Lymph node yield after rectal resection in patients treated with neoadjuvant radiation for rectal cancer: A systematic review and meta-analysis. Eur J Cancer. 2017;72:84-94. [PMID: 28027520 DOI: 10.1016/j.ejca.2016.10.031]

Lymph node ratio prognosticates overall survival in patients with stage IV colorectal cancer

BACKGROUND

Lymph node ratio (LNR) is suggested to address the shortcomings of using only lymph node yield (LNY) or status in colorectal cancer (CRC) prognosis. This study explores how LNR affects survival in patients with metastatic colorectal cancer (mCRC), seeking to provide clearer insights into its application.

METHODS

This observational cohort study investigated stage IV patients with CRC (1995-2021) who underwent an upfront resection of their primary tumour at Concord Hospital, Sydney. Clinicopathological data were extracted from a prospective database, and LNR was calculated both continuously and dichotomously (LNR of 0 and LNR > 0). The primary endpoint was overall survival (OS). The associations between LNR and various clinicopathological variables were tested using regression analyses. Kaplan-Meier and Cox regression analyses estimated OS in univariate and multivariate survival models.

RESULTS

A total of 464 patients who underwent a primary CRC resection with clear margins (mean age 68.1 years [SD 13.4]; 58.0% M; colon cancer [n = 339,73.1%]) had AJCC stage IV disease. The median LNR was 0.18 (IQR 0.05-0.42) for colon cancer (CC) resections and 0.21 (IQR 0.09-0.47) for rectal cancer (RC) resections. A total of 84 patients had an LNR = 0 (CC = 66 patients; RC = 18 patients). The 5-year OS for the CC cohort was 10.5% (95% CI 8.7-12.3) and 11.5% (95% CI 8.4-14.6) for RC. Increasing LNR demonstrated a decline in OS in both CC (P < 0.001) and RC (P < 0.001). In patients with non-lymphatic dissemination only (LNR = 0 or N0 status), there was better survival compared with those with lymphatic spread (CC aHR1.50 [1.08-2.07;P = 0.02], RC aHR 2.21 [1.16-4.24;P = 0.02]).

CONCLUSIONS

LNR is worthy of consideration in patients with mCRC. An LNR of 0 indicates patients have a better prognosis, underscoring the need for adequate lymphadenectomy to facilitate precise mCRC staging.

Tissue morphometric measurements do not predict survival following colorectal cancer surgery

BACKGROUND

Ex vivo tissue morphometric (TM) measurements have been proposed as a quality marker for colorectal cancer (CRC) surgery. However, their survival associations require clarification. This study aimed to evaluate the feasibility of capturing TM measurements based on ex vivo fresh specimen images and explore the association between these TM measurements and survival outcomes.

METHODS

A prospective cohort study at Concord Hospital, Sydney was conducted with Stage I to III CRC patients (2009-2019) who underwent an anterior resection (AR) or right hemicolectomy (RH). Using high-resolution digital photographs of fresh CRC specimens, ex vivo tissue morphometric (TM) measurements-resected mesentery area (TM A), distances from high vascular tie to tumour (TM B) and bowel wall (TM C), and bowel length (TM D)-were recorded using Image J. Overall survival (OS) and disease-free survival (DFS) estimates and their associations to clinicopathological variables were investigated with Kaplan-Meier and Cox regression analyses. Linear regression models tested association between TM measurements and lymph node (LN) yield.

RESULTS

Of the 1,425 patients who underwent CRC surgery, TM measurements were performed on 312 patients, with an average age of 69.4 years (SD 12.3), of whom 52.9% were male. The majority had an AR (57.8%). Among AR patients, a 5-year OS rate of 77.4% and a DFS rate of 70.1% were observed, with TM measurements bearing no relationship to survival outcomes. Similarly, RH patients exhibited a 5-year OS rate of 67.2% and a DFS rate of 63.1%, with TM measurements again showing no association with survival. Only TM D (P = 0.02) measurements were associated with the number of LNs examined.

CONCLUSION

This study successfully demonstrates the feasibility of measuring TM measurements on photographs of ex vivo fresh specimens following CRC surgery. The lack of association with survival outcomes questions the utility of TM measurements as a quality metric of CRC surgery.

Short-term outcomes of short- and long-course chemoradiotherapy before total mesorectal excision for locally advanced rectal tumors: A single-center study in Taiwan utilizing propensity score matching

BACKGROUND

Locally advanced rectal tumors are typically treated with neoadjuvant chemoradiotherapy. Short-course chemoradiotherapy (SCRT, 2500 cGy in five fractions) is a convenient alternative to concurrent chemoradiotherapy with long-course radiotherapy (CCRT, 4500 cGy in 25 fractions) without sacrificing efficacy. We aimed to compare the short-term outcomes of SCRT and CCRT in patients with mid- and low- rectal tumors who underwent total mesorectal excision using real-world data.

METHODS

We retrospectively reviewed the data of patients with locally advanced rectal cancer who underwent radical resection after neoadjuvant chemoradiotherapy from 2011 to 2022. We analyzed the clinicopathological findings and prognostic factors for disease-free and overall survival in the SCRT and CCRT groups and compared the outcomes using propensity score matching.

RESULTS

Among the 66 patients in the two groups, no disparities were noted in the demographic features, pathological remission, or downstaging rates. Nonetheless, the SCRT group exhibited superior 3-year disease-free survival (81.8% vs 62.1%, p = 0.011), whereas the overall survival did not differ significantly between the two groups. The initial carcinoembryonic antigen (CEA) levels and neoadjuvant SCRT were associated with the recurrence rates [hazard ratio (HR) = 1.13-4.10; HR = 0.19-0.74], but the harvested lymph node count was not (HR = 0.51-1.97).

CONCLUSION

Among patients with locally advanced rectal cancer, SCRT combined with four cycles of FOLFOX was shown to enhance short-term disease-free survival. Factors impacting recurrence include the initial CEA level and SCRT, but not the harvested lymph node count.

Effect of Tumor Regression Grade on Survival and Disease-Free Interval in Patients Operated on for Locally Advanced Rectal Cancer

INTRODUCTION

Colorectal cancer is the fourth leading cause of cancer-related death in both men and women in our population. In this regard, rectal cancer accounts for more than half of colorectal cancer deaths, and its incidence is expected to increase in the coming years. There have been significant changes in neoadjuvant therapy regimens, with promising results, as demonstrated by the recent RAPIDO and PRODIGE23 studies. Around 40% of patients diagnosed with locally advanced rectal cancer show some degree of response to neoadjuvant treatment, with complete tumor regression observed in up to one in five patients.

