TNM classification: clarification of number of regional lymph nodes for pN0

Prognostic impact of the number of resected lymph node on survival in Colorectal Cancer

Introduction Colorectal Cancer (CRC) is the third most common cancer and the second leading cause of death in Western countries. In Portugal, in the North, emerges as the second most common cancer. The presence of lymph node metastasis is an important predictor of overall and disease-free survival and several studies recommend the evaluation of at least 12–14 regional lymph nodes, as it contributes to improve cancer staging and patient outcomes.

Aims Epidemiological characterization of the studied population and identify a possible relationship between the number of lymph nodes evaluated in the surgical specimen and survival.

Methods We preceded to the study of 1065 CCR patients, submitted to surgical resection between 1 January 2000 and 31 August 2012, in Braga Hospital.

Discussion/Conclusion The results of the epidemiological characterization of this population are coincident with those described in the literature. It was observed a significant correlation between age, tumor size, serosal invasion, differentiation, tumor penetration, venous and lymphatic invasion, metastasis, TNM stage and the number of lymph nodes evaluated. However, we did not observe a statistically significant correlation between patient survival and number of lymph nodes evaluated (p > 0.05). A possible explanation is the practice of oncologists, addressing patients with less than 12 nodes identified in the surgical specimen as “N-positive” and undergoing adjuvant therapy. A better harvest and careful analysis of lymph nodes would lead to more accurate staging, avoiding overtreatment and side effects associated, and allow better economic management of hospital resources, in real N0 patients.

Evaluation of pharyngeal swallowing pressure using high-resolution manometry during transoral surgery for oropharyngeal cancer

BACKGROUND

Transoral robotic surgery is frequently described, driven by the desire to offer a less morbid alternative to chemoradiation. However, the objective evaluation of post-operative function has rarely been reported. Therefore, high-resolution manometry was used in this study to evaluate the impact of changes in peri-operative swallowing function on pharyngeal pressure events.

METHODS

Ten patients with various stages of oropharyngeal cancer underwent transoral surgery. High-resolution manometry and videofluoroscopic swallow studies were performed before surgery and two months afterwards. The following parameters were obtained: velopharyngeal and mesopharyngeal post-deglutitive upper oesophageal sphincter pressures, velo-meso-hypopharyngeal contractile integral, upper oesophageal sphincter relaxation pressure, and pharyngeal velocity.

RESULTS

There was no significant difference in pharyngeal pressure or contractile integral pre- versus post-operatively. However, pharyngeal velocity was significantly higher post-operatively than pre-operatively.

CONCLUSION

High-resolution manometry showed that transoral surgery in patients without pre-operative dysphagia preserved pharyngeal constriction. However, transoral surgery might produce scar formation in the pharynx, which could lead to narrowing of the pharynx.

Prognostic impact of at least 12 lymph nodes after neoadjuvant therapy in rectal cancer: A meta-analysis

BACKGROUND

The number of dissected lymph nodes (LNs) in rectal cancer after neoadjuvant therapy has a controversial effect on the prognosis.

AIM

To investigate the prognostic impact of the number of LN dissected in rectal cancer patients after neoadjuvant therapy.

METHODS

We performed a systematic review and searched PubMed, Embase (Ovid), MEDLINE (Ovid), Web of Science, and Cochrane Library from January 1, 2000 until January 1, 2020. Two reviewers examined all the publications independently and extracted the relevant data. Articles were eligible for inclusion if they compared the number of LNs in rectal cancer specimens resected after neoadjuvant treatment (LNs ≥ 12 vs LNs < 12). The primary endpoints were the overall survival (OS) and disease-free survival (DFS).

