Lymph node yield in the pathological staging of resected nonmetastatic colon cancer: The more the better?

Number of Lymph Nodes Examined as a Prognosis Factor in Patients With Stage II or III Colon Cancer

BACKGROUND

Lymph node (LN) examination is important for staging colorectal cancer. Examining < 12 LN has been associated with a poor prognosis. However, surgical and pathological advances have led to increase examined LN, necessitating the reassessment of the best cutoff for prognosis.

PATIENTS AND METHODS

We reviewed patients with stage II-III colon cancer from the Yonsei Cancer Center Registry (YCC) database and the Netherlands Cancer Registry (NCR). The optimal LN cutoff was determined by comparison with hazard ratio (HR) in 12 LN. We compared higher vs. lower LN cutoff effects on a 6-year overall survival (OS).

RESULTS

From 2005 to 2015, the proportion with < 12 LN decreased significantly (P < .001). There was no significant association between 6-year OS and LN yield in all stages II-III patients (HR = 1.21, P = .116), stage II (HR = 1.39, P = .068), and stage III (HR = 1.18, P = .297) colon cancer based on the standard 12 LN examined, whereas the 20 LN cutoff examined was associated with a significant increase in 6-year OS in all patients (HR = 1.51, P < .001). Multivariate regression revealed a significant decrease in 6-year OS in stage II (HR = 1.39, P = .026) and stage III (HR = 1.47, P < .001) with < 20 LN yield. In the NCR, < 20 LN was associated with poorer 6-year OS in stage II-III patients (HR = 1.25, P < .001), stage II (HR = 1.43, P < .001), and stage III (HR = 1.13, P = .007).

CONCLUSION

Over the past decade, inadequate LN examinations have significantly decreased. Compared to < 12 LN, < 20 LN examined is more associated with a worse prognosis in patients who underwent surgery.

Preoperative angio-CT colonography improves the quality of lymph node dissection during minimally invasive right hemicolectomy: a propensity score-matched study

BACKGROUND

Minimally invasive right hemicolectomy for cancer with complete mesocolic excision is a difficult procedure to perform. The aim of this single-center prospective study was to evaluate whether preoperative angio-CT colonography (A-CTC) improved the quality of lymph node dissection during this surgery.

METHODS

All patients undergoing elective minimally invasive right hemicolectomy for colon adenocarcinoma with complete mesocolic excision between 01/2020 and 12/2023 have been prospectively included. The primary endpoint was the number of lymph nodes examined in the surgical specimen, including the total number of lymph nodes and the percentage of patients with at least 12 lymph nodes examined. Secondary endpoints included operating time, intraoperative complications, overall postoperative morbidity, and length of hospital stay. A propensity score was constructed with groups matched 3:1 using nearest neighbor matching based on the propensity score.

RESULTS

Of the 161 patients included, 44 had A-CTC (27%) and 117 had conventional CT scans. After propensity score matching, patients in the A-CTC group had significantly more lymph nodes on the surgical specimen (24 vs. 20, p = 0.006) and a better quality of lymph node dissection (≥ 12 examined lymph nodes: 100% vs. 87%, p < 0.001). Median operative times were similar between the two groups (184 vs. 180 min, p = 0.07), but two patients (2%) in the conventional CT group experienced an intraoperative bleeding complication. Postoperative morbidity and length of hospital stay were comparable.

CONCLUSIONS

Preoperative 3D reconstruction of vascular anatomy with A-CTC is useful and improves the quality of lymph node dissection during minimally invasive right hemicolectomy for cancer.

Factors influencing lymph node yield in head and neck squamous cell carcinoma: A scoping review

OBJECTIVES

In head and neck cancer surgery, several studies have demonstrated the prognostic significance of lymph node yield (LNY). To our knowledge, no review has evaluated both the contributing factors to LNY and its impact on survival outcomes across all head and neck squamous cell carcinoma (HNSCC) subsites.

MATERIALS AND METHODS

A scoping review of LNY in HNSCC was conducted according to The Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) framework to answer the following research questions: 1) Which surgeon, pathologist, and patient characteristics influence LNY? 2) Which anatomic subsites does LNY impact survival?

