph Node Metastasis in Colorectal Cancer

Purpose: To develop and validate a gene-related nomogram for predicting the risk of lymph node (LN) metastasis preoperatively in patients with colorectal cancer (CRC). Methods: RNA-seq data of 581 CRC and 51 normal cases with clinical features were downloaded from TCGA database. In the evaluation cohort with 381 CRC cases, the LASSO regression was used to reduce dimensionality of gene signatures extracted to build gene score. A gene-related nomogram was performed based on the multivariable logistic regression analysis. The performance of the nomogram was assessed by the discrimination, calibration, and clinical usefulness not only in the evaluation, but also in the validation cohort with 200 CRC cases. Results: A total of 12,590 differentially expressed genes were selected, in which 59 candidates associated with LN metastasis in differentially expressed genes set were screened by LASSO to form the gene score. Based on the analysis of multivariate logistic regression, the gene-related nomogram showed good calibration and discrimination not only in the evaluation cohort (concordance-index 0.93; 95%CI 0.91-0.96), but also in the validation cohort (concordance-index 0.70; 95%CI 0.63-0.78). The decision curve analysis of the gene-related nomogram also provides constructive guidance for the design of operation plan, preoperatively. Conclusions: The presented genes nomogram may predict the LN metastasis in CRC patients, preoperatively. And 59 hub genes were defined related to LN metastasis of CRC, which can serve as treatment targets for the further study. Preoperative biopsy and gene analysis are needed to develop the operation plan in clinical practice.

Comparison of Short-Term Outcomes Between 3D and 2D Imaging Laparoscopic Colectomy with D3 Lymphadenectomy for Colon Cancer

BACKGROUND

Three-dimensional (3D) imaging for laparoscopy was introduced to overcome the limitations of conventional two-dimensional (2D) imaging that lacked depth perception and spatial orientation. This study aimed to evaluate the effect of 3D imaging in laparoscopic colectomy with D3 lymphadenectomy for colon cancer.

METHODS

From February 2014 to October 2016, the prospective database of 278 consecutive patients with colon cancer was analyzed retrospectively; these patients underwent laparoscopic surgery with 2D (n = 111) and 3D (n = 167) imaging, with curative intent.

RESULTS

No difference was found in sex, body mass index, history of abdominal surgery, and American Society of Anesthesiologists grade between the 3D and 2D groups. The estimated blood loss was less in the 3D group than in the 2D group (50 mL [30-100 mL] versus 100 mL [50-100 mL], P < .001). The number of resected lymph nodes was higher in the 3D group (n = 47 [37.5-60] versus 41 [32-51.5], P = .001). However, a difference in operative time was not observed in both groups (150 minutes [125-175 minutes] versus 155 minutes [135-177.5 minutes], P = .186). Postoperative morbidity was similar in both groups (7.8% versus 8.1%, P = 1.000). Time to pass first flatus (3 days [2-4 days] versus 3 days [3-4 days], P = .746) and postoperative hospital stay (6 days [6-8 days] versus 6 days [6-7 days], P = .087) were also similar.

CONCLUSIONS

This study shows that laparoscopic colectomy with D3 lymphadenectomy for colon cancer using 3D laparoscopic systems appears to be beneficial, with less blood loss, which should be addressed in prospective studies.

Which Lymph Nodes Contain Metastases in Colon Cancer Patients? A Retrospective Histopathological Evaluation of 156 Patients

Background. We hypothesized that a reliable N0 status can be established by sampling and evaluating the largest lymph nodes in the resected large-bowel specimen of patients with colon cancer. Patients and methods. This was a retrospective analysis of all surgical colon cancer patients treated between 2008 and 2010, excluding those who had received neoadjuvant treatment. We analyzed the relationship between lymph node size and the presence of metastasis. Furthermore, we examined other prognostic factors for a histopathological N+ status. Results. Our patient group consisted of 156 patients with a median age of 73 years (range = 29-91 years). A total of 2044 lymph nodes (a median of 12 per patient, range = 2-47 nodes) were harvested, 1803 (88.2%) without and 241 (11.8%) with tumor spread. Using a unique ranking model, we found that in 58 out of the 59 N+ patients (98.3%, 95% confidence interval = 90.9% to 99.9%), the largest tumor-positive node was among the 5 largest lymph nodes in the specimen. The examination of ≥10 lymph nodes had no effect on the chance of finding a positive lymph node compared with examination of <10 nodes ( P = .46). Conclusion. In our study, the N-stage was determined by the 5 largest nodes in almost all specimens. The chance of finding a small tumor-positive node when the larger ones were clean was very small.

