Insufficient examined lymph node count underestimates staging in pN3a patients after curative gastrectomy: a multicenter study with external validation

Construction of a modified TNM staging system and prediction model based on examined lymph node counts for gastric cancer patients at pathological stage N3

Background

Examined lymph node (ELN) count is a critical factor affecting the number of metastatic lymph nodes (MLNs). The impact of the ELN number on survival and staging remains unclear.

Methods

This study included 4,291 stage N3 GC patients from the SEER database (training cohort) and 567 stage N3 GC patients from the FAHZZU database (validation cohort). The optimal ELN count and stage migration were investigated, and a modified TNM (mTNM) staging system including the ELN count was proposed. LASSO regression and random forest analyses were used to screen and evaluate the variables associated with survival, and an mTNM-based nomogram was constructed. The performance of the mTNM staging system and mTNM-based nomogram were compared with that of the 8th edition of the TNM staging system.

Results

The optimal threshold of the ELN count was identified as 21. An insufficient number of ELNs (≤ 21) was associated with poorer survival outcomes and led to stage migration in all N3 patients. A new mTNM staging system was proposed, integrating the ELN count into the TNM staging system (8th edition). LASSO regression analysis revealed that age, tumor size, adjuvant chemotherapy, adjuvant radiotherapy, and the mTNM system were associated with overall survival (OS) outcomes, and random forest analysis revealed that the mTNM system was the most important variable for predicting survival. An mTNM-based nomogram was constructed to predict 1-, 3-, and 5-year OS rates. Compared with the TNM staging system (8th edition), the mTNM staging system and mTNM-based nomogram showed superior prognosis discriminative ability, better predictive accuracy, and greater net improvement in survival outcomes.

Conclusions

The optimal ELN count for N3 GC patients was 21. The mTNM staging system and mTNM-based nomogram showed superior discriminative ability, predictive accuracy, and greater net benefit for OS outcomes.

Modified traditional TNM staging of pyriform sinus and hypopharyngeal and laryngeal cancer based on lymph node ratio and its clinical significance: a population-based study combined with external validation

BACKGROUND

To evaluate the application value of a new tumor-node-metastasis lymph node ratio-modified (TLNRM) staging prediction model based on lymph node ratio (LNR) in patients with pyriform sinus and hypopharyngeal and laryngeal cancer (PHLC).

MATERIALS AND METHODS

A total of 2257 patients with pathologically diagnosed PHLC from 2004 through 2019 were collected from the SEER database for analysis. The N staging of AJCC was replaced by LNR, and we compared the differences in patient prognosis and judgment ability between the new TLNRM staging and the 8th edition TNM staging. At the same time, data from 1094 people in our hospital were included for external verification and validation.

RESULTS

We selected four cutoff points based on LNR and reclassified N staging into five groups (LNR1-5). Compared to the traditional TNM staging (8th edition), the new TLNRM staging showed a statistically significant 5-year overall survival difference. The decision curve showed that the new TLNRM staging had a higher net benefit for different decision thresholds than the traditional TNM staging system's prediction line. The smaller Akaike information criterion (AIC) and Bayesian information criterion (BIC) suggested that the new staging system had a higher sensitivity to prognosis evaluation compared to the traditional staging system. TLNRM stage III patients can benefit from radiotherapy, while TLNRM IVA and IVB patients can benefit from chemoradiotherapy. The same conclusion has been drawn from external validation data from our center.

CONCLUSIONS

Compared with the traditional 8th edition AJCC staging system, the new TLNRM staging system has advantages in predicting the staging and prognosis of PHLC patients and can independently guide postoperative chemoradiotherapy in patients.

