Non-surgical factors influencing lymph node yield in colon cancer

Complete mesocolic excision for colon cancer: current status and controversies

According to Hohenberger's original description, complete mesocolic excision for colon cancer involves precise dissection of the avascular embryonic plane between the parietal retroperitoneum and visceral peritoneum of the mesocolon. This ensures mesocolic integrity, access to high ligation of the supplying vessels at their origin and an associated extended lymphadenectomy. Results from centres which have adopted this approach routinely have demonstrated that oncological outcomes can be improved by the rigorous implementation of established principles of cancer surgery. Meticulous anatomical dissection along embryonic planes is a well-established principle of precision cancer surgery used routinely by the specialist colorectal surgeon. Therefore, the real question concerns the need for true central vascular ligation and associated extended (D3) lymphadenectomy or otherwise, particularly along the superior mesenteric vessels when performing a right colectomy. Whether this approach results in improved overall or disease-free survival remains unclear and its role remains controversial particularly given the potential for significant morbidity associated with a more extensive central vascular dissection. Current literature is limited by considerable bias, as well as inconsistent and variable terminology, and the results of established randomized trials are awaited. As a result of the current state of equipoise, various national guidelines have disparate recommendations as to when complete mesocolic excision should be performed if at all. This article aims to review the rationale for and technical aspects of complete mesocolic excision, summarize available short and long term outcome data and address current controversies.

Lymph Node Yield in Lung Cancer Resection is Associated With Demographic and Institutional Factors

INTRODUCTION

Lymphadenectomy is routinely performed during surgical resection of nonsmall cell lung cancer (NSCLC). Lymph node yield and number of nodal stations sampled are important prognostic markers viewed as surrogates of surgical quality. The purpose of this study was to identify factors associated with these quality metrics after resection of NSCLC.

MATERIALS AND METHODS

We identified NSCLC patients undergoing resection at a single institution from 2010 to 2021. Cases were matched to detailed pathologist reports, which included lymph node yield and number of stations sampled. Demographic and clinical characteristics were analyzed individually using unadjusted linear regression to identify factors associated with lymph node yield and number of stations sampled. Multivariable linear regression analyses were performed to evaluate the same end points, using covariates determined through stepwise-backwards selection.

RESULTS

The study cohort included 836 patients. Multivariable regression demonstrated that male sex, history of cardiothoracic surgery, and individual pathologist were independently associated with lymph node yield. Among 18 pathologists, interpathologist coefficients with respect to lymph node yield varied from -5.61 to 11.25. Multivariable regression demonstrated White race and history of cardiothoracic surgery to be independently associated with number of nodal stations sampled, as well as individual surgeon and pathologist.

CONCLUSIONS

Lymph node yield and number of nodal stations sampled after NSCLC resection may vary based on patient demographic and clinical characteristics, as well as institutional factors. These factors should be accounted for when using these metrics as markers of surgical quality and prognosis of NSCLC.

Immune microenvironment and lymph node yield in colorectal cancer

BACKGROUND

Lymph node (LN) harvesting is associated with outcomes in colonic cancer. We sought to interrogate whether a distinctive immune milieu of the primary tumour is associated with LN yield.

METHODS

A total of 926 treatment-naive patients with colorectal adenocarcinoma with more than 12 LNs (LN-high) were compared with patients with 12 or fewer LNs (LN-low). We performed immunohistochemistry and quantification on tissue microarrays for HLA class I/II proteins, beta-2-microglobulin (B2MG), CD8, CD163, LAG3, PD-L1, FoxP3, and BRAF V600E.

RESULTS

The LN-high group was comprised of younger patients, longer resections, larger tumours, right-sided location, and tumours with deficient mismatch repair (dMMR). The tumour microenvironment showed higher CD8+ cells infiltration and B2MG expression on tumour cells in the LN-high group compared to the LN-low group. The estimated mean disease-specific survival was higher in the LN-high group than LN-low group. On multivariate analysis for prognosis, LN yield, CD8+ cells, extramural venous invasion, perineural invasion, and AJCC stage were independent prognostic factors.

CONCLUSION

Our findings corroborate that higher LN yield is associated with a survival benefit. LN yield is associated with an immune high microenvironment, suggesting that tumour immune milieu influences the LN yield.

Impact of DNA mismatch repair proteins deficiency on number and ratio of lymph nodal metastases in colorectal adenocarcinoma

BACKGROUND

Approximately 15 % of colorectal adenocarcinomas (CRCs) are characterized by an altered expression of DNA mismatch repair (MMR) proteins (i.e. MMR deficiency [MMRd]). Lymph node ratio (LNR) represents one of the most important prognostic markers in non-advanced CRCs. No significant data are available regarding LNR distribution depending on MMR status.