RESULTS

Nine articles were included in the meta-analyses. Statistical analysis revealed a statistically significant difference in OS [hazard ratio (HR) = 0.76, 95% confidence interval (CI): 0.66-0.88, I² = 12.2%, P = 0.336], DFS (HR = 0.76, 95%CI: 0.63-0.92, I² = 68.4%, P = 0.013), and distant recurrence (DR) (HR = 0.63, 95%CI: 0.48-0.93, I² = 30.5%, P = 0.237) between the LNs ≥ 12 and LNs < 12 groups, but local recurrence (HR = 0.67, 95%CI: 0.38-1.16, I² = 0%, P = 0.348) showed no statistical difference. Moreover, subgroup analysis of LN negative patients revealed a statistically significant difference in DFS (HR = 0.67, 95%CI: 0.52-0.88, I² = 0%, P = 0.565) between the LNs ≥ 12 and LNs < 12 groups.

CONCLUSION

Although neoadjuvant therapy reduces LN production in rectal cancer, our data indicate that dissecting at least 12 LNs after neoadjuvant therapy may improve the patients’ OS, DFS, and DR.

The influence of cervical lymph node number of neck dissection on the prognosis of the early oral cancer patients

Background/purpose

The status of neck lymph nodes (LNs) plays an important role in survival of oral cavity cancer. Early stage oral cancer patients are still at a risk for locoregional metastasis. We aimed to determine the number of LNs that needs to be retrieved for adequate diagnosis and treatment of the neck tumor.

Materials and methods

We conducted a retrospective study of 126 oral cavity cancer patients who underwent wide excision and 3 types of neck dissection at MacKay Memorial Hospital, Taiwan. Data from the operative and pathology reports were collected and analyzed. The significant difference was defined as p < 0.05 by SPSS 21.0 and Prizm 5 software.

Results

There was a significant difference between the total retrieved LNs and tumor differentiation and nerve invasion on multivariate analysis. Receiveroperating characteristic (ROC) curve showed significant difference in the total number of neck LNs between the survival and expired groups. The cut-off point was 36.5 nodes. However, there was no difference in survival between supraomohyoid and modified radical neck dissection.

Conclusion

Retrieval of adequate LNs can improve oral cancer survival rates. If total number of neck nodes examined is <37 with poor differentiation and/or nerve invasion, early oral cancer patients with neck dissection have a lower survival rate and are candidates for adjuvant therapy.

Predictive models of adjuvant chemotherapy for patients with stage ii colorectal cancer: A retrospective study

BACKGROUND

It remains controversial whether patients with Stage II colorectal cancer would benefit from adjuvant chemotherapy after radical resection. The aim of this study was to establish two mathematical models to identify the suitable patients for adjuvant chemotherapy.

METHODS

The current study comprised of two steps. In the first step, 353 patients with Stage II colorectal cancer who underwent surgical procedures at the Third Affiliated Hospital of Sun Yat-sen University between June 2006 and December 2015 were entered and followed up for 6-120 months. Their clinical data were collected and enrolled into the database. We established two mathematical models by univariate and multivariate Cox regression analysis to identify the target patients; in the second step, 230 patients under the same standard between January 2012 and December 2016 were entered and followed up for 3-62 months to verify the two models' validation.

RESULTS

In the first step, totally 340 surgical patients with Stage II colorectal cancer were finally enrolled in this study. Statistical analysis showed that tumor differentiation (TD) (P < 0.001), lymphovascular invasion (LVI) (P < 0.001), uncertain or positive margins (UPM) (P < 0.001), and fewer lymph nodes (LNs) (<12) retrieved (P < 0.001) were correlated with the overall survival (OS) and disease free survival (DFS). We obtained two models: (1) OS risk score = 1.116 × TD + 2.202 × LVI + 3.676 × UPM + 1.438 × LN - 0.493; (2) DFS risk score = 0.789 × TD + 2.074 × LVI + 3.183 × UPM + 1.329 × LN - 0.432. According to the models and cutoff points [(0.07, 1.33) and (-0.04, 1.30), respectively], patients can be divided into three groups: low-risk, moderate-risk, and high-risk. Moreover, the high-risk group patients could benefit from adjuvant chemotherapy. In the second step, totally 221 patients were finally used to verify the models' validation. The results proved that the models were accurate and feasible (P< 0.05).

