Prognosis for gastric carcinomas with an insufficient number of examined negative lymph nodes

Revolutionizing T3-4N0-2M0 gastric cancer staging with an innovative pN classification system

BACKGROUND

Current pathological nodal (pN) classification exhibits limitations in prognostic stratification of pT3-4N0-2M0 gastric cancer (GC) patients. Therefore, this study aimed to develop and validate a new lymph nodal staging based on the number of examined lymph nodes (ELNs) and lymph node ratio (LNR).

METHODS

Data from 7883 pT3-4N0-2M0 GC patients were collected from the SEER database and Zhejiang Cancer Provincial Hospital. Optimal cutoff values for ELNs and LNR were determined using X-tile software. Kaplan-Meier methods, Log-rank tests, and Cox regression analyses were employed in this study. Patients were categorized into three new pN stages: new pN0 (pN0 with ELNs >16), new pN1 (pN0 with ELNs ≤16 or pN1-2 with LNR ≤0.15), and new pN2 (pN1-2 with LNR >0.15). The prognostic predictive power of both the current and new pN staging was evaluated using Akaike information criterion (AIC), Bayesian information criterion (BIC), Concordance index (C-index), and the Receiver operating characteristic (ROC) curve.

RESULTS

The new pN classification exhibited excellent performance in Kaplan-Meier survival analysis. After adjusting for confounding factors, the new pN staging emerged as an independent prognostic indicator in GC patients. In the SEER cohort, the new pN staging demonstrated enhanced prognostic prediction accuracy over the AJCC pN staging (AIC: 75578.85 vs 75755.06; C-index: 0.642 vs 0.630, P < 0.001). Similar findings were validated in the China cohort.

CONCLUSION

This study developed and validated an improved pN classification for pT3-4N0-2M0 GC patients. It is advisable for surgeons to consider ELNs and LNR when assessing postoperative prognosis in GC patients.

Normalization weighted combination scores re-evaluate TNM staging of gastric cancer: a retrospective cohort study based on a multicenter database

BACKGROUND

The pathological depth of tumor invasion (pT) and lymph node metastasis (pN) are critical independent prognostic factors for patients with gastric cancer (GC), representing effective methods for evaluating prognosis. In this study, the authors employed a normalization weight combination score to calculate the weight ratio of the pT stage and pN stage. Subsequently, the authors established a novel weighted TN (wTN) staging model based on these T and N weights, evaluating its prognostic capacity.

METHODS

This study utilized a training cohort from A Medical University Cancer Hospital and a validation cohort from the SEER database. Least absolute shrinkage and selection operator (LASSO) and Cox regression were employed to screen clinical characteristics. Multivariate linear regression and cluster analysis calculated the weight ratio of T stage and N stage in the training and validation cohorts, respectively, followed by re-staging. Prognostic value was evaluated using C-index, likelihood ratio, Wald, and Score tests for wTN stage and tumor-node-metastasis (TNM) stage. A nomogram model was developed, and accuracy was assessed using receiver operating characteristic curve (ROC), decision curve analysis (DCA), and restricted cubic spline (RCS) analyses.

RESULTS

LASSO was used for initial screening, selecting eight potential features for Cox analysis. Age, tumor size, metastasis lymph nodes (MLNs), and tumor location were confirmed as independent prognostic factors. wTN was calculated in the training and validation cohorts, and nomograms were established with the independent factors. N stage had a higher weight proportion than T stage in both cohorts (0.625/0.375 in training cohort, 0.556/0.444 in validation cohort). wTN outperformed the 8th TNM stage in C-index, likelihood ratio, Wald, and Score tests in the training cohort, with successful validation in the validation cohort. Stratified analysis of distinct pathological types further demonstrates that wTN staging exhibits superior prognostic performance.

CONCLUSION

The wTN staging model based on T stage and N stage weights has a good prognostic value for GC patients. The same conclusion was obtained in different pathological stratification.

Efficacy of Lymph Node Location-Number Hybrid Staging System on the Prognosis of Gastric Cancer Patients

BACKGROUND

Lymph node metastasis location and number significantly affects the prognosis of patients with gastric cancer (GC). This study was designed to examine a new lymph node hybrid staging (hN) system to increase the predictive ability for patients with GC.

METHODS

This study analyzed the gastrointestinal treatment of GC at the Harbin Medical University Cancer Hospital from January 2011 to December 2016, and selected 2598 patients from 2011 to 2015 as the training cohort (hN) and 756 patients from 2016 as the validation cohort (2016-hN). The study utilized the receiver operating characteristic curve (ROC), c-index, and decision curve analysis (DCA) to compare the prognostic performance of the hN with the 8th edition of AJCC pathological lymph node (pN) staging for GC patients.