PURPOSE OF THE STUDY

The aim of the present work was to compare pathological and clinical characteristics of MMRd tumors versus MMR proficient (MMRp) cases. Particular attention was paid to how these molecular sub-groups relate to the LNR.

MATERIALS AND METHODS

A mono-Institutional series of 1037 consecutive surgically treated stage I-IV CRCs were retrospectively selected and data were obtained from pathological reports. Cases were characterized for MMR/MSI status by means of immunohistochemistry or for microsatellite instability (MSI) analysis.

RESULTS

MMRd/MSI tumors (n = 194; 18.7 %) showed significant differences in comparison to MMRp lesions for sex (female prevalence 50.5 % vs 40.7 %; p = 0.013), age (74.2 vs 69.2; p < 0.001), location (right side; p < 0.001), diameter (larger than MMRp; p < 0.001), growth pattern (expansive pattern of growth; p < 0.001), peri- (p = 0.0002) and intra-neoplastic (p = 0.0018) inflammatory infiltrate, presence of perineural invasion (p < 0.001), stage (lower stage at presentation; p < 0.001), grade (higher prevalence of high-grade tumors; p < 0.001), and LNR (lower; p < 0.001).

CONCLUSIONS

MMRd/MSI tumors are a distinct molecular CRC subtype characterized by a significantly lower LNR in comparison to MMRp lesions. These data further support the prognostic impact of MMRd/MSI status in early-stage CRCs.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Predictors of underlying carcinoma in patients with suspected acute diverticulitis

BACKGROUND

A subset of patients who undergo colon resection for suspected diverticulitis will unexpectedly be found to have cancer. We hypothesized that a subset of variables could be used to help predict a diagnosis of cancer preoperatively.

METHODS

National Surgical Quality Improvement Program data (2012-2018) were used to identify all patients with a preoperative diagnosis of diverticulitis who had unexpected cancer using postoperative staging data. Key characteristics of the study groups were compared with χ² tests and multivariate logistic regression modeling.

RESULTS

A total of 17,368 patients were identified with an operative indication of acute diverticulitis. Of these, 164 (0.94%) had an unexpected postoperative diagnosis of cancer. Most cancer patients had locally advanced tumors (T1-2: 15%; T3: 39%; T4: 45%), and 37.1% had positive lymph nodes. Rates of margin positivity and inadequate lymph node harvest were 1.2% and 15.9%, respectively. In bivariate analyses, cancer patients had increased age (P < .01), decreased albumin (P < .001), and increased rates of preoperative anemia (P = .01), sepsis (P < .01), and weight loss (>10% in 6 months) (P < .001). The only variables significantly associated with cancer in multivariate regression analysis were sepsis (odds ratio 2.14, 95% confidence interval [1.3-3.6]; P < .01), weight loss (odds ratio 2.31, 95% confidence interval [1.1-4.4]; P = .01), and preoperative albumin level (odds ratio 0.64, 95% confidence [0.45-0.92]; P < .01).

CONCLUSION

An unexpected postoperative diagnosis of cancer occurs in a small percentage of patients with suspected diverticulitis. Surgeons should have a high index of suspicion for cancer in patients with sepsis or malnutrition.

Pathology protocol increases lymph node yield in neck dissection for oral cavity squamous cell carcinoma

BACKGROUND

Lymph node yield (LNY) is a proposed quality indicator in neck dissection for oral cavity squamous cell carcinoma (OCSCC).

METHODS

Retrospective series including 190 patients with OCSCC undergoing neck dissection between 2016 and 2018. A change in pathologic grossing protocol was initiated during the study period to assess residual adipose tissue. A generalized linear model was used to assess the impact of multiple variables on LNY.

RESULTS

Mean LNY was 28.59 (SD = 17.65). The protocol identified a mean of 10.32 lymph nodes per case. Multivariable analysis identified associations between LNY and use of the pathology protocol (P = .02), number of dissected lymph node levels (P < .001), presence of pathologic lymph nodes (P = .002), body mass index (P = .02), prior neck surgery (P = .001), and prior neck radiation (P = .001).

CONCLUSIONS

Assessment of residual adipose tissue within neck dissection specimens improves accuracy of LNY. LNY in neck dissection is influenced by multiple factors including methods of pathologic assessment.

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.

Gender comparison of clinical, histopathological, therapeutic and outcome factors in 185,967 colon cancer patients

Introduction

Colorectal carcinomas represent the third most common cause of cancer-related deaths in Germany. Although the incidence is significantly higher in men compared with women and gender is a well-established crucial factor for outcome in other diseases, detailed gender comparisons for colon cancer are lacking.

Methods

This retrospective population-based cohort study included all patients diagnosed with colon cancer in Germany between 2000 and 2016 who were included in the common dataset of colorectal cancer patients from the quality conference of the German Cancer Society. We compared clinical, histopathological, and therapeutic characteristics as well as overall and recurrence-free survival.

