Determining of metastatic lymph node ratio in patients who underwent D2 dissection for gastric cancer

Lymph-node ratio is an important clinical determinant for selecting the appropriate adjuvant chemotherapy regimen for curative D2-resected gastric cancer

PURPOSE

Adjuvant chemotherapy for gastric cancer, particularly stage III, improves survival after curative D2 gastrectomy. We investigated the clinical value of the lymph-node ratio (LNR; number of metastatic lymph nodes/number of lymph nodes examined) for selecting the appropriate adjuvant chemotherapy regimen in patients with D2-resected stage II/III gastric cancer.

METHODS

We reviewed the data of 819 patients who underwent curative D2 gastrectomy followed by adjuvant chemotherapy. Of them, 353 patients received platinum-based chemotherapy and 466 received TS-1. The patients were categorized into three groups according to their LNR (LNR 1, 0-0.1; LNR 2, > 0.1-0.25; and LNR 3, > 0.25), and their disease-free survival (DFS) was evaluated.

RESULTS

The DFS curves of the patients were well separated according to stage and LNR. In multivariate analyses, an LNR > 0.1 was strongly associated with the 3-year DFS (hazard ratio 2.402, 95% confidence interval 1.607-3.590, P < 0.001). Platinum-based chemotherapy improved the 3-year DFS compared to TS-1 in patients with LNR 3 group in stage III gastric cancer (platinum vs. TS-1, median DFS 26.87 vs. 16.27 months, P = 0.028). An LNR > 0.1 was associated with benefiting from platinum-based adjuvant chemotherapy in stage III gastric cancer patients with lymphovascular invasion (platinum vs. TS-1, median DFS 47.57 vs. 21.77 months, P = 0.011).

CONCLUSIONS

The LNR can be used to select the appropriate adjuvant chemotherapy regimen for patients with D2-resected gastric cancer, particularly in stage III.

Prognostic value of fibrosis ratio in metastatic lymph nodes of node-positive advanced gastric cancer

Lymph node metastasis plays a crucial role in predicting prognosis in advanced gastric cancer (AGC). In the present study, we formulated a fibrosis ratio (FR), defined as the number of metastatic lymph nodes with fibrosis divided by the total number of lymph nodes, and sought to determine whether it can be used to predict the prognosis of patients with AGC and improve on existing node staging. We retrospectively analyzed 161 patients who underwent curative resection for node-positive AGC between 2001 and 2010, evaluating the association between FR, lymph node ratio (LNR), and micrometastasis, and the relationship between FR and clinicopathologic findings, overall survival (OS) and disease-free survival (DFS). A high FR was significantly related to T stage (P < .001), N stage (P < .001), tumor stage (P < .001), lymphatic invasion (P < .001), and venous invasion (P = .007). FR was significantly correlated with an increased number of metastatic lymph nodes (P = .001, R = 0.869) and LNR (P = .001, R = 0.943), but not with total harvested lymph nodes. Patients with micrometastases had a lower FR, compared with those without micrometastases (P < .001). A survival analysis showed poor OS for patients in the entire cohort (P < .001); N1 (P = .002), N2 (P = .004), N3a (P = .010), and N3b (P = .003) stages; and groups with high LNR (P = .013) and low LNR (P = .001). DFS was also poor for the entire cohort (P < .001) and the N2 (P = .013), N3b (P = .002), high-LNR (P = .036), and low-LNR (P = .001) groups, but not the N1 or N3a group. Univariate and multivariate analyses revealed that high FR was an independent prognostic factor for OS (hazard ratio [HR], 2.780; CI, 1.655-4.670; P < .001) and DFS (HR, 2.051; CI, 1.199-3.508; P = .009) in AGC. Collectively, our findings indicate that high FR is associated with adverse clinicopathologic parameters in AGC, clearly establishing nodal fibrosis as a pathological finding with value in predicting poor prognosis of patients with AGC. Thus, combining current N stage and LNR diagnostics with FR could improve prognostic prediction in AGC.

Impact of lymph node ratio in selecting patients with resected gastric cancer for adjuvant therapy

BACKGROUND

The impact of adjuvant chemotherapy and chemo-radiation therapy in the treatment of resectable gastric cancer remains varied. We sought to define the clinical impact of lymph node ratio on the relative benefit of adjuvant chemotherapy or chemo-radiation therapy among patients having undergone curative-intent resection for gastric cancer.

METHODS

Using the multi-institutional US Gastric Cancer Collaborative database, 719 patients with gastric adenocarcinoma who underwent curative-intent resection between 2000 and 2013 were identified. Patients with metastasis or an R2 margin were excluded. The impact of lymph node ratio on overall survival among patients who received chemotherapy or chemo-radiation therapy was evaluated.

