Significance Of Lymph Node Dissection Research Articles

Abstract 2394: Significance of regional lymph node dissection in patients with clear cell sarcoma and epithelioid sarcoma

Abstract Objective Clear cell sarcoma (CCS) and epithelioid sarcoma (ES) are common as soft-tissue sarcoma subtypes causing lymph node metastasis (LNM), but the role of regional lymph node dissection is still unclear especially in these patients without imaging evidence of LNM. Here we retrospectively investigated the significance of lymph node dissection for patients with CCS and ES. Methods Forty-one patients (CCS: 13, ES: 28) with no distant metastasis other than in the regional lymph nodes were enrolled in this study. Of these 41 patients, those without LNM on imaging findings were categorized into two groups: "with dissection (WD)" group and "no dissection (ND)" group, respectively. Overall survival (OS), lymph node metastatic-free survival (LNMFS), progression-free survival (PFS), and post-operative LNM rate were compared between two groups. Results There were 26 patients who had undergone regional lymph node dissection and 15 patients who had not undergone regional lymph node dissection (ND group). Histopathological examination revealed metastasis to the lymph nodes in 9 of the 26 patients (38.5%). 9 patients were suspected of having LNM based on preoperative imaging findings such as CT or FDG PET/CT. Among the remaining 17 patients (WD group) in whom LNM was not suspected based on preoperative imaging findings, 6 patients (35.3%) had LNM. OS (p=0.03), LNMFS (p<0.01), and PFS (p<0.01) were all significantly better in the WD group. The postoperative LNM rate was significantly lower in the WD group than in the ND group (p=0.03), and there were no significant differences in OS, LNMFS, or PFS between the CCS and ES groups in terms of histological type. Discussion Even in cases where LNM was not suspected on preoperative imaging, LNM was present in more than 30% of cases. The possibility of regional LNM should be borne in mind in soft-tissue sarcomas, which frequently present with LNM, regardless of imaging findings. We also suggested that simultaneous dissection of the regional lymph nodes at the time of resection of the primary tumor improves the prognosis. Although ES and CCS are ultra-rare sarcomas, further validation with the accumulation of case series is desirable. Citation Format: Toshiyuki Takemori, Eisuke Kobayashi, Shintaro Iwata, Koichi Ogura, Shuhei Osaki, Suguru Fukushima, Akira Kawai. Significance of regional lymph node dissection in patients with clear cell sarcoma and epithelioid sarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2394.

The significance of lymph node dissection at the left side of superior mesenteric artery (SMA) during Whipple’s procedure for pancreatic head cancer

The significance of lymph node dissection at the left side of superior mesenteric artery (SMA) during Whipple’s procedure for pancreatic head cancer

Prognostic significance of lymph node dissection for lung cancer surgery: a narrative review.

Theoretically, systematic lymph node dissection (SLND) in lung cancer surgery is a technique that leaves less cancer cells behind and is speculated to improve the prognosis, but its prognostic significance still remains controversial. In addition, the social environment surrounding lymph node dissection has changed with the advent of limited surgery for peripheral small-sized lung cancer and emergence of immune check inhibitor (ICI). Therefore, we reconsidered the role of lymph node dissection. By referring to past reports, we reviewed the process leading up to the establishment of SLND in lung cancer surgery. We compared five randomized prospective comparative studies on SLND and lymph node sampling (LNS) in lung cancer surgery. Of the five randomized prospective comparative studies, two reported an improvement in overall survival (OS) with SLND, but the remaining three reported no significant difference in OS between SLND and LNS. One out of the five reports revealed a significant increase in complications with SLND. For peripheral non-small cell lung cancer (NSCLC) cases with tumor diameter ≤2 cm and consolidation-to-tumor ratio >0.5 segmentectomy was found to significantly improve the hazard ratio of OS, when compared to a lobectomy. However, the proportion of SLND and lobe-specific lymph node dissection (L-SLND) in each group seems to be unclear. In segmentectomy, the dissection of intersegmental lymph nodes tends to be lenient, and therefore it seems necessary to examine the significance of lymph node dissection in segmentectomy. ICIs are already showing excellent effects, and it may be necessary to examine how they will be affected by removal of regional lymph nodes where cancer-specific cytotoxic T lymphocytes (CTLs) are concentrated. SLND is essential for accurate staging, but ideally-in a host with no cancer cells in the lymph node or a host with cancer cells having a high sensitivity to ICI-it might be better to leave the regional lymph node. SLND may not be the right choice in all cases. A time may come when the extent of lymph node dissection is determined individually for each case. Future verification results are awaited.