MATERIALS AND METHODS

Retrospective observational study. A total of 181 patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy followed by surgery were analyzed. Clinical and pathological data were collected from the patients, including assessment of tumor regression through histopathological studies after surgery. The Mandard tumor regression grading system was used to categorize tumor response into different grades.

RESULTS

The results showed a significant association between the degree of tumor regression and several important clinical outcomes. Specifically, patients with higher tumor regression had significantly better disease-free survival than those with less regression (p = 0.004). In addition, tumor regression was also correlated with the incidence of local recurrence (p = 0.018) and distant metastasis (p = 0.032). These associations suggest that tumor responsiveness to neoadjuvant therapy may influence the long-term progression of the disease. Regarding tumor deposits and the presence of lymphadenopathy, these factors were also found to be significantly associated with clinical outcomes. Patients with tumor deposits had a higher incidence of local recurrence (p = 0.025) and distant metastases (p = 0.041), while the presence of lymphadenopathy increased the risk of local recurrence (p = 0.013). These findings highlight the importance of evaluating not only tumor regression but also other pathological markers to predict prognosis and guide clinical management.

CONCLUSIONS

The degree of tumor regression was not an independent predictor of survival compared to other variables such as nodal stage and presence of tumor deposits. This indicates that while tumor regression is an important factor, other elements also play a crucial role in determining the prognosis of patients with locally advanced rectal cancer. This study provides additional evidence for the importance of tumor regression, tumor deposits, and lymphadenopathy as predictors of clinical outcomes in patients with rectal cancer treated with neoadjuvant chemoradiotherapy.

INFLUENCE OF NEOADJUVANT THERAPY ON THE RATIO OF LYMPH NODES

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

BACKGROUND

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

BACKGROUND

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

Association between the number of retrieved lymph nodes and demographic/tumour-related characteristics in colorectal cancer: a systematic review and meta-analysis

OBJECTIVE

Clinical practice guidelines recommend retrieving at least 12 lymph nodes for correct staging in colorectal cancer. However, it is difficult to retrieve adequate lymph nodes because of various factors. We aimed to evaluate the association between the number of retrieved lymph nodes and demographic/tumour-related characteristics in colorectal cancer.

DESIGN

Systematic review and meta-analysis of primary studies.

DATA SOURCES

PubMed, Embase, Cochrane and Web of Science were searched from January 2016 to June 2023.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies that evaluated the association between retrieved lymph nodes and demographic/tumour-related characteristics in colorectal cancer were included.

DATA EXTRACTION AND SYNTHESIS

OR with 95% conference intervals was extracted and pooled.

RESULTS

A total of 54 studies containing 2 05 821 patients were included in this meta-analysis. The results showed that fewer nodes were retrieved from elderly patients (OR=0.70, 95% CI (0.54 to 0.90), p=0.005), and from tumours located in the left colon than in the right colon (OR=0.43, 95% CI (0.33 to 0.56), p<0.001). More lymph nodes were obtained from females than males (OR=1.15, 95% CI (1.04 to 1.28), p=0.006), from the advanced T stage (T3+T4) than T1+T2 stage (OR=1.57, 95% CI (1.25 to 1.97), p<0.001) and from the N2 stage than N0 stage (OR=1.32, 95% CI (1.15 to 1.51), p<0.001). Body mass index, ethnicity, N1 stage, M stage, tumour differentiation and lymph-vascular invasion were not significantly associated with the lymph node yield.

CONCLUSIONS

The study results suggest that clinicians have an increased opportunity to retrieve sufficient lymph nodes for accurate pathological staging to guide treatment decisions in patients with colorectal cancer who are young, female, with tumours located in the right colon, advanced T stage and N2 stage.

Endoscopic ultrasound-guided injection of carbon nanoparticles suspension to label rectal cancer before neoadjuvant chemoradiotherapy: a retrospective cohort study

Background

Localization of the primary tumor and ensuring safe distal surgical margins (DSMs) following neoadjuvant chemoradiotherapy (nCRT) are challenging in locally advanced rectal cancers (LARCs). This study investigated the effectiveness of carbon nanoparticles suspension (CNS) for labeling the primary tumor and allowing precise tumor resection after nCRT.

Methods

Clinicopathological data of LARC patients who underwent nCRT followed by laparoscopic radical anal preservation surgery at our center between January 2018 and February 2023 were prospectively collected. The patients were divided into the CNS tattooed (CNS) and non-tattooed (control) groups. In the CNS group, CNS was injected in four quadrants on the anal side 1 cm away from the lower tumor margin. DSMs were determined through intraoperative distal rectal examination in the control group and observation of CNS tattoos in the CNS group. DSM lengths and positive DSM rates were compared between the two groups to analyse the feasibility and effectiveness of CNS for labeling LARCs before nCRT.

Results

There was no statistically significant difference in the basic demographic data, effectiveness of nCRT, or post-operative recovery rates between the two groups (all P > 0.05). In the CNS group, CNS tattoos were observed on the outside of the rectal wall, with an overall efficiency of 87.1% (27/31). The CNS group had fewer positive DSMs and safer DSM lengths (2.73 ± 0.88 vs 2.12 ± 1.15 cm, P = 0.012) than the control group (P < 0.05).

Conclusions

Endoscopic ultrasound-guided injection of CNS tattoos before nCRT could effectively label the LARCs, ensuring safe DSMs during anus-preserving surgeries (Chictr.org.cn No.: ChiCTR2300068991).

Prognostic significance of lymph node yield on oncologic outcomes according to tumor response after preoperative chemoradiotherapy in rectal cancer patients

PURPOSE

This study aimed to evaluate the predictive value of lymph node yield (LNY) for survival outcomes according to tumor response after preoperative chemoradiotherapy (PCRT) in patients with rectal cancer.

METHODS

This study was a retrospective study conducted in a tertiary center. A total of 1,240 patients with clinical stage II or III rectal cancer who underwent curative resection after PCRT between 2007 and 2016 were included. Patients were categorized into the good response group (tumor regression grade [TRG], 0-1) or poor response group (TRG, 2-3). Propensity score matching was performed for age, sex, and pathologic stage between LNY of ≥12 and LNY of <12 within tumor response group. The primary outcome was 5-year disease-free survival (DFS) and overall survival (OS).

RESULTS

LNY and positive lymph nodes were inversely correlated with TRG. In good responders, 5-year DFS and 5-year OS of patients with LNY of <12 were better than those with LNY of ≥12, but there was no statistical significance. In poor responders, the LNY of <12 group had worse survival outcomes than the LNY of ≥12 group, but there was also no statistical significance. LNY of ≥12 was not associated with DFS and OS in multivariate analysis.

CONCLUSION

LNY of <12 showed contrasting outcomes between the good and poor responders in 5-year DFS and OS. LNY of 12 may not imply adequate oncologic surgery or proper staging in rectal cancer patients treated by PCRT. Furthermore, a decrease in LNY should be comprehended differently according to tumor response.

