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

True significance of the number of retrieved lymph nodes in stage II colon cancer resected by minimally invasive surgery: Influence of tumor sidedness

BACKGROUND

In patients with stage II colon cancer (CC) undergoing minimally invasive surgery, the association between the clinical significance of lymph node yield and tumor localization remains unknown. We aimed to determine the optimal number of lymph nodes to be retrieved based on tumor localization in patients with stage II CC undergoing minimally invasive surgery.

METHODS

This was a multicenter retrospective study. Overall, 263 patients with stage II CC who underwent laparoscopic surgery between January 1, 2008 and December 31 were enrolled. The primary outcome was the optimal number of lymph nodes retrieved based on tumor localization.

RESULTS

The median number of retrieved lymph nodes was 30 and 26 in the right-(n = 125) and left-sided (n = 138) CC groups, respectively (p = .0007). Inadequate dissection (<12 nodes) occurred in 4.2% of patients: 1.6% in the right-sided CC group and 6.5% in the left-sided CC group. Multivariate Cox regression analysis showed a decreasing trend in adjusted hazard ratios with increasing nodes, with an optimal cutoff of 15 lymph nodes in the left-sided CC group (adjusted hazard ratio, 5.868; 95% confidence interval, 1.247-27.62; p = .02). Lymph node yield was not independently associated with survival in the right-sided CC group.

CONCLUSIONS

For patients with left-sided stage II CC undergoing laparoscopic surgery, aiming for at least 15 retrieved lymph nodes may be optimal for accurate staging and prognostic assessment. The optimal lymph node yield likely varies based on tumor location, requiring further investigation in right-sided CC.

Prognostic and predictive value of examined lymph node count in stage III colorectal cancer: a population based study

BACKGROUND

The role of tumor-draining lymph nodes in the progression of malignant tumors, including stage III colorectal cancer (CRC), is critical. However, the prognostic and predictive value of the number of examined lymph nodes (ELNs) are not fully understood.

METHODS

This population-based study retrospectively analyzed data from 106,843 patients with stage III CRC who underwent surgical treatment and registered in three databases from 2004 to 2021. The Surveillance, Epidemiology, and End Results (SEER) cohort was divided using into training and test cohorts at a ratio of 3:2. We employed restricted cubic spline (RCS) curves to explore nonlinear relationships between overall survival (OS) and ELNs counts and performed Cox regression to evaluate hazard ratios across different ELNs count subtypes. Additional validation cohorts were utilized from the First Affiliated Hospital, Sun Yat-sen University and The Cancer Genome Atlas (TCGA) under the same criteria. Outcomes measured included OS, cancer-specific survival (CSS), and progression-free survival (PFS). Molecular analyses involved differential gene expression using the "limma" package and immune profiling through CIBERSORT. Tissue microarray slides and multiplex immunofluorescence (MIF) were used to assess protein expression and immune cell infiltration.

RESULTS

Patients with higher ELNs counts (≥ 17) demonstrated significantly better long-term survival outcomes across all cohorts. Enhanced OS, CSS, and PFS were notably evident in the LN-ELN group compared to those with fewer ELNs. Cox regression models underscored the prognostic value of higher ELNs counts across different patient subgroups by age, sex, tumor differentiation, and TNM stages. Subtype analysis based on ELNs count revealed a marked survival benefit in patients treated with adjuvant chemotherapy in the medium and large ELNs counts (≥ 12), whereas those with fewer ELNs showed negligible benefits. RNA sequencing and MIF indicated elevated immune activation in the LN-ELN group, characterized by increased CD3+, CD4+, and CD8 + T cells within the tumor microenvironment.

CONCLUSIONS

The number of ELNs independently predicts survival and the immunological landscape at the tumor site in stage III CRC, underscoring its dual prognostic and predictive value.

Extended procedure has no oncological benefits over segmental resection in the treatment of non-metastatic splenic flexure colon cancer, a population-based cohort study and a single center's decade-long experience

To compare the oncological survival outcome between extended resections (ER) and segmental resection (SR) for non-metastatic splenic flexure tumors. A total of 10,063 splenic flexure colon cancers patients who underwent ER (n = 5546) or SR (n = 4517) from 2010 to 2018 were included from the Surveillance, Epidemiology, and End Results (SEER)-registered database. Additionally, we included 135 patients from our center who underwent ER (n = 54) or SR (n = 81) between 2011 and 2021. Survival rates were compared between groups. To reduce the inherent bias of retrospective studies, propensity score matching (PSM) analysis was performed. In the SEER database, patients in the ER group exhibited higher pT stage, pN stage, larger tumor size, and elevated rates of CEA level, perineural invasion, and tumor deposits compared to those in the SR group (each P < 0.05). The 5-year cancer-specific survival (CSS) rate was slightly lower in the ER group than in the SR group (79.2% vs. 81.6%, P = 0.002), while the 5-year overall survival (OS) rates were comparable between the two groups (66.2% vs. 66.9%, P = 0.513). After performing PSM, both the 5-year CSS and 5-year OS rates were comparable between the ER and SR groups (5-year CSS: 84.9% vs. 83.0%, P = 0.577; 5-year OS: 70.6% vs. 66.0%, P = 0.415). These findings were consistent in the subgroup analysis that included only patients with stage III disease or tumor size ≥ 7 cm. Furthermore, although the number of harvested lymph nodes was higher in the ER group compared to the SR group (14.4 vs. 12.7, P < 0.001), the number of invaded lymph nodes remained similar between the two groups (0.5 vs. 0.5, P = 0.90). Similarly, our center's data revealed comparable 3-year OS and 3-year disease-free survival (DFS) rates between the two groups. ER have no significant oncological benefits over SR in the treatment of non-metastatic splenic flexure colon cancer, even for locally advanced cases.

Standardization of Colon Resection for Cancer: An Overview of the American College of Surgeons Commission on Cancer Standard 5.6

The purpose of this editorial is to review the American College of Surgeons Commission on Cancer Standard 5.6, which pertains to curative intent colon resections performed for cancer. We first provide a broad overview of the Operative Standard, followed by the underlying rationale, technical components, and documentation requirements.

Enlarged tumour-draining lymph node with immune-activated profile predict favourable survival in non-metastatic colorectal cancer

BACKGROUND

The tumour-draining lymph node (TDLN) plays a pivotal role in the suppression of malignant tumour, however, the immunological profile and prognostic differences between large TDLN (L-TDLN) and small TDLN (S-TDLN) in colorectal cancer (CRC) remain unclear.

METHODS

We conducted a study using data from the Chinese National Cancer Center (CNCC) database, identifying 837 CRC patients with non-metastatic TDLN, and categorised them into L-TDLN and S-TDLN groups. The long-term survival outcomes and adjuvant therapy efficacy were compared between the two groups. Furthermore, we evaluated the differences in immune activation status and immune cell subsets between patients in L-TDLN and S-TDLN groups by RNA sequencing and immunohistochemical (IHC) staining.

RESULTS

Patients with L-TDLN demonstrated better long-term outcomes compared to those with S-TDLN. Among patients with L-TDLN, there was no significant difference in long-term outcomes between those who received adjuvant chemotherapy and those who did not. The RNA sequencing data revealed a wealth of immune-activating pathways explored in L-TDLN. Furthermore, IHC analysis demonstrated higher numbers of CD3+ and CD8 + T cells in L-TDLN and the corresponding CRC lesions, as compared to patients with S-TDLN.

CONCLUSION

Enlarged TDLN exhibited an activated anti-tumour immune profile and may serve as an indicator for favourable survival in non-metastatic CRC.

Size and number of lymph nodes were risk factors of recurrence in stage II colorectal cancer

BACKGROUND

Size and number of lymph nodes (LNs) were reported to be associated with the prognosis of stage II colorectal cancer (CRC). The purpose of this study was to determine the prognostic role of the size of LNs (SLNs) measured by computer tomography (CT) and the number of retrieved LNs (NLNs) in the relapse-free survival (RFS) and overall survival (OS) among stage II CRC patients.