Results

A total of 185,967 patients were included in the study, of which 85,685 were female (46.1%) and 100,282 were male (53.9%). The proportion of women diagnosed with colon cancer decreased from 2000 to 2016 (f: 26.6 to 40.1%; m: 24.9 to 41.9%; p < 0.001), and the proportion of very old patients was especially high in women (f: 27.3%; m: 15.6%; p < 0.001). The localization in women was more right-sided (f: 45.0%, m: 36.7%; p < 0.001), and women had a higher tumor grading and a higher UICC stage (especially stage III nodal-positive) at diagnosis of primary colon cancer (UICC III: f: 22.7%, m: 21.0%; p < 0.001). We could detect a significantly better overall (hazard ratio: 0.853, lower 95%: 0.841, upper 95%: 0.864; p < 0.001) and recurrence-free survival (hazard ratio: 0.857, lower 95%: 0.845, upper 95%: 0.868; p < 0.001) in women compared with men, even though women received chemotherapy less frequently compared with men (f: 26.1%, m: 28.1%; p < 0.001).

Conclusion

We could detect several variables that differed significantly between men and women regarding clinical, histopathological, therapeutic, and outcome factors. We believe that it is crucial to consider gender as a key factor in the diagnosis and treatment of colon cancer. Sex-specific diagnostic tools could lead to an earlier diagnosis of colon cancer in women, and ways to increase the rate of chemotherapy in women should be evaluated. Furthermore, we recommend stratifying randomized trials by gender.

Electronic supplementary material

The online version of this article (10.1007/s00423-019-01850-6) contains supplementary material, which is available to authorized users.

Exploration of exact significance of lymph node ratio and construction of a novel stage in colon cancer with no distant metastasis

Aim

Lymph node ratio (LNR) seems to be more precise than classic N stage in classifying cancer stage. Thus, we aim to construct a modified classification system based on LNR for colon cancer without distant metastasis.

Methods

This study enrolled two independent cohorts of patients. The primary cohort enrolled 2,152 patients from 2008 to 2013 in Zhongshan Hospital, Fudan University. The validation cohort consisted of 77,406 patients from the Surveillance, Epidemiology, and End Results (SEER) registry from 2004 to 2014. The inclusion criteria were: pathologically confirmed colon cancer, and American Joint Committee on Cancer (AJCC) stage I/II/III. The exclusion criteria included: incomplete follow-up information, rectal cancer, and multiple primary sites. The prognostic value of LNR for overall survival was evaluated. The cutoff value of LNR was determined by the X-tile. Predictive performance of modified classification was determined by the concordance index.

Results

After analysis, 0.05 and 0.50 were determined as the best threshold values of LNR. A value of <0.05, 0.05–0.50 and >0.50 was reclassified as the mN0, mN1 and mN2 stage. A modified classification based on mN0, mN1, and mN2 was further constructed for stage I/II/III colon cancer. C-index of the modified classification was statistically more precise than AJCC classification (0.687 versus 0.605, P<0.001). The same results can also be determined in the validation cohort (0.715 versus 0.640, P<0.001). Furthermore, a prognostic nomogram including independent factors was constructed. The constructed nomogram showed good performance according to the calibration curve.

Conclusion

The clinical value of LNR level was preferable to classic N stage in colon cancer patients. Our proposed classification based on LNR and AJCC T category can effectively differentiate patients with varied survival outcomes.

A Review of Current Challenges in Colorectal Cancer Reporting

Context.—

Pathologic assessment of colorectal cancer resection specimens plays an important role in postsurgical management and prognostication in patients with colorectal cancer. Challenges exist in the evaluation and reporting of these specimens, either because of difficulties in applying existing guidelines or related to newer concepts.

Objective.—

To address challenging areas in colorectal cancer pathology and to provide an overview of the literature, current guidelines, and expert recommendations for the handling of colorectal cancer resection specimens in everyday practice.

Data Sources.—

PubMed (US National Library of Medicine, Bethesda, Maryland) literature review; reporting protocols of the College of American Pathologists, the Royal College of Pathologists of the United Kingdom, and the Japanese Society for Cancer of the Colon and Rectum; and classification manuals of the American Joint Committee on Cancer and the Union for International Cancer Control.

Conclusions.—

This review has addressed issues and challenges affecting quality of colorectal cancer pathology reporting. High-quality pathology reporting is essential for prognostication and management of patients with colorectal cancer.

Acetone clearance of mesocolic or mesorectal fat increases lymph node yield and may improve detection of high-risk Stage II colorectal cancer patients

AIM

Lymph node (LN) status is key to determining the need for adjuvant therapy in colorectal cancer (CRC) and for disease which has progressed to Stage II (T3-T4, N0, M0). A yield of fewer than 12 LNs is considered a risk factor similar to high-grade histology and vascular, lymphatic and perineural invasion. The aim of this retrospective study was to investigate the effect of acetone fat clearance of the mesocolon or mesorectum on LN yield and the identification of patients with high-risk Stage II CRC.