Comprehensive lymph node morphometry in rectal cancer using acetone compression

Aims

Acetone compression (AC) is an elution compression technique for the comprehensive pathological examination of fatty tissue. Here AC is combined with digital morphometry to evaluate the impact of preoperative (neoadjuvant) chemoradiotherapy (neoCRT) on lymph node (LN) numbers and morphology in locally advanced rectal cancer. AC is compared with complete embedding of the mesorectal fat (whole mesorectal embedding (WME)) to exclude artificial alterations and to the standard technique, manual dissectioning (MD).

Methods

320 rectal cancer specimens were subjected to LN morphometry. Neoadjuvant CRT was applied in 204 specimens. LNs were prepared either with AC (n=138), WME (n=51) or MD (n=131). 8523 LNs were assessed including 530 nodes with metastases.

Results

LN prepared by AC and WME showed similar morphologies. AC revealed reduced LN sizes in neoCRT specimens compared with primary resection (2.2; 2.4 mm, p=0.049) while the LN number was comparable (27; 30/specimen). AC yielded 28 LN/specimen on average, MD yielded 22 LN (p<0.001). In neoCRT specimens, MD yielded less LN compared with primary resection (19; 25). MD detected less small LN (<2 mm; MD: 25%; AC: 56%) while 24 of the 135 LN metastases found by AC were ≤2 mm in diameter.

Conclusions

AC does not alter LN morphology and is especially suited to retrieve small LN after neoadjuvant CRT of rectal cancer. Neoadjuvant multimodality treatment caused reduced LN sizes while the LN numbers were not affected. When compared with MD, AC proved more reliable in the retrieval of LN from rectal cancer specimens after neoCRT.

The total number of lymph nodes in resected colon cancer specimens is affected by several factors but the lymph node ratio is independent of these

The number of lymph nodes retrieved from the specimen may be a surrogate measure of the adequacy of extensive colon cancer surgery, but many variables may influence the total lymph node yield of any specimen. We examined which variables would be influential both for negative and positive node sampling.The combined results from 428 patients from three hospitals A to C treated in 2007-2009 with single colon cancers having R0 segmental resections were analysed. The surgical technique and pathology staining methods were slightly different between the hospitals.The mean number of lymph nodes was 15.8 (range 1-60). Twelve or more lymph nodes were harvested in 78% of the specimens. In the multivariate Poisson regression analysis of all TNM stages, the factors associated with the total lymph node harvest were age, pathology handling, tumour location and size (p < 0.001), whereas for TNM stage III alone the pathology handling (p < 0.001) and a radical operating technique (p = 0.003) were highly significant. The total number of lymph nodes was the only significant factor for the number of positive lymph nodes (Posln) according to the multivariate negative regression analysis (p = 0.02) but the analysis of the lymph node ratio (LNR) detected no statistically significant variable.Several factors, and especially the specimen processing technique, were important for the total number of harvested lymph nodes. The number of Posln varied between segments and increased with the total number of harvested lymph nodes, but for LNR no variable was important. LNR seemed to abolish the combined effect of tumour location and the total lymph node yield in prognosis assessment.

D3 Lymph Node Dissection in Right Hemicolectomy with a No-touch Isolation Technique in Patients With Colon Cancer

BACKGROUND

The role of lymph node dissection in the management of right-sided colon cancer remains controversial.

OBJECTIVE

The aim of this study was to investigate the surgical treatment of curable right-sided colon cancer by using D3 lymphadenectomy with a no-touch isolation technique and to determine the extent of lymph node dissection optimal for the prognosis of right-sided colon cancer.