Examined lymph node numbers influence prognosis in rectal cancer treated with neoadjuvant therapy

Background

The number of lymph nodes examined (LNe) is often insufficient in patients with rectal cancer (RC) treated with neoadjuvant therapy; however, its prognostic value remains controversial. Thus, we retrospectively explored whether LNe had an influence on staging and prognosis and investigated whether there was a cut-off value for better prognosis in patients with RC treated with neoadjuvant therapy.

Methods

Data were collected from seven prospective hospital databases in China from July 2002 to May 2018. Binary logistic regression models were used to predict lymph node metastasis. The cut-off value for LNe was determined using X-tile 3.6.1. Survival outcomes and risk factors were analyzed using the log-rank test and Cox regression model.

Results

A total of 482 patients were included, of whom 459 had complete overall survival (OS) information. Using the percentile method, the total number of lymph nodes examined (TLNe) was 14-16 (40th-60th percentile), and the proportion of patients with lymph node metastasis reached a maximum of 48.1%. Cox multivariate analysis showed that the odds ratio (OR) remained the highest when TLNe was 14-16 (OR = 3.379, P = 0.003). The 3-year and 5-year OS were 85.4% and 77.8%, respectively. Negative lymph nodes examined (NLNe) of ≤6 was an independent risk factor for 3-year and 5-year OS (3-year OS 71.1% vs. 85.9%, P = 0.004; 5-year OS 66.3% vs. 74.3%, P = 0.035). Subgroup analysis for patients with ypN + showed that higher 3-year and 5-year OS were achieved when the TLNe was >10, 78.8% vs. 54.0% (P = 0.005), and 60.8% vs. 36.0% (P = 0.012), respectively. Patients with ypN0M0 had a higher 5-year OS when the TLNe was >19 (P = 0.055).

Conclusion

The TLNe and NLNe influenced the staging accuracy and demonstrated prognostic value in patients with RC treated with neoadjuvant therapy.

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.

Adverse impact of tumor deposits in lymph node negative rectal cancer - a national cohort study

PURPOSE

This study aimed to investigate the prognostic effect of tumor deposits (TDs) in lymph node negative rectal cancer.

METHODS

Patients who had undergone surgery for rectal cancer with curative intention between 2011 and 2014 were extracted from the Swedish Colorectal Cancer Registry. Patients with positive lymph nodes, undisclosed TD status, stage IV disease, non-radical resections, or any outcome (local recurrence (LR), distant metastasis (DM) or mortality) within 90 days after surgery were excluded. TDs status was based on histopathological reports. Cox-regression analyses were used to examine the prognostic impact of TDs on LR, DM, and overall survival (OS) in lymph node-negative rectal cancer.

RESULTS

A total of 5455 patients were assessed for inclusion of which 2667 patients were analyzed, with TDs present in 158 patients. TD-positive patients had a lower 5-year DM-free survival (72.8%, p < 0.0001) and 5-year overall survival (75.9%, p = 0.016), but not 5-year LR-free survival (97.6%) compared to TD-negative patients (90.2%, 83.1% and 95.6%, respectively). In multivariable regression analysis, TDs increased the risk of DM [HR 4.06, 95% CI 2.72-6.06, p < 0.001] and reduced the OS [HR 1.83, 95% CI 1.35-2.48, p < 0.001]. For LR, only univariable regression analysis was performed which showed no increased risk of LR [HR 1.88, 95% CI 0.86-4.11, p = 0.11].

CONCLUSION

TDs are a negative predictor of DM and OS in lymph node-negative rectal cancer and could be taken into consideration when planning adjuvant treatment.

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.

Total Neoadjuvant Therapy in Rectal Cancer: Multi-center Comparison of Induction Chemotherapy and Long-Course Chemoradiation Versus Short-Course Radiation and Consolidative Chemotherapy

BACKGROUND

Total neoadjuvant therapy for locally advanced rectal cancer may include induction chemotherapy and chemoradiation or short-course radiotherapy and consolidative chemotherapy.

METHODS

Patients with clinical stage 2 or 3 rectal cancer who received induction chemotherapy followed by long-course chemoradiation at the University of Colorado (2016-2020) or short-course radiotherapy followed by consolidative chemotherapy at Washington University (2017-2020) were assessed.

RESULTS

Eighty-four patients received induction chemotherapy and chemoradiation and 83 received short-course radiotherapy and consolidative chemotherapy. Among patients with complete re-staging evaluation, clinical complete response rates were similar, 49% (18/37) and 53% (44/83), respectively (p = 0.659). In the induction chemotherapy and chemoradiation group, 80% (n = 67) underwent surgery and 28% (n = 19) achieved a pathologic complete response. In the short-course radiotherapy and consolidative chemotherapy group, 44 (53%) patients underwent surgery and 11% (n = 5) had a pathologic complete response. Overall, a complete response was observed in 43% (n = 36) of patients who received induction chemotherapy and chemoradiation compared to 53% (n = 44) who received short-course radiotherapy and consolidative chemotherapy (p = 0.189). Perioperative outcomes were similar in patients who received induction chemotherapy and chemoradiation compared to short-course radiotherapy and consolidative chemotherapy: intraoperative complications (2% vs 7%), complete mesorectal specimen (85% vs 84%), anastomotic leak (9% vs 7%), organ/space infection (9% vs 5%), readmission (19% vs 21%), and reoperation (8% vs 9%), respectively (all p > 0.05).

CONCLUSIONS

In patients with clinical stage 2 or 3 rectal cancer, total neoadjuvant therapy with either induction chemotherapy and chemoradiation or short-course radiotherapy followed by consolidative chemotherapy were associated with similar perioperative morbidity and complete response rates.

Comparison of robotic versus laparoscopic lateral lymph node dissection for advanced lower rectal cancer: a retrospective study at two institutions

BACKGROUND

Lateral lymph node dissection (LLND) represents a technically challenging procedure. This study aimed to evaluate the perioperative, genitourinary functional and mid-term oncological outcomes of laparoscopic lateral lymph node dissection (LLLND) and robotic lateral lymph node dissection (RLLND) for advanced lower rectal cancer (ALRC).

METHODS

Between January 2015 and April 2021, consecutive patients who underwent RLLND and LLLND at two high-volume centres were enrolled. The perioperative outcomes, genitourinary function recovery and mid-term oncological outcomes of the patients were compared. A subgroup analysis of patients who underwent neoadjuvant chemoradiotherapy (nCRT) was performed.