The correlation between No. 6 and No. 14v lymph node metastasis and the value of dissecting these lymph nodes in radical gastrectomy

Radical gastrectomy with D2 lymphadenectomy has been widely performed as the standard surgery for patients with gastric cancer in major medical centers in China and abroad. However, the exact extent of lymph node dissection is still controversial. In the latest version of the Japanese Gastric Cancer Treatment Guidelines, No. 14v lymph nodes (along the root of the superior mesenteric vein) are again defined as loco-regional lymph nodes, and it is clarified that distal gastric cancer presenting with infra-pyloric regional lymph node (No.6) metastasis is recommended for D2+ superior mesenteric vein (No. 14v) lymph node dissection. To explore the relevance and clinical significance of No.6 and No.14v lymphadenectomy in radical gastric cancer surgery, a review of the national and international literature revealed that No.6 lymph node metastasis was associated with No.14v lymph node metastasis, that No.6 lymph node status was a valid predictor of No.14v lymph node negative status and false negative rate, and that for gastric cancer patients with No. 14v lymph node negative and No.6 lymph node positive, the dissection of No.14v lymph node may also have some significance. The addition of No. 14v lymph node dissection in radical gastrectomy is safe, but it is more important to distinguish the patients who can benefit from it. Professor Liang Han of Tianjin Medical University Cancer Hospital is currently leading a multicenter, large-sample, prospective clinical trial (NCT02272894) in China, which is expected to provide higher level evidence for the clinical significance of lymph node dissection in No.14v.

Characteristics of lymph node (No.5 and No.6) metastasis and significance of lymph node dissection in Siewert type II esophagogastric junction adenocarcinoma (AEG): No.5 and No.6 lymph node metastases of AEG and clearance.

Background:To analyze the characteristics, related risk factors, and prognosis of lymph node metastasis (Number [No.] 5 and No.6) in the group of adenocarcinoma of esophagogastric junction (AEG).Methods:The patients with Siewert II AEG who underwent total gastrectomy and D2 lymph node dissection from September 2015 to December 2018 in Lanzhou University Second Hospital were enrolled in this study. The pathological features of the postoperative specimens were analyzed (sex, age, maximum diameter, location, depth of invasion, degree of differentiation, neurological and vascular invasion, etc), and the lymph node metastasis rate of No.5, No.6 groups were calculated. The analysis was performed by IBM SPSS statistical software. The risk factors associated with lymph node metastasis in No.5 and No.6 groups were analyzed. Survival analysis was performed by Kaplan-M method, and survival rate was estimated, Log-rank test was used for comparison, and the difference was statistically significant at P < .05.Results:There were 142 cases of Siewert type II AEG with the positive rate of No.5 lymph nodes being 10.81% (8/74), and the positive rate of No.6 lymph nodes was 8.33% (11/132). No.5 and No.6 lymph nodes metastasis were not associated with gender, age, tumor maximum diameter, location (cardiac left/cardiac right) (P > .05), and were associated with invasion depth, differentiation degree, nerve and vascular invasion (P < .05). In the No.5 lymph node-positive group, the 3-year Overall Survival (OS) was 25.0%, and the No.5 lymph node-negative group had a 5-year OS of 57.8%, which was statistically different (P < .05). The 3-year OS was 18.2% in No.6 node-positive group and 53.8% in No.6 node-negative group, and the difference was statistically significant (P < .05).Conclusion:For Siewert type II AEG, the lymph node metastasis rate was higher in No.5 and No.6 groups when the tumor invaded all layers of gastric wall and was poorly differentiated complicated with vascular nerve invasion, and the lymph node metastasis rate was lower at 3 years, which may be more appropriate for total gastrectomy +D2 lymph node dissection.

Clinical Significance of Lymph Node Dissection and Lymph Node Metastasis in Primary Appendiceal Tumor Patients After Curative Resection: a Retrospective Multicenter Cohort Study

PurposeDue to its rarity and biological heterogeneity, guidelines for primary appendiceal tumor (PAT) are based on scarce evidence, resulting in no strong recommendations. The present study explored prognosis-related factors, including the timing of lymph node dissection (LND), in PAT patients after curative resection (CR) to determine the optimal surgical therapies. MethodsWe retrospectively collected and analyzed data from 404 patients with PATs who underwent CR at 43 tertiary hospitals from 2000 to 2017. This manuscript is based on revised manuscript during review process. Please, change the bold characters to normal characters in the manuscript. ResultsAfter propensity score matching, there were no marked differences in the recurrence-free survival (RFS) or overall survival (OS) between the primary and secondary LND groups (P = 0.993 and 0.728). A multivariate analysis showed that lymph node metastasis (LNM) was an independent factor for the RFS (hazard ratio [HR] 2.59; 95% confidence interval [CI] 1.09–6.13; P = 0.031) and OS (HR 4.70; 95% CI 1.40–15.76; P = 0.012). There were significant associations between the LNM rates and tumor depth (P <0.0001) and the histological type (P = 0.006). There was no LNM in patients with low-grade appendiceal mucinous neoplasm (LAMN) or well-differentiated mucinous adenocarcinoma (G1) or patients with any Tis or T1 PATs. ConclusionsLNM was an independent prognostic predictor in PATs after CR with LND. Tumor depth and histological type were not prognostic predictors but were LNM predictors. Secondary LND based on the pathological findings of resected specimens is considered an acceptable surgical management without a worse prognosis than primary LND, and it may be omitted in LAMN+G1 or in any Tis and T1 PATs.

Is lymph node dissection for neuroendocrine carcinoma of the stomach effective as it is for adenocarcinoma?

BackgroundWe evaluated the significance of lymph node dissection for gastric neuroendocrine carcinoma (NEC) by calculating the therapeutic value index for each station. MethodsThis study included 2164 advanced gastric cancer patients (common-type [Common-GC], n = 2125; and gastric NEC [NEC-GC], n = 39). Clinicopathological data were collected, and survival, type of recurrence, and the index for each type of gastrectomy were determined. ResultsNEC-GC was characterized by an older population (P = 0.009), upper tumor location (P = 0.021), frequent venous invasion (P < 0.001), and less neural invasion (P = 0.043). NEC-GC tended to be more frequent in men (P = 0.152), and to be associated with total gastrectomy (P = 0.177) and M1 cases (P = 0.167).The five-year overall survival rates of the Common-GC and NEC-GC groups were 73.8% (95% confidence interval: 71.8–75.6) and 54.7% (37.5–68.9), respectively (P = 0.016).Both groups showed similar index values in each station. Regarding the index of the peri-gastric nodal station (D1 station)/stations away from the stomach (D2 station), although the index of the D1 station was similar in the two groups (41.3 and 43.1), the index of the D2 station in the NEC-GC group was approximately half that of the Common-GC group (10.0 and 5.3).The total recurrence rates of the two groups were similar (P = 0.871). However, the rates of hematogenous and lymphatic recurrence tended to be higher in the NEC-GC group (P = 0.132 and P = 0.152). ConclusionsThe therapeutic efficacy of the D1 station was similar in Common-GC and NEC-GC but that of the D2 station was worse in NEC-GC. Gastrectomy with D2 dissection would be less effective for NEC-GC.