CONCLUSIONS

According to the predictive models, patients with Stage II colorectal cancer in the high-risk group are strongly recommended for adjuvant chemotherapy, thus facilitating the individualized and precise treatment.

Non-surgical factors influencing lymph node yield in colon cancer

There are numerous factors which can affect the lymph node (LN) yield in colon cancer specimens. The aim of this paper was to identify both modifiable and non-modifiable factors that have been demonstrated to affect colonic resection specimen LN yield and to summarise the pertinent literature on these topics. A literature review of PubMed was performed to identify the potential factors which may influence the LN yield in colon cancer resection specimens. The terms used for the search were: LN, lymphadenectomy, LN yield, LN harvest, LN number, colon cancer and colorectal cancer. Both non-modifiable and modifiable factors were identified. The review identified fifteen non-surgical factors: (13 non-modifiable, 2 modifiable) which may influence LN yield. LN yield is frequently reduced in older, obese patients and those with male sex and increased in patients with right sided, large, and poorly differentiated tumours. Patient ethnicity and lower socioeconomic class may negatively influence LN yield. Pre-operative tumour tattooing appears to increase LN yield. There are many factors that potentially influence the LN yield, although the strength of the association between the two varies greatly. Perfecting oncological resection and pathological analysis remain the cornerstones to achieving good quality and quantity LN yields in patients with colon cancer.

Stage-Dependent Frequency of Lymph Node Metastases in Patients With Rectal Carcinoma After Preoperative Chemoradiation: Results from the CAO/ARO/AIO-94 Trial and From a Comparative Prospective Evaluation With Extensive Pathological Workup

BACKGROUND

For patients with ycT1/2 rectal carcinomas after neoadjuvant chemoradiotherapy, local excision instead of radical surgery has increasingly been discussed as a way to avoid postoperative morbidity associated with radical surgery.

OBJECTIVE

The purpose of this study was to determine the incidence of lymph node metastases in total mesorectal excision specimens with ypT0, ypT1/2, and ypT3/4 rectal cancers.

DESIGN

This is a prospective and retrospective cohort study.

SETTINGS

This study was conducted in tertiary referral hospitals that are part of the German Rectal Cancer Study Group.

PATIENTS

A total of 479 patients with stage II and III rectal cancers treated within phase III trials of the German Rectal Cancer Study Group were evaluated. Specimens from 81 patients treated in the Working Group of Surgical Oncology/Working Group of Radiation Oncology/Working Group of Medical Oncology of the Germany Cancer Society (CAO/ARO/AIO-04) trial were prospectively studied with extensive microscopic screening of the entire mesorectum. The frequency and localization of nodal metastases were specified and compared with those of 398 patients having received neoadjuvant chemoradiation within the CAO/ARO/AIO-94 trial.

MAIN OUTCOME MEASURES

Frequency and localization of mesorectal lymph node metastases in patients with ypT0, ypT1/2, or ypT3/4 cancer were measured.

RESULTS

A mean number of 28.0 ± 13.7 nodes were detected per specimen within the prospective group. A total of 25% of patients in the ypT1/2 group had nodal metastases compared with 40% in the ypT3/4 group. Patients with node-positive ypT1/2 had a mean number of 2.2 metastases, and 55% of these metastases were located far from the primary lesion in the proximal mesorectum. Within the CAO/ARO/AIO-94 cohort (n = 398), 19% of patients with ypT1/2 (ypT1 = 22%; ypT2 = 18%) had ypN+ status compared with 43% with ypT3/4 cancers (ypT3 = 40%; ypT4 = 73%).

LIMITATIONS

Low numbers of patients with ypT0 limited the evaluation of nodal metastases in pathologic complete responders.

CONCLUSIONS

Even in good responders (ypT1/2), >20% of rectal carcinomas still harbored residual lymph node metastases. Local excision for patients with ycT1/2 rectal cancers would, thus, miss metastases in a considerable percentage and might involve the risk of significant undertreatment in a number of patients.

