OBJECTIVE: The burden of metastatic lymph node (LN) stations might reflect a distinct N subcategory with a more aggressive biology and behaviour than the traditional N classification.
METHODS: Between 2008 and 2018, we analyzed 1236 patients with pN1/2 lung cancer. Survival was analyzed based on LN station metastasis, determining the optimal threshold for the number of metastatic LN stations that provided additional prognostic information. N prognostic subgrouping was performed using thresholds for the number of metastatic LN stations with the maximum chi-square log-rank value, and validated at each pT-stage.
RESULTS: Survival showed stepwise statistical deterioration with an increase in the number of metastatic LN stations., Threshold values for the number of metastatic LN stations were determined and N prognostic subgroupswas created as sN-alpha; one LN station metastases (n = 632), sN-beta; two-three LN stations metastases (n = 505), and sN-gamma; ≥4 LN stations metastasis (n = 99). The 5-year survival rate was 57.7% for sN-alpha, 39.2% for sN-beta, and 12.7% for sN-gamma (chi-square log rank = 97.906, p < 0.001). A clear tendency of survival deterioration was observed from sN-alpha to sN-gamma in the same pT stage, except for pT4 stage. Multivariate analysis showed that age (p < 0.001), sex (p = 0.002), tumour histology (p < 0.001), IASLC-proposed N subclassification (p < 0.001), and sN prognostic subgroups (p < 0.001) were independent risk factors for survival.
CONCLUSIONS: The burden of metastatic LN stations is an independent prognostic factor for survival in patients with lung cancer. It could provide additional prognostic information to the N classification.

BACKGROUND: Neoadjuvant chemoradiotherapy (nCRT) and surgery have been recommended as the standard treatments for locally advanced esophageal squamous cell carcinoma (ESCC). In addition, nodal metastases decreased in frequency and changed in distribution after neoadjuvant therapy. This study aimed to examine the optimal strategy for lymph node dissection (LND) in patients with ESCC who underwent nCRT.
METHODS: The hazard ratios (HRs) for overall survival (OS) and disease-free survival (DFS) were calculated using the Cox proportional hazard model. To determine the minimal number of LNDs (n-LNS) or least station of LNDs (e-LNS), the Chow test was used.
RESULTS: In total, 333 patients were included. The estimated cut-off values for e-LNS and n-LNS were 9 and 15, respectively. A higher number of e-LNS was significantly associated with improved OS (HR: 0.90; 95% CI 0.84-0.97, P = 0.0075) and DFS (HR: 0.012; 95% CI: 0.84-0.98, P = 0.0074). The e-LNS was a significant prognostic factor in multivariate analyses. The local recurrence rate of 23.1% in high e-LNS is much lower than the results of low e-LNS (13.3%). Comparable morbidity was found in both the e-LNS and n-LND subgroups.
CONCLUSIONS: This cohort study revealed an association between the extent of LND and overall survival, suggesting the therapeutic value of extended lymphadenectomy during esophagectomy. Therefore, more lymph node stations being sampled leads to higher survival rates among patients who receive nCRT, and standard lymphadenectomy of at least 9 stations is strongly recommended.

BACKGROUND: The benefits of lymph node (LN) dissection at each station have not previously been fully investigated in perihilar cholangiocarcinoma (PHCC) and distal cholangiocarcinoma (DCC).
METHODS: The efficacy index (EI) was calculated in patients who underwent surgery for PHCC (n = 134) and DCC (n = 135) by multiplying the frequency of metastasis to the LN station and the 5-year overall survival (OS) rate of patients with metastasis to that station.
RESULTS: In PHCC, the frequency of metastasis, 5-year OS rates, and the EI in para-aortic LNs (4.7%, 0%, and 0, respectively) and posterior pancreaticoduodenal LNs (8.1%, 0%, and 0, respectively) were lower than those in hepatoduodenal ligament LNs (30.1%, 24.1%, and 7.25, respectively) and LNs along the common hepatic artery (CHA) (16.2%, 15.0%, and 2.43, respectively). In DCC, these values were lower in LNs along the CHA (6.4%, 0%, and 0, respectively) than in the posterior pancreaticoduodenal LNs (31.2%, 34.5%, and 10.8, respectively), the hepatoduodenal ligament LNs (14.8%, 15.2%, and 2.25, respectively), and para-aortic (4.0%, 25.0%, and 0.99, respectively) LNs.
CONCLUSIONS: According to the EI, this study raises concerns about the effectiveness of dissection in the posterior pancreaticoduodenal LNs in PHCC and LNs along the CHA in DCC.