RESULTS

A total of 205 patients were included in the analysis, with 95 in the RLLND group and 110 in the LLLND group. The patients in the RLLND group had a longer operative time, less blood loss, and more harvested internal iliac lymph nodes than did those in the LLLND group. In postoperative complication, urinary retention was less frequent in the RLLND group than in the LLLND group. Additionally, the RLLND group had better genitourinary function recovery. Similar results were also observed from the nCRT subgroup analysis. Moreover, there was no significant difference in mid-term oncological outcomes between the two groups. Further subgroup analysis indicated that the patients who underwent nCRT + LLLND/RLLND had better local control than those who underwent only LLLND/RLLND.

CONCLUSIONS

RLLND is safe and feasible for ALRC and is associated with more harvested internal iliac lymph nodes and better genitourinary function recovery. NCRT combined with minimally invasive LLND could constitute an improved strategy for ALRC.

Assessing the Association Between Endoscopic Tattooing and Lymph Node Yield in Rectal Cancer

INTRODUCTION

Preoperative endoscopic tattooing is an effective tool for intraoperative tumor localization in colon cancer. Endoscopic tattooing in rectal cancer may have unidentified benefits on lymph node yield, making it easier for pathologists to identify nodes during histopathologic assessment. There remains concern that tattoo ink may alter anatomical planes, increasing surgical difficulty.

METHODS

Retrospective chart reviews from 2016 to 2021 of n = 170 patients presenting with rectal cancer were divided into two groups: with (n = 79) and without (n = 91) endoscopic tattoos. Demographics, operative details, tumor characteristics, prior chemoradiation, and pathologic details were collected. Primary outcome was total lymph node yield. Secondary outcomes were rates of adequate (> 12) nodes, margin status, and operative variables including operative time.

RESULTS

No differences between pathologic stage, tumor height, high inferior mesenteric artery ligation, operative times, conversion rate, or surgical approach (open versus minimally invasive) were noted between groups. Receipt of neoadjuvant chemoradiation was less frequent in the endoscopic tattooing group (53.2% versus 76.9%, P ≤ 0.001). Total node number and rate of adequate lymph node yield were higher with endoscopic tattooing (20.5 ± 7.6 versus 16.8 ± 6.6 lymph nodes and 100.0% versus 83.5% adequate lymph node harvest, both P ≤ 0.001). Rates of positive circumferential and distal margins and complete total mesorectal excision were also similar. Regression analysis identified endoscopic tattooing (Incidence Risk Ratio 1.17, 95% confidence interval 1.04-1.31) and operative time more than 300 min (Incidence Risk Ratio 0.88, 95% confidence interval 0.77-0.99) had significant effects on lymph node harvest. Removal of patients with inadequate lymph node yield resulted in similar rates of total and positive lymph nodes.

CONCLUSIONS

Endoscopic rectal tattooing is associated with increased lymph node yield (including after neoadjuvant chemoradiotherapy) without sacrificing oncologic or perioperative outcomes, although this effect is inconsistent when only considering patients with an adequate lymph node yield.

Lymph node yield less than 12 is not a poor predictor of survival in locally advanced rectal cancer after laparoscopic TME following neoadjuvant chemoradiotherapy

Purpose

Previous studies have confirmed that neoadjuvant chemoradiotherapy (nCRT) may reduce the number of lymph nodes retrieved in rectal cancer. However, it is still controversial whether it is necessary to harvest at least 12 lymph nodes for locally advanced rectal cancer (LARC) patients who underwent nCRT regardless of open or laparoscopic surgery. This study was designed to evaluate the relationship between lymph node yield (LNY) and survival in LARC patients who underwent laparoscopic TME following nCRT.

Methods

Patients with LARC who underwent nCRT followed by laparoscopic TME were retrospectively analyzed. The relationship between LNY and survival of patients was evaluated, and the related factors affecting LNY were explored. To further eliminate the influence of imbalance of clinicopathological features on prognosis between groups, propensity score matching was conducted.

Results

A total of 257 consecutive patients were included in our study. The median number of LNY was 10 (7 to 13) in the total cohort. There were 98 (38.1%) patients with 12 or more lymph nodes harvested (LNY ≥12 group), and 159 (61.9%) patients with fewer than 12 lymph nodes retrieved (LNY <12 group). There was nearly no significant difference between the two groups in clinicopathologic characteristics and surgical outcomes except that the age of LNY <12 group was older (P<0.001), and LNY <12 group tended to have more TRG 0 cases (P<0.060). However, after matching, when 87 pairs of patients obtained, the clinicopathological features were almost balanced between the two groups. After a median follow-up of 65 (54 to 75) months, the 5-year OS was 83.9% for the LNY ≥12 group and 83.6% for the LNY <12 group (P=0.893), the 5-year DFS was 78.8% and 73.4%, respectively (P=0.621). Multivariate analysis showed that only patient age, TRG score and ypN stage were independent factors affecting the number of LNY (all P<0.05). However, no association was found between LNY and laparoscopic surgery-related factors.

Conclusions

For LARC patients who underwent nCRT followed by laparoscopic TME, the number of LNY less than 12 has not been proved to be an adverse predictor for long-term survival. There was no correlation between LNY and laparoscopic surgery-related factors.

Clinical Safety and Effectiveness of Robotic-Assisted Surgery in Patients with Rectal Cancer: Real-World Experience over 8 Years of Multiple Institutions with High-Volume Robotic-Assisted Surgery

Simple Summary

The aim of this retrospective observational study was to evaluate perioperative and short-term oncological outcomes of robotic-assisted rectal surgery (RRS) in hospitals with a high-volume of robotic-assisted surgeries. This study enrolled patients with rectal adenocarcinoma undergoing RRS from three high-volume institutions from December 2011 to June 2020. Compared with other studies, our results revealed the equivalent or superior perioperative and short-term oncological outcomes. Hence, RRS is an effective, safe, and feasible technique for patients with rectal cancers in high-volume hospitals.

Abstract

The perioperative and short-term oncological outcomes of robotic-assisted rectal surgery (RRS) are unclear. This retrospective observational study enrolled patients with rectal adenocarcinoma undergoing RRS from three high-volume institutions in Taiwan. Of the 605 enrolled patients, 301 (49.75%), 176 (29.09%), and 116 (19.17%) had lower, middle, and upper rectal cancers, respectively. Low anterior resection (377, 62.31%) was the most frequent surgical procedure. Intraoperative blood transfusion was performed in 10 patients (2%). The surgery was converted to an open one for one patient (0.2%), and ten (1.7%) patients underwent reoperation. The overall complication rate was 14.5%, including 3% from anastomosis leakage. No deaths occurred during surgery and within 30 days postoperatively. The positive rates of distal resection margin and circumferential resection margin were observed in 21 (3.5%) and 30 (5.0%) patients, respectively. The 5-year overall and disease-free survival rates for patients with stage I–III rectal cancer were 91.1% and 86.3%, respectively. This is the first multi-institutional study in Taiwan with 605 patients from three high-volume hospitals. The overall surgical and oncological outcomes were equivalent or superior to those estimated in other studies. Hence, RRS is an effective and safe technique for rectal resection in high-volume hospitals.