METHOD

After conventional LN retrieval, fatty tissue derived from the mesocolon or mesorectum of 80 CRC specimens was incubated in acetone for 24 h. A second dissection was then performed by a trained technician. The total number of LNs as well as tumour involvement (LNpositive and LNnegative) were assessed at each stage. In addition, LN morphology was assessed and clinicopathological data were extracted from existing pathology reports.

RESULTS

Eighty CRC specimens were available for study. 1548 (94%) LN were negative and 96 (6%) were positive. The median (range) LN yield per specimen was 12 (3-41) LN increasing to 18 (4-48) LN after fat clearance (P < 0.001). After fat clearance, 534 additional LNs were identified in 75 (94%) of the specimens, and all but 10 were negative. The pN stage did not change in six patients who were found to be LN positive after fat clearance. However, the number of high-risk Stage II CRC patients decreased from 11 to 7. Although important for these patients, this downstaging did not reach statistical significance (P = 0.125).

CONCLUSION

Acetone clearance of mesocolic or mesorectal fat increases median LN yield and may in a larger study decrease the number of patients classified as having high-risk Stage II CRC.

Evaluation on prognostic efficacy of lymph nodes ratio (LNR) and log odds of positive lymph nodes (LODDS) in complicated colon cancer: the first study in emergency surgery

BACKGROUND

Lymph node involvement is one of the most important prognostic factors in colon cancer. Twelve is considered the minimum number of lymph nodes necessary to retain reliable tumour staging, but several factors can potentially influence the lymph node harvesting. Emergent surgery for complicated colon cancer (perforation, occlusion, bleeding) could represent an obstacle to reach the benchmark of 12 nodes with an accurate lymphadenectomy. So, an efficient classification system of lymphatic involvement is crucial to define the prognosis, the indication to adjuvant therapy and the follow-up. This is the first study with the aim to evaluate the efficacy of lymph nodes ratio (LNR) and log odds of positive lymph nodes (LODDS) in the prognostic assessment of patients who undergo to urgent surgery for complicated colonic cancer.

METHODS

This is a retrospective study carried out on patients who underwent urgent colonic resection for complicated cancer (occlusion, perforation, bleeding, sepsis). We collected clinical, pathological and follow-up data of 320 patients. Two hundred two patients met the inclusion criteria and were distributed into three groups according to parameter N of TNM, LNR and LODDS. Survival analysis was performed by Kaplan-Meier curves, investigating both overall survival (OS) and disease-free survival (DFS).

RESULTS

The median number of harvested lymph nodes was 17. In 78.71% (n = 159) of cases, at least 12 lymph nodes were examined. Regarding OS, significant differences from survival curves emerged for ASA score, surgical indication, tumour grading, T parameter, tumour stage, N parameter, LNR and LODDS. In multivariate analysis, only LODDS was found to be an independent prognostic factor. Concerning DFS, we found significant differences between survival curves of sex, surgical indication, T parameter, tumour stage, N parameter, LNR and LODDS, but none of these confirmed its prognostic power in multivariate analysis.

CONCLUSIONS

We found that N, LNR and LODDS are all related to 5-year OS and DFS with statistical significance, but only LODDS was found to be an independent prognostic factor for OS in multivariate analysis.

Factors influencing the number of retrieved lymph nodes after colorectal resection: a retrospective study from a single institute

Accurate diagnosis of lymph node (LN) metastasis is important to determine the staging and consequent treatment of resected colorectal cancer. Therefore, factors influencing the number of retrieved LNs were explored. This study included 400 patients that underwent surgical resection for Stage 0-III colorectal cancer from 2009 to 2014 in Kochi Medical School. In all cases, surgeons retrieved the LNs within the resected mesentery immediately after the operation without fixation. Age, gender, body mass index (BMI), American Association Anesthesiologist (ASA) scores, tumor locations, maximum tumor diameters, nodal status, and pathological tumor types were extracted as patient and tumor factors. The extent of LN dissection and surgical approaches (laparoscopic or laparotomy) were extracted as operative factors. Multivariate regression analysis was performed to identify independent predictive factors for LN number retrieved, after potential influential factors were explored by univariate analysis. As results, we found that the median number of retrieved LNs was 13, ranging from 1 to 50. Approximately 60% of the patients thus received an adequate examination (LN number of 12 or more). Multivariate analysis using the remaining factors of univariate analysis identified BMI, tumor diameter, nodal status, and extent of dissection as independent predictive factors for the number of retrieved LNs (P < 0.05). If any or all these factors are present, a vigorous search for LNs using additional measures, such as visual enhancement and fat dissolution method, should be considered.