METHODS

Consecutive patients diagnosed with stage II CRC at Fudan University Shanghai Cancer Center (FUSCC) from January 2011 to December 2015 were reviewed, and 351 patients were randomly divided into two cohorts for cross-validation. The optimal cut-off values were obtained using X-tile program. Kaplan-Meier curves and Cox regression analyses were conducted for the two cohorts.

RESULTS

Data from 351 stage II CRC patients were analyzed. The cut-off values for SLNs and NLNs were 5.8 mm and 22, respectively, determined by the X-tile in the training cohort. In the validation cohort, Kaplan-Meier curves demonstrated SLNs (P = 0.0034) and NLNs (P = 0.0451) were positively correlated with RFS but not with OS. The median follow-up time in the training cohort and the validation cohort were 60.8 months and 61.0 months respectively. Univariate and multivariate analysis revealed that both SLNs (training cohort: Hazard Ratio (HR) = 2.361, 95% Confidence interval (CI): 1.044-5.338, P = 0.039; validation cohort: HR = 2.979, 95%CI: 1.435-5.184, P = 0.003) and NLNs (training cohort: HR = 0.335, 95%CI: 0.113-0.994, P = 0.049; validation cohort: HR = 0.375, 95%CI: 0.156-0.900, P = 0.021) were independent prognostic factors for RFS whereas not for OS.

CONCLUSION

SLNs and NLNs are independent prognostic factors for patients with stage II CRC. Patients with SLNs > 5.8 mm and NLNs ≤ 22 are apt to have higher risk of recurrence.

Radiological lymph-node size improves the prognostic value of systemic inflammation index in rectal cancer with pathologically negative nodes

BACKGROUND

The relationship between the radiological lymph node (rLN) size and survival outcome in node-negative rectal cancer is still uncertain. In this study, we aimed to explore the role of enlarged rLN in predicting the survival of node-negative rectal cancers.

METHODS

We retrospectively reviewed the records of 722 node-negative rectal cancer who underwent curative resection. Factors associated with DFS (disease-free survival) and CSS (cancer-specific survival) were assessed with univariate and multivariate analysis. Survival analysis was performed according to presence with or without enlarged rLN. Combining rLN with NLR as a new index-inflammation immune score (IIS) for predicting survival. Comparing different models to assess the predictive powers.

RESULTS

A total of 119 patients had tumor recurrence and 73 patients died due to cancer. Patients with enlarged rLN (≥5 mm) was significantly associated with better DFS (HR:0.517, 95%CI:0.339-0.787, p = 0.002) and CSS (HR:0.43, 95%CI:0.242-0.763, p = 0.004). The risk factors of recurrence were rLN, neutrophil-lymphocyte ratio (NLR), CEA level, and distance from the anal verge. The risk of recurrence increased by 1.88- and 2.83-fold for the high score in IIS compared with the low and intermediate score group (All p < 0.001). Similarly, the high score in IIS also increased the risk of cancer-specific death. In the model comparison, the AIC and LR were improved by including the rLN into the NLR model for DFS and CSS prediction (All p < 0.05).

CONCLUSIONS

Node-negative rectal cancer patients with enlarged rLN had a better survival outcome. IIS might be a more comprehensive and complete inflammation immune index for survival prediction.

The effect of preoperative endoscopic tattooing using India ink on lymph node yield in laparoscopic colectomy for stage I right-sided colon cancer

PURPOSE

The purpose of this study is to evaluate the effect of preoperative endoscopic tattooing using India ink (ETI) on the number of retrieved lymph nodes (LNs) dissected during laparoscopic surgery for stage I right-sided colon cancer (RCC).

METHODS

This single-center, retrospective study included stage I RCC patients who underwent laparoscopic surgery between January 2010 and December 2021. The clinicopathological background and number of LNs retrieved were compared between patients managed with and without ETI. A multiple linear regression analysis was used to examine the effect of independent variables on the LN yield.

RESULTS

A total of 169 patients were enrolled. Of these, 89 patients (52.7%) were classified into the ETI group, and 80 (47.3%) were classified into the no-ETI group. There were no significant differences in age, sex, body mass index, or tumor progression between the two groups. A univariate analysis showed that the number of LNs retrieved was significantly higher in female (26 vs. 24, p = 0.026), with tumor localization in the ascending or transverse colon (20 in the cecum, 26 in the ascending colon, 27 in the transverse colon, p < 0.001), and with preoperative ETI (28 vs. 21, p < 0.001). In a multivariate linear regression analysis, female sex (p = 0.0011), D3 lymphadenectomy (p = 0.046), and preoperative ETI (p = 0.012) were independently associated with the LN yield.

CONCLUSION

In laparoscopic surgery for stage I RCC, preoperative ETI increased the number of LNs retrieved and allowed for appropriate staging.

Development and validation of the novel subclassification of pN3 for patients with esophageal cancer

Background

Patients with stage pN3 esophageal cancer (EC) have a large number of metastatic lymph nodes (mLNs) and have poor prognosis. This study was to elucidate whether subclassification of pN3 according to the number of mLNs could improve the discrimination ability of EC patients.

Methods

This study retrospectively analyzed patients with pN3 EC from the Surveillance, Epidemiology, and End Results (SEER) database as a training cohort and SEER validation cohort. Patients with pN3 esophageal cancer from the Affiliated Cancer Hospital of Harbin Medical University were used as the validation cohort. The optimal cutoff value of mLNs was identified using the X-tile software, and group pN3 into pN3-I and pN3-II based on mLNs. Kaplan-Meier method and log-rank test were used to analyze the disease-specific survival (DSS). The Cox proportional hazards regression analysis was used to identify the independent prognostic factors.

Results

For the training cohort, patients with 7 to 9 mLNs were categorized as pN3-I, while those with more than 9 mLNs were categorized as pN3-II. There were 183 (53.8%) pN3-I and 157 (46.2%) pN3-II. The 5-year DSS rates of pN3-I and pN3-II in the training cohort were 11.7% and 5.2% (P=0.033), and the pN3 subclassification was an independent risk factor associated with patient prognosis. More RLNs may not improve patient prognosis, but the use of mLNs/RLNs is effective in predicting patient prognosis. Furthermore, the pN3 subclassification was well validated in the validation cohort.

Conclusion

Subclassification of pN3 can better distinguish survival differences in EC patients.

Survival Contradiction in Stage II, IIIA, And IIIB Colon Cancer: A Surveillance, Epidemiology, and End Result-Based Analysis

There exists an inconsistency between stage and survival in the current American Joint Committee on Cancer (AJCC) staging system for colon cancer. In this study, we compared the clinicopathological characteristics and prognosis of colon cancer patients with stage II, IIIA, and IIIB disease based on the surveillance, epidemiology, and end results (SEER) database. Kaplan-Meier analysis was used to generate overall survival (OS) and cancer-specific survival (CSS) curves. The Cox regression was employed to identify risk factors. The competing risk model was completed by the cumulative incidence function and Gray's test. In the final population of 31,361 colon cancer patients, Kaplan-Meier curve analysis showed that stage IIIA had the highest OS and CSS, followed by stage IIA and IIIB, and IIB and IIC showed the worst OS and CSS. In the Cox model, the stage was proven to be an independent prognostic factor. In the competing risk model, stage IIIA colon cancer patients had the lowest 5-year cancer-specific death rate in stages II, IIIA, and IIIB. In conclusion, the prognosis of colon cancer patients in stage IIA was worse than that of patients in stage IIIA, while the survival rate of stage IIB and IIC was lower than that of stage IIIB.