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

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

The efficiency of neoadjuvant chemotherapy in colon cancer with mismatch repair deficiency

Colon cancers with mismatch repair deficiency (dMMR) have specific clinicopathologic characteristics compared with mismatch repair proficiency (pMMR); however, the effect of MMR status on the efficiency of neoadjuvant chemotherapy (NCT) remains unclear. In our study, 439 dMMR and 26 pMMR colon cancer patients with or without NCT from 2010 to 2017 were retrospectively collected. Clinicopathological features, treatment response, and survival were compared between different groups. In the dMMR group, patients with NCT were likely to have higher CEA (abnormal CEA: 51.6% vs. 17.4%, p < 0.001), more multiorgan resection (38.7% vs. 16.8%, p = 0.006), and larger postoperative tumor diameter (7.26 vs. 6.21, p = 0.033) than those without NCT, but nearly half of cT4b patients who had NCT (42.9%, 9/21) avoid multiorgan resection. pT4 stage (HR, 14.97; 95% CI, 1.88-118.92; p = 0.010), number of positive lymph nodes (HR, 1.17; 95% CI, 1.09-1.26; p < 0.001), and tumor deposit (HR, 6.73; 95% CI, 2.08-21.74; p = 0.001) were independent prognosis factors of disease-free survival (DFS). For the advanced tumor subset, there is no significant difference between patients with or without NCT for OS (p = 0.13) and DFS (p = 0.11), although the survival rate of NCT was higher than non-NCT patients. Moreover, tumor regression grade was similar between dMMR and pMMR patients who had NCT. This study showed that NCT was more likely to be employed in dMMR patients with advanced tumors and may reduce the rate of multiorgan resection for cT4b dMMR patients. More large-scaled researches are needed to further explore if MMR status could predict the efficacy of neoadjuvant chemotherapy in patients with colon cancer.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

TRIAL REGISTRATION NUMBER

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

Multicenter validation of the PREDICT score for prediction of local recurrence after total mesorectal excision of rectal cancer

BACKGROUND

Total mesorectal excision (TME) is the gold standard treatment for rectal cancer. Although TME has managed to decrease the rates of local recurrence after rectal cancer resection, local recurrence is still recorded at varying rates. The present study aimed to validate the PREDICT score in the prediction of local recurrence of rectal cancer after TME with curative intent.

METHODS

This was a retrospective multicenter study on patients with nonmetastatic low or middle rectal cancer who underwent TME. The total PREDICT score was calculated for every patient and related to the onset of local recurrence. According to the final score, patients were allocated to one of three risk groups: low, moderate, and high, and the rates of local recurrence in each group were calculated and compared.

RESULTS

The present study included 262 patients (50.4% males) with a mean age of 47.1 years. The overall local recurrence rate was 12.6%. 29.4% of patients were in the low-risk group, 63.7% in the moderate-risk group, and 6.9% in the high-risk group. The local recurrence rate was 3.9% (95% confidence interval [CI]: 0.8-10.9) in the low-risk group, 13.2% (95% CI: 8.4-19.3) in the moderate risk group, and 44.4% (95% CI: 21.5-69.2) in the high-risk group (p < 0.0001). The sensitivity of the PREDICT score was 72.7%, the specificity was 88.1%, and the accuracy was 86.3%.

CONCLUSIONS

The PREDICT score had good diagnostic accuracy in the prediction of local recurrence after TME and a good discriminatory ability in the differentiation between patients at different risks to develop local recurrence.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

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

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/35243.

Comparison of laparoscopic and open colectomy for splenic flexure colon cancer: a systematic review and meta-analysis

PURPOSE

This study examined the short- and long-term outcomes of laparoscopic and open splenic flexure colon cancer (SFCC) surgery.

METHOD

Systematic literature searches were performed in PubMed and Ovid to compare laparoscopic and open colectomy for SFCC. The last search was conducted on November 7, 2021. Surgical and survival outcomes were collected and analyzed. This meta-analysis was performed using Review Manager Software (v 5.3).

RESULTS

This study included seven publications with 2397 patients published between 2011 and 2021. A significant difference in operative time was seen in the laparoscopic group (P = 0.01, WMD = 50.13, 95%CI [10.32, 89.94], I² = 97%); loss of blood estimated (P < 0.001, WMD =  -101.88, 95%CI [-161.65, -42.11], I² = 82%) and the incidence of overall complications (P < 0.001, OR = 0.53, 95%CI [0.38, 0.75], I² = 0%) of laparoscopic procedure were greatly decreased. There were similar results as compared in the two groups in terms of lymph node harvesting (P = 0.71, WMD = 0.49, 95%CI [-2.13, 3.12], I² = 93%) and the distance of proximal (P = 0.50, WMD =  -1.09, 95%CI [-4.26, 2.08], I² = 96%) or distal (P = 0.18, WMD = 2.44, 95%CI [-1.13, 6.01], I² = 97%) resection margin. In addition, no significant differences were observed on overall/disease-free survival over 3/5 years between the two procedures. An analysis of subgroups that used propensity matching scores produced similar results.

CONCLUSION

The laparoscopic procedure is clinically safe and feasible for SFCC. It shows the advantages in decreasing intraoperative blood loss and overall complications, and the long-term survival outcomes would not be affected. Randomized clinical trials with a larger sample size are warranted in the future for further investigation.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Lymph Nodes With Germinal Centers Are Not Associated With Tumor Response After Neoadjuvant Treatment in Locally Advanced Rectal Cancer

In patients with locally advanced rectal cancer, neoadjuvant radiotherapy or chemoradiotherapy followed by total mesorectal excision as a standard of care. We aimed to explore the number, size, germinal centers, extracapsular invasion of lymph nodes (LN), and their impact on overall survival and disease free survival. Furthermore we also investigated the characteristics of lymph nodes in patients who received neoadjuvant therapy and those who underwent surgery between 2011 and 2018. The count and measurement of lymph nodes was assessed by careful visual inspection and manual palpation. The predictive cut-off value of the lymph node ratio (LNR) was determined based on the receiver operating characteristic (ROC), method and the survival outcomes based on Kaplan-Meier curves. We found that the size and the number of lymph nodes decreased significantly after neoadjuvant treatment. The mean LN for patients who received neoadjuvant therapy was 12.68 ± 6.69 and for patients who did not receive neoadjuvant therapy was 16.29 ± 5.61 ( P = .012). The average size for patients who received neoadjuvant therapy followed by surgery was 3.30 ± 1.10 versus 4.22 ± 1.18 mm for control group (surgery only) ( P < .001), an LNR of 0.13 (sensitivity: 86%, specificity: 47%, AUC: 60%, 95% CI, 0.41%-0.76%) predicted recurrence and metastasis. Presence of lymph nodes with germinal centers was significantly associated with absence of vascular invasion, nodal tumor deposits, distant metastasis, and lower age group (<50 years). However there was no association seen between overall survival and relapse free, total number of lymph nodes enlarged and extracapsular invasion in positive nodes.