Prognostic and Predictive Model for Stage II Colon Cancer Patients With Nonemergent Surgery: Who Should Receive Adjuvant Chemotherapy?

No ideal prognostic model has been applied to clearly identify which suitable high-risk stage II colon cancer patients with negative margins undergoing nonemergent surgery should receive adjuvant chemotherapy routinely. Clinicopathologic and prognostic data of 333 stage II colon cancer patients who underwent D2 or D3 lymphadenectomy during nonemergent surgery were retrospectively analyzed. Four pathologically determined factors, including adjacent organ involvement (RR 2.831, P = 0.001), histologic differentiation (RR 2.151, P = 0.009), lymphovascular invasion (RR 4.043, P < 0.001), and number of lymph nodes retrieved (RR 2.161, P = 0.011), were identified as independent prognostic factors on multivariate analysis. Importantly, a simple cumulative scoring system clearly categorizing prognostic risk groups was generated: risk score = ∑ coefficient' × status (AOI + histological differentiated + lymphovascular invasion + LNs retrieved). Our new prognostic model may provide valuable information on the impact of lymphovascular invasion, as well as powerfully and reliably predicting prognosis and recurrence for this particular cohort of patients. This model may identify suitable patients with an R0 resection who should receive routine postoperative adjuvant therapy and may help clinicians to facilitate individualized treatment. In this study, we aim to provide an ideal and quantifiable method for clinical decision making in the nonemergent surgical treatment of stage II colon cancer. Our prognostic and predictive model should be applied in multicenter, prospective studies with large sample sizes, in order to obtain a more reliable clinical recommendation.

Sphincter preservation in distal CT2N0 rectal cancer after preoperative chemoradiotherapy

BACKGROUND

Preoperative chemoradiotherapy is usually not indicated for cT2N0 rectal cancer. Abdominoperineal resection is the standard treatment for distal rectal tumors. The aim of the study was to evaluate the actual sphincter-preservation rate in patients with distal cT2N0 rectal cancer given neoadjuvant chemoradiotherapy.

METHODS

Data were retrospectively collected for all patients who were diagnosed with distal cT2N0 rectal cancer at a tertiary medical center in 2000-2008 and received chemoradiotherapy followed by surgery (5-7 weeks later).

RESULTS

Thirty-three patients (22 male) of median age 65 years (range, 32-88) were identified. Tumor distance from the anal verge ranged from 0 to 5 cm. R0 resection with sphincter preservation was accomplished in 22 patients (66%), with a 22% pathological complete response rate. Median follow-up time was 62 months (range 7-120). There were no local failures. Crude disease-free and overall survival were 82% and 86%, respectively. Factors associated with sphincter preservation were tumor location (OR=0.58, p=0.02, 95% CI=0.37-0.91) and pathological downstaging (OR=7.8, p=0.02, 95% CI=1.35-45.85). Chemoradiotherapy was well tolerated.

CONCLUSION

High rates of sphincter preservation can be achieved after preoperative chemoradiotherapy for distal cT2N0 rectal cancer, with tolerable toxicity, without compromising oncological outcome.

Volume of surgical activity and lymph node evaluation for patients with colorectal cancer in France

BACKGROUND

The correct examination of lymph nodes is decisive for tumour classification into stage 2 and stage 3. The aim of this specialised population-based study was to investigate the influence of clinical factors and volume of surgical activity on lymph node assessment in France for patients diagnosed with localised colorectal cancer.

METHODS

From 1997 to 2004, French digestive cancer registries recorded a total of 4197 cases of colorectal cancer. The volume of surgical activity was appreciated by the annual number of digestive surgery admissions in 2004. The probability of having at least 12 lymph nodes examined after surgical resection was analysed using a multilevel logistic regression model.

RESULTS

Only 1900 patients had more than 12 lymph nodes examined (45.2%). The percentage of patients with at least 12 lymph nodes examined after tumour resection is directly associated with the volume of surgical activity within care centres for patients diagnosed between 1997 and 2000. This association was no longer significant during the second period study (2001-2004).