OBJECTIVE: The number of lymph nodes is used to determine the prognosis in patients with gastric cancer undergoing D2 lymph node dissection. However, a group of extraperigastric lymph nodes, including lymph node 8a, are also considered to be effective in prognosis. In our clinical experience, in most patients during D2 lymph node dissection, the lymph nodes are removed en-bloc with the specimen and are not marked separately. The aim was to analyze the importance and prognostic impact of 8a lymph node metastasis in patients with gastric cancer.
METHODS: Patients who underwent gastrectomy and D2 lymph node dissection for gastric cancer between 2015 and 2022 were included in the study. Patients were divided into two groups based on metastasis to the 8a lymph node: metastatic and nonmetastatic. The effect of clinicopathologic features and the prevalence of lymph node metastasis on the prognosis of the two groups were analyzed.
RESULTS: The present study included 78 patients. The mean number of dissected lymph nodes was 27 (IQR, 15-62). There were 22 (28.2%) patients in the 8a lymph node metastatic group. Patients with 8a lymph node metastatic disease had shorter overall survival and shorter disease-free survival. Those with metastatic 8a lymph nodes among pathologic N2/3 patients had shorter overall and disease-free survival rates (p < 0.05).
CONCLUSIONS: In conclusion, we believe that anterior common hepatic artery (8a) LN metastasis is a key factor that negatively affects both disease-free and overall survival in patients with locally advanced gastric cancer.

UNASSIGNED: The appropriate extent of lymphadenectomy for pancreatic cancer of the body/tail has not been standardized worldwide. The present study evaluated the optimal extent of harvesting lymph nodes.
UNASSIGNED: Patients who underwent distal pancreatectomy for invasive ductal carcinoma of the pancreas between 2007 and 2018 were retrospectively reviewed. Patients were subclassified into three groups depending on the tumor location: pancreatic body (Pb), proximal pancreatic tail (Ptp), and distal pancreatic tail (Ptd). The pancreatic tail was further divided into even sections of Ptp and Ptd. Patterns of lymph node metastasis and the impact of lymph node metastasis on the prognosis were examined.
UNASSIGNED: A total of 120 patients were evaluated. Fifty-eight patients had a tumor in the Pb, 38 in the Ptp, and 24 in the Ptd. No patients with a Ptd tumor had metastasis beyond the peripancreatic and splenic hilar lymph nodes (LN-PSH). All patients with metastasis to the lymph nodes along the common hepatic artery (LN-CHA) or along the left lateral superior mesenteric artery (LN-SMA) also had metastasis to the LN-PSH. Recurrence after surgery occurred significantly earlier in this population. In a multivariate analysis, metastasis to the LN-CHA or LN-SMA (hazard ratio [HR] 3.3; P = .04) was an independent risk factor for overall survival. Furthermore, high levels of preoperative serum CA19-9 (HR 10.9; P = .013) were a predictive factor for metastasis to the LN-CHA or LN-SMA.
UNASSIGNED: Metastasis to the LN-CHA or LN-SMA was rare but a significant prognostic factor in patients with pancreatic body/tail cancer.

BACKGROUND: The nodal stage of pancreatic ductal adenocarcinoma (PDAC) is revised in the AJCC 8th edition. Studies on the prognosis of PDAC according to lymph node metastasis (LNM) are still ongoing. We attempted to find the patterns of nodal involvement and to reveal its clinical significance to overall survival (OS).
METHODS: We analyzed 585 patients who received pancreatic head cancer surgery diagnosed as PDAC from January 2007 to December 2016. Patients were classified into three groups: Group 1 (G1, patients without LNM), Group 2 (G2, those with LNM only in the peripancreatic area), and Group 3 (G3 those with LNM in the other area and/or peripancreatic LNM). Risk factors were analyzed by Cox-regression test and overall survival was compared by Kaplan-Meier analysis.
RESULTS: LNM in peripancreatic area was the most common (88.7%). In the multivariate analysis, T stage, nuclear differentiation, adjuvant treatment, and the G2 and G3 were independent risk factors for OS (G2 over G1, HR 1.384, 95% CI 1.046-1.802; P = .036 and G3 over G1, HR 2.383, 95% CI 1.378-4.103; P = .001). G3 showed worse OS than G2 (P = .006). In the N1 status, LNM to the pericholedochal (PC) and superior mesenteric artery (SMA) areas resulted in worse OS than the G2 (P = .011 and P = .019).
CONCLUSIONS: We found that LNM beyond the peripancreatic area significantly affects OS in pancreatic head cancer patients. Depending on the station of the LNM, different risk-stratification and treatment strategies will need to be considered.