RESULTS

Median patient age was 65 years, and the majority of patients were male (56.2%). The majority of patients underwent either subtotal (40.6%) or total gastrectomy (41.0%), with the remainder undergoing distal gastrectomy or wedge resection (18.4%). On pathology, median tumor size was 4 cm; most patients had a T3 (33.0%) or T4 (27.9%) lesion with lymph node metastasis (59.7%). Margin status was R0 in 92.5% of patients. A total of 325 (45.2%) patients underwent resection alone, 253 (35.2%) patients received 5-FU or capecitabine-based chemo-radiation therapy, whereas the remaining 141 (19.6%) received chemotherapy. Median overall survival was 40.9 months, and 5-year overall survival was 40.3%. According to lymph node ratio categories, 5-year overall survival for patients with a lymph node ratio of 0, 0.01-0.10, >0.10-0.25, >0.25 were 54.1%, 53.1 %, 49.1 % and 19.8 %, respectively. Factors associated with worse overall survival included involvement of the gastroesophageal junction (hazard ratio 1.8), T-stage (3-4: hazard ratio 2.1), lymphovascular invasion (hazard ratio 1.4), and lymph node ratio (>0.25: hazard ratio 2.3; all P < .05). In contrast, receipt of adjuvant chemo-radiation therapy was associated with an improved overall survival in the multivariable model (versus resection alone: hazard ratio 0.40; versus chemotherapy: hazard ratio 0.45, both P < .001). The benefit of chemo-radiation therapy for resected gastric cancer was noted only among patients with lymph node ratio >0.25 (versus resection alone: hazard ratio R 0.34; versus chemotherapy: hazard ratio 0.45, both P < .001). In contrast, there was no noted overall survival benefit of chemotherapy or chemo-radiation therapy among patients with lymph node ratio ≤0.25 (all P > .05).

CONCLUSION

Adjuvant chemotherapy or chemo-radiation therapy was utilized in more than one-half of patients undergoing curative-intent resection for gastric cancer. Lymph node ratio may be a useful tool to select patients for adjuvant chemo-radiation therapy, because the benefit of chemo-radiation therapy was isolated to patients with greater degrees of lymphatic spread (ie, lymph node ratio >0.25).

Lymph node ratio as a novel and simple prognostic factor in advanced gastric cancer

TNM staging is no doubt the most critical prognostic factors, representing tumor (T)/lymph node metastasis (N)/distant metastasis (M) in gastric cancer. Lymph node ratio-based N system (Nr) has been repeatedly reported to be of prognostic relevance in advanced gastric cancer independent of stage in the multivariate analysis world-wide, and proposed as more sophisticated than N with regard to predicting accurate prognosis. As a result, proposed TNrM system may predict survival more accurately than the present TNM staging system for patients undergoing limited lymph node analysis. It could adjust stage migration when the lymph node number was used as staging factor. Although correlation of the number of metastatic lymph nodes and lymph node ratio is obvious, biological characteristics other than that could also have been reflected on. It may indicate how successful the operation of lymph node dissection was, or it may be revealing the potential of the patient's lymph node immune-reaction. Recently, high lymph node ratio is closely associated with EGFR expression in advanced gastric cancer. When efficiency of applying lymph node ratio as a biomarker is verified and confirmed in an expansive research, and when cancer causing molecules are identified, as well as the competence as a treatment target is studied, the new biomarker, namely, lymph node ratio, could find itself in a limelight in gastric cancer treatment in the future.

Prognosis of patients with gastric cancer and solitary lymph node metastasis

AIM: To investigate the relationship of solitary lymph node metastasis (SLNM) and age with patient survival in gastric cancer (GC).

METHODS: The medical records databases of China’s Beijing Cancer Hospital at the Peking University School of Oncology and Shanghai Tenth People’s Hospital affiliated to Tongji University were searched retrospectively to identify patients with histologically proven GC and SLNM who underwent surgical resection between October 2003 and December 2012. Patients with distant metastasis or gastric stump carcinoma following resection for benign disease were excluded from the analysis. In total, 936 patients with GC + SLNM were selected for analysis and the recorded parameters of clinicopathological disease and follow-up (range: 13-2925 d) were collected. The Kaplan-Meier method was used to stratify patients by age (≤ 50 years-old, n = 198; 50-64 years-old, n = 321; ≥ 65 years-old, n = 446) and by metastatic lymph node ratio [MLR < 0.04 (1/25), n = 180; 0.04-0.06 (1/25-1/15), n = 687; ≥ 0.06 (1/15), n = 98] for 5-year survival analysis. The significance of intergroup differences between the survival curves was assessed by a log-rank test.