Retrospective Cohort Analysis of the Effect of Age on Lymph Node Harvest, Positivity, and Ratio in Colorectal Cancer

Introduction: Colon cancer among young patients has increased in incidence and mortality over the past decade. Our objective was to determine if age-related differences exist for total positive nodes (TPN), total lymph node harvest (TLH), and lymph node ratio (LNR). Material and Methods: A retrospective review of stage III surgically resected colorectal cancer patient data in the National Cancer Database (2004−2016) was performed, reviewing TPN, TLH, and LNR (TPN/TLH). Results: Unadjusted analyses suggested significantly higher levels of TLH and TPN (p < 0.0001) in younger patients, while LNR did not differ by age group. On adjusted analysis, TLH remained higher in younger patients (<35 years 1.56 (CI 95 1.54, 1.59)). The age-related effect was less pronounced for LNR (<35 years 1.16 (CI 95 1.13, 1.2)). Conclusion: Younger patients have increased TLH, even after adjusting for known confounders, while age does not have a strong independent impact on LNR.

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

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

Lymph Nodes as Anti-Tumor Immunotherapeutic Tools: Intranodal-Tumor-Specific Antigen-Pulsed Dendritic Cell Vaccine Immunotherapy

Simple Summary

In the field of cancer therapy, lymph nodes are important not only as targets for metastases resection but also as prudent target organs for cancer immunotherapy. Lymph nodes comprise a complete structure for the accumulation of a large number of T cells and their distribution throughout the body after antigen presentation and activation of dendritic cells. This review highlights current topics on the importance of lymph node structure in antitumor immunotherapy and intranodal-antigen-presenting mature dendritic cell vaccine therapy. We also discuss the rationale behind intranodal injection methods and their applications in neoantigen vaccine therapy, a new cancer immunotherapy.

Abstract

Hundreds of lymph nodes (LNs) are scattered throughout the body. Although each LN is small, it represents a complete immune organ that contains almost all types of immunocompetent and stromal cells functioning as scaffolds. In this review, we highlight the importance of LNs in cancer immunotherapy. First, we review recent reports on structural and functional properties of LNs as sites for antitumor immunity and discuss their therapeutic utility in tumor immunotherapy. Second, we discuss the rationale and background of ultrasound (US)-guided intranodal injection methods. In addition, we review intranodal administration therapy of tumor-specific-antigen-pulsed matured dendritic cells (DCs), including neoantigen-pulsed vaccines.

Analysis of the risk factor of insufficient examined lymph nodes in stage II colon cancer from the perspective of stage migration: A retrospective study combined with external validation

BACKGROUND

An insufficient examined lymph node (ELN) count is a high risk factor for recurrence in patients with stage II colon cancer (CC). This study aimed to explore this risk factor in relation to stage migration.

METHODS

We screened 18,544 patients with stage II (pT3/4N0M0) and IIIB (pT3/4N1M0) CC diagnosed after radical resection from 2010 to 2015, using the National Cancer Institute Surveillance, Epidemiology, and End Results database. Propensity score matching was used to balance confounding factors for short-term and long-term survival, and survival analysis was carried out using the Kaplan-Meier method and log-rank test. The optimal cutoff for the number of ELNs in patients with stage II CC was determined using X-tile software. Independent prognostic factors were screened using Cox proportional hazards regression analysis. Finally, the results were externally validated in 318 patients with stage Ⅱ and ⅢB CC in our hospital from 2013 to 2015.

RESULTS

The best cutoff value for the number of ELNs in patients with stage II CC was 14. Multivariate analysis identified age, grade, histology, tumor size, T stage, N stage, ELN count, and chemotherapy as independent prognostic factors, and the Akaike and Bayesian information criteria values for the prognostic value of ELN count were relatively small. Patients with stage II CC with <15 ELNs had similar prognoses to patients with stage ⅢB CC (P = 0.939). Subgroup analysis and external validation yielded similar results.

CONCLUSION

Patients with stage II CC should be considered as stage ⅢB if the ELN count is insufficient.

The importance of MRI for rectal cancer evaluation

Magnetic resonance imaging (MRI) has gained increasing importance in the management of rectal cancer over the last two decades. The role of MRI in patients with rectal cancer has expanded beyond the tumor-node-metastasis (TNM) system in both staging and restaging scenarios and has contributed to identifying "high" and "low" risk features that can be used to tailor and personalize patient treatment; for instance, selecting the patients for neoadjuvant chemoradiation (NCRT) before the total mesorectal excision (TME) surgery based on risk of recurrence. Among those features, the status of the circumferential resection margin (CRM), extramural vascular invasion (EMVI), and tumor deposits (TD) have stood out. Moreover, MRI also has played a role in surgical planning, especially when the tumor is located in the low rectum, when the relationship between tumor and the anal canal is important to choose the best surgical approach, and in cases of locally advanced or recurrent tumors invading adjacent pelvic organs that may require more complex surgeries such as pelvic exenteration. As approaches using organ preservation emerge, including transanal local excision and "watch-and-wait", MRI may help in the patient selection for those treatments, follow up, and detection of tumor regrowth. Additionally, potential MRI-based prognostic and predictive biomarkers, such as quantitative and semi-quantitative metrics derived from functional sequences like diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE), and radiomics, are under investigation. This review provides an overview of the current role of MRI in rectal cancer in staging and restaging and highlights the main areas under investigation and future perspectives.

In-House Validated Map of Lymph Node Stations in a Prospective Cohort of Colorectal Cancer: A Tool for a Better Preoperative Staging

Preoperative staging of colorectal cancer (CRC) based on imaging techniques such as computed tomography (CT) or magnetic resonance imaging (MRI) is crucial for identification and then removal of the positive lymph nodes (LNs). The aim of this study was to evaluate the correlation between preoperatively seen morphologic criteria (number, size, shape, structure, borders, or enhancement patterns) and histopathological features of LNs using an in-house validated map of nodal stations. A total of 112 patients with CRC that underwent surgery were preoperatively evaluated by CT scans. The locoregional, intermediate, and central LNs were CT-mapped and then removed during open laparotomy and examined under microscope. The analysis of correlations was interpreted using the suspicious-to-positive ratio (SPR) parameter. The greatest correlation was found in tumors located in the sigmoid colon, descending colon and middle rectum; SPR value was 1.12, 1.18, and 1.26, respectively. SPR proved to be 0.59 for cases of the transverse colon. Regarding the enhancement type, the dotted pattern was mostly correlated with metastatic LNs (OR: 7.84; p < 0.0001), while the homogenous pattern proved a reliable indicator of nonmetastatic LNs (OR: 1.99; p < 0.05). A total of 1809 LNs were harvested, with a median value of 15 ± 1.34 LNs/case. Transdisciplinary approach of CRC focused on pre-, intra-, and postoperatively mapping of LNs might increase the accuracy of detecting metastasized nodes for tumors of the distal colon and middle rectum but not for those of the transverse colon. In addition to morphologic criteria, the enhancement pattern of LNs can be used as a predictor of nodal involvement improving the CT-based preoperative staging.

Magnetic resonance imaging-radiomics evaluation of response to chemotherapy for synchronous liver metastasis of colorectal cancer

BACKGROUND

Synchronous liver metastasis (SLM) is an indicator of poor prognosis for colorectal cancer (CRC). Nearly 50% of CRC patients develop hepatic metastasis, with 15%-25% of them presenting with SLM. The evaluation of SLM in CRC is crucial for precise and personalized treatment. It is beneficial to detect its response to chemotherapy and choose an optimal treatment method.

AIM

To construct prediction models based on magnetic resonance imaging (MRI)-radiomics and clinical parameters to evaluate the chemotherapy response in SLM of CRC.

