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Valerie Rusch
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J Thorac Cardiovasc Surg 2006;132:1374-1381
© 2006 The American Association for Thoracic Surgery


General Thoracic Surgery

The prognostic importance of the number of involved lymph nodes in esophageal cancer: Implications for revisions of the American Joint Committee on Cancer staging system

Nabil Rizk, MDa,*, Ennapadam Venkatraman, PhDb, Bernard Park, MDa, Raja Flores, MDa, Manjit S. Bains, MDa, Valerie Rusch, MDa

a Thoracic Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY
b The Biostatistics Service, Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY.

Received for publication December 19, 2005; revisions received March 28, 2006; accepted for publication July 12, 2006.

* Address for reprints: Nabil Rizk, MD, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10021 (Email: rizkn{at}mskcc.org).


    Abstract
 Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 References
 
OBJECTIVE: The American Joint Committee on Cancer (AJCC) staging system for esophageal cancer is controversial because it relies on arbitrary definitions of the anatomic location of lymph nodes to establish N and M status. It has been proposed that the number of involved lymph nodes may better predict survival. We reviewed our experience to determine the prognostic impact of the number of involved nodes and the extent of lymphadenectomy on the current staging system.

METHODS: Records of all patients who underwent resection of previously untreated adenocarcinoma and squamous cell carcinoma of the esophagus and gastroesophageal junction were reviewed. Overall survival according to the AJCC staging system and the number of involved lymph nodes was analyzed by the method of Kaplan and Meier and by recursive partitioning methods.

RESULTS: Data were available on 336 patients operated on between January 1996 and September 2003. Recursive partitioning analysis using AJCC staging variables reproduced the AJCC staging system. When the number of involved lymph nodes is added, patients with more than 4 involved lymph nodes have survival similar to that of patients with M1 disease, and patients with no involved lymph nodes have the best prognosis. Recursive partitioning analysis identified 18 lymph nodes as the minimal number required for accurate staging. In patients who have 18 or more lymph nodes removed, survival is only predicted by the presence of nodal involvement and M1 disease.

CONCLUSION: Our analysis suggests that revisions of the current AJCC staging system for esophageal cancer should include N staging based on the number of involved lymph nodes and minimal requirements for the extent of lymphadenectomy.



Abbreviations and Acronyms AJCC = American Joint Committee on Cancer



    Introduction
 Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 References
 
GoThe current version of the American Joint Committee on Cancer (AJCC) staging system1Go for esophageal cancer has not changed significantly from previous ones, and it remains controversial. A major concern is that the current descriptors for N staging are based on arbitrary definitions of the anatomic locations of lymph nodes, which may not correlate accurately with overall survival. Previous reports from our group and others2-8Go suggest that the number of involved lymph nodes predicts survival more reliably. In addition, the current staging system does not fully address the issue of what constitutes an adequate lymphadenectomy for staging. Both of these features have already been incorporated into the staging of gastric cancer, which now includes three nodal groupings (N0, N1, and N2) based on the number of involved lymph nodes, and there is a minimal requirement for the number of lymph nodes to be removed below which staging is considered unreliable.1Go

The purpose of this study is to analyze our recent experience with a large group of patients with esophageal cancer treated exclusively by surgical resection, using recursive partitioning methods as a robust statistical approach to evaluate the issue of lymph node involvement in esophageal cancer staging. Specifically, we address whether the number of involved lymph nodes should be part of a staging system and what constitutes an adequate lymphadenectomy for staging purposes. In addition, we investigate the significance of M1a nodes relative to N1 nodes. Of note, we do not address in this study separate but important issue within the staging system, namely whether the T1 descriptor should be dichotomized into two separate categories as has been advocated by some.3Go Similarly, we do not address other factors that might contribute to a future staging system, such as tumor differentiation, vascular and neural invasion, and extracapsular nodal invasion. Although these are important considerations, we do not have a sufficient number of patients to answer these questions.


    Methods
 Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 References
 
Acquisition of Clinical Data
We undertook a retrospective review of all esophagectomies performed for cancer at Memorial Sloan-Kettering Cancer Center between January 1996 and September 2003. January 1996 is the time point at which an institutional electronic medical record system was instituted, and it is therefore a date from which highly reliable data can be obtained. Patients who did not have survival information available were excluded from this analysis. We also excluded patients who received induction chemotherapy or radiation before surgery. We included patients who had adenocarcinoma or squamous cell carcinoma of the thoracic esophagus with or without involvement of the gastroesophageal junction and gastric cardia.

The data collected included patient demographics, the tumor histologic type and location, the depth of tumor invasion, and the number and location of all malignant and benign lymph nodes. Overall survival, as calculated from the time of operation, was confirmed from the Social Security Death Index. January 2004 was the censoring date for survival.

TNM Classification
The T, N, and M descriptors and staging classification used for this analysis were those defined in the sixth edition of the AJCC Cancer Staging Manual,1 the version in use at the time this analysis was performed. Because of some variations in the nomenclature used by surgeons and pathologists in identifying the exact location of lymph nodes within a resected specimen, lymph nodes were consistently identified as "celiac axis" if they were labeled as left gastric, splenic, celiac, or hepatic. Within the chest, lymph nodes were identified as subcarinal lymph nodes if they were labeled as level 7, left main stem, or right main stem. M1a nodes were labeled according to the primary tumor location. "Celiac axis" nodes were M1a for distal esophageal, gastroesophageal junction, and gastric cardia tumors that involved the gastroesophageal junction. Cervical lymph nodes were M1a for tumors of the proximal one third of the esophagus. The total number of involved lymph nodes included any positive lymph node found excluding remote nodes that would be assigned as M1b. The overall number of lymph nodes included the sum of all involved lymph nodes plus all benign lymph nodes found. Disease was considered M1b if nodes were positive outside the regional basin or if visceral metastases were identified. Within the various analyses, we include two M categories, namely M1b and M1. M1 combines the M1a and M1b descriptors. These two M categories are used in an attempt to establish whether M1b and M1a are distinct groups. Because M1a nodes and the number of involved lymph nodes are so closely associated, M1a could not be analyzed in a similar manner. Therefore, analyses that did not distinguish between M1b and M1 nodes were used as indirect evidence of the relevance of M1a nodes. The T stage was based on the depth of tumor invasion into the esophageal wall as described in the AJCC staging manual.

Statistical Analysis
Patient characteristics are described with categorical variables and medians and range are used for continuous variables. Survival time was measured from the date of surgery to the date of death or last follow-up. Survival curves were estimated by the Kaplan-Meier method.9Go Maximum log-rank analysis10Go was used to determine the optimal cutoffs for lymph node numbers. Recursive partitioning11Go was used to develop a scheme to classify patients into stage categories, because the goal of a staging system is to group the patients into homogenous categories with respect to their prognosis (in this case overall survival). Because several clinical characteristics (T, N, M, lymph node numbers) affect the prognosis of a patient, traditional multivariable modeling such as Cox proportional hazards regression to account for these covariates does not provide a simple way to group the patients by prognostic categories. Recursive partitioning, on the other hand, partitions the patients recursively at each step into two groups on the basis of the covariate that gives the maximal separation with respect to their prognosis. In addition to providing an algorithm to group the patients into categories, it accounts for interactions between factors and, therefore, was considered the most appropriate statistical method for this study. Recursive partitioning was done using the RPART routines of Therneau and Atkinson.12Go This algorithm partitions patients after scaling the survival times so as to fit an exponential model. The hazard rates in the "exponential-scaled" times of terminal nodes are reported. Also reported in the analyses is the number of patient who died relative to the overall number of patients within the subset.


    Results
 Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 References
 
Clinical Data
During the study period, 710 esophagectomies were performed, and 336 of these were appropriate for this analysis. A total of 284 patients received chemotherapy and radiation and 60 patients received chemotherapy alone before surgery and were therefore excluded. Additional patients were excluded because of lack of follow-up (n = 10), histologic classification other than squamous or adenocarcinoma (n = 10), inadequate pathologic data (n = 5), and prior esophageal resection (n = 5). The median age of the 234 (69.6%) men and 102 (30.4%) women was 66.8 years. Patient demographics, tumor location and histologic type, and the numbers of involved lymph nodes are shown in Tables 1 and 2. Go According to the 2002 AJCC staging system, 30 patients had stage 0 disease, 84 stage I, 67 stage IIa, 31 stage IIb, 70 stage III, 27 stage IVa, and 27 patients had stage IVb disease.


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TABLE 1. Characteristics of the 336 patients studied
 

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TABLE 2. Relationship between AJCC stage and number of positive lymph nodes
 
AJCC Staging System
Kaplan-Meier analysis of overall survival showed poor discrimination between stages IIa and IIb (P = .71), as well as between stages IVa and IVb (P = .81) (Figure 1). Recursive partitioning analysis using the variables T, N, and M (M1b and M1) essentially recreates the AJCC staging system with the exception of the M descriptor (Figures 2 and E1). Go The most important determinant of overall survival in this analysis is the presence of involved lymph nodes. Among patients with N0 tumors, T stage had a significant impact on survival, with stages T0, T1, and T2-4 forming distinct survival curves. Among node-positive patients, T1-2 N1 M0, T3-4 N1 M0, and T3-4 N1 M1 form separate survival curves. This analysis indicates no significant difference between the M1 and M1b categories. In summary, recursive partitioning analysis using the established variables within the AJCC system supports the current stage groupings except for the distinction between IVa and IVb, which should be combined.


Figure 1
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Figure 1. Kaplan-Meier analysis of overall survival showed poor discrimination between stages IIa and IIb (P = .71), as well as between stages IVa and IVb (P = .81).

 

Figure 2
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Figure 2. Recursive partitioning analysis using the variables T, N, and M (M1b and M1) essentially recreates the AJCC staging system with the exception of the M descriptor. AJCC, American Joint Committee on Cancer.

 

Figure 1
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Figure E1. Recursive partitioning analysis using T, N, M as variables.

 
Significance of the Number of Involved Lymph Nodes
Recursive partitioning analysis that includes the number of involved lymph nodes as a variable in addition to T, N, and M (M1b and M1) identified the presence of more than 4 involved lymph nodes as the single most important discriminator of survival, irrespective of T stage (Figures 3 and E2). Go This group of patients, which includes 29 of 54 patients having either stage IVa or IVb disease according to the AJCC system, has an overall survival (median 14.1 months) that is similar to that of the remaining patients who are in stage IV under the current AJCC system (median 18.5 months) (P = .24). A more focused analysis of survival in relationship to the number of involved lymph nodes was done in T2-3 tumors. This analysis excluded T1 lesions because only 14 of these 98 patients had lymph nodes involved, and including these patients in the analysis would have the effect of biasing the survival in favor of node-negative patients. T4 patients were also excluded because there were only 2 patients in this group, both of whom were node positive. Results from this analysis show that 0 and more than 4 positive lymph nodes form distinct prognostic groups in T2-3 tumors and that in patients with between 3 and 4 positive lymph nodes the prognosis worsens significantly (Figure 4). Thus, within AJCC stages IIb, III, and IVa, distinct survival curves are generated if patients are separated by these 3 nodal groupings (Figure E3). In summary, recursive partitioning analysis that includes the number of involved lymph nodes as a variable identifies greater than 4 positive lymph nodes as equivalent to current AJCC stage 4. Additional analysis further identifies 3 prognostic nodal groupings in T2-3 tumors, namely 0, 1 to 3-4, and more 4 positive nodes. This analysis also does not support the distinction between M1a and M1b.


Figure 3
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Figure 3. Recursive partitioning analysis that includes the number of involved lymph nodes as a variable in addition to T, N, and M (M1b and M1) identified the presence of more than 4 involved lymph nodes as the single most important discriminator of survival, irrespective of T stage.

 

Figure 2
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Figure E2. Recursive partitioning analysis using T, N, M and number of positive lymph nodes as variables. LN, Lymph nodes.

 

Figure 4
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Figure 4. In T2-3 tumors, patients with no positive lymph nodes have the best prognosis, and patients with 4 or more positive lymph nodes have the worst prognosis.

 

Figure 3
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Figure E3. Recursive partitioning analysis using T, N, M, number of positive lymph nodes, and total number of lymph nodes as variables. LN, Lymph nodes.