Evaluation of the Site and Frequency of Lymph Node Metastasis with Non-Functioning Pancreatic Neuroendocrine Tumor

Backgrounds: The optimal lymph node dissection range in patients with non-functioning pancreatic neuroendocrine tumors is not yet clear. In this study, we investigated the site and frequency of lymph node metastasis and the significance of lymph node dissection in patients with non-functioning pancreatic neuroendocrine tumors. Methods: This retrospective study analyzed 74 patients who underwent a curative pancreatectomy for non-functioning pancreatic neuroendocrine tumors between 2000 and 2016. The site and frequency of lymph node metastasis and clinicopathological factors were evaluated. Results: The rate of synchronous lymph node metastasis was 17.6%, with 11.1 and 29.4% for tumors with diameters of 10–19 mm and ≥20 mm, respectively. Lymph node metastasis was not observed for tumors with a diameter <10 mm. Lymph node metastasis was observed along the anterior (17a: 13.3%, 17b: 12.5%) and posterior (13a: 5.9%, 13b: 26.7%) surfaces of the pancreatic head and the superior mesenteric artery (14p: 12.5%, 14d: 7.7%) in patients with non-functioning pancreatic head neuroendocrine tumors, in the common hepatic (8a: 5.3%), splenic (10: 14.3%, 11p: 17.6%, 11d: 12.5%), and super mesenteric artery (14d: 14.3%) in patients with non-functioning pancreatic body neuroendocrine tumors, and only in the splenic artery (11p: 8.3%, 11d: 7.7%) in patients with non-functioning pancreatic tail neuroendocrine tumors. Grade 2 (HR = 6.21) and synchronous lymph node metastasis (HR = 10.4) were significant risk factors for disease-free survival. The 5-year disease-free survival was 95.7, 72.6, and 0% in patients with 0, 1, and 2 prognostic factors, respectively. Conclusions: This study clarified the site and frequency of lymph node metastasis and the optimal range of lymph node dissection in patients with non-functioning pancreatic neuroendocrine tumors.

Endoscopic lymph node dissection for thymic malignancies: lateral thoracic intercostal and subxiphoid approaches.

The significance of lymph node dissection for thymic malignancies is currently unclear. Recently, endoscopic surgery has been indicated for the surgical treatment of thymic malignancies. We discussed the range of possible lymph node metastasis following surgery for thymic malignancies, depending on whether the lateral thoracic intercostal or the subxiphoid approach was used. While the video-assisted thoracoscopic surgery (VATS) lateral approach cannot be used for lymph nodes in the anterior region on the opposite side, it is simple enough to be used for deep-region lymph nodes. Taking an approach from the right facilitates paratracheal lymph node dissection. Taking an approach from the left may facilitate para-aortic and subaortic lymph node dissection. In addition, placing the patient in the lateral decubitus position also facilitates subcarinal lymph node dissection. The advantages of the subxiphoid approach are that a good field of vision of the cervical region can be obtained with a camera inserted from the midline of the body and the phrenic nerve on both sides can be confirmed. Accordingly, anterior lymph node dissection can be performed in a manner similar to median sternotomy. Deep-region lymph node dissection is more difficult via the subxiphoid approach than via the lateral thoracic intercostal approach. While paratracheal lymph nodes can be dissected to some extent, it is difficult to dissect subcarinal lymph nodes. If one prioritizes thorough anterior region lymph node dissection, either the subxiphoid or the bilateral lateral thoracic region approach needs to be taken. The subxiphoid approach offers the same view from the body midline as median sternotomy. Therefore, it is superior to the VATS lateral approach with regard to region lymph node dissection.

Prognostic Significance of Lymph Node Dissection Along the Upper-third-stomach in Patients With Lower-third Gastric Cancer.

The extent of lymph node (LN) dissection is defined according to the type of gastrectomy regardless of tumor location in recent Japanese gastric cancer treatment guidelines. However, lymphatic flow from lower-third stomach mainly drain to supra- and infra-pyloric nodes, as well as to partially lesser curvature nodes along the descending limb of the left gastric artery. In this study, we evaluated the prognostic impact of LN dissection of right paracardial (No. 1) and left greater curvature (No. 4sb) nodes in gastric cancer of lower-third stomach (LGC). A total of 239 patients with LGC who underwent distal gastrectomy at our hospital were retrospectively analyzed. The therapeutic value index (TVI) of each node was calculated by multiplying the incidence of LN metastasis by the 5-year survival rate of patients with metastasis to each nodal station. The incidence of No. 1 LN metastasis was 4.5% (positive/negative; 5/110 cases, unknown or no description; 129 cases). The 5-year survival rate of patients with metastasis to the node was 0%, and consequently the TVI of No. 1 LN station was "0". Similarly, the TVI of No. 4sb was found to be "0". Survival benefit of dissection of No. 1 and No. 4sb LNs was presumed to be extremely low, suggesting that dissection of these two LNs could be omitted in LGC patients when undergoing distal gastrectomy.