RESULTS

Surgeon experience and variation in pathology protocols and personnel can impact LNY. Extent of nodal dissection, advanced tumor characteristics, and treatment at an academic facility are associated with increased LNY. Patient characteristics such as age <40, male gender, and BMI > 30 are associated with increased LNY. In the oral cavity, LNY > 18 is an independent predictor of improved overall survival (OS), disease free survival (DFS), and disease-specific survival (DSS). In the oropharynx, published studies show mixed results with regards to the impact of LNY on OS, DFS, and DSS. LNY has not been associated with OS or DFS in the larynx, irrespective of nodal threshold.

CONCLUSIONS

Provider and patient characteristics may impact LNY. LNY ≥ 18 is associated with a survival benefit in the oral cavity and HNSCC overall. Further investigation of LNY particularly in prospective clinical trials is required prior to its adoption as a quality metric in HNSCC.

Characterization of the T-cell receptor repertoire associated with lymph node metastasis in colorectal cancer

Purpose

Colorectal cancer (CRC) is a leading cause of cancer-related mortality worldwide, with lymph node (LN) metastasis playing a pivotal role in disease progression. This study aimed to explore the T-cell receptor (TCR) repertoire among CRC patients, distinguishing those with LN metastasis from those without, in order to uncover potential biomarkers for predicting metastasis.

Methods

We analyzed the TCR repertoire in CRC patients with and without LN metastasis. A classification model utilizing random forest analysis was developed to assess the predictive potential of the TCR repertoire.

Results

The findings demonstrated a significant increase in the number of V-J combinations and immune CDR3 sequences in patients with LN metastasis compared to the control group. The classification model achieved high accuracy in differentiating patients with LN metastasis, with AUC values ranging from 0.514 to 0.794. Specific V-J combinations and CDR3 sequences were identified as significant predictors of the model's predictive accuracy.

Conclusion

These results suggest that the TCR repertoire is altered in CRC patients exhibiting LN metastasis, potentially influencing disease progression. This study highlights the importance of TCR repertoire analysis as a non-invasive biomarker for predicting LN metastasis in CRC patients.

Revisiting the survival paradox between stage IIB/C and IIIA colon cancer

Patients with stage IIB/C (T4a-bN0) colon cancer often exhibit worse survival rates compared to those with stage IIIA (T1-2N1, T1N2a) colon cancer. This study re-evaluates the survival paradox using the latest Surveillance, Epidemiology, and End Results (SEER) data (released on April 17, 2024) to inform potential revisions to the staging criteria. Utilizing SEER data with 8th edition TNM staging criteria, 4692 colon cancer patients diagnosed between 2018 and 2021 were analyzed with chi-square test. Cox regression and Kaplan-Meier survival analysis were employed to assess factors associated with cancer-specific survival (CSS) and overall survival (OS). The 3-year CSS rates for stage IIB and IIC were 73.1% and 70.3%, respectively, whereas stage IIIA had a substantially higher CSS rate of 91% (P < 0.001). Similarly, the OS rates were 64.9% and 63.0% for stage IIB and IIC, respectively, compared to 83.1% for stage IIIA (P < 0.001). Multivariate analyses revealed stage IIIA patients had significantly lower risks of cancer-specific mortality (hazard ratio (HR) = 0.374, 95% CI: 0.296-0.473, P < 0.001) and overall mortality (HR = 0.575, 95% CI: 0.483-0.685, P < 0.001) compared to stage IIB patients. The upcoming 9th edition of the AJCC staging system should address this paradox by integrating advanced diagnostic markers and emphasizing the aggressive biology of T4 tumor, providing more accurate prognostic information and guiding more effective treatment strategies for colon cancer patients.

Lymph node harvesting after laparoscopic complete mesocolic excision colectomy in colon cancer with practical application of glacial acid, absolute ethanol, water, and formaldehyde solution: A prospective cohort study

Objectives

Quality of surgery has recently become an essential topic in the prognosis of colon cancer. Complete mesocolic excision for colon cancer has recently gained popularity with high-quality surgery. Patient specimens after complete mesocolic excision with central vessel ligation procedures have an integrity of the mesocolon and the yield of three fields of lymph node harvest. We apply the glacial acid, absolute ethanol, water, and formaldehyde solution to each specimen based on the Japanese classification of lymph node groups and station numbers. We aim to identify the distribution and status of lymph node metastasis according to each tumor site and some pathological characteristics related to this disease.