DESIGN

This research is a retrospective cohort study from a prospectively collected database.

SETTING

The investigation took place in a specialized colorectal surgery department.

PATIENTS

: Data on 370 consecutive patients who underwent D3 lymph node dissection for right-sided colon cancer with a no-touch isolation technique were identified.

MAIN OUTCOME MEASURES

The survival of patients with involvement of main nodes at the roots of colonic arterial trunks along superior mesenteric vessels through intermediate nodes in the right mesocolon was determined.

RESULTS

The 5-year overall survival of patients with stage I (n = 73, 19.7%), II (n = 155, 41.9%), and III (n = 142, 38.4%) cancer were 94.5%, 87.6%, and 79.2%. The 5-year disease-specific survival of patients with stages I, II, and III cancer were 100.0%, 94.5%, and 85.0%. Eleven patients (3.0%) had metastatic involvement of main lymph nodes, whereas 49 (13.2%) had metastases to intermediate lymph nodes. The 5-year overall survival and disease-specific survival of patients with metastases to main lymph nodes were 36.4% for both, and 5-year overall survival and disease-specific survival of patients with metastases to intermediate lymph nodes were 77.6% and 83.5%.

LIMITATIONS

This study was limited by its nonrandomized retrospective design.

CONCLUSIONS

D3 lymphadenectomy with a no-touch isolation technique allows curative resection and long-term survival in a cohort of patients with cancer of the right colon.

Detailed stratification of TNM stage III rectal cancer based on the presence/absence of extracapsular invasion of the metastatic lymph nodes

BACKGROUND

The presence/absence of extracapsular invasion in metastatic lymph nodes has been reported as being significantly correlated with the prognosis in a wide variety of cancers. However, the influence of extracapsular invasion in the metastatic lymph nodes on the prognosis in patients with stage III rectal cancer has not yet been investigated.

OBJECTIVE

We investigated the presence/absence of extracapsular invasion in the metastatic nodes of the relevant main/lateral lymph node group in patients with rectal cancer to determine the usefulness of this parameter for stratifying the prognosis of patients with stage III rectal cancer.

DESIGN

This was a single-institution study.

SETTINGS

This study was conducted at a single institution.

PATIENTS

We enrolled 101 consecutive patients with stage III rectal cancer who had undergone curative surgery with extended lymph node dissection and investigated the presence/absence of extracapsular invasion in the regional metastatic lymph nodes to determine the usefulness of such stratification for a more precise prediction of the patient prognosis.

MAIN OUTCOME MEASURES

The main outcomes measured were the disease-free and overall survival rates.

RESULTS

Univariate analysis revealed a significantly poorer prognosis, in terms of both the disease-free survival rate (p = 0.003) and overall survival rate (p = 0.008), of the pN3-extracapsular invasion-positive cases in comparison with the pN3-extracapsular invasion-negative cases. Multivariate analysis revealed the presence/absence of extracapsular invasion in the metastatic lymph nodes as the only variable that was statistically significantly associated with the disease-free survival rate (p = 0.011).

LIMITATIONS

This was a retrospective study in a small number of patients from a single institution. There were no comparator groups.

CONCLUSIONS

Detailed stratification of pN3 cases based on the presence/absence of extracapsular invasion in metastatic lymph nodes has the potential to contribute significantly to more available prediction of the prognosis of patients with stage III colorectal cancer.

Adequate lymph node recovery improves survival in colorectal cancer patients

INTRODUCTION

Current recommendations suggest recovery of 12 lymph nodes during surgical resection for colorectal cancer (CRC) for proper staging and prognostication. Adequate lymph node recovery has been associated with improved patient survival, with results inconsistent.

METHODS

We examined factors for association with adequate lymph node recovery and used findings to adjust survival analyses to clarify whether adequate lymph node examination is associated with CRC survival or associated with a subset of characteristics that biases lymph node recovery.