METHODS

A total of 102 CRC patients with 223 SLM lesions were identified and divided into disease response (DR) and disease non-response (non-DR) to chemotherapy. After standardizing the MRI images, the volume of interest was delineated and radiomics features were calculated. The MRI-radiomics logistic model was constructed after methods of variance/Mann-Whitney U test, correlation analysis, and least absolute shrinkage and selection operator in feature selecting. The radiomics score was calculated. The receiver operating characteristics curves by the DeLong test were analyzed with MedCalc software to compare the validity of all models. Additionally, the area under curves (AUCs) of DWI, T2WI, and portal phase of contrast-enhanced sequences radiomics model (Ra-DWI, Ra-T2WI, and Ra-portal phase of contrast-enhanced sequences) were calculated. The radiomics-clinical nomogram was generated by combining radiomics features and clinical characteristics of CA19-9 and clinical N staging.

RESULTS

The AUCs of the MRI-radiomics model were 0.733 and 0.753 for the training (156 lesions with 68 non-DR and 88 DR) and the validation (67 lesions with 29 non-DR and 38 DR) set, respectively. Additionally, the AUCs of the training and the validation set of Ra-DWI were higher than those of Ra-T2WI and Ra-portal phase of contrast-enhanced sequences (training set: 0.652 vs 0.628 and 0.633, validation set: 0.661 vs 0.575 and 0.543). After chemotherapy, the top four of twelve delta-radiomics features of Ra-DWI in the DR group belonged to gray-level run-length matrices radiomics parameters. The radiomics-clinical nomogram containing radiomics score, CA19-9, and clinical N staging was built. This radiomics-clinical nomogram can effectively discriminate the patients with DR from non-DR with a higher AUC of 0.809 (95% confidence interval: 0.751-0.858).

CONCLUSION

MRI-radiomics is conducive to predict chemotherapeutic response in SLM patients of CRC. The radiomics-clinical nomogram, involving radiomics score, CA19-9, and clinical N staging is more effective in predicting chemotherapeutic response.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Importance of lymph node immune responses in MSI-H/dMMR colorectal cancer

Patients with colorectal cancers (CRCs) generally exhibit improved survival through intensive lymph node (LN) dissection. However, recent progress in cancer immunotherapy revisits the potential importance of regional LNs, where T cells are primed to attack tumor cells. To elucidate the role of regional LN, we investigated the immunological status of nonmetastatic regional LN lymphocytes (LNLs) in comparison with those of the tumor microenvironment (tumor-infiltrating lymphocytes; TILs) using flow cytometry and next-generation sequencing. LNLs comprised an intermediate level of the effector T cell population between peripheral blood lymphocytes (PBLs) and TILs. Significant overlap of the T cell receptor (TCR) repertoire was observed in microsatellite instability–high/mismatch repair–deficient (MSI-H/dMMR) CRCs with high tumor mutation burden (TMB), although limited TCRs were shared between nonmetastatic LNs and primary tumors in microsatellite stable/MMR proficient (MSS/pMMR) CRC patients with low TMB. In line with the overlap of the TCR repertoire, an excessive LN dissection did not provide a positive impact on long-term prognosis in our MSI-H/dMMR CRC cohort (n = 130). We propose that regional LNs play an important role in antitumor immunity, particularly in MSI-H/dMMR CRCs with high TMB, requiring care to be taken regarding excessive nonmetastatic LN dissection in MSI-H/dMMR CRC patients.

Effects of a high body mass index on the short-term outcomes and prognosis after radical gastrectomy

PURPOSE

This study aimed to investigate the effects of a high body mass index (BMI) on the outcomes of radical gastrectomy for gastric cancer.

METHODS

We conducted a retrospective cohort study of 1729 patients with stage I to III gastric cancer who received open radical gastrectomy from February 2003 to August 2011. The patients were divided into 3 groups according to their BMI: a low BMI group (BMI < 18.5 kg/m²), normal BMI group (18.5 ≤ BMI < 25 kg/m²), and high BMI group (BMI ≥ 25 kg/m²).

RESULTS

A total of 871 patients were included in the final analysis, of which the median BMI was 22.7 kg/m² (range 13.6-44.9 kg/m²). A high BMI increased the risk of postoperative intestinal fistula but not the risk of a reduced number of examined lymph nodes or hospital death. Furthermore, a high BMI did not negatively affect the overall survival (OS) of gastric cancer patients.

CONCLUSIONS

A high BMI increased the operative morbidity after radical gastrectomy for gastric cancer. However, a high BMI did not negatively affect the quality of lymphadenectomy or the OS of gastric cancer patients in experienced high-volume centers. A careful approach during operation and meticulous perioperative management are required for gastric cancer patients with a high BMI.

Prognostic impact of tumour sidedness in patients with stage II colon cancer: a single-centre retrospective study

BACKGROUND

The search for high-risk factors in stage II colon cancer (CC) is ongoing and several high-risk factors for stage II CC have been identified; however, the effects of tumour sidedness on prognosis are not clear. This study aims to determine whether tumour sidedness could be identified as another high-risk factor for stage II CC.

METHODS

We retrospectively analysed 189 patients with stage II CC and compared clinicopathological findings and long-term outcomes between the patients with right colonic cancer (RCC) and with left colonic cancer (LCC). Prognostic factors for survival were determined using univariate and Cox proportional regression analyses.

RESULTS

A total of 72 patients were diagnosed with RCC and 117 patients were diagnosed with LCC. Patients with RCC were significantly older (P < 0.001), and the number of harvested lymph nodes was greater in the RCC group (RCC: 25 versus LCC: 19; P = 0.003). The overall survival (OS) was worse in the RCC group than the OS in the LCC group (5-year survival rate - RCC: 81.3% versus LCC: 90.4%; P = 0.025). Cox proportional regression analysis showed that tumour sidedness was an independent prognostic factor for both OS (hazard ratio (HR) 3.78, 95% confidence interval (CI) 1.61-8.85, P = 0.022) and DFS (HR 2.58, 95% CI 1.33-4.99, P = 0.005).

CONCLUSION

Patients with RCC have more negative prognostic factors and worse long-term outcomes than those with LCC in stage II CC. Tumour sidedness is a high-risk factor in stage II CC patients.

Metastasis to lymph nodes around the vascular tie worsens long-term oncological outcomes following complete mesocolic excision and conventional colectomy for right-sided colon cancer

BACKGROUND

Oncologic outcomes after complete mesocolic excision (CME) in colon cancer are under investigation. The aim of our study was to compare CME and conventional colectomy (CC) in terms of pathological and oncological outcomes for right colon cancer and to evaluate the impact of lymph node metastasis around the vascular tie on survival.

METHODS

Consecutive patients with right colon cancer who had CME or CC between January 2011 and August 2018 at two specialized centers in Turkey were included. Statistical analyses were performed with respect to demographic characteristics, operative and pathologic outcomes, harvested and metastatic lymph nodes around the vascular tie (LNVT), recurrences, and survival.

RESULTS

There were 91 patients in the CME group (58 males, mean age 64 ± 16 years) and 192 patients in the CC group (96 males, mean age 66 ± 14 years). The mean number of harvested lymph nodes (CME: 42 ± 15 vs CC: 34 ± 13, p = 0.01) and LNVT were higher in the CME group (CME: 3.2 ± 2.2 vs CC: 2.4 ± 1.6, p = 0.001). LNVT metastases were 7.7% and 8.3% in the CME and CC groups, respectively (p = 0.85). Three-year overall and disease-free survival rates were 96.4% and 90.9% in the CME group and 90.4% and 87.6% in the CC group in stage I-III patients (p > 0.05). In stage III patients, the 3-year overall survival (92.5% vs 63.5%, p = 0.03) and disease-free survival (85.6% vs 52.1%, p = 0.008) were significantly better in LNVT-negative patients than in LNVT-positive patients.

CONCLUSION

LNVT metastasis seems to be the key factor associated with poor disease-free and overall survival in right colon cancer regardless of the radicality of surgery.

Nomogram predicting cancer-specific mortality in early-onset rectal cancer: a competing risk analysis

BACKGROUND

The incidence of rectal cancer has meaningfully increased in young patients. However, quantitative evaluation for the competing data of early-onset rectal cancer is lacking. So, we performed a competing risk analysis to calculate the cumulative incidence of death for patients with early-onset rectal cancer and developed a nomogram to predict the probability of cancer-specific mortality for these patients.