RESULTS: The 5-year survival rate of the entire GC + SLNM patient population was 49.9%. Stratification analysis showed significant differences in survival time (post-operative days) according to age: ≤ 50 years-old: 950.7 ± 79.0 vs 50-64 years-old: 1697.8 ± 65.9 vs≥ 65 years-old: 1996.2 ± 57.6, all P < 0.05. In addition, younger age (≤ 50 years-old) correlated significantly with mean survival time (r = 0.367, P < 0.001). Stratification analysis also indicated an inverse relationship between increasing MLR and shorter survival time: < 0.04: 52.8% and 0.04-0.06: 51.1% vs≥ 0.06: 40.5%, P < 0.05. The patients with the shortest survival times and rates were younger and had a high MLR (≥ 0.06): ≤ 50 years-old: 496.4 ± 133.0 and 0.0% vs 50-65 years-old: 1180.9 ± 201.8 and 21.4% vs≥ 65 years-old: 1538.4 ± 72.4 and 37.3%, all P < 0.05. The same significant trend in shorter survival times and rates for younger patients was seen with the mid-range MLR group (0.04-0.06), but the difference between the two older groups was not significant. No significant differences were found between the age groups of patients with MLR < 0.04. Assessment of clinicopathological parameters identified age group, Borrmann type, histological type and tumor depth as the most important predictors of the survival rates and times observed for this study population.

CONCLUSION: GC patients below 51 years of age with MLR of SLNM above 0.06 have shorter life expectancy than their older counterparts.

Application value of multi-slice spiral computed tomography for imaging determination of metastatic lymph nodes of gastric cancer

AIM: To evaluate the application value of multi-slice spiral computed tomography (MSCT) for imaging determination of metastatic lymph nodes of gastric cancer and to explore reasonable diagnostic criteria.

METHODS: Sixty patients with gastric cancer underwent 64 MSCT scans before operation. Gastric cancer samples and perigastric lymph nodes were obtained after operation, formalin fixation and haematoxylin-eosin staining. The metastatic conditions of gastric cancer and perigastric lymph nodes were determined under a light microscope. A total of 605 lymph nodes were grouped and assessed according to distribution, size, shape and degree of lymph node enhancement. Then, the findings were compared with the postoperative pathological results.

RESULTS: Among 605 lymph nodes, 358 were confirmed as metastatic, accounting for 59.2%. A total of 535 lymph nodes were detected in original axis images combined with multiplanar reconstruction images of MSCT. The metastatic lymph nodes had specific signs in computed tomography. This study showed that the long diameter of lymph nodes ≥ 8 mm indicated metastasis; the sensitivity and specificity were 79.6% and 78.8%, respectively. The difference of the mean value of lymph node enhancement density ≥ 80 Hu indicated metastasis; the sensitivity and specificity were 81.6% and 75.6%, respectively. The ratio of short diameter to long diameter of lymph nodes ≥ 0.7 indicated metastasis; the sensitivity and specificity were 85.6% and 71.8%, respectively.

CONCLUSION: MSCT is a non-invasive and reliable method for preoperative examination of gastric cancer. Sensitivity and specificity for prediction of lymph node metastasis are high.

Lymph node ratio predicts local recurrence for periampullary tumours

BACKGROUND

To better define the prognostic role of nodal disease, evaluation of metastatic lymph node ratio (MLR) has been performed, and this method has recently gained prominence in various gastrointestinal cancers. The present study attempts to identify prognostic factors and evaluate the independent prognostic influence of MLR in patients who have undergone curative pancreaticoduodenectomy.

METHODS

In our institution within the study period, 111 patients received curative pancreaticoduodenectomy for periampullary cancers. Clinicopathologic data were collected and MLR was calculated for each of the patients. Patients were then divided into four groups based on MLR value: MLR 1 = 0; MLR 2 = 0.01-0.2; MLR 3 0.21-0.4; and MLR 4 >0.4.

RESULTS

Increasing MLR correlates with high recurrence rate and lower overall survival (OS) with significance (P < 0.001, P < 0.001). The recurrent group showed significantly lower OS than the non-recurrent group (P < 0.001). In the multivariate analysis for recurrence, MLR was identified as the only independent prognostic factor (P < 0.001).

CONCLUSIONS

The simple and easily obtainable MLR is well qualified as a prognostic factor in patients who undergo curatively radical resection for periampullary cancer. Furthermore, MLR can overcome the limitations of evaluation of lymph nodes status, allowing it to be used as a potential prognostic factor.