Finally there is no association between lymph nodes with germinal centers and tumor response after neoadjuvant treatment in locally advanced rectal cancer.

Pathological Features and Prognostication in Colorectal Cancer

The prognostication of colorectal cancer (CRC) has traditionally relied on staging as defined by the Union for International Cancer Control (UICC) and American Joint Committee on Cancer (AJCC) TNM staging classifications. However, clinically, there appears to be differences in survival patterns independent of stage, suggesting a complex interaction of stage, pathological features, and biomarkers playing a role in guiding prognosis, risk stratification, and guiding neoadjuvant and adjuvant therapies. Histological features such as tumour budding, perineural invasion, apical lymph node involvement, lymph node yield, lymph node ratio, and molecular features such as MSI, KRAS, BRAF, and CDX2 may assist in prognostication and optimising adjuvant treatment. This study provides a comprehensive review of the pathological features and biomarkers that are important in the prognostication and treatment of CRC. We review the importance of pathological features and biomarkers that may be important in colorectal cancer based on the current evidence in the literature.

Prognostic Value of the Distribution of Lymph Node Metastasis in Locally Advanced Rectal Cancer After Neoadjuvant Chemoradiotherapy

Background: The objective of this study is to assess the prognostic value of lymph node metastasis distribution (LND) in locally advanced rectal cancer (LARC) after neoadjuvant chemoradiotherapy (nCRT). Methods: This study included 179 patients with pathological stage III LARC who underwent nCRT followed by radical surgery. LND was classified into three groups: LND1, lymph node metastasis at the mesorectum (140/179, 78.2%); LND2, lymph node metastasis along the inferior mesenteric artery trunk nodes (26/179, 14.5%); LND3, lymph node metastasis at the origin of the IMA (13/179, 7.3%). Clinicopathologic characteristics were analyzed to identify independent prognostic factors. Result: LND showed better stratification for 3-year DFS (LND1 66.8, LND2 50, and LND3 15.4%, P < 0.01) compared to the ypN (3-year DFS: N1 59.9 and N2 60.3%, P = 0.34) and ypTNM (3-year DFS: IIIA 68.6%, IIIB 57.5%, and IIIC 53.5, P = 0.19) staging systems. Similar results were found for 3-year LRFS and DMFS. According to multivariate survival analysis, LND was shown to be an independent prognostic factor for DFS, LRFS, and DMFS in patients with positive lymph nodes (P < 0.01, in all cases). Conclusion: LND is an independent prognostic factor in stage III rectal cancer after nCRT. LND can be used as a supplementary indicator for the ypTNM staging system in patients with LARC after nCRT.

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

Purpose

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

Patients and Methods

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

Results

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

Conclusion

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Effects of neoadjuvant chemotherapy plus chemoradiotherapy on lymph nodes in rectal adenocarcinoma

The pathological nodal stage, determination of which requires examination of ≥ 12 lymph nodes, is one of the main prognostic factors in rectal cancer. Neoadjuvant chemoradiotherapy (CRT) may reduce the number of both lymph nodes retrieved and positive lymph nodes. Induction chemotherapy before CRT aimed at reducing the rate of distant metastases. However, the impact of this new treatment on number of lymph nodes retrieved and positive lymph nodes is unknown. This study was performed to evaluate the effects of neoadjuvant chemotherapy on lymph nodes in locally advanced rectal cancer treated by CRT. We retrospectively included patients with T2 - 4 Nx M0 rectal cancer and compared those receiving neoadjuvant chemotherapy plus CRT with those receiving CRT alone. From 2012 to 2019, 85 patients were treated with neoadjuvant chemotherapy + CRT and 189 with CRT alone. The number of lymph nodes retrieved (19 vs. 17, respectively, P = 0.434), the rate of specimens with ≥ 12 lymph nodes (92% vs. 88%, respectively, P = 0.397), and the median number of positive lymph nodes (1 vs. 2, respectively, P = 0.878) were similar between the two groups. However, the rate of pN0 was higher after neoadjuvant chemotherapy + CRT compared to CRT (75% vs. 62%, respectively, P = 0.030). Neoadjuvant chemotherapy before CRT for locally advanced rectal cancer did not modify the number of lymph nodes retrieved or the number of positive lymph nodes compared to CRT alone. However, it significantly increased the rate of tumors without any positive lymph nodes (ypN0).

Lymph Node Yield and Ratio in Selective and Modified Radical Neck Dissection in Head and Neck Cancer-Impact on Oncological Outcome

Background: Lymph node metastases are associated with poor prognosis in head and neck squamous cell carcinoma (HNSCC). Neck dissection (ND) is often performed prior to or after (chemo)radiation (CRT) and is an integral part of HNSCC treatment strategies. The impact of CRT delivered prior to ND on lymph node yield (LNY) and lymph node ratio (LNR) has not been comprehensively investigated. Material and methods: A retrospective cohort study was conducted from January 2014 to 30 June 2019 at the University Hospital of Bern, Switzerland. We included 252 patients with primary HNSCC who underwent NDs either before or after CRT. LNY and LNR were compared in patients undergoing ND prior to or after CRT. A total of 137 and 115 patients underwent modified radical ND (levels I to V) and selective ND, respectively. The impact of several features on survival and disease control was assessed. Results: Of the included patients, 170 were male and 82 were females. There were 141 primaries from the oral cavity, 55 from the oropharynx, and 28 from the larynx. ND specimens showed a pN0 stage in 105 patients and pN+ in 147. LNY, but LNR was not significantly higher in patients undergoing upfront ND than in those after CRT (median: 38 vs. 22, p < 0.0001). Cox hazard ratio regression showed that an LNR ≥ 6.5% correlated with poor overall (HR 2.42, CI 1.12-4.89, p = 0.014) and disease-free survival (HR 3.416, CI 1.54-754, p = 0.003) in MRND. Conclusion: ND after CRT leads to significantly reduced LNY. An LNR ≥6.5% is an independent risk factor for decreased overall, disease-free, and distant metastasis-free survival for MRND.