METHODS

We abstracted data of patients with early-onset rectal cancer between 2004 and 2016 by using the Surveillance, Epidemiology, and End Results program database. The cumulative incidence function was used to calculate the crude cancer-specific mortality of early-onset rectal cancer. Fine and Gray's proportional sub-distribution hazard model was adopted to explore the risk factors of cancer-specific death. Then, we establish a nomogram to predict their 3-, 5-, and 10-year probabilities.

RESULTS

We identified 9917 patients with early-onset rectal cancer, and they were randomly divided into training (n = 6941) and validation (n = 2976) cohorts. In the training cohort, the 3-, 5-, and 10-year cumulative incidences of cancer-specific death after diagnosis for early-onset rectal cancer were 11.4%, 19.9%, and 28.8%, respectively. Fine and Gray's model showed that sex, race, marital status, histology, T stage, N stage, M stage, examined lymph nodes, and pretreatment carcinoembryonic antigen were independently associated with cancer-specific mortality. Such factors were selected to develop a prognostic nomogram.

CONCLUSION

The competing risk nomogram has an ideal performance for predictive cancer-specific mortality in early-onset rectal cancer.

Pathways of spread in rectal cancer: a reappraisal of the true routes to distant metastatic disease

Rectal cancer can spread in a number of ways which have been previously recognised and validated as prognostic markers. These routes of spread are not adequately recognised in the stage grouping of the tumour-node-metastasis system, which focuses predominantly on the depth of invasion and nodal status, thus limiting its prognostic accuracy. Tumour spread involving veins occurs in 40% of patients. Venous channels have greater direct access to distant sites by means of a vascular 'anatomical highway'. This rapid spread of tumour cells to distant metastatic sites by veins cannot occur by means of lymph node pathways. Thus, lymph nodes have been overestimated in their importance. Distinction between local tumour spread (lymph node metastases, perineural and lymphatic invasion) and tumour spread mediated by a direct vascular pathway to distant dissemination (extramural venous invasion and tumour deposits) must be made as the implications for prognosis and choice of treatment are not likely to be equal. Improved precision of radiological and pathological assessment is needed to scrutinise and carefully document each route of tumour spread. Only with this accurate information will it be possible to correctly weight each feature and develop a more prognostically accurate staging method that would allow separation of true high- and low-risk groups and subsequent improvements in patient care.

Tumor proportion in colon cancer: results from a semiautomatic image analysis approach

The tumor stroma ratio (TSR) is a promising prognostic biomarker in colon cancer, which could provide additional risk stratification for therapy adaption. The objective of our study was the investigation of the prognostic significance of TSR at different tumor sites in a simple semiautomatic approach with the open-source program ImageJ. We investigated 206 pT3 and pT4 adenocarcinomas of no special type. According to our established thresholds, 31 tumors (15%) were classified as low tumor proportion (TP) (≤ 15% TP), 42 tumors (20%) were classified as high TP (≥ 54% TP), and 133 tumors (65%) were classified as medium TP. High and low TP were associated with an adverse overall survival in comparison to medium TP (p = 0.001 and p = 0.03). Furthermore, the TP was an independent risk factor of occurrence of distant metastasis next to T status, microsatellite status, and tumor budding. The 5-year survival rate was 49% in patients with high TP, 48% in patients with low TP, and 68% in patients with medium TP (p = 0.042, n = 160). Patients with a high TP had less often tumor budding (p = 0.012), lymphovascular invasion (p = 0.049), and less harvested lymph nodes (p = 0.042) in comparison to low TP tumors. The results provide first evidence that a high tumor proportion/low stroma proportion is also associated with an adverse prognosis and that this subgroup might be difficult to identify with other classical histopathologic characteristics that are linked to an adverse prognosis.

How Many Nodes Need to be Removed to Make Esophagectomy an Adequate Cancer Operation, and Does the Number Change When a Patient has Chemoradiotherapy Before Surgery?

INTRODUCTION AND DESIGN

Node dissection during esophagectomy is an important aspect of esophageal cancer staging. Controversy remains as to how many nodes need to be resected in order to properly stage a patient and whether the removal of more nodes carries a stage-independent survival benefit. A review of the literature performed by a group of experts in the subject may help define a minimum accepted number of lymph nodes to be resected in both primary surgery and post-induction therapy scenarios.

RESULTS AND CONCLUSIONS

The existing evidence generally supports the goal of obtaining a minimum of 15 lymph nodes for pathological examination in both primary surgery and post-induction therapy scenarios.

Examining the relationship between lymph node harvest and survival in patients undergoing colectomy for colon adenocarcinoma

BACKGROUND

Current standards for lymph node harvest in colorectal cancer surgery may be inadequate. Higher lymph node yield may improve survival, but the number of lymph nodes needed to optimize survival is unknown. The objective of this study was to examine the relationship between lymph node yield and overall survival in patients undergoing colectomy for nonmetastatic colon adenocarcinoma.

METHODS

The 2010 to 2014 National Cancer Database was queried for patients undergoing colectomy for nonmetastatic colon adenocarcinoma. Adjusted restricted cubic splines were used to model the nonlinear relationship between lymph node harvest and overall survival. Cox proportional hazard determined independent predictors of overall survival.

RESULTS

A total of 261,423 patients were included. Restricted cubic splines demonstrated that the adjusted improvements in overall survival stabilized after 24 nodes. Patients were divided into: <12, 12 to 23, and ≥24 nodes. On survival analysis, patients with ≥24 nodes had better survival across all N stages compared to other groups (P < .001). Lymph node harvest ≥24 nodes was independently associated with improved overall survival compared to 12 to 23 nodes (hazard ratio 0.82; 95% confidence interval, 0.80-0.85).

CONCLUSION

Lymph node harvest ≥24 nodes is associated with improved survival in colorectal cancer patients. These data may provide indirect evidence for a more extensive lymphadenectomy for colon cancer.

Deficient mismatch repair as a prognostic marker in stage II colon cancer patients

BACKGROUND

A number of reports have evaluated the relationship between deficient DNA mismatch repair (dMMR) and colorectal cancer prognosis. Unfortunately, the exact prognostic role of dMMR has not been clearly established due to contradictory results. This study aims to determine the prognostic impact of dMRR in stage II colon cancer patients only. The appropriate identification of high-risk stage II colon cancers is of paramount importance in the selection of patients who may benefit from adjuvant treatment after surgery.

METHODS

Four hundred and fifty-two patients with curative resection of stage II colon cancer were included. Hospital records were used as data source, providing clinical, surgical, pathology, oncology and follow-up information for statistical analysis focusing on overall survival (OS) and time to progression (TTP). Mismatch repair status was determined by immunohistochemistry. Patient survival was followed-up for a mean of 77·35 months.

RESULTS

dMMR was detected in 93 of 452 patients (20·6%). No impact on overall survival (Log-Rank, p = 0·583, 95% CI 0·76-1·67). However, the hazard ratio 0·50 for TTP was highly significant (Log-Rank, p = 0·012, 95% CI 0·28-0·87) in patients with dMMR compared with those with mismatch repair proficient tumours (pMMR).

CONCLUSIONS

Patients with dMMR tumours have a lower risk for recurrence compared to those with pMMR tumours, but this finding did not correlate to better overall survival.

The relation between oncologic outcomes and metastatic lymph node location following laparoscopic resection of stage III colon cancer

PURPOSE

Colon cancers are staged by assessing more than 12 lymph nodes, but there is still a controversy over the number of lymph nodes. Only a few studies of metastatic lymph node position in colon cancer have been published with its significance not completely understood. This study aimed to compare survival rates according to metastatic lymph node position following radical lymph node dissection for stage III colon cancers.