Ratio between negative and positive lymph nodes is suitable for evaluation the prognosis of gastric cancer patients with positive node metastasis

Objective

To date, there is no consensus to evaluate the most appropriate category of the nodal metastasis for precise predication the prognosis of gastric cancer patients with positive node metastasis after curative surgery.

Methods

We retrospectively analyzed the clinicopathologic characteristics and overall survival (OS) of 299 gastric cancer patients with positive node metastasis after curative surgery for evaluation the optimal category of the nodal metastasis.

Results

With the univariate and multivariate survival analyses, the depth of primary tumor invasion was identified as the independent predicators with the OS of 299 gastric cancer patients with nodal metastasis postoperatively, as were the number of positive lymph nodes (PLNs), the number of negative lymph nodes (NLNs), and the ratio between negative and positive lymph nodes (RNPL). The RNPL was identified to be more suitable for predication the OS of gastric cancer patients with positive node metastasis than the ratio between positive and dissected lymph nodes (RPDL) by using the stratum procedure of survival analysis. Besides, we found both PLNs and NLNs were independently correlated with OS of gastric cancer patients with nodal metastasis when RNPL, instead of RPDL, was controlled in the partial correlation model.

Conclusions

RNPL, a new category of the nodal metastasis, was suitable for predication the OS of gastric cancer patients with nodal metastasis after curative resection, as were the PLNs, and NLNs.

Prognostic significance of the metastatic lymph node ratio in patients with gastric cancer

BACKGROUND

In gastric cancer, the classification of lymph node status is still a controversial prognostic factor. Recent studies have proposed a new prognostic factor (metastatic lymph node ratio: MLR) for gastric cancer patients who undergo curative resection. The present study tested the hypothesis that MLR was better than the current pN staging system by analyzing the correlation between MLR and the International Union Against Cancer/American Joint Committee on Cancer (UICC/AJCC) staging system, by analyzing the correlation between MLR and 5-year overall survival (OS), by comparing area under the curve (AUC), and by performing univariate and multivariate analyses for OS.

METHODS

Of 409 patients who were diagnosed with gastric adenocarcinoma between January 2003 and December 2006, 370 patients underwent curative resection and were included in this study. The prognostic significance of the number of metastatic lymph nodes and the metastatic lymph node ratio were compared in AUC and univariate and multivariate Cox regression analyses.

RESULTS

MLR was significantly correlated with the depth of invasion and the number of lymph node metastases (p < 0.001). Increasing MLR also was statistically correlated with a lower 5-year OS rate (p < 0.001). The AUC of MLR and the number of lymph node metastases were not significantly different (p = 0.825). MLR was an independent prognostic factor on multivariate analysis, but the number of metastatic lymph nodes was not.

CONCLUSIONS

MLR can be a prognostic factor in patients who undergo radical resection for gastric cancer and can overcome the limitations of existing prognostic factors.

Do patients with pN0 gastric cancer benefit from prophylactic extended lymphadenectomy?

PURPOSE

To investigate the impact of prophylactic extended lymphadenectomy on survival for patients with node-negative (pN0) advanced gastric cancer according to the extent of lymph node dissection.

METHODS

This study retrospectively investigated the clinicopathological characteristics and prognostic outcomes of 458 patients who had pN0 advanced gastric cancer between 1995 and 2001. Postoperative survival was compared in patients who underwent different extents of prophylactic lymphadenectomy.

RESULTS

The overall 5-year and 10-year survival rates were 62.01% (284/458) and 40.83% (187/458), respectively. The survival rates differed significantly in patients who underwent a different extent of prophylactic lymphadenectomy (≤D1+ versus D2 versus D3 versus ≥D3) (X(2) = 8.59, P = 0.035). Survival in patients who received less than D1+ dissection, however, were not significantly better than patients who received D2 dissection (X(2) = 0.907, P = 0.341). Survival in patients who received D2 dissection was significantly better than survival in patients who received D3 dissection (X(2) = 5.685, P = 0.017). No differences in postoperative survival rates were observed between patients who received D3 dissection and those received more than D3 dissection (X(2) = 2.468, P = 0.116). Patients who were older than 60 years and receive more than D2 dissection experienced significantly worse postoperative survival than those who received less than D2 dissection (X(2) = 14.885, P = 0.001). The extent of prophylactic lymphadenectomy did not significantly affect local tumor recurrence in patients with node-negative advanced gastric cancer (X(2) = 0.458, P = 0.928).

CONCLUSIONS

D2 prophylactic lymphadenectomy is appropriate for pN0 patients who were less than 60 years old, and less than D2 dissection was suitable for the older cases.