CONCLUSION(S)

This population-based study reports that only 55% of colorectal patients have a sufficient number of lymph nodes examined. This insufficient number of examined lymph nodes could be considered as a potential prospect for increasing treatment quality in cancer patients in France.

Number of lymph nodes after neoadjuvant therapy for rectal cancer: How many are needed?

Dear readers,

In the February 2012 issue of the World J Gastrointest Surg (4(2):32-35) Scabini and Ferrando published an editorial entitled “Number of lymph nodes after neoadjuvant therapy for rectal cancer: how many are needed?”.It has been brought to our attention that segments of the editorial are identical or closely resemble the essential parts of the discussion of the original article “Preoperative chemoradiotherapy does not necessarily reduce lymph node retrieval in rectal cancer specimens ¨C Results from a prospective evaluation with extensive pathological work-up” that was published in the Journal of Gastrointestinal Surgery in 2009. Given the striking similarities of the two works, the World J Gastrointest Surg has decided to retract the editorial by Scabini and Ferrando.

Timothy M. Pawlik, MD, MPH, PhD

Editor-in-Chief, World Journal of Gastrointestinal Surgery

An evaluation of the number of lymph nodes examined and survival for node-negative esophageal carcinoma: data from China

BACKGROUND

The current American Joint Committee on Cancer (AJCC) staging system for esophageal cancer does not define the minimum number of lymph nodes (LNs) necessary for accurate nodal staging. This study aimed to seek the minimum number of LNs examined for adequate nodal staging of patients with node-negative esophageal cancer.

METHODS

We conducted a retrospective review of 592 patients undergoing R0 resection with node-negative esophageal carcinoma between December 1996 and December 2004. The relationship between the total number of examined LNs and death from esophageal cancer was investigated by means of a scatterplot of this variable versus Martingale residuals from a Cox proportional hazard regression model without the variable of interest. A smoothed line fit of the scatterplot was applied to detect the reasonable cutoff point.

RESULTS

The patients were classified into four categories according to the number of examined LNs: < or =5, 6 to 9, 10 to 17, and > or =18. A reduced hazard ratio of death was observed with an increasing number of LNs examined. The 5-year cancer-specific survival rate was 42.8% among patients with < or =5 LNs examined, compared with 52.6, 56.8, and 75% for those with 6-9 LNs, 10-17 LNs, and > or =18 LNs, respectively. Multivariate Cox regression analysis suggested that female sex, lower grade of cell differentiation, lower T category and increasing number of examined LNs were independent factors favoring cancer-specific survival.

CONCLUSIONS

At least 18 LNs should be resected for accurate staging of operable esophageal carcinoma. However, a validation from other institute is warranted.

Preoperative chemoradiotherapy does not necessarily reduce lymph node retrieval in rectal cancer specimens--results from a prospective evaluation with extensive pathological work-up

PURPOSE

Preoperative chemoradiotherapy (CRT) is supposed not only to reduce lymph node metastases but also lymph node recovery in rectal cancer specimens. The objective of this prospective study was to determine the effects of chemoradiation on mesorectal lymph node retrieval under terms of a meticulous histopathological evaluation.

METHODS

Specimens from 64 consecutive patients with stage II/III rectal cancer receiving preoperative 5-FU-based CRT were investigated. All patients were treated within the German Rectal Cancer Trial CAO/ARO/AIO-04. After surgery (including quality assessed total mesorectal excision), extensive pathological diagnostics was performed with embedding and microscopic evaluation of the whole mesorectal soft tissue compartment.

RESULTS

A total number of 2,021 lymph nodes were recovered (31.6 per specimen) within pathological work-up. There was no significant correlation between the number of retrieved nodes and patient- as well as tumor-dependent parameters. Lymph node size constantly amounted for less than 0.5 cm. Twenty patients (31.3%) had persistent nodal metastases. A considerable incidence of residual micrometastatic involvement in lymph nodes <0.3 cm (in 9.4% of all patients) was detected by extensive pathologic work-up.

CONCLUSION

Reliable nodal staging with high numbers of detected nodes was feasible after neoadjuvant CRT. Micrometastases frequently occur in small lymph nodes detected by microscopic evaluation.

The future of the TNM staging system in colorectal cancer: time for a debate?

TNM staging has made a major contribution to the clinical management of patients with cancer over the past 50 years, but are we sure it delivers what is needed to provide adequate advice in the 21st century, and are there ways in which the system can be improved? This article, by pathologists with a special interest in colorectal cancer, is intended to offer constructive criticism towards the TNM classification of colorectal cancer, make suggestions for improvement, and recommend the adoption of a robust evidence base for this system.

Nodal Staging in Adenocarcinoma of the Gastro-Esophageal Junction. Proposal of a Specific Staging System

PURPOSE

This study was aimed at developing a proper nodal staging system for GEJ adenocarcinoma.

METHODS

The study analyzed 113 patients with GEJ adenocarcinoma consecutively resected at the Department of General Surgery and Surgical Oncology of the University of Siena and at the Department of General Surgery of the University of Verona. Both the number (TNM) and site (JGCA) of lymph node metastasis was evaluated in considering nodal staging.

RESULTS

The TNM and JGCA staging systems coincided only in 56.3% of cases. Nodal involvement resulted to be the most important prognostic factor considering both the staging systems (P < 0.001). An extremely poor prognosis and a prominent risk of death were observed for patients with more than six metastatic nodes (TNM pN2-3) as well as for patients with involvement of second and third tier nodes (JGCA pN2-3) (P < 0.001). The combined prognostic significance of the two classifications showed a similar risk of death for patients with less than seven metastatic nodes (TNM pN1) located beyond the first tier (JGCA pN2-3) and for patients with more than six involved nodes (TNM pN2-3) independently from the interested level (JGCA pN1-3). Accordingly, these classes were pooled together and four classes considered: pN0, TNM-JGCA pN1, TNM pN2-3 or JGCA pN2-3, M1a (P < 0.001).

CONCLUSIONS

The combination of the TNM and JGCA staging systems herein proposed is extremely practical from a clinical point of view and leads to the stratification of pN+ patients in two classes only with very different risk of death.

Macrophage migration inhibitory factor stimulates angiogenic factor expression and correlates with differentiation and lymph node status in patients with esophageal squamous cell carcinoma

OBJECTIVE

The objectives of this study were: 1) to examine the expression of macrophage migration inhibitory factor (MIF) in esophageal squamous cell carcinoma (ESCC); 2) to see if a relationship exists between MIF expression, clinicopathologic features, and long-term prognosis; and 3) to ascertain the possible biologic function of MIF in angiogenesis.

SUMMARY BACKGROUND DATA

MIF has been linked to fundamental processes such as those controlling cell proliferation, cell survival, angiogenesis, and tumor progression. Its role in ESCC, and the correlation of MIF expression and tumor pathologic features in patients, has not been elucidated.

METHODS

The expression of MIF in tumor and nontumor tissues was examined by immunohistochemical staining. Concentrations of MIF, vascular endothelial growth factor (VEGF), and interleukin-8 (IL-8) in patients' sera and in the supernatant of tumor cells culture were examined by ELISA. Correlations with clinicopathologic factors were made.

RESULTS

In 72 patients with ESCC, intracellular MIF was overexpressed in esophagectomy specimens. The expression of MIF correlated with both tumor differentiation and lymph node status. The median survival in the low-MIF expression group (<50% positively stained cancer cells on immunohistochemistry) and high expression group (>/=50% positively stained cancer cells) was 28.3 months and 15.8 months, respectively (P = 0.03). The 3-year survival rates for the 2 groups were 37.7% and 12.1%, respectively. MIF expression was related to microvessel density; increased MIF serum levels also correlated with higher serum levels of VEGF. In addition, in vitro MIF stimulation of esophageal cancer cell lines induced a dose-dependent increase in VEGF and IL-8 secretion.

CONCLUSIONS

These results demonstrate, for the first time, that human esophageal carcinomas express and secrete large amounts of MIF. Through its effects on VEGF and IL-8, MIF may serve as an autocrine factor in angiogenesis and thus play an important role in the pathogenesis of ESCC.

TNM, sixth edition: new developments in general concepts and rules

This article describes changes and clarifications in the 6th edition of TNM that concern site-independent rules, regarding such aspects as sentinel lymph node biopsy, methods to distinguish between micrometastasis and isolated tumor cells, classification of tumors undergoing treatment, tumor deposits in lymph drainage beds, the number of lymph nodes needed for pathologic classification, and classification of residual tumor. These changes mainly reflect advances in diagnosis and treatment, and modulate rather than change the basic rules of classification.

Comparison of old and new TNM systems for nodal staging in adenocarcinoma of the gastro-oesophageal junction

Background

Adenocarcinoma of the gastro-oesophageal junction is considered a distinct clinical entity, although the current pathological tumour node metastasis (pTNM) classification does not consider this tumour specifically. A prospective study was undertaken to determine the prognostic importance of lymph node involvement in adenocarcinoma of the gastro-oesophageal junction, analysing both a number- and site-based classification, in order to develop a clinically useful nodal staging system.

Methods

Two classification systems were analysed in 116 patients who underwent resection for adenocarcinoma of the gastro-oesophageal junction from January 1988 to August 2001. The Cox regression model was used to evaluate the prognostic significance of the site and number of positive nodes.

Results

The number- and site-based staging systems coincided only in 42 (56 per cent) of 75 patients; in particular, the old pN1 classification was upstaged in 13 of 41 patients and the old pN2 was downstaged in 13 of 34 patients. Lymph node involvement was the most important prognostic factor in both classifications (P &lt; 0·001). The risk of death was significantly influenced by the site of nodal metastasis among patients with a similar number of involved nodes (relative risk with respect to pN0: 2·18 for pN1 with one to six nodes; 6·53 for pN2 with one to six nodes; 7·53 for pN1 with more than six nodes; 39·13 for pN2 with more than six nodes).

Conclusion

Adenocarcinoma of the gastro-oesophageal junction requires a specific lymph node classification which should take into account both the number and site of nodal metastases.

The new TNM classification of lymph node metastasis minimises stage migration problems in gastric cancer patients

The present study aimed at investigating whether in gastric cancer patients stage migration occurs with extension of lymphadenectomy, when node metastases are staged according to the new pN classification (UICC 1997). The investigation involved 921 patients, who underwent R0 gastric resection for gastric cancer between 1988 and 1998 in three different Italian centres: Verona (n=236), Forlì (n=409), Siena (n=276). The relation among lymphadenectomy and pN category was assessed by Kendall's partial rank-order correlation coefficient, controlling for depth of tumour invasion. A direct evaluation of the Will Rogers phenomenon was accomplished in the Verona series, by comparing the number of positive nodes actually observed with the number of positive nodes which would have been retrieved by a less extended lymphadenectomy (D1). The number of positive nodes increased remarkably with the enlargement of lymphadenectomy, especially in pT2 patients (from 2.2+/-3.9 in D1 to 3.9+/-5.0 in D3) and in pT3/pT4 patients (from 5.1+/-5.9 in D1 to 11.3+/-12.6 in D3). Non-parametric statistics highlighted a weak (Kendall's partial T=0.128) but significant (P<0.001) correlation between pN category and extension of lymphadenectomy. In the direct analysis of the Verona series, 22 patients out of 230 (9.6%) migrated to a lower pN tier when ignoring positive nodes retrieved from the second and third level. This percentage increased to 39.1% (90 out of 230) when adopting the TNM 87 classification. In conclusion stage migration is of minor importance in gastric cancer patients, staged according to the new pN classification.