D3 LYMPHADENECTOMY IN RIGHT COLONIC RESECTION

Lymph node dissection in colon cancer is without a doubt necessary, it is just the extent of that dissection that is still under debate. As the individual steps of an oncologic operation cannot be separated from each other, analysis of the significance of lymph node dissection alone is difficult. It has been proven that the T category is directly related to the number and central spread of lymph node metastases. Micrometastases and isolated tumor cells may be detected in lymph nodes by using special staining techniques; their presence may worsen prognosis significantly and approximate it to UICC stage III. The numbers of dissected lymph nodes and the ratio of involved versus dissected lymph nodes have been used as markers for quality of surgery and histopathological evaluation. JMS 2018: 21 (2):109-113

Attention should be paid to the lymph node dissection after neoadjuvant therapy: interpretation of Chinese expert consensus on mediastinal lymph node dissection in esophagectomy for esophageal cancer (2017 edition)

At present, no consensus has been reached on the methods of dissection of lymph nodes in radical resection of esophageal carcinoma, especially the number and range of lymph node dissection after neoadjuvant therapy, and the sensitivity of the number of lymph node dissection to the pathological N stage after neoadjuvant therapy is low. Therefore, the significance of lymph node dissection needs to be further confirmed. The dissection of the chest lymph nodes is necessary, regardless of the method of lymph node dissection. According to the American Joint Commission for Cancer (AJCC)/Union for International Cancer Control (UICC) and the Japan Esophagus Society (JES) standards, Chinese expert consensus on mediastinal lymph node dissection in esophagectomy for esophageal cancer (2017 edition) puts forward the Chinese standard of the thoracic lymph node grouping of esophageal carcinoma in order to meet the practical needs of Chinese patients. Key words: Esophageal neoplasms; Thoracic surgical procedures; Lymph node excision; Neoadjuvant therapy

Prognostic impact of primary tumor resection and lymph node dissection in stage IV colorectal cancer with unresectable metastasis: a propensity score analysis in a multicenter retrospective study.

Retrospective studies have shown that primary tumor resection improves the prognosis of patients with colorectal cancer with unresectable metastasis (mCRC). Prognostic significance of lymph node dissection (LND) in mCRC has not been examined previously. The aim of this study was to investigate the prognostic impact of primary tumor resection and LND in mCRC. A total of 1,982 patients with mCRC from January 1997 to December 2007 were retrospectively studied. The impact of primary tumor resection and LND on overall survival (OS) was analyzed using Cox proportional hazards model and propensity score analysis to mitigate the selection bias. Covariates in the models for propensity scores included treatment period, institution, age, sex, carcinoembryonic antigen, tumor location, histology, depth, lymph node metastasis, lymphovascular invasion, and number of metastatic organs. In a multivariate analysis, primary tumor resection and treatment in the latter period were associated with an improved OS, and age over 70 years, female sex, lymph node metastasis, and multiple organ metastasis were associated with a decreased OS. In the propensity-matched cohort, patients treated with primary tumor resection showed a significantly better OS than those without tumor resection (median OS 13.8 vs. 6.3 months; p = 0.0001). Furthermore, among patients treated with primary tumor resection, patients treated with D3 LND showed a significantly better OS than those with less extensive LND (median OS 17.2 vs. 13.7 months; p < 0.0001). It was suggested that primary tumor resection with D3 LND improves the survival of patients with mCRC.