Log odds of positive lymph nodes is an excellent prognostic factor for patients with rectal cancer after neoadjuvant chemoradiotherapy

Background

Neoadjuvant chemoradiotherapy (NCRT) results in fewer lymph nodes harvested and causes staging migration. Therefore, we compared the prognostic value of the logarithmic odds of positive lymph nodes (LODDS) with the lymph node ratio (LNR) and the American Joint Committee on Cancer (AJCC) ypN stage in patients with locally advanced rectal cancer (LARC) after NCRT.

Methods

A total of 445 patients with LARC who received NCRT and underwent radical surgery between January 2004 and December 2015 were recruited, and data from 4881 patients included in the Surveillance, Epidemiology and End Results (SEER) database between 2010 and 2013 were analyzed to verify our results. The time-dependent area under the receiver operating characteristic curve (TimeROC) was used to evaluate the discriminative ability of the different lymph node staging systems.

Results

ypN staging failed to satisfactorily stratify the patients treated with NCRT [the 3-year disease-free survival (DFS) rates were 65.7% and 55.4% for the ypN1 and ypN2 groups, respectively, P=0.252]. The LODDS classification was significantly associated with DFS, and the 3-year DFS rates for the LODDS0, LODDS1, and LODDS2 groups were 89.9%, 72.4%, and 53.9%, respectively (P<0.05 across all groups). Furthermore, the LODDS classification system was able to subclassify patients with ypN0 stage tumors regardless of whether ≥12 or <12 total lymph nodes (TLNs) were harvested. TimeROC analysis showed that the LODDS classification (AUC, median: 0.722, range: 0.692–0.754) had a higher accuracy for determining the prognosis than the ypN stage (AUC, median: 0.691, range: 0.684–0.712) or the LNR (AUC, median: 0.703, range: 0.685–0.730) classification, regardless of lymph node status. These results were verified using the SEER database.

Conclusions

The LODDS was a better prognostic factor for DFS than ypN staging or the LNR-based approach in patients with LARC after NCRT, particularly those with <12 TLNs harvested or ypN0 stage disease.

Operative Feasibility and Short-Term Oncologic Outcome of Rigid Versus Flexible Platforms in Transanal Total Mesorectal Excision

Several transanal platforms were used to perform transanal total mesorectal excision (TaTME). They can be classified into rigid reusable platforms or flexible single-use platforms. The choice of transanal platform usually depends on the availability and the surgeon's discretion. To the best of our knowledge, this is the first study to compare the operative and oncologic outcome of flexible and rigid platforms during TaTME. This is a retrospective cohort study in which rectal cancer patients operated by TaTME in two tertiary centers from June 2013 to April 2019 were included. They were classified into two groups according to the platform used either the rigid platform group (n = 17) or the flexible platform (n = 14). Operative feasibility and short-term oncologic data were analyzed and reported. A total number of 31 patients were divided into either the rigid platform group (n = 17) versus the flexible platform one (n = 14). Shorter operating time, less blood loss, better TME specimens, and lymph node yield were reported in the flexible platform group. Flexible platforms were associated with better operative outcomes. Although there were no differences in circumferential and distal margins between the two groups, better TME specimens' quality and lymph node yield were reported in the flexible platform group. Future prospective trials are encouraged to provide better evidence.

Identifying Outlier Hospitals in Gastric Cancer Lymph Node Yield Using the National Cancer Database

BACKGROUND

Lymph node (LN) yield is a key quality indicator that is associated with improved staging in surgically resected gastric cancer. The National Comprehensive Cancer Network recommends a yield of ≥15 LNs for proper staging, yet most facilities in the United States fail to achieve this number. The present study aimed to identify factors that could affect LN yield on a facility level and identify outlier hospitals.

METHODS

This was a retrospective review of adults (aged ≥18 y) with gastric cancer (Tumor-Node-Metastasis Stages I-III) who underwent gastrectomy. Data were analyzed from the National Cancer Database (2004-2016). Multivariate analysis identified patient and tumor characteristics, whereas an observed-to-expected ratio of identified outlier hospitals. Facility factors were compared between high and low outliers.

RESULTS

A total of 26,590 patients were included in this study. Of these patients, only 50.3% had an LN yield ≥15. The multivariate model of patient and tumor characteristics demonstrated a concordance index was 0.684. A total of 1245 facilities were included. There were 198 low outlier LN yield hospitals and 135 high outlier LN yield hospitals (observed-to-expected ratio of 0.42 ± 0.24 versus 1.38 ± 0.19, P < 0.0001). There was a difference in facility type between low and high outliers (P < 0.0001). High LN yield hospitals had a larger surgical volume than low LN yield hospitals (median 8.4 [4.9, 13.5] versus 3.5 [2.4, 5.2]; P < 0.0001).

CONCLUSIONS

Nearly half of the population exhibited low compliance to National Comprehensive Cancer Network recommendations. Facility-level disparities exist as high yearly surgical volume and academic facility status distinguished high-performing outlier hospitals.

Management, treatment and prognostic significance of lateral lymph node metastases in rectal cancer-a regional cohort study

PURPOSE

Lateral lymph node metastases in rectal cancer remain a clinical challenge. Different treatment regimens have been suggested. This retrospective regional cohort study examines outcome after combined oncological and surgical treatment of MRI-positive lateral lymph nodes (LLN).

METHODS

Data from the Swedish Colorectal Cancer Registry (SCRCR) and patient records were used for retrospective analysis of resected high-risk rectal cancers between 2009 and 2014. The aim was to compare tumour characteristics, neoadjuvant therapy, recurrence and outcome after lateral lymph node dissection.

RESULTS

One thousand and one hundred nineteen cases were identified and after exclusion 344 patients with cT3-T4 ≤ 10 cm from the anal verge were analysed. Thirty (8.7%) patients with MRI-positive LLN were identified. Synchronous distant metastases were associated with MRI-positive LLN (p-value 0.019). Long-course chemoradiotherapy was clinical practice in cases of MRI-positive LLN. No differences in local (p-value 0.154) or distant (p-value 0.343) recurrence rates between MRI-positive LLN patients and MRI-negative patients were detected. Only four patients underwent lateral lymph node dissection (LLND). There was no significant difference in overall survival during follow-up between the MRI-negative (CI at 95%; 99-109 months) and MRI-positive group (CI at 95%; 69-108 months; p-value 0.14).

CONCLUSION

Lateral lymph node metastases present a challenging clinical situation. The present study shows that combination of neoadjuvant therapy and selective LLND is an applicable strategy in cases of MRI-positive LLN.

Impact factors of lymph node retrieval on survival in locally advanced rectal cancer with neoadjuvant therapy

BACKGROUND

Conventional clinical guidelines recommend that at least 12 lymph nodes should be removed during radical rectal cancer surgery to achieve accurate staging. The current application of neoadjuvant therapy has changed the number of lymph node dissection.