 
Impact of Overall Lymph Node Number on AJCC Staging
A recursive partitioning analysis that includes the total number of lymph nodes resected as a variable in addition to T, N, and M (M1b and M1) stages and the number of involved lymph nodes reveals again that patients with more than 4 lymph nodes involved had the worst survival. Furthermore, among of T2-3 tumors with 0 to 4 involved lymph nodes, survival was significantly better if more than 18 lymph nodes were removed (Figures 5 and E4). Go The more extensive lymphadenectomy in the group with more than 18 lymph nodes removed was reflected in the abdominal compartment (mean 14.5 vs 7.2 lymph nodes), the thoracic compartment (mean 11.3 vs 4.6 lymph nodes), and the region spanning the gastroesophageal junction (mean 7.8 vs 4.4 lymph nodes). The consequence of requiring a minimal lymphadenectomy for adequate staging is evident in a recursive partitioning analysis performed only in patients who had more than 18 nodes removed, using T, N, and M (M1b and M1) and the number of involved lymph nodes as variables. In this analysis, the depth of invasion (T stage) is no longer a significant predictor of survival, with the best prognostic group being T anyN (0 positive nodes), followed by T anyN (1-4 positive nodes) M0. Tumors that were T anyN (1-4 positive nodes) M1 or T anyN (>4 positive nodes) M0-1 all had similarly poor prognoses (Figures 6 and E5). The probable reason for this difference in survival based on the extent of lymphadenectomy is inadequate staging and stage migration. This is demonstrated in an analysis of the likelihood of identifying involved lymph nodes when tumors are stratified by depth of invasion (Table 3). In T2 tumors, both the likelihood of finding N1 nodes (P < .01) and the mean number of positive nodes identified (P = .046) are higher if more than 18 lymph nodes are removed. Similarly, in T3 tumors, the mean number of positive nodes found is greater in patients with an adequate lymphadenectomy (P = .01), whereas the likelihood of finding any N1 nodes was the same (P = .8). In summary, this analysis identifies 18 total lymph nodes as a threshold, below which patients’ extent of disease is likely understaged. When an adequate lymphadenectomy is done, furthermore, depth of invasion no longer is prognostic of survival, likely owing to a more thorough assessment of the true likelihood of nodal involvement.


Figure 5
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Figure 5. Among of T2-3 tumors with 0 to 4 involved lymph nodes, survival was significantly better if more than 18 lymph nodes were removed.

 

Figure 4
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Figure E4. Recursive partitioning analysis using T, N, M and total number of lymph nodes as variables in patients with more than 18 lymph nodes removed. LN, Lymph nodes.

 

Figure 6
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Figure 6. In patients with an adequate lymphadenectomy (>18 lymph nodes removed), depth of invasion is no longer a significant predictor of survival.

 

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TABLE 3. Relationship between depth of invasion and the likelihood of lymph node involvement based on the extent of the lymphadenectomy
 
Significance of Lymph Node Location (N1 vs M1a)
The impact of node location on prognosis is difficult to ascertain from this group of patients because of the strong association between M1a nodes and a large nodal burden. Eighteen of the 27 patients with M1a nodes (63%) had more than 4 involved lymph nodes, and of the remaining 9 patients, 4 had fewer than 18 lymph nodes removed. Within the group of adequately staged patients, therefore, only 5 of 127 patients (4%) with fewer than 4 involved lymph nodes had M1a nodes, further strengthening the association of M1a nodes with a large lymph node burden. Indirectly, each analysis that included the M1 and M1b categories pointed to the lack of distinctness of M1a from M1b nodes.


    Discussion
 Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 References
 
The current AJCC staging system for esophageal cancer emphasizes the importance of depth of invasion (T) and the involvement of lymph nodes based on anatomic location (N1, M1a). This is different from the current staging systems for other gastrointestinal tract cancers, including gastric and colorectal cancer, in which N stage is based on the number of involved lymph nodes and minimal requirements for lymphadenectomy exist. For example, in patients with adequately staged gastric cancer, the number of involved lymph nodes has been shown to reflect the true burden of disease and, therefore, to predict outcome.13-15Go

Similar findings regarding the importance of lymph node numbers have been reported in esophageal cancer,2-8,15,16Go but with varying recommendations as to the number and exact cutoffs for lymph node groupings. In our previous study, based on a smaller, more heterogeneous, and earlier patient cohort, we suggested separating tumors according to whether they were N0 or had 1 to 3 or 4 or more lymph nodes involved.2Go Most studies have also recommended 3 nodal groupings,3-7Go while some recommend 415,16Go and others 2 groupings.8Go The basis for selecting these various cutoffs is not specified in most of these studies, however, and often it is not evident how the interactions between the various staging variables were accounted for. For instance, although Baba and associates7Go propose 3 nodal groupings (N0-1, N2-5, N > 5), it is not stated how these numbers were chosen, nor were these groupings subjected to a multivariate analysis. Similarly, while Igaki and associates8Go restrict their evaluation to T1 and T2 lesions, they do not specify how their lymph node groupings were selected. In our current study, we use recursive partitioning analysis as a nonbiased means to identify appropriate lymph node cutoffs, with the additional advantage that this type of analysis accounts for interactions with other variables. Furthermore, the recursive partitioning algorithm uses a cross-validation approach to prevent the overfitting of data. Thus, we have confidence in the reproducibility of the inferences drawn even though the size of the data used is limited. This resulted in the identification of 3 nodal groups in patients with adequately staged disease.