RESULTS

The ROC verification of the training cohort and validation cohort based on each hN staging and pN staging showed that for each N staging, the hN staging had a training cohort with an AUC of 0.752 (0.733, 0.772) and a validation cohort with an AUC of 0.812 (0.780, 0.845). In the pN staging, the training cohort had an AUC of 0.728 (0.708, 0.749), and the validation cohort had an AUC of 0.784 (0.754, 0.824). c-Index and DCA also showed that hN staging had a higher prognostic ability than pN staging, which was confirmed in the training cohort and the verification cohort, respectively.

CONCLUSION

Lymph node location-number hybrid staging can significantly improve the prognosis of patients with GC.

Prognostic and Predictive Model of the Log Odds of the Negative Lymph Node/T Stage Ratio in Resectable Gastric Adenocarcinoma Patients

PURPOSE

There are few reports on disease-specific survival (DSS) prediction systems for resected gastric cancer (GC) patients. The aim of this study was to create a nomogram based on the log odds of the negative lymph node/T stage ratio (LONT) for individual risk prediction.

METHODS

We applied the Surveillance, Epidemiology, and End Results (SEER) Program database released in 2021 to screen GC patients from 2010 to 2015. Using a competitive risk model, we plotted the cumulative risk curve of variables for gastric cancer-specific death and death from other causes at each time point. According to the minimum BIC, we constructed and assessed a nomogram for the 12-month, 36-month, and 60-month cumulative mortality probabilities assessed by time-dependent ROC curves (time-AUCs), the C-index, Brier scores, decision curve analysis (DCA), and calibration curves.

RESULTS

A total of 3895 patients were ultimately included and randomly assigned to two sets: the training set (n = 2726, 70%) and the validation set (n = 1169, 30%). The LONT was a remarkable independent predictor of gastric cancer-specific death (high versus low: 0.705, 95% CI 0.524-0.95, p = 0.021). The variables selected based on the minimum BIC were as follows: location, AJCC, AJCC.T, AJCC.N, radiotherapy, LONT.cat, and chemotherapy. According to the time-AUC, C-index, Brier score, DCA, and calibration curves, the nomogram risk score had excellent survival prediction ability for DSS.

CONCLUSIONS

A low LONT was associated with a high cumulative incidence of DSS. A prognostic nomogram model based on the LONT could effectively predict DSS for resectable GC patients.

Misclassification of nodal stage in gastric cancer: 16 lymph nodes is not enough

Background

In gastric cancer, nodal stage plays an important role. Insufficient lymph node harvesting or incomplete examination may lead to misclassification and affect postoperative strategy and group survival. This study’s objective was to determine the minimum number of examined lymph nodes needed in gastric cancer and compare this to the minimum lymph node count according to the current Union for International Cancer Control (UICC) classification using real world data.

Methods

Based on anatomical data, expected mean lymph node counts and their 95% confidence intervals for complete D2 lymphadenectomy were calculated. Using stochastic analysis, a threshold for correct classification in 95% of cases was determined. Survival data of nodal negative gastric cancer patients was extracted from the Surveillance, Epidemiology, and End Results (SEER)-Database for 2010–2017. Patients reaching at least the calculated theoretical threshold were compared to the minimum threshold according to the current UICC classification.

Results

The expected lymph node count was 30 (95% CI: 28–32; range 17–52), corresponding to a 27 lymph nodes. In nodal negative patients with exactly 16 and at least 27 examined lymph nodes, relative 5 year survival was 79 and 89% in T1/T2 and 39 and 64% T3/T4 gastric cancer, respectively. Theoretically, when only 16 lymph nodes are analyzed, nodal negative staging may be incorrect in up to 47% of cases.

Conclusions

A minimum threshold of 16 examined lymph nodes cannot be justified. Retrospective analysis confirmed systematic misclassification of patients with insufficient lymphadenectomy in nodal negative gastric cancer patients. Correct lymphadenectomy and thorough examination of the surgical specimen is mandatory.

A New Scoring System to Predict Lymph Node Metastasis and Prognosis After Surgery for Gastric Cancer

Background

Lymph node metastasis is one of the most important factors affecting the prognosis of gastric cancer patients. The purpose of this study is to develop a new scoring system to predict lymph node metastasis in gastric cancer using preoperative tests in various combinations of inflammatory factors and to assess the predictive prognosis value of the new scoring system for the postoperative gastric cancer patients.