METHODS

This retrospective study evaluated data prospectively collected at a tertiary teaching hospital from 349 patients who underwent laparoscopic colectomy with radical node dissection between December 2009 and December 2014. Lymph nodes were numbered and classified into lymph node metastasis (LNM) groups LNM1, LNM2, and LNM3 and their short- and long-term outcomes were compared.

RESULTS

The LNM1, LNM2, and LNM3 groups included 229, 94, and 26 patients, respectively. Patient characteristics differed by locations (p < 0.001). A mean 34.6 lymph nodes were harvested, and a mean 2.6, 5, and 9 metastatic nodes were identified, respectively (p < 0.001), a finding that is proportional to the cancer stage (tau-b = 0.284, p < 0.001; rho = 0.3, p < 0.001). The 5-year disease-free survival rate did not differ among the three groups; however, the LNM3 group had the poorest overall and cancer-specific survival rates. Risk factors associated with cancer-specific survival rate were identified with neural invasion, poorly differentiated tumors, and the location of pathologic lymph nodes (LNM).

CONCLUSION

Metastatic lymph node location affects oncologic outcomes of stage III colon cancer. The patients for LNM3 metastasis should receive a more aggressive adjuvant treatment.

Immunologic Biomarkers and Biomarkers for Immunotherapies in Gastrointestinal Cancer

Gastrointestinal (GI) cancers contribute significantly to the worldwide cancer burden. Pathologic evaluation is indispensable for the estimation of prognosis and therapeutic strategy. At present, immunotherapies are evolving into efficient therapeutic approaches, which are accompanied by the need for biomarkers to predict therapy response. In colorectal cancers, the only predictive biomarker for Food and Drug Administration-approved immunotherapy is the mismatch repair status. Besides, pathogenic polymerase epsilon mutations, tumor mutational burden, neoantigen load, and features of the immune contexture could soon find their way into clinical routine. Furthermore, in colorectal cancer, the Immunoscore, which is defined by the amount of CD3+ and CD8+ T-cells in the tumor center as well as at the infiltrative margin, might supplement the TNM system in the future (as TNM-Immune). This immunologic biomarker was shown to be impressively prognostic and predictive in colorectal cancer. In conclusion, there is increasing evidence of immunologic as well as predictive biomarkers for immunotherapies in GI cancers. Nevertheless, future progress is necessary for the variety of current advances to be implemented in clinical care.

Biology-Based Surgery: The Extent of Lymphadenectomy in Cancer of the Colon

The progression of colon cancer (CC) involves hematogenous and lymphatic spread to locoregional lymph nodes (LN), distant LN, and metastatic sites including the liver. The biological mechanisms that govern CC progression remain elusive. The Halsted model assumes an orderly, stepwise progression from the primary tumor to nearby nodes, henceforth to anatomically more distant nodes, and ultimately to distant organs. The Fisher model, on the other hand, regards the release of metastatic cells as early and essentially random events. The underlying biology has important implications for the ideal extent of surgery: when the Fisher model is correct, efforts to remove apical (central), extramesenteric, or para-aortic LN are unlikely to affect the oncological outcome. Recent data from phylogenetic studies suggest that cancer cell populations differ genetically among different LN stations and from distant metastases. Circulating tumor cells and other liquid biomarkers can be detected in the circulation of patients with early-stage disease. Local recurrence in CC is uncommon, and it is associated with a high risk of systemic progression and poor survival. Clinical studies comparing standard colectomy with extensive surgery (high ligation of the inferior mesenteric artery, complete mesocolic excision, D3 dissection, and para-aortic or extramesenteric node dissection) show that these techniques increase the LN count, while any beneficial effect on the risk of local recurrence or disease-free survival is at present uncertain due to the lack of controlled trials. Ongoing randomized trials comparing extensive vs. standard surgery for CC will generate important answers.

The Number of Natural Killer Cells in the Largest Diameter Lymph Nodes Is Associated with the Number of Retrieved Lymph Nodes and Lymph Node Size, and Is an Independent Prognostic Factor in Patients with Stage II Colon Cancer

OBJECTIVE

We previously reported that the largest diameter of retrieved lymph nodes (LNs) correlates with the number of LNs and is a prognostic factor in stage II colon cancer. We examine whether T, B, and natural killer (NK) cells in LNs are related to the number of LNs and survival.

METHODS

The subjects comprised 320 patients with stage II colon cancer. An LN with the largest diameter was selected in each patient. The positive area ratios of cells that stained for CD3 and CD20, and the numbers of CD56-positive cells were measured.

RESULTS

The CD3-positive area ratio was 0.39 ± 0.08 and CD20-positive area ratio was 0.42 ± 0.10. The mean number of CD56-positive cells was 19.3 ± 22.7. The area ratios of B cells and T cells and the number of NK cells were significantly related to the sizes of the largest diameter LNs. The number of NK cells significantly correlated with the number of LNs and was an independent prognostic factor. On multivariate analysis, pathological T stage (T4 or T3; HR 4.71; p < 0.001) and the number of CD56-positive cells (high or low; HR 0.22; p < 0.001) were found to be independent prognostic factors.

CONCLUSIONS

The number of NK cells in the largest diameter LNs can most likely be used as a predictor of recurrence.

The prognostic significance of lymph node size in node-positive colon cancer

OBJECTIVES

To (i) show the outcome benefits of enlarged lymph nodes in node-positive colon cancer cases, as it was shown previously in negative node cases; (ii) disprove the stage migration theory and (iii) list the factors affecting lymph node size and yield.

METHODS

A retrospective study including 234 node-positive colon cancer cases was scheduled and performed. All recovered lymph nodes (6969) from 234 cases were microscopically examined in regard to (a) lymph node size (b) presence of metastasis (c) extent of intra-nodal metastasis. On the basis of resulting data, a statistical analysis was performed.

RESULTS

Metastases occurred in all size categories, though more often in larger lymph nodes. Fifty-one percent of all metastasised nodes were 2 to 6 mm in size. Approximately half of all nodes >10 mm were microscopically free of cancer. Cases with a small lymph node metastasis to lymph node size ratio (MSR) had a better prognosis than others: 85 months (95% CI: 72-97) vs. 67 months (95% CI: 47-88), p <0.001 (mean, overall survival). To differentiate between cases with the same ratio but different absolute lymph nodes sizes, we divided the cases into two groups that differed in their number of moderate to large lymph nodes. The group with more moderate to large lymph nodes showed a clear outcome benefit: 104 months (95% CI: 86-122) vs. 66 months (95% CI: 54-77), p = 0.014 (mean, overall survival).

CONCLUSIONS

Metastasised lymph nodes affect all size categories, and large lymph nodes are not always metastasised. The combination of enlarged lymph nodes and a small lymph node metastasis to lymph node size ratio (MSR) is associated with a better prognosis than others. When enlarged lymph nodes were considered as surrogate markers of an effective local immune response due to nodal hyperplasia, the immune system could be seen as the confounder affecting both lymph node size and prognosis. Our results are pointing in this direction and, along with other reasons, are challenging the stage migration theory.

Effect of pathologist's dedication on lymph node detection rate and postoperative survival in colorectal cancer

AIM

As adjuvant chemotherapy in colorectal cancer relies on the identification of lymph node metastases, the pathologist's dedication may have a considerable influence on postoperative survival.

METHOD

The aim of this retrospective study was to assess the impact of the pathologist's dedication on lymph node detection rate and postoperative survival in patients operated on by a single experienced colorectal surgeon within a 5-year period. We assessed 229 patients undergoing total mesorectal excision or complete mesocolic excision by the senior author between 1 January 2009 and 31 December 2013. Pathologists were grouped as 'general pathologist' or 'dedicated pathologist' depending on their dedication/specialization.