RESULTS

In 74% of subjects (1,036/1,397) an adequate number of lymph nodes was examined. A stepwise multivariate regression analysis showed procedure year, cancer stage, tumor size, and age at diagnosis were significantly associated with lymph node recovery. These and other factors associated with survival status were adjusted for in further analyses, revealing no difference in unadjusted overall survival by adequacy of lymph node recovery (HR = 0.90, 95% CI: 0.75-1.08, P = 0.239). However, in adjusted Cox proportional hazards analysis, adequate lymph node recovery was associated with reduced risk for death (HR = 0.71, 95% CI: 0.57-0.89, P = 0.002).

CONCLUSION

The current recommendation for retrieval and examination of at least 12 lymph nodes is appropriate for proper treatment and prognostication in patients undergoing surgical resection for CRC.

Japanese Society for Cancer of the Colon and Rectum Guidelines 2010 for the treatment of colorectal cancer: comparison with western guidelines

SUMMARY The Japanese Society for Cancer of the Colon and Rectum published guidelines (GLs) for the treatment of colorectal cancer in 2005 to show standard treatment strategies and to standardize the quality of care for patients with colorectal cancer in Japan. The Japanese Society for Cancer of the Colon and Rectum GLs differ from western GLs in terms of the scope of lymph node dissection (D3 dissection is standard in Japan), treatment strategy for ≥cT3 low rectal cancer (preoperative chemo-radiation vs lateral lymph node dissection), use of oxaliplatin-containing regimens as adjuvant chemotherapy for stage III diseases (first choice vs not first choice), use of neoadjuvant chemotherapy for resectable liver metastases (established vs not established treatment) and surveillance for recurrence (more intensive in Japan with shorter intervals between CT scans).

Colorectal cancer lymph node staining by activated carbon nanoparticles suspension in vivo or methylene blue in vitro

AIM: To investigate whether activated carbon nanoparticles suspension (ACNS) or methylene blue (MB) can increase the detected number of lymph nodes in colorectal cancer.

METHODS: Sixty-seven of 72 colorectal cancer patients treated at our hospital fulfilled the inclusion criteria of the study which was conducted from December 2010 to February 2012. Seven patients refused to participate. Eventually, 60 patients were included, and randomly assigned to three groups (20 in each group): ACNS group (group A), MB group (group B) and non-stained conventional surgical group (group C). In group A, patients received subserosal injection of 1 mL ACNS in a 4-quadrant region around the mass. In group B, the main artery of specimen was identified and isolated after the specimen was removed, and 2 mL MB was slowly injected into the isolated, stretched and fixed vessel. In group C, no ACNS and MB were injected. All the mesentery lymph nodes were isolated and removed systematically by visually inspecting and palpating the adipose tissue.

RESULTS: No difference was observed among the three groups in age, gender, tumor location, tumor diameter, T-stage, degree of differentiation, postoperative complications and peritoneal drainage retention time. The total number of detected lymph nodes was 535, 476 and 223 in the three groups, respectively. The mean number of detected lymph nodes per patient was significantly higher in group A than in group C (26.8 ± 8.4 vs 12.2 ± 3.2, P < 0.001). Similarly, there were significantly more lymph nodes detected in group B than in group C (23.8 ± 6.9 vs 12.2 ± 3.2, P < 0.001). However, there was no significant difference between group A and group B. There were 50, 46 and 32 metastatic lymph nodes dissected in 13 patients of group A, 10 patients of group B and 11 patients of group C, without significant differences among the three groups. Eleven of the 60 patients had insufficient number of detected lymph nodes (< 12). Only one patient with T_4a rectal cancer had 10 lymph nodes detected in group B, the other 10 patients were all from group C. Based on the different diameter categories, the number of detected lymph nodes in groups A and B was significantly higher than in group C. However, there was no statistically significant difference between group A and group B. The metastatic lymph nodes were not significant different among the three groups. Similarly, tumor location, T stage and tumor differentiation did not affect the staining results. Body mass index was a minor influencing factor in the two different staining methods. The stained lymph nodes can easily be identified from the mesenteric adipose tissues, and the staining time for lymph nodes was not significantly different compared with unstained group. None of the patients in groups A and B had drug-related complications.

CONCLUSION: Both activated carbon nanoparticles suspension in vivo and methylene blue in vitro can be used as tracers to increase the detected number of lymph nodes in colorectal cancer.