Method

This study includes 380 gastric cancer patients, 307 in the training set and 73 in the validation set. We obtain three inflammatory markers, CRA (C-reactive protein/albumin), SIRI (systemic inflammatory response index), and PLR (platelets/lymphocytes), by calculating and comparing the results of preoperative laboratory tests. By using these three indicators, a new scoring system is developed to predict lymph node metastases, assess patients’ prognoses, and compare clinicopathological characteristics in different patient subgroups. A nomogram is constructed to show and assess the predictive efficacy of every index for lymph node metastasis and survival.

Results

In the new scoring system, higher scores are associated with more advanced pathological stage (p < 0.001), perineural invasion (p < 0.001), and vascular invasion (p = 0.001). Univariate and multivariable Cox regression analyses show that perineural invasion, vascular invasion, smoking history, and high scores on the new scoring system are significant risk factors for OS and RFS. High-scoring subgroups as an independent prognostic factor could predict overall survival (OS) and relapse-free survival (RFS). High scores on the new scoring system are significantly associated with the degree of lymph node metastasis (p < 0.001). CAR and PLR play very important roles in predicting lymph node metastasis in gastric cancer. CAR is a vital major marker in the prediction of patient survival.

Conclusions

The new scoring system can effectively predict the patients’ lymph node metastasis with gastric cancer and can independently predict the prognosis of patients.

The log odds of negative lymph nodes/T stage: a new prognostic and predictive tool for resected gastric cancer patients

Purpose

When only the TNM classification is used to predict survival in gastric cancer (GC) patients, the impact of the degree of lymphadenectomy on the prognosis is neglected. This study aimed to establish a more effective nomogram based on the log odds of negative lymph nodes/T stage ratio (LONT) to predict survival in surgically treated GC patients.

Methods

The data of resected GC patients were extracted from the Surveillance, Epidemiology, and End Results Program (SEER) database. Univariate and multivariate Cox regression analyses were used to identify the significant prognostic factors. The prognostic performance was assessed using a calibration plot, concordance index (C-index), and area under the (time-dependent receiver operating characteristic) curve (AUC) to compare the predicted survival probability based on the nomogram score groups.

Results

The results showed LONT as an independent prognostic factor for cancer-specific survival (CSS) and overall survival (OS), independent of clinicopathological factors. After removing potential redundancy, only LONT, T stage, N stage, location and age were used in the final nomogram model. The model had a higher C-index (0.736 ± 0.012) and AUC (0.798) than the TNM staging system (0.685 ± 0.012 and 0.744). The nomogram score could predict a significant survival difference between any two adjacent groups in terms of CSS and OS.

Conclusion

High LONT is associated with improved survival of gastric cancer patients, independent of other clinicopathological factors. The prognostic nomogram model based on LONT could effectively predict CSS and OS for resectable GC patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00432-021-03654-y.

Prognostic impact of nodal status and therapeutic implications

The prognostic impact of lymph node (LN) metastases in gastric cancer is generally accepted. In primarily resected patients the pN-category and LN ratio are independent prognostic factors. Number of involved LNs, number of resected LNs, lymphangiosis and micrometastases also influence the prognosis significantly. To guarantee a proper D2 lymphadenectomy (LAD) at least 25 LNs according to the German S3 guidelines for the treatment of gastric cancer should be removed. Also in neoadjuvantly treated patients the ypN-category and LN ratio play an important prognostic role, despite the fact that UICC staging system was development based only on primarily resected patients. The role of response of LNs in neoadjuvantly treated patients is still unclear and needs further investigation. It seems to be less important than the response of the primary tumor. Limited data exists, suggesting that preoperative treatment might reduce the number of LNs involved and improve ypN-category. Due to further development in gastric cancer like laparoscopic resection and effective perioperative treatment in locally advanced tumor the role and the prognostic impact of LAD is again in the focus of discussion.

A new predictive model combined of tumor size, lymph nodes count and lymphovascular invasion for survival prognosis in patients with lymph node-negative gastric cancer

BACKGROUND

Various factors may affect the clinical prognosis of lymph node-negative gastric cancer (GC) patients. This study aimed to provide evaluable prognostic information of combination of tumor size (Ts), lymph nodes count (LNs) and lymphovascular invasion (LVI) in lymph node-negative GC patients.

METHODS

A total of 1,019 node-negative GC patients were enrolled in this retrospective study from 2000 to 2010. The cutoff points of Ts and LNs were determined using X-tile and patients were randomly categorized into training and validation sets by the sample size ratio 1:1. The clinicopathologic characteristics were analyzed and survival prognostic factors were identified, whereas the survival prediction accuracy was also compared by C-index during the different independent prognostic factors.