RESULTS

Dedicated pathologists found statistically significantly more lymph nodes in colorectal specimens than general pathologists [23 (interquartile range 24) vs 14 (interquartile range 11), respectively; P < 0.001]. The detection rate of ≥ 12 lymph nodes per specimen was significantly higher in the dedicated pathologist group [65/74 (87.8%) vs 105/155 (67.7%); P = 0.016]. However, postoperative survival did not differ in the respective subgroups. In the multivariable analysis by Cox proportional hazard model, International Union against Cancer Stage IV was the only factor associated with decreased disease-specific survival (hazard ratio 28.257; 95% CI 3.850-207.386; P = 0.001).

CONCLUSION

In our centre, the pathologist's dedication has an impact on lymph node detection rate but does not influence postoperative disease-specific survival.

Survival Contradiction Between Stage IIA and Stage IIIA Rectal Cancer: A Retrospective Study

Background: When compared with patients harboring stage IIB and stage IIC disease, those with stage IIIA colorectal cancer have a better prognosis. We aimed to compare the cause-specific survival (CSS) of the patients with stage IIA rectal cancer with that of the patients with stage IIIA rectal cancer.

Methods: Data analyzed about patients with stage IIA and stage IIIA rectal cancer was from the US Surveillance, Epidemiology, and End Results (SEER) database. We then validated the results using data derived from Fudan University Shanghai Cancer Center (FUSCC).

Results: A total of 16,788 patients (13,551 staged IIA and 3,237 staged IIIA) were identified in SEER database. A multivariate analysis manifested that patients with stage IIIA disease were more likely to have a better CSS (HR 0.894, 95% CI 0.816-0.979, p=0.016) compared with patients with stage IIA rectal cancer. In the subgroup of patients whose number of lymph nodes harvested (LNH) <12, multivariate analysis signified that patients with stage IIIA disease were more prone to have favorable CSS (HR 0.805, 95% CI 0.719-0.901, p<0.001) compared with patients with stage IIA rectal cancer. In LNH≥12 subgroup, the Kaplan-Meier analysis revealed no significant difference between patients experiencing stage IIA and IIIA rectal cancer (p=0.618). Validation of data from FUSCC proved that patients with stage IIIA rectal cancer were more inclined to have better CSS (HR 0.407, 95% CI 0.187-0.885, p=0.019) in comparison to those with stage IIA rectal cancer. Specifically, in LNH<12 subgroup, the survival outcomes of stage IIIA patients were significantly better than that of the stage IIA patients (p=0.019), while there was no statistical significance between these two stages in the subgroup of patients with LNH≥12 (p=0.180).

Conclusions: Patients with stage IIA rectal cancer have poorer CSS than patients with stage IIIA rectal cancer, particularly when inadequate lymph nodes are harvested.

A Population-based Study on Lymph Node Retrieval in Patients with Esophageal Cancer: Results from the Dutch Upper Gastrointestinal Cancer Audit

BACKGROUND

For esophageal cancer, the number of retrieved lymph nodes (LNs) is often used as a quality indicator. The aim of this study is to analyze the number of retrieved LNs in The Netherlands, assess factors associated with LN yield, and explore the association with short-term outcomes. This is a population-based study on lymph node retrieval in patients with esophageal cancer, presenting results from the Dutch Upper Gastrointestinal Cancer Audit.

STUDY DESIGN

For this retrospective national cohort study, patients with esophageal carcinoma who underwent esophagectomy between 2011 and 2016 were included. The primary outcome was the number of retrieved LNs. Univariable and multivariable regression analyses were used to test for association with ≥ 15 LNs.

PATIENTS AND RESULTS

3970 patients were included. Between 2011 and 2016, the median number of LNs increased from 15 to 20. Factors independently associated with ≥ 15 LNs were: 0-10 kg preoperative weight loss (versus: unknown weight loss, odds ratio [95% confidence interval]: 0.71 [0.57-0.88]), Charlson score 0 (versus: Charlson score 2: 0.76 [0.63-0.92]), cN2 category (reference: cN0, 1.32 [1.05-1.65]), no neoadjuvant therapy and neoadjuvant chemotherapy (reference: neoadjuvant chemoradiotherapy, 1.73 [1.29-2.32] and 2.15 [1.54-3.01]), minimally invasive transthoracic (reference: open transthoracic, 1.46 [1.15-1.85]), open transthoracic (versus open and minimally invasive transhiatal, 0.29 [0.23-0.36] and 0.43 [0.32-0.59]), hospital volume of 26-50 or > 50 resections/year (reference: 0-25, 1.94 [1.55-2.42] and 3.01 [2.36-3.83]), and year of surgery [reference: 2011, odds ratios (ORs) 1.48, 1.53, 2.28, 2.44, 2.54]. There was no association of ≥ 15 LNs with short-term outcomes.

CONCLUSIONS

The number of LNs retrieved increased between 2011 and 2016. Weight loss, Charlson score, cN category, neoadjuvant therapy, surgical approach, year of resection, and hospital volume were all associated with increased LN yield. Retrieval of ≥ 15 LNs was not associated with increased postoperative morbidity/mortality.

Lymph node retrieval after dissolution of surrounding adipose tissue for pathological examination of colorectal cancer

Examination of >12 lymph nodes (LNs) is important for the diagnostic accuracy of nodal status following resection of colorectal cancer. In the present study, the efficacy of a fat dissolution technique for LN retrieval was evaluated using resected colon and rectum mesentery. First, the resected mesentery was searched for LNs by inspection and palpation immediately after surgery. Subsequently, fat dissolution liquid was applied to the remnant fat and the LN search was repeated. The primary endpoint was whether the second assessment would increase the number of evaluated LNs. Recruitment of 20 patients was planned. The study was conducted after institutional review board approval and written informed consent was obtained. Among 20 participants, 1 patient was excluded because LN dissection was not performed. The median number of LNs identified at the first and second assessments was 13 and 6, respectively, producing a significant increase in total LNs evaluated (13 vs. 20, respectively; P<0.01; paired t-test). One positive node was identified among the additionally identified LNs (0.9%, 1/107). The second assessment increased the number of LNs assessed to >12 in 4 patients, and although staging was not changed, the treatment was potentially altered in 2 stage II patients. The maximum diameter of the additionally obtained LNs was significantly smaller compared with those from the first assessment (4 vs. 7.7 mm, respectively; P<0.01; Wilcoxon signed-rank test). After the fat dissolution technique, the tumor cells were satisfactorily stained by carcinoembryonic antigen and cytokeratin-20. In conclusion, applying fat dissolution liquid to the remnant adipose tissue of the mesentery of the colon and rectum identified additional LNs. This method should be considered when insufficient LNs are identified after conventional LN retrieval.

Assessing the adequacy of lymph node yield for different tumor stages of colon cancer by nodal staging scores

Background

According to the current official guidelines, at least 12 lymph nodes (LNs) are qualified as an adequate sampling for colon cancer patients. However, patients evaluated with less nodes were still common in the United States, and the prevalence of positive nodal disease may be under-estimated because of the false-negative assessment. In this study, we present a statistical model that allows preoperative determination of the minimum number of lymph nodes needed to confirm a node-negative disease with certain confidence.

Methods

Adenocarcinoma colon cancer patients with stage T1-T3, diagnosed between 2004 and 2013, who did not receive neoadjuvant therapies and had at least one lymph node pathologically examined, were extracted from the Surveillance, Epidemiology and End Results (SEER) database. A beta binomial distribution was used to estimate the probability of an occult nodal disease is truly node-negative as a function of total number of LNs examined and T stage.

Results

A total of 125,306 patients met study criteria; and 47,788 of those were node-positive. The probability of falsely identifying a patient as node-negative decreased with an increasing number of nodes examined for each stage, and was estimated to be 72% for T1 and T2 patients with a single node examined and 57% for T3 patients with a single node examined. To confirm an occult nodal disease with 90% confidence, 3, 8, and 24 nodes need to be examined for patients from stage T1, T2, and T3, respectively.

Conclusions

The false-negative rate of diagnosed node negative, together with the minimum number of examined nodes for adequate staging, depend preoperatively on the clinical T stage. Predictive tools can recommend a threshold on the minimum number of examined nodes regarding to the favored level of confidence for each T stage.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3491-2) contains supplementary material, which is available to authorized users.