Effects of Degreasing Pretreatment on Immunohistochemistry and Molecular Analysis of Gastrointestinal and Breast Cancer Samples

Lymph node status is a key factor in determining stage, treatment, and prognosis in cancers. Small lymph nodes in fat-rich gastrointestinal and breast cancer specimens are easily missed in conventional sampling methods. This study examined the effectiveness of the degreasing pretreatment with dimethyl sulfoxide (DMSO) in lymph node detection and its impact on the analysis of clinical treatment-related proteins and molecules. Thirty-three cases of gastrointestinal cancer specimens from radical gastrectomy and 63 cases of breast cancer specimens from modified radical mastectomy were included. After routine sampling of lymph nodes, the specimens were immersed in DMSO for 30 minutes for defatting. We assessed changes in the number of detected lymph nodes and pN staging in 33 gastrointestinal cancer specimens and 37 breast cancer specimens. In addition, we analyzed histologic characteristics, Masson trichrome special staining, and immunohistochemistry (gastrointestinal cancer: MMR, HER2, and PD-L1; breast cancer: ER, PR, AR, HER2, Ki-67, and PD-L1). Molecular status was evaluated for colorectal cancer (KRAS, NRAS, BRAF, and microsatellite instability) and breast cancer (HER2) in gastrointestinal cancer specimens and the remaining 26 breast cancer specimens. Compared with conventional sampling, DMSO pretreatment increased the detection rate of small lymph nodes (gastrointestinal cancer: P < .001; breast cancer: P < .001) and improved pN staging in 1 case each of gastric cancer, colon cancer, and rectal cancer (3/33; 9.1%). No significant difference in the morphology, special staining, protein, and molecular status of cancer tissue after DMSO treatment was found. Based on these results and our institutional experience, we recommend incorporating DMSO degreasing pretreatment into clinical pathologic sampling practices.

Examined lymph node count for gastric cancer patients after curative surgery

Lymph node (LN) metastasis is the most common form of metastasis in gastric cancer (GC). The status and stage of LN metastasis are important indicators that reflect the progress of GC. The number of LN metastases is still the most effective index to evaluate the prognosis of patients in all stages of LN metastasis. Examined LN (ELN) count refers to the number of LNs harvested from specimens by curative gastrectomy for pathological examination. This review summarizes the factors that influence ELN count, including individual and tumor factors, intraoperative dissection factors, postoperative sorting factors, and pathological examination factors. Different ELN counts will lead to prognosis-related stage migration. Fine LN sorting and regional LN sorting are the two most important LN sorting technologies. The most direct and effective way to harvest a large number of LNs is for surgeons to perform in vitro fine LN sorting.

Prognostic significance of metastatic lymph node ratio in patients with gastric cancer after curative gastrectomy: a single-center retrospective study

BACKGROUND

The objective of this study was to evaluate the prognostic value of Metastatic lymph node ratio (MLNR) after curative gastrectomy in patients with gastric cancer (GC) and the potential for new indicators to strengthen the current guidelines.

METHODS

We retrospectively researched 3864 GC patients with curative gastrectomy between February 2011 and February 2016. The following clinical data were collected from the included patients: gender, type of gastrectomy, tumor location, T stage, N stage, ELN, tumor size, age at surgery, perineural invasion, vascular invasion, TNM stage, survival time and survival status. Patients were divided into low-MLNR (L-MLNR), and high-MLNR (H-MLNR) groups based on adjusted the X-tile cutoff-value of 0.25 for MLNR, the survival rates and clinicopathological characteristics of each group were compared. For the assessment of significant associations between clinicopathological characteristics and patients' survival, univariate and multivariate analyses were performed using the Kaplan-Meier method and Cox proportional hazards analysis. The log-rank test was used to examine the statistical significance of differences among different survival curves. Clinicopathological features significantly associated with MLNR were assessed by the Chi-square test and multinomial logistic regression. The discriminative ability was measured by calculating the Bayesian Information Criterion (BIC) values for each category. Assessment of the effect of clinicopathological features on MLNR for predicting prognosis of GC patients used stratum analysis through Kaplan-Meier analysis and Cox proportional risk Analysis.