Methods

A prospective cohort study was performed on 45 laparoscopic complete mesocolic excision surgery patients.

Results

2791 lymph nodes were harvested after complete mesocolic excision surgery. The average number was 62.0 ± 22.3 nodes. The mean tumor size (in the largest dimension) was 4.2 ± 1.8 cm. The average length of the resected bowel segments was 29.1 ± 7.7 cm. There are 63 (2.3%) node metastases in 2791 lymph nodes, in which 17/45 (37.8%) patients had pN(+). The minimum positive node size was 1 mm. The positive pericolic lymph nodes (station 1) accounted for the highest rate, with 53 nodes (1.9%). The number of lymph nodes in young age ⩽60 is more significant than in older. The results were similar, with a more significant node retrieval in the group with a tumor size >4.5 cm and specimen length >25 cm. The number of lymph nodes in lower tumor invasive (pT1,3) was smaller than pT4. Our research shows that the cecum, ascending, and descending colon had greater nodes than others, with a mean number of 78.6, 74.2, and 71.3, respectively.

Conclusions

The metastasis and harvested lymph nodes accounted for the highest rate of colon cancer in station 1 and the lowest rate in station 3. The number of retrieved lymph nodes was significantly associated with tumor location, size, specimen length, and patient age.

Extent of Lymph Node Harvest: A Retrospective Cohort Comparison of Intracorporeal Versus Extracorporeal Anastomosis in Right Hemicolectomy

Background: Minimally invasive surgery has been demonstrated to have clear advantages in colon cancer management, with a decrease in the morbidity and mortality associated with surgery. With the introduction of intracorporeal anastomosis (ICA), the entire mesenteric dissection and division is performed under vision laparoscopically and may lead to superior lymph node harvest. The aim of our study is to evaluate lymph node harvest in patients undergoing totally laparoscopic right hemicolectomy with ICA compared to laparoscopic-assisted right hemicolectomy with extracorporeal anastomosis (ECA). Methods: This is a single institution retrospective cohort study. Eligible patients underwent laparoscopic right hemicolectomy at our institution between 2012 and 2022. Patients were identified using a hospital database, and surgeon office databases. Patients included underwent laparoscopic right hemicolectomy for neoplastic lesions (colon cancer/unresectable polyps), or benign etiologies. We excluded patients who underwent laparotomy (intra-operative conversion), resection without anastomosis, resection for IBD, or lack of documented lymph node number. Data were compared using two-sided t-test evaluation with a 95% confidence interval. Results: A total of 679 patients were included, 493 ECA (72.6%) and 186 ICA (27.4%). Patient demographics (age, biologic sex, American Society of Anesthesiologists and body mass index) were not significantly different. Lymph node harvest was significantly higher in those with ICA (24 ± 14 versus 21 ± 1, P < .05). In subgroup analysis, this difference was maintained in patients with malignant processes (27 ± 14 versus 23 ± 10, P < .05). Conclusions: In our experience, ICA has higher lymph node harvest in comparison to ECA. This may improve outcomes and options for adjuvant therapies in malignant indications.

Indocyanine Green (ICG) in Robotic Gastrectomy: A Retrospective Review of Lymphadenectomy Outcomes for Gastric Cancer

Radical gastrectomy is essential for gastric cancer treatment. While guidelines advise dissecting at least 16 lymph nodes, some research suggests over 30 nodes might be beneficial. This study assessed ICG-guided robotic gastrectomy's effectiveness in thorough lymph node dissection. We analyzed data from 393 stage II or III gastric cancer patients treated at Seoul St. Mary's Hospital from 2016-2022. Patients were categorized into conventional laparoscopy (G1, n = 288), ICG-guided laparoscopy (G2, n = 61), and ICG-guided robotic surgery (G3, n = 44). Among 391 patients, 308 (78.4%) achieved proper lymphadenectomy. The ICG-robotic group (G3) showed the highest success rate at 90.9%. ICG-guided robotic surgery was a significant predictor for achieving proper lymphadenectomy, with an odds ratio of 3.151. In conclusion, ICG-robotic gastrectomy improves lymphadenectomy outcomes in selected gastric cancer cases, indicating a promising surgical approach for the future.

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.