The extent of lymphadenectomy and its impact on staging, on the other hand, has not been directly addressed in studies of the staging of esophageal cancer. There is, however, indirect evidence of the impact of a lymphadenectomy on staging. In publications that report more extensive lymphadenectomies, reported survival is typically better stage for stage than would be expected.4,17Go Although proponents of the more extensive operations attribute this survival advantage to surgical technique,18,19Go this finding could be at least partially attributed to "stage migration" owing to better identification of involved lymph nodes.20Go Indeed, patients who undergo cervical node dissection (3-field) frequently have occult positive lymph nodes detected,17,18,21Go possibly as a result of skip metastases.22Go Further evidence that a more extensive lymphadenectomy leads to potential stage migration was shown by Nigro and associates,23Go wherein they demonstrate that in T1 tumors, patients who undergo an en bloc esophagectomy are significantly more likely to have positive lymph nodes identified than patients who have a transhiatal esophagectomy. In our current study, we show that stage for stage, survival is worse if a lesser lymphadenectomy is done. Moreover, we show that this survival difference is likely to the result of stage migration because the probability of identifying positive lymph nodes is directly correlated to the adequacy of the lymphadenectomy. As a consequence, when only including patients with an adequate lymphadenectomy, depth of invasion no longer is prognostic of outcome, and a 3-tiered staging system is created based primarily on the number of involved lymph nodes. Because of the close association between the depth of invasion and the likelihood of lymph node involvement,17,24Go it is not surprising that when nodal status is adequately assessed, depth of invasion would no longer provide surrogate information regarding the nodal status and T status would no longer independently predict survival. Supporting evidence for this includes data from Hsu and coworkers,25Go who found that, once there was nodal involvement, T status no longer predicted survival. Likewise, Altorki and colleagues17Go showed that the survival of patients with AJCC stage I is similar to that of patients with stage IIa disease, indicating little influence of depth of invasion on survival in patients with adequately staged node-negative disease. This is in contrast to Orringer, Marshall, and Iannettoni’s experience26Go with transhiatal esophagectomy, wherein the 5-year survival of stage I is significantly better than in stage IIa.

Evaluation of the significance of M1a nodes in this group of patients showed that there is a strong correlation between M1a status and a large nodal burden. In addition, while a univariate comparison of survival between patients with M1a nodes compared with those with N1 nodes does indeed show the former to have a worse survival (10.6 months vs 20.8 months, P = .006, respectively), in none of our analyses did M1a independently predict survival when analyzed in conjunction with lymph node number. This result is at odds with some reports,27Go whereas others have supported this finding.3,28Go Our previous study supported both lymph node numbers and location as prognostic variables.2Go That study, however, included significantly fewer patients (n = 216), 15% of whom received preoperative therapy. Furthermore, the analysis of lymph node location in our earlier study was done independently of lymph node number, with the only supporting evidence for the importance of M1a nodes being the lack of correlation between lymph node number and lymph node location.

There are several drawbacks in our current study. Although the median number of nodes removed is relatively high compared with most studies, it clearly is also less than what some others have reported. In addition, by performing only the equivalent of a 2-field lymphadenectomy, we are not assessing cervical lymph nodes. These issues might contribute to understaging. A separate concern, which we do not address in this study because of the number of patients, is the potential difference in staging between squamous cell carcinoma and adenocarcinoma, an issue raised by Siewert and associates,24Go among others. Similarly, the question of whether T1 lesions should be stratified into T1a and T1b3Go can only be addressed if both depth of invasion and nodal involvement are addressed. Unfortunately, this cohort of patients is too small to yield a valid answer, with only 26 T1a lesions and 69 T1b lesions, only 13 including lymph node involvement. Last, a significant number of patients with advanced-stage disease were excluded from this analysis (n = 344). At our institution, we at present commonly use preoperative chemoradiotherapy in patients whose clinical stage is IIa or greater, reflecting a change in practice compared with the earlier periods in this study. As such, the majority of patients in this analysis who have an advanced pathologic stage represent patients from earlier time points in this series. For instance, in 1996, 82% of the patients in this analysis were in AJCC stage II or higher, whereas in 2003 the stage distribution included 65% of patients with AJCC stages 0 or I. Furthermore, as a group, the patients in this series were older than patients in our institution who received preoperative therapy (66.8 vs 59.8, P < .001, respectively), reflecting a bias to not offer multimodality treatment in older patients. While excluding patients who received preoperative therapy is necessary for proper interpretation of the staging characteristics, the impact of the consequent selection bias is unclear.

In summary, the analyses presented in this study suggest that several modifications could improve the current esophageal cancer staging system, including a recommendation that a minimum of 18 lymph nodes be removed for reliable staging and that the N stage be separated into 3 categories, namely N0, 1 to 4 positive nodes, and more than 4 positive nodes. Although not definitive, our results suggest that these groupings for lymph node involvement could supplant the M1a and M1b descriptors in the current staging system. Thus, a revised staging system could include M0 and M1 descriptors only with M1 designating distant visceral metastases, as is common in the AJCC staging systems for other malignant diseases. A study with a larger number of patients would be necessary to incorporate these proposed lymph node groupings (in the context of an adequate lymphadenectomy) into a formal staging system. Furthermore, future studies with larger numbers of patients will be necessary to incorporate additional prognostic variables such as lymph node size, evidence of extracapsular nodal invasion, and other histologic and perhaps molecular characteristics of the tumor.

In conclusion, we would recommend that any future staging system for esophageal cancer include the number of involved lymph nodes rather than just whether lymph nodes are involved. Furthermore, for the staging system to reliably represent the true tumor burden, we would also recommend that a minimum number of lymph nodes be removed.29Go


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    References
 Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 References
 

  1. AJCC Cancer Staging. 6th ed.. New York: Springer-Verlag; 2002.
  2. Korst R, Rusch VW, Venkatraman E, Bains MS, Burt ME, Downey RJ, et al. Proposed revision of the staging classification for esophageal cancer. J Thorac Cardiovasc Surg 1998;115:660-670.[Abstract/Free Full Text]
  3. Rice TW, Blackstone EH, Rybicki LA, Adelstein DJ, Murthy SC, DeCamp MM, et al. Refining esophageal cancer staging. J Thorac Cardiovasc Surg 2003;125:1103-1113.[Abstract/Free Full Text]
  4. Hagen JA, DeMeester SR, Peters JH, Chandrasoma P, DeMeester TR. Curative resection for esophageal adenocarcinoma: analysis of 100 en bloc esophagectomies. Ann Surg 2001;234:520-531.[Medline]
  5. Ellis FHE, Healy GJ, Krasna MJ, Williamson WA, Balogh K. Esophagogastrectomy for carcinoma of the esophagus and cardia: a comparison of findings and results after standard resection in three consecutive eight-year intervals with improved staging criteria. J Thorac Cardiovasc Surg 1997;113:836-848.[Abstract/Free Full Text]
  6. Collard JM. Exclusive radical surgery for esophageal adenocarcinoma. Cancer 2001;91:1098-1104.[Medline]
  7. Baba M, Aikou T, Yoshinaka H, Natsugoe S, Fukumoto T, Shimazu H, et al. Long-term results of subtotal esophagectomy with three-field lymphadenectomy for carcinoma of the thoracic esophagus. Ann Surg 1994;219:310-316.[Medline]
  8. Igaki H, Kato H, Tachimori Y, Nakanishi Y. Prognostic evaluation of patients with clinical T1 and T2 squamous cell carcinomas of the thoracic esophagus after 3-field lymph node dissection. Surgery 2003;133:368-374.[Medline]
  9. Kaplan EL, Meier P. Nonparametric estimator from incomplete observations. J Am Stat Assoc 1958;55:457-481.
  10. Lausen B, Schumacher M. Maximally selected rank statistics. Biometrics 1992;48:73-85.
  11. Breiman L, Friedman JH, Olshen RA, Stone CJ. Classification and regression trees. Belmont [CA]: Wadsworth International Group; 1984.
  12. Therneau TM, Atkinson EJ. An introduction to recursive partitioning using the RPART routine. Technical Report 61. Rochester [MN]: Mayo Clinic, Section of Statistics; 1997.