RESULTS

Survival analysis indicated that MLNR was negatively associated with overall survival (OS) (p < .001) and was an independent prognostic predictor in 3864 GC patients (p < .001). MLNR had significant prognostic significance in various subgroups with clinicopathological characteristics (gender, type of gastrectomy, tumor location, T stage, N stage, ELN, tumor size, age at surgery, perineural invasion, vascular invasion, and TNM stage) (p < .001).

CONCLUSIONS

The MLNR may become a new indicator to assess the prognosis of GC patients who underwent curative gastrectomy. The results may have potential clinical implications that should be considered when developing clinical practice guidelines or the design of the future investigation.

A Pilot Study of Prognostic Value of Metastatic Lymph Node Count and Size in Patients with Different Stages of Gastric Carcinoma

Background

The correlation between the preoperative lymph node count (LNC) on multidetector computed tomography (MDCT) and the prognosis of gastric carcinoma (GC) remains to be defined. This research aims to evaluate the prognostic value of LNC on MDCT in GC patients based on tumor-node-metastasis (TNM) staging, using different size criteria for counting.

Methods

The clinical data of 126 patients with gastric adenocarcinoma undergoing gastrectomy were retrospectively analyzed. Lymph nodes greater than 8mm and 5mm on MDCT were counted and recorded. The prognostic implications of LNC on MDCT for patient survival were analyzed according to different size criteria for counting and tumor TNM staging.

Results

When 8mm was used as the counting criterion, LNC on MDCT had no significant effect on the overall survival (OS) of the entire cohort. In addition, the OS of T1–T2 GC patients with LNC on MDCT ≥1 was significantly worse than that of patients with LNC on MDCT <1. When 5mm was used as the counting criterion, LNC on MDCT was found to be significantly associated with the OS of the entire cohort. In the subgroup analysis, patients with relatively advanced (T3-T4, N+ and III) GC with LNC on MDCT >7 showed a significantly worse OS than those with LNC on MDCT ≤7. LNC on MDCT >7 with 5mm as the counting criterion and Stage III were independent risk factors for adverse prognosis.

Conclusion

The prognostic value of LNC on MDCT based on different size criteria varies in patients with different stages of GC. LNC of a smaller size (5mm) on MDCT may be a prognostic factor for patients with relatively advanced GC.

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.

A novel pN3 gastric cancer staging system with superior prognostic utility based upon the examination of over 31 lymph nodes: a propensity score-matching analysis

Background

Individuals with pN3 gastric cancer (GC) account for a large proportion of pN + GC, and exhibit poor survival outcomes. The pN3 stage is defined based upon the number of metastatic lymph nodes (mLNs), but the subclassification of pN3 patients based upon the number of examined LNs (eLNs) is rarely performed.

Methods

In total, 2894 pTxN3M0 GC patients in the Surveillance, Epidemiology, and End Results database that had undergone surgery from 2000 to 2016 were selected for analysis. The X-tile software was used to select the optimal cutoff values. Cox proportional regression analyses were used to evaluated hazard ratios corresponding to the risk of death. Selection bias was minimized via propensity score matching (PSM).

Results

As the number of eLNs rose, the risk of death for patients trended downwards. Survival analyses indicated that patients with ≤ 31 eLNs exhibited significantly poorer survival outcomes as compared to patients with > 31 eLNs (5-year OS: 18.4% vs. 24.7%), and this result remained significant when analyzing 857 pairs of patients following PSM analysis. Significant differences in prognosis were additionally observed when comparing pN3a and pN3b patients with ≤ 31 or > 31 eLNs under pT3/4a stage. For pT4b stage, pN3a patients with > 31 eLNs also exhibited a better prognosis than other patients. The novel TNM staging system designed exhibited excellent utility as a tool for the prognostic evaluation of this GC patient population.

Conclusions

These results suggest that in pN3 GC, a minimum of 32 LNs should be examined. The novel TNM staging system for pN3 patients described herein, which was developed based upon the number of eLNs, may thus be of value in clinical settings.