RESULTS

The cutoff points for Ts were 3cm and 5cm, while 14 was the cutoff point for LNs. Age, T stage, Ts, LNs and LVI were identified as independent prognostic factors in node-negative GC patients, and a new prognostic predictive model, TsNL staging system which was composed of Ts, LNs and LVI, was proposed in this study. Compared with T staging system, significant improvement of predictive accuracy for TsNL system was found. Furthermore, nomogram based on TsNL was more accurate in prognostic prediction than that based on Ts, LNs and LVI, separately.

CONCLUSIONS

Age, T stage, Ts, LNs and LVI were independent prognostic factors in lymph node-negative GC patients. The TsNL staging system, composed of Ts, LNs and LVI, which was closely associated with clinicopathologic features, may improve the prognostic prediction accuracy in node-negative GC patients.

Usefulness of the log odds of positive lymph nodes to predict and discriminate prognosis in gastric carcinomas

BACKGROUND

The lymph node ratio (LNR) and log odds of positive lymph nodes (LODDS) have been proposed to minimize the stage migration phenomenon. The value of the LODDS and LNR staging systems to predict and discriminate prognosis was assessed and compared to the International Union Against Cancer (UICC) TNM classification (pN).

METHODS

Three hundred and twenty-six patients with gastric carcinoma were retrospectively studied. Disease-specific survival rates were calculated for every pN, LNR, and LODDS category.

RESULTS

Four LNR categories (0, 1-25, 26-75, and >76 %) and four LODDS categories (-5 to -3, > -3 to -1, > -1 to 3, and >3 to 5) were established. In the multivariate analysis, only the stage pT3-4 versus pT1-2 (HR 1.88, 95 % CI 1.11-3.20, p=0.02) and LODDS as continuous variable (HR 1.40, 95 % CI 1.21-1.61, p<0.001) remained as independent prognostic factors. In patients with <16 lymph nodes retrieved, only the LODDS system could discriminate different disease-specific survival curves for every category. LODDS categories were able to discriminate subgroups with different prognoses in pN stages and LNR categories.

CONCLUSIONS

The LODDS staging system was superior to the pN classification and LNR system to discriminate risk prognosis especially in patients with an insufficient number of retrieved lymph nodes.

Lessons learned from a comparative analysis of surgical outcomes of and learning curves for laparoscopy-assisted distal gastrectomy

Purpose

Before expanding our indications for laparoscopic gastrectomy to advanced gastric cancer and adopting reduced port laparoscopic gastrectomy, we analyzed and audited the outcomes of laparoscopy-assisted distal gastrectomy (LADG) for adenocarcinoma; this was done during the adoptive period at our institution through the comparative analysis of short-term surgical outcomes and learning curves (LCs) of two surgeons with different careers.

Materials and Methods

A detailed comparative analysis of the LCs and surgical outcomes was done for the respective first 95 and 111 LADGs performed by two surgeons between July, 2006 and June, 2011. The LCs were fitted by using the non-linear ordinary least squares estimation method.

Results

The postoperative morbidity and mortality rates were 14.6% and 0.0%, respectively, and there was no significant difference in the morbidity rates (12.6% vs. 16.2%, P=0.467). More than 25 lymph nodes were retrieved by each surgeon during LADG procedures. The LCs of both surgeons were distinct. In this study, a stable plateau of the LC was not achieved by both surgeons even after performing 90 LADGs.

Conclusions

Regardless of the experience with gastrectomy or laparoscopic surgery for other organs, or the age of surgeon, the outcome was quite acceptable; the learning process differ according to the surgeon's experience and individual characteristics.

[Lymph node dissection: what for? From esophagus to rectum: surgical and lymph node related prognostic factors]

Surgery has still a key role in curative treatment of digestive carcinomas, and for almost all localisations, lymph node status is a major prognostic factor. As far as oesophageal and gastric cancer are concerned, there is not yet any internationally standardized approach. Occidental guidelines recommend more limited lymph node dissections than Asiatic ones. Lymph node numbers requested during surgery of such cancers remain high, at least 23 lymph nodes for oesophageal cancer, and 25 for a D2 or D1.5 lymphadenectomy for gastric cancer. Generalisation of neo-adjuvant and adjuvant treatments has not yet modified these standards. On the other hand, rectal cancer surgery is well standardized since the global adoption of Total Mesorectal Excision (TME) for the late eighties. Development of mini-invasive techniques (laparoscopy and robot-assisted surgery) enabled an important decrease of surgery related morbidity as well as an enhanced post-operative recovery. However, rectal cancer surgery still has an important morbidity. Development of neo-adjuvant chemo-radiotherapy as well as in-depth knowledge of risk factor of lymph node invasion opened up the path for transanal full thickness resection without lymphadenectomy. The goal of such an approach is to avoid TME's morbidity without risking local recurrence rate increase. As a consequence, this technique might need to be completed with a TME case histological factors are not favorable.