Patterns and Prognostic Significance of Lymph Node Dissection for Surgical Treatment of Perihilar and Intrahepatic Cholangiocarcinoma

IntroductionThe prognostic significance of lymph node dissection (LND), the number and status of harvested lymph nodes (LNs), and the lymph node ratio (LNR) are still under debate in intrahepatic (ICC) and perihilar (PCC) cholangiocarcinoma. The aims of this study were to evaluate the prognostic value of the extent of LN dissection, the number of positive LNs, the distribution of positive LNs along different LN stations, and the LNR in a cohort of patients with ICC and PCC who underwent surgical resection and to compare the different prognostic values of lymph node involvement. Material and MethodsA retrospective analysis was done evaluating extent of LND, number, status, and location of harvested LNs in a cohort of 145 patients with cholangiocarcinoma submitted to surgical resection with curative intent from 1990 to 2012. ResultsSeventy patients had ICC and 75 had PCC. The median survival times of patients with N0 and N+ tumors were 42 and 19 months in ICC patients (p = 0.05) and 42 and 22 months in PCC patients (p = 0.01). In patients without LN metastases, the median survival times of patients with up to three LNs retrieved and with more than three LNs retrieved were 38 and 69 months in ICC patients (p = 0.05) and 18 and 43 months in PCC patients (p = 0.04), respectively. In N+ patients, the location of positive LNs (hepatoduodenal ligament or other regional stations) did not influence overall survival in ICC or PCC patients (p = 0.6). The median survival times of patients with LNRs of 0 and >0.25 were 43 and 19 months in ICC patients (p = 0.01); the 0–0.25 group did not reach the value. In PCC patients, median survival of 0, 0–0.25, and >0.25 groups of patients were 42, 23, and 11 months (p = 0.01), respectively. ConclusionsLN metastasis is a major prognostic factor after surgical resection of cholangiocarcinoma. The number of harvested LNs and the LNR showed a high prognostic value in ICC and PCC.

Extended Lymphadenectomy in Colon Cancer is Crucial

No one doubts that lymph node dissection in colon cancer is necessary, it is just the extent of that dissection that is still under debate. As the individual steps of an oncologic operation cannot be separated from each other, analysis of the significance of lymph node dissection alone is difficult. It has been proven that the T category is directly related to the number and central spread of lymph node metastases. Micrometastases and isolated tumor cells may be detected in lymph nodes by using special staining techniques; their presence may worsen prognosis significantly and approximate it to UICC stage III. The numbers of dissected lymph nodes and the ratio of involved versus dissected lymph nodes have been used as markers for quality of surgery and histopathological evaluation. Recent results underscore the importance of technique and extent of dissection. Dissection must be performed along the embryologic planes of the mesocolon and leave them intact. A high vascular tie with preservation of the central hypogastric nerves must be applied in order to achieve the best oncologic results while preserving quality of life. Extended lymphadenectomy is oncologically relevant only when it is combined with removal of the primary tumor with adequate longitudinal clearance, an intact complete mesocolon, and high vascular tie. It is part of a concept in which the tumor-bearing specimen is harvested as an enveloped package to minimize the risk of tumor cell spillage and local recurrence.

Mo1495 Patterns and Prognostic Significance of Lymph-Node Dissection for Surgical Treatment of Peri-Hilar and Intrahepatic Cholangiocarcinoma

Mo1495 Patterns and Prognostic Significance of Lymph-Node Dissection for Surgical Treatment of Peri-Hilar and Intrahepatic Cholangiocarcinoma

Clinical Significance of Lymph Node Dissection in Patients with Muscle-Invasive Upper Urinary Tract Transitional Cell Carcinoma Treated with Nephroureterectomy

We investigated the value of lymph node dissection in patients with cN0 muscle-invasive transitional cell carcinoma of the upper urinary tract (UUT-TCC). Medical records of 152 patients with cN0 muscle-invasive UUT-TCC, who underwent nephroureterectomy between 1986 and 2005, were reviewed. Sixty-three patients (41.4%) underwent lymph node dissection. The median number of lymph nodes harvested was 6 (range, 1 to 35), and from these, lymph node involvement was confirmed in 9 patients (14.3%). Locoregional recurrence (LR) and disease-recurrence (DR) occurred in 29 patients and 63 patients, respectively. Fifty-five patients (36.2%) had died of cancer at the last follow-up. The number of lymph nodes harvested was associated with the reduction of LR (χ2trend=6.755, P=0.009), but was not associated with DR (χ2trend=1.558, P=0.212). In the survival analysis, N stage (P=0.0251) and lymph node dissection (P=0.0073) had significant influence on LR, but not on DR or disease-specific survival. However, the number of lymph nodes harvested did not affect LR-free, DR-free, or disease-specific survival. We conclude that lymph node dissection may improve the control of locoregional cancer, as well as staging accuracy, in cN0 muscle-invasive UUT-TCC, but that it does not clearly influence survival.

Significance of lymph node dissection of the superior mediastinal region in esophageal cancer patients

The effect of the superior mediastinal lymph node dissection was compared retrospectively with that of standard dissection in 108 esophageal cancer patients. Five-year survival rates were 46.3% in patients who underwent standard surgery (group A) and 39.3% in patients who underwent superior mediastinal lymph node dissection (group B). The survival curves were basically the same. Nineteen out of 42 (45.2%) tumors in group A and 24 out of 66 (36.4%) tumors in group B recurred. The distribution of the first sites of recurrence did not differ significantly between groups. However, 14 tumors (67%) in group A recurred in the lymph nodes, but only seven tumors recurred (28%) in the lymph nodes in group B. Eleven tumors (52%) in group A recurred to superior mediastinal nodes, but only one tumor (4%) recurred to a superior mediastinal node in group B. Fourteen of the group B patients showed metastasis to superior mediastinal lymph nodes and none of these patients survived for more than 5 years. Eleven of these 14 patients showed metastasis to only one or two nodes. Based on our data and other reported findings, we conclude that extended lymphadenectomy of the superior mediastinal region alone does not contribute to improved survival of esophageal cancer patients, but it does contribute to the prevention of lymph node recurrence in this region.

Prognostic significance of lymph node dissection in gastric cancer.

The results for 162 patients who underwent curative gastrectomy for gastric cancer from January 1988 to June 1994 were analysed statistically with special reference to the effect of lymph node dissection. Median survival was 69.3 months and the overall cumulative 5-year survival rate was 50.2 (95 per cent confidence interval (c.i.) 41.6-58.1) per cent. By univariate analysis age, histology, depth of tumour invasion, node involvement, number of metastatic lymph nodes and type of lymphadenectomy were found to be significant factors related to survival time. Multivariate analysis with the Cox model and stratified for tumour node metastasis stage revealed that only the number of metastatic nodes (P = 0.04) and the extent of lymphadenectomy (P = 0.003) affected survival independently. With respect to D1 lymphadenectomy, the relative risk associated with D2 and D4 lymphadenectomy was respectively 0.61 (95 per cent c.i. 0.34-1.10) and 0.26 (95 per cent c.i. 0.12-0.60). The 5-year survival rate was 28 per cent for patients who had a D1 dissection, 63 per cent for those who had D2 and 68 per cent for those who had D4. These results suggest that extended lymphadenectomy (D2) and especially superextended lymphadenectomy (D4) can improve survival in patients with gastric cancer.

The Number of Metastatic Lymph Nodes in Extrahepatic Bile Duct Carcinoma as a Prognostic Factor

The number of lymph nodes with metastases is known to be an important prognostic factor in carcinomas of many organs. The insufficient sampling of lymph nodes has also been associated with worse outcome in several types of carcinoma. However, the prognostic significance of lymph node dissection is not well characterized in extrahepatic bile duct (EBD) carcinomas. For 209 patients with EBD carcinoma, the total number of retrieved lymph nodes and the number of metastatic lymph nodes were evaluated, and other clinicopathologic variables were correlated with patient survival. The number of retrieved lymph nodes was not significantly correlated with survival in this study. The presence of metastasis to lymph nodes significantly decreased survival of patients with EBD carcinoma. The patients with 5 or more metastatic lymph nodes had significantly worse survival than those with 4 or less metastatic lymph nodes. To evaluate the prognosis of the patients with EBD carcinomas more precisely, the number of metastatic lymph nodes as well as the status of metastasis to lymph nodes should be examined and reported. Based on the present data, we propose that nodal classification should be divided into N1 (metastasis in 1 to 4 regional lymph nodes) and N2 (metastasis in 5 or more regional lymph nodes).