  13. Karpeh M, Leon L, Klimstra D, Brennan MF. Lymph node staging in gastric cancer: is location more important than number?. An analysis of 1,038 patients. Ann Surg 2000;232:362-371.[Medline]
  14. Ichikura T, Tomimatsu S, Uefuji K, Kimura M, Uchida T, Morita D, et al. Evaluation of the New American Joint Committee on Cancer/International Union Against Cancer classification of lymph node metastasis from gastric carcinoma in comparison with the Japanese classification. Cancer 1999;86:553-558.[Medline]
  15. Roder J, Bottcher K, Busch R, Wittekind C, Hermanek P, Siewert JR. Classification of regional lymph node metastasis from gastric carcinoma. Cancer 1998;82:621-631.[Medline]
  16. Feith M, Stein H, Siewert R. Patterns of lymphatic spread of Barrett’s cancer. World J Surg 2003;27:1052-1057.[Medline]
  17. Altorki N, Kent M, Ferrara C, Port J. Three-field lymph node dissection for squamous cell and adenocarcinoma of the esophagus. Ann Surg 2002;236:177-183.[Medline]
  18. Lerut T, Coosemans W, DeLeyn P, Moons J, Nafteux P, Van Raemdonk D. Extended surgery for cancer of the esophagus and gastroesophageal junction. J Surg Res 2004;117:58-63.[Medline]
  19. Hulscher JBF, Van Sandick JW, DeBoer AGEM, Wijnhoven BP, Tijssen JG, Fockens P, et al. Extended transthoracic resection compared with limited transhiatal resection for adenocarcinoma of the esophagus. N Engl J Med 2002;347:1662-1669.[Abstract/Free Full Text]
  20. Hulscher JBF, Van Sandick JW, Offerhaus GJA, Tilanus HW, Obertop H, Van Lanschot JJB. Prospective analysis of the diagnostic yield of extended en bloc resection for adenocarcinoma of the esophagus or gastric cardia. Br J Surg 2001;88:715-719.[Medline]
  21. Tachibana M, Dhar DK, Kinugasa S, Kotoh T, Shibakita M, Ohno S, et al. Esophageal cancer with distant lymph node metastasis: prognostic significance of metastatic lymph node ratio. J Clin Gastroenterol 2000;31:318-322.[Medline]
  22. Hosch SB, Stoecklein NH, Pichlmeier U, Rehders A, Scheunemann P, Niendorf A, et al. Esophageal cancer: the mode of lymphatic tumor cell spread and its prognostic significance. J Clin Oncol 2001;19:1970-1975.[Abstract/Free Full Text]
  23. Nigro JJ, Hagen JA, DeMeester TR, DeMeester SR, Peters JH, Oberg S, et al. Prevalence and location of nodal metastases in distal esophageal adenocarcinoma confined to the wall: implications for therapy. J Thorac Cardiovasc Surg 1999;117:16-25.[Abstract/Free Full Text]
  24. Siewert RJ, Stein H, Feith M, Bruecher B, Bartels H, Fink U. Histologic tumor type is an independent prognostic parameter in esophageal cancer: lessons from more than 1,000 consecutive resections at a single center in the Western world. Ann Surg 2001;234:360-369.[Medline]
  25. Hsu CP, Chen CY, Hsia JY, Shai SE. Prediction of prognosis by the extent of lymph node involvement in squamous cell carcinoma of the thoracic esophagus. Eur J Cardiovasc Surg 2001;19:10-13.
  26. Orringer MB, Marshall B, Iannettoni, MD. Transhiatal esophagectomy: clinical experience and refinements. Ann Surg 1999;230:392-403.[Medline]
  27. Eloubeidi MA, Wallace MB, Hoffman BJ, Leveen MB, Van Velse A, Hawes RH, et al. Predictors of survival for esophageal cancer patients with and without celiac axis lymphadenopathy: impact of staging endosonography. Ann Thorac Surg 2001;72;:212-220.[Abstract/Free Full Text]
  28. Christie NA, Rice TW, DeCamp MM, Goldblum JR, Adelstein DJ, Zuccaro G, et al. M1A/M1B esophageal carcinoma: clinical relevance. J Thorac Cardiovasc Surg 1999;188:900-907.
  29. Siewert RJ, Feith M, Werner M, Stein H. Adenocarcinoma of the esophagogastric junction: results of surgical therapy based on anatomical/topographic classification in 1002 consecutive patients. Ann Surg 2000;232:353-361.[Medline]



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