AIM

To investigate factors affecting the number of lymph nodes dissected after neoadjuvant chemoradiotherapy in locally advanced rectal cancer and to evaluate the relationship of the total number of retrieved lymph nodes (TLN) with disease-free survival (DFS) and overall survival (OS).

METHODS

A total of 231 patients with locally advanced rectal cancer from 2015 to 2017 were included in this study. According to the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) tumor-node-metastasis (TNM) classification system and the NCCN guidelines for rectal cancer, the patients were divided into two groups: group A (TLN ≥ 12, n = 177) and group B (TLN < 12, n = 54). Factors influencing lymph node retrieval were analyzed by univariate and binary logistic regression analysis. DFS and OS were evaluated by Kaplan-Meier curves and Cox regression models.

RESULTS

The median number of lymph nodes dissected was 18 (range, 12-45) in group A and 8 (range, 2-11) in group B. The lymph node ratio (number of positive lymph nodes/total number of lymph nodes) (P = 0.039) and the interval between neoadjuvant therapy and radical surgery (P = 0.002) were independent factors of the TLN. However,TLN was not associated with sex, age, ASA score, clinical T or N stage, pathological T stage, tumor response grade (Dworak), downstaging, pathological complete response, radiotherapy dose, preoperative concurrent chemotherapy regimen, tumor distance from anal verge, multivisceral resection, preoperative carcinoembryonic antigen level, perineural invasion, intravascular tumor embolus or degree of differentiation. The pathological T stage (P < 0.001) and TLN (P < 0.001) were independent factors of DFS, and pathological T stage (P = 0.011) and perineural invasion (P = 0.002) were independent factors of OS. In addition, the risk of distant recurrence was greater for TLN < 12 (P = 0.009).

CONCLUSION

A shorter interval to surgery after neoadjuvant chemoradiotherapy for rectal cancer under indications may cause increased number of lymph nodes harvested. Tumor shrinkage and more extensive lymph node retrieval may lead to a more favorable prognosis.

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.

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.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

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

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

The safety and effectiveness of carbon nanoparticles suspension in tracking lymph node metastases of colorectal cancer: a prospective randomized controlled trial

OBJECTIVE

This study was to evaluate the safety and effectiveness of carbon nanoparticles suspension in tracking lymph node metastases of colorectal cancer.

METHODS

Eligible patients diagnosed with stages I-III colorectal cancer in Fudan University Shanghai Cancer Center between 1 May 2017 and 31 May 2018 fulfilling the inclusion criteria were included in this prospective randomized controlled study. All the patients were randomly allocated to two groups: the nanocarbon group and the control group. Patients' clinicopathological characteristics were compared between the nanocarbon group and the control group. For continuous variables, data were presented as mean (±SD) and differences between the two groups were compared by the Mann-Whitney U test; for categorical variables, data was presented as frequency (%) and the Pearson's chi-squared test was used to compare the differences between two groups.

RESULTS

All the patients' characteristics between two groups did not achieve statistical significance (P > 0.05). Patients in nanocarbon group were more likely to be associated with more lymph nodes retrieved totally compared with control group (19.84 ± 6.428 vs. 17.41 ± 7.229, P < 0.001). The number of lymph nodes retrieved in nanocarbon group were more likely to be ≥12 than that in the control group (P = 0.005).

CONCLUSIONS

Our study confirmed the safety of using carbon nanoparticles suspension as a tracer in colorectal cancer. More importantly, nanocarbon could significantly increase the detected number of lymph nodes in colorectal cancer, which can help improve the accuracy of lymph node staging and even improve patients' survival.

The prognostic impact of neoadjuvant chemoradiotherapy on lymph node sampling in patients with locally advanced rectal cancer

According to the American Joint Committee on Cancer, at least 12 lymph nodes are required to accurately stage locally advanced rectal cancer (LARC). Neoadjuvant chemoradiation therapy (NACRT) reduces the number of lymph nodes retrieved during surgery. In this study, we evaluated the effect of NACRT on lymph node retrieval and prognosis in patients with LARC. We performed an observational study of 142 patients with LARC. Although our analysis was retrospective, data were collected prospectively. Half the patients were treated with NACRT and total mesorectal excision (TME) and the other half underwent TME only. The number of lymph nodes retrieved and the number of metastatic lymph nodes were significantly reduced in the NACRT group (P > 0.001). In the univariate and multivariate analyses, only NACRT and patient age were significantly associated with reduced lymph node retrieval. The number of metastatic lymph nodes and the lymph node ratio (LNR) both had a significant effect on prognosis when the patient population was examined as a whole (P = 0.003 and P = 0.001, respectively). However, the LNR was the only significant, independent prognostic factor in both treatment groups (P = 0.007 for the NACRT group; P = 0.04 for the no-NACRT group). NACRT improves patient prognosis only when the number of metastatic lymph nodes is reduced. The number of metastatic lymph nodes and the LNR are important prognostic factors. Lymph node retrieval remains an indispensable tool for staging and prognostic assessment of patients with rectal carcinoma treated with NACRT.

Impact of Radiotherapy on Neck Dissection Nodal Count in Patients With Head and Neck Cancer

OBJECTIVES/HYPOTHESIS

Our study aimed to review the impact of preoperative radiotherapy (RT) and other factors on the lymph node count of neck dissection (ND) specimens from patients with head and neck cancer (HNC). A retrospective study was conducted on all patients with head and neck cancers who had undergone NDs in Singapore General Hospital between 1992 and 2013.

STUDY DESIGN

Retrospective study.

METHODS

Patients were categorized into two groups: patients treated with RT with or without chemotherapy before ND and patients who had undergone ND surgery without previous history of RT. The primary endpoint for this study would be the lymph node count from ND.

RESULTS

The study cohort consists of 1,024 NDs on 829 patients. There were 597 (58.3%) radical/modified radical NDs involving levels I-V. Within this group, 75 (12.6%) NDs had preoperative RT. Preoperative RT and age were found to significantly reduce nodal yield in both univariate and multivariate analysis in the radical/modified radical ND subgroup. In our multivariate analysis, preoperative RT was shown to decrease the nodal yield by 7.464 (P = .0002, 95% confidence interval [CI]: -11.35 to -3.58). Advanced age independently decreases nodal yield, even after accounting for the effect of RT (P = .0002, 95% CI: -0.27 to -0.08). In addition, preoperative RT has a more pronounced effect in reducing lymph node count in the older age group.

CONCLUSIONS

Preoperative RT and advanced age are independent and synergistic factors that reduce nodal count from NDs in patients with head and neck cancers.

LEVEL OF EVIDENCE

4 Laryngoscope, 130: 1947-1953, 2020.