Population-based study to re-evaluate optimal lymph node yield in colonic cancer

BACKGROUND

It is well established that lymph node (LN) yield in colonic cancer resection has prognostic significance, although optimal numbers are not clear. Here, LN thresholds associated with both LN positivity and survival were evaluated in a single population-based data set.

METHODS

Treatment records were linked to the Ontario Cancer Registry to identify a 25 per cent random sample of all patients with stage II/III colonic cancer between 2002 and 2008. Multivariable regression and Cox models evaluated factors associated with LN positivity and cancer-specific survival (CSS) respectively. Optimal thresholds were obtained using sequential regression analysis.

RESULTS

On adjusted analysis of 5508 eligible patients, younger age (P < 0·001), left-sided tumours (P = 0·003), higher T category (P < 0·001) and greater LN yield (relative risk 0·89, 95 per cent c.i. 0·81 to 0·97; P = 0·007) were associated with a greater likelihood of LN positivity. Regression analyses with multiple thresholds suggested no substantial increase in LN positivity beyond 12-14 LNs. Cox analysis of stage II disease showed that lower LN yield was associated with a significant increase in the risk of death from cancer (CSS hazard ratio range 1·55-1·74; P < 0·001) compared with a greater LN yield, with no significant survival benefit beyond a yield of 20 LNs. Similarly, for stage III disease, a lower LN yield was associated with an increase in the risk of death from cancer (CSS hazard ratio range 1·49-2·20; P < 0·001) versus a large LN yield. In stage III disease, there was no observed LN threshold for survival benefit in the data set.

CONCLUSION

There is incongruity in the optimal LN evaluation for colonic cancer. Although the historically stated threshold of 12 LNs may ensure accurate staging in colonic cancer, thresholds for optimal survival are associated with far greater yields.

A nomogram improves AJCC stages for colorectal cancers by introducing CEA, modified lymph node ratio and negative lymph node count

Lymph node stages (pN stages) are primary contributors to survival heterogeneity of the 7^th AJCC staging system for colorectal cancer (CRC), indicating spaces for modifications. To implement the modifications, we selected eligible CRC patients from the Surveillance Epidemiology and End Results (SEER) database as participants in a training (n = 6675) and a test cohort (n = 6760), and verified tumor deposits to be metastatic lymph nodes to derive modified lymph node count (mLNC), lymph node ratio (mLNR), and positive lymph node count (mPLNC). After multivariate Cox regression analyses with forward stepwise elimination of the mLNC and mPLNC for the training cohort, a nomogram was constructed to predict overall survival (OS) via incorporating preoperative carcinoembryonic antigen, pT stages, negative lymph node count, mLNR and metastasis. Internal validations of the nomogram showed concordance indexes (c-index) of 0.750 (95% CI, 0.736-0.764) and 0.749 before and after corrections for overfitting. Serial performance evaluations indicated that the nomogram outperformed the AJCC stages (c-index = 0.725) with increased accuracy, net benefits, risk assessment ability, but comparable complexity and clinical validity. All the results were reproducible in the test cohort. In summary, the proposed nomogram may serve as an alternative to the AJCC stages. However, validations with longer follow-up periods are required.

Analysis of histological and immunological parameters of metastatic lymph nodes from colon cancer patients reveals that T-helper 1 type immune response is associated with improved overall survival

Lymph node (LN) involvement in colonic carcinoma (CC) is a grave prognostic sign and mandates the addition of adjuvant treatment. However, in light of the histological variability and outcomes observed, we hypothesized that patients with LN metastases (LNM) comprise different subgroups.We retrospectively analyzed the histological sections of 82 patients with CC and LNM. We studied various histological parameters (such as tumor grade, desmoplasia, and preservation of LN architecture) as well as the prevalence of specific peritumoral immune cells (CD8, CD20, T-bet, and GATA-3). We correlated the histological and immunological data to patient outcome.Tumor grade was a significant prognostic factor even in patients with LNM. So was the number of LN involved (N1/N2 stage). From the morphological parameters tested (LN extracapsular invasion, desmoplasia in LN, LN architecture preservation, and mode of metastases distribution), none was found to be significantly associated with overall survival (OS). The mean OS of CD8 low patients was 66.6 ± 6.25 versus 71.4 ± 5.1 months for CD8 high patients (P = 0.79). However, T-helper (Th) 1 immune response skewing (measured by Th1/Th2 ratio >1) was significantly associated with improved OS. For patients with low ratio, the median OS was 35.5 ± 5 versus 83.5 months for patients with high Th1/Th2 ratio (P = 0.001).The histological presentation of LNM does not entail specific prognostic information. However, the finding of Th1 immune response in LN signifies a protective immune response. Future studies should be carried to verify this marker and develop a strategy that augments this immune response during subsequent adjuvant treatment.

A new simple morphology-based risk score is prognostic in stage I/II colon cancers

A portion of stage I/II colon cancers (10-20%) exhibit an adverse clinical course. The administration of adjuvant chemotherapy is recommended only in certain high-risk situations. However, these risk factors recently failed to predict benefit from adjuvant therapy. We composed a new morphology-based risk score that includes pT1/2 versus 3/4 stage, vascular or lymphovascular invasion, invasion type according to Jass, tumor budding and paucity (less than two) of lymph nodes larger than 5 mm. The occurrence of each of these factors accounts for one point in the score (Range 0-5). This score was evaluated in a retrospective study that included 301 cases. The overall survival differed significantly between the three groups with median survival times of 103, 90, and 48 months, respectively. Multivariable analysis revealed morphology-based risk-high risk and low risk-as the sole independent factors for the prediction of death. Morphology-based risk scoring was superior to microsatellite status and NCCN risk stratification. This method identifies a group of patients that comprises 18% of the stage II cases with an adverse clinical course. Further studies are necessary to confirm its prognostic value and the possible therapeutic consequences.

Clinical Significance of International Union Against Cancer pN Staging and Lymph Node Ratio in Node-Positive Colorectal Cancer after Advanced Lymph Node Dissection

BACKGROUND

Lymph node retrieval in colorectal cancer can be improved by using advanced histopathological techniques like methylene blue-assisted lymph node dissection, which results in a doubling or even tripling of the lymph node count in comparison with conventional lymph node dissection techniques. However, it is not clear whether the established lymph node staging systems are suitable for predicting patients' prognoses under these circumstances.

OBJECTIVE

The aim of this study was to determine whether the current lymph node staging systems are suitable when advanced dissection methods are used.

DESIGN

This is a retrospective cohort study.

SETTING AND PATIENTS

We formed a study group (methylene blue-assisted lymph node dissection) of 293 patients and a control group (conventional lymph node dissection) of 232 patients, each with node-positive cases. Conventional pN staging according to the International Union Against Cancer, seventh edition, and lymph node ratio were applied.

MAIN OUTCOME MEASURES

Overall survival was compared by using the different staging systems in a uni- and multivariable fashion.

RESULTS

The lymph node ratio values were reduced in the advanced methylene blue-assisted lymph node dissection group in comparison with the conventional lymph node dissection group (0.1 vs 0.3, p < 0.001). Although pN staging proved to be reliable, the cutoff values for lymph node ratio staging had to be adapted. The new cutoffs (0.07, 0.15, and 0.34) were prognostic. However, multivariable analysis revealed pN staging and vascular invasion, but not lymph node ratio, as independently prognostic in the methylene blue-assisted lymph node dissection group.

LIMITATIONS

The study group and historical control group are not perfectly balanced because the case number in the stage III subgroup of the control group is small.

CONCLUSIONS

pN staging proved to be a robust prognostic marker in colorectal cancer under the circumstances of improved lymph node harvest. After adaptation of the cutoff values, lymph node ratio is also prognostic but not superior to pN staging.