The aim of the present study was to compare the metastatic ratio between calcified lymph node stations (CLNS) and non-CLNS (NCLNS) and to explore the impact of CLNS on surgical outcomes. Consecutive patients with non-small cell lung cancer (NSCLC) scheduled to receive surgical treatment between June and December 2020 were included in the present study. Their clinical and radiological data were prospectively collected and analyzed. A total of 91 patients with NCLNS and 64 patients with CLNS were enrolled in the present study. Out of the 91 patients, 38 (24.516%) patients had 61/343 (17.784%) lymph node stations (LNS) that were metastasized. On a per-patient basis, the differences in the LNS metastatic ratio were not significant between the CLNS with NCLNS groups. However, on a per-nodal station basis, all differences in the LNS metastatic ratio between the groups were significant not only in the all-LNS group (P=0.004), but also in the LNS group which in patients with solely CLNS or NCLNS (P=0.009) and in the patients with CLNS (P=0.010). Pathology, T stage and calcification were independent predictive factors for LNS metastasis (P=0.002, P=0.021 and P=0.044, respectively). More patients with CLNS than patients with NCLNS received thoracotomy or conversion from video-assisted thoracoscopic surgery to thoracotomy (P=0.006). The operating time and blood loss were significantly higher in patients with CLNS than in those without (P<0.001 and P<0.001, respectively). Although CLNS are a risk reduction factor for metastasis and their dissection is time- and blood-consuming in patients with NSCLC, their thorough removal is advisable, since metastases were identified in ~15% of patients and 9% of CLNS.

The Japanese Classification of Gastric Carcinoma was established by the Japanese Research Society for Gastric Cancer in 1962. The latest 15th edition was published in 2017. One of its main features is that lymph nodes are numbered as stations. The number of groups has increased from 16 to 36 in 55 years. Seven groups (nos. 1, 2, 5, 7, 9, 10, and 15) were retained from the original classification. Nine groups (nos. 3, 4, 6, 8, 11, 12, 13, 14, and 16) were sub-divided into two or more groups. Furthermore, seven groups (nos. 17, 18, 19, 20, 110, 111, and 112) were added in the 6th, 11th, and 12th editions. This numbering system helps surgeons recognize the exact lymph nodes that need to be dissected. However, the numbering system has become extremely complicated. It is necessary to organize the historical background of each lymph node station and share the definitions clearly. This review focuses on nine anatomical zones around the stomach and summarizes the history of lymph node stations in the Japanese Classification of Gastric Carcinoma. Lymph node stations will continue to be modified in the future, and the historical background may be useful in future revisions.

OBJECTIVE: The current nodal staging for lung cancer is defined only by the anatomical site of metastasis. However, the International Association for the Study of Lung Cancer (IASLC) proposed further subdivisions of the N descriptor that considers the locations and numbers of involved lymph node stations. This study aimed to test the new IASLC categories and compare their prognostic abilities to those of our proposed model that considers only the number of involved lymph node stations instead of the sites of metastasis.
METHODS: Between September 2002 and December 2016, 1581 patients who underwent complete resection for pathologically diagnosed Tis-4N0-2M0 non-small cell lung cancer were retrospectively analyzed. We evaluated the survival rates according to the patients\' N classification as recently proposed by the IASLC and by the number of involved lymph node stations, and determined the optimal N classification.
RESULTS: The 5-year survival rates for patients with IASLC stages N1a, N1b, N2a1, N2a2, and N2b were 71.5%, 49.9%, 73.7%, 62.1%, and 46.9%, respectively. These results showed relatively good categorizations; however, some prognostic overlaps existed and not all differences were significant. After redefining the number of involved stations as Nα for 1, Nβ for 2-3, and Nγ for ≥ 4 without considering the metastasis sites, the 5-year survival rates for patients in these categories were 72.1%, 58.3%, and 29.6%, respectively; the differences between them were significant.
CONCLUSIONS: The number of involved lymph node stations is a more accurate prognostic indicator in patients with completely resected non-small cell lung cancer.

The aim of this study was to assess the prognoses of patients with non-small cell lung cancer (NSCLC) according to the current nodal (N) categories of the tumor, node and metastasis (TNM) classification and the number of involved lymph node stations.
Five hundred and seventy patients with NSCLC underwent surgery from 1 January 2005 to 31 December 2009 and were analysed retrospectively. Postoperative overall survival was analysed according to two nodal classifications: the current N0, N1, N2 and N3 categories and those based on the number of involved nodal stations: N0, N1a (single N1), N1b (multiple N1), N2a1 (single N2 without N1), N2a2 (single N2 with N1), N2b1 (multiple N2 without N1) and N2b2 (multiple N2 with N1).
Five-year survival rates were 76.1%, 53.4% and 26.3% for N0, N1 and N2, respectively (P < 0.001). When survival was analysed by the number of involved nodal stations, the groups with significant differences were maintained; otherwise, they were merged, and new codes were assigned as follows for exploratory analyses: NA (N0), NB (N1a), NC (N1b, N2a (i.e., N2a1 and N2a2) and N2b1) and ND (N2b2). Five-year survival rates were 76.1%, 60.0%, 39.1%, and 11.4% for NA, NB, NC and ND, respectively, and there were significant differences among them. This N classification was an independent prognostic factor in multivariate analyses.
Pending prospective and international validation, it is practical to merge the current N categories with the number of involved lymph node stations when evaluating the postoperative prognosis of NSCLC patients.