Colorectal adenocarcinoma: quality of the assessment of lymph node metastases

The impact of surgeon and pathologist on lymph node retrieval in colorectal cancer and its impact on survival for patients with Dukes' stage B disease

OBJECTIVE

An adequate lymph node harvest is necessary for accurate Dukes' stage discrimination in colorectal cancer. The aim of this study is to identify the effect of variables, including the individual surgeon and pathologist, on lymph node harvest in a single institution.

METHOD

Three hundred and eighty one consecutive patients had resection for colorectal cancer, in a single unit. Factors influencing lymph node retrieval, including individual surgeon and reporting pathologist, were subjected to uni- and multivariate analysis. Actuarial survival of all patients with Dukes' stage B and C disease was then calculated and survival compared between Dukes' stage B and C at differing levels of lymph node harvest.

RESULTS

The unit median lymph node harvest was 13 nodes/patient (95% CI 13.1-14.5). There was no difference in lymph node harvest between specialist colorectal surgeons and the pooled results of four nonspecialist consultant surgeons. However, there was a significant difference between reporting pathologists (P < 0.001). On univariate analysis, operation type, operative urgency, Dukes' stage, T-stage, reporting pathologist and use of neoadjuvant therapy in rectal cancer, were found to significantly affect lymph node retrieval. On multivariate analysis, operation type, T-stage, reporting pathologist and neoadjuvant therapy in rectal cancer remained significant variables. Patients with one or more lymph node metastasis had greater nodal harvests than those without (median 15 vs 12 P = 0.02). Survival of patients with Dukes' stage B disease was found to improve as lymph node harvest increased.

CONCLUSION

Overall lymph node harvest, in this unit, varied according to the reporting pathologist but not operating surgeon. As lymph node harvest increased to 15 per patient, the probability of identifying a metastatic node increased.

Factors influencing lymph node harvest in colorectal surgery

BACKGROUND AND AIMS

Lymphadenectomy in colorectal cancer is a critical component concerning prognosis and survival of patients. Several variables influence the number of harvested lymph nodes (LN). However, results of studies are contradictory, and influencing factors remain to be identified. The aim of the present study was to identify factors that have a significant influence on the number of assessed LN in oncologic colorectal cancer resection.

MATERIALS AND METHODS

Three hundred and forty-one patients (190 men and 151 women), who underwent a colorectal cancer resection in a curative intention in the years 2000-2005, were analysed retrospectively. All specimens were histologically examined by two pathologists.

RESULTS

In a median, 15.1 LN per operation were resected. Early tumour stage (p<0.01), length of resected bowel segment (p<0.05) and right-sided location (p<0.001) had a significant influence on the number of resected LN. Age, gender, surgeon volume, differentiation of the tumour, LN metastases, lymphatic invasion and depth of tumour invasion had no significant association with harvested LN number. Furthermore, the presence or absence of the vermiform appendix and the length of the resected ileum segment in right-sided resections did not significantly affect the assessed LN.

CONCLUSION

The question arises whether for colorectal cancers of all locations the same amount of resected and analysed LNs should be lasting to fulfill oncologic criteria, as the number of harvested LNs depends on several parameters.

Number and size of lymph nodes recovered from dukes B rectal cancers: correlation with prognosis and histologic antitumor immune response

PURPOSE

In rectal cancer variation in lymph node recovery influences the detection of nodal metastases and prognosis among Dukes B (Stage II) cases. However, the possible prognostic importance of node size and inherent patient/tumor characteristics in determining node recovery has not been studied.

METHODS

We examined 269 Dukes B (Stage II) rectal tumors, with a mean of 12 nodes per case. Primary tumor characteristics were correlated with the number and size of recovered nodes. Clinical follow-up permitted determination of long-term survival.

RESULTS

The five-year survival of 94 Dukes B cases with nine or fewer nodes was 69.4 percent vs. 87.6 percent in 175 cases with ten or more nodes (P = 0.001). Lymph nodes were smaller in patients dying of recurrence; among 130 Dukes B patients whose mean node diameter was <4 mm, survival was 73.3 vs. 88 percent when mean nodal diameter was > or =4 mm. The number and size of recovered nodes was related to patient age, histologic antitumor immune response, and tumor growth pattern. By combining the number and size of nodes, a poor prognosis subgroup of 98 Dukes B patients with relatively few large nodes (no more than 5 measuring > or =4 mm) was identified with a five-year survival of 65.6 percent compared with 89.6 percent for the remaining 158 Dukes B cases (P < 0.0001).

CONCLUSIONS

In Dukes B rectal tumors, the number and size of lymph nodes are related to inherent patient and tumor characteristics and permit the identification of Dukes B cases at increased risk of recurrence. A valid comparison of nodal sampling efficiency between centers necessitates measuring and counting harvested lymph nodes.

Current status of sentinel lymph node navigation surgery in breast and gastrointestinal tract

Sentinel lymph node biopsy (SLNB) has been developed as a new diagnostic and therapeutic modality in melanoma and breast cancer surgery. The purpose of the SLNB include preventing the operative morbidity and improving the pathologic stage by focusing on fewer lymph nodes using immunocytochemic and molecular technology has almost achieved in breast cancer surgery. The prognostic meaning of immunocytochemically detected micrometastases is also evaluating in the SLN and bone marrow aspirates of women with early-stage breast cancer. SLNB using available techniques have suggested that the lymphatic drainage of the gastrointestinal tract is much more complicated than other sites, skip metastasis being rather frequent because of an aberrant lymphatic drainage outside of the basin exist. At the moment, the available data does not justify reduced extent of lymphadenectomy, but provides strong evidence for an improvement in tumor staging on the basis of SLNB. Two large scale prospective multi-center trials concerning feasibility of gamma-probe and dye detection for gastric cancer are ongoing in Japan. Recent studies have shown favorable results for identification of SLN in esophageal cancer. CT lymphography with endoscopic mucosal injection of iopamidol was applicable for SLN navigation of superficial esophageal cancer. The aim of surgical treatment is complete resection of the tumor-infiltrated organ including the regional lymph nodes. Accurate detection of SLN can achieve a selection of a more sophisticated tailor made approach. The patient can make a individualized choice from a broader spectrum of therapeutic options including endoscopic, laparoscopic or laparoscopy-assisted surgery, modified radical surgery, and typical radical surgery with lymph node dissection. Ultrastaging by detecting micrometastasis at the molecular level and the choice of an adequate treatment improve the postoperative quality of life and survival. However these issues require further investigation.

The prognostic significance of total lymph node harvest in patients with T2-4N0M0 colorectal cancer

In patients with radically resected colorectal carcinoma, lymph node involvement is particularly important for a good prognosis and adjuvant therapy. The number of such lymph node recoveries is still controversial, with recommendations ranging from 6 to 17 nodes. The aim of this study is to determine if a specified minimum number of lymph nodes examined per surgical specimen can have any effect on the prognosis of patients who have undergone curative resection for T(2-4)N(0)M(0) colorectal carcinoma. Between September 1999 and January 2005, a total of 366 patients who underwent radical resection for T(2-4)N(0)M(0) colorectal carcinoma were retrospectively analyzed in a single institution. All specimen segments were fixed, with node identification performed by sight and palpation. We excluded 186 patients who received postoperative adjuvant chemotherapy via oral or intravenous transmission to prevent possible chemotherapeutic effects on patients' prognosis; therefore, a total of 180 patients with T(2-4)N(0)M(0) colorectal carcinoma were enrolled into this study. After the pathological examination, a mean of 12 lymph nodes (range 0-66) was harvested per tumor specimen. No postoperative relapse was found in this group, where the number of examined lymph nodes was 18 or more. Univariate analysis identified the size of the tumor, depth of invasion, grade of tumor, and number of examined lymph nodes, which were significantly correlated with postoperative relapse (all P < 0.05). Meanwhile, both the depth of tumor invasion and the number of harvested lymph nodes were independent predictors for postoperative relapse (P < 0.05). The 5-year overall survival rate of T(2-4)N(0)M(0) colorectal carcinoma patients who had 18 or more lymph nodes examined was significantly higher than those who had less than 18 nodes examined (P = 0.015). Nodal harvest in patients undergoing radical resection for colorectal carcinoma was highly significant in the current investigation. Our results suggest that harvesting and examining a minimum of 18 lymph nodes per surgical specimen might be taken into consideration for more reliable staging of lymph node-negative colorectal carcinoma.

Lymph node evaluation and survival after curative resection of colon cancer: systematic review

BACKGROUND

Adequate lymph node evaluation for cancer involvement is important for prognosis and treatment of patients with colon cancer. The number of lymph nodes evaluated may be a measure of quality in colon cancer care and appears to be inadequate in most patients treated for colon cancer. We performed a systematic review of the evidence for the association between lymph node evaluation and oncologic outcomes in patients with colon cancer.

METHODS

Medline, Scopus, Cochrane, and the National Guidelines Clearinghouse databases were searched from January 1, 1990, through June 30, 2006, for studies in which survival data as a function of number of lymph nodes evaluated were available. These studies were evaluated for methodologic quality, design, and data source. A total of 61,371 patients were included.

RESULTS

Seventeen studies from nine countries were eligible for systematic review, including two secondary analyses of multicenter randomized trials of adjuvant chemotherapy for colon cancer, five population-based observational studies, and 10 single-institution retrospective cohort studies. Despite heterogeneity in methodology and differences in threshold numbers of lymph nodes evaluated (range = 6-40 lymph nodes), 16 of 17 studies reported that increased survival of patients with stage II colon cancer was associated with increased numbers of lymph nodes evaluated. Four of six studies with data from stage III patients also reported a positive association with survival among patients with stage III colon cancer.

CONCLUSIONS

The number of lymph nodes evaluated after surgical resection was positively associated with survival of patients with stage II and stage III colon cancer. These results support consideration of the number of lymph nodes evaluated as a measure of the quality of colon cancer care.

Additional lymph node examination from entire submission of residual mesenteric tissue in colorectal cancer specimens may not add clinical and pathologic relevance

The examination of lymph nodes in colorectal cancer is a critical procedure for determining the stage, which determines prognosis and need for adjuvant therapy. The current recommendation is to harvest at least 12 lymph nodes by conventional manual node dissection (MND). Recent studies have suggested that all lymph nodes in mesenteric tissue should be retrieved using a special method such as the entire submission of residual mesenteric tissue (ESMT) after MND. We investigated the efficacy of ESMT with its potential impact on the pN stage. After an MND in 48 consecutive colorectal cancer resection specimens, the residual mesenteric tissues were entirely submitted for routine histologic examination by ESMT. After initial MND, 933 (mean, 19.4) lymph nodes were found, and there were 29 pN0, 10 pN1, and 9 pN2 cases. By ESMT after MND, 1132 (mean, 23.6) additional lymph nodes were found. Most (88.6%) of them were 2.0 mm or less in maximum dimension, and of the 1132 additional lymph nodes, 14 (1.2%) lymph nodes revealed tumor metastases. Although there was no additional nodal metastasis in any of the initial 29 pN0 cases, additional nodal metastases were found in 10 of the original 19 node-positive cases. Two of the 10 cases with additional positive nodes identified would be upstaged from pN1 to pN2. Both of these cases had fewer than 12 nodes identified by MND but had 1 and 2 additional nodes identified by ESMT. Our study demonstrated that MND seems to be accurate and efficient in evaluating tumors with pN stage of pN0. Although ESMT may be useful to assess the correct pN stage in pN1 cases with fewer than 12 lymph nodes in MND, it may not add any additional information in pN0 cases or in node-positive cases with 12 or more lymph nodes found by MND.

L1 expression as a marker for poor prognosis, tumor progression, and short survival in patients with colorectal cancer

BACKGROUND

L1, a new target gene for Wnt/beta-catenin-TCF signaling, has been identified in the invasive front of colorectal cancer cells in vitro study. The L1 molecule is localized on the cell surface in tumor tissues, accompanied with loss of beta-catenin and E-cadherin. However, such association between L1 expression and prognosis of colorectal cancer has not yet been investigated in clinical study. We investigated the expression of L1, E-cadherin, and beta-catenin in tumor cells to determine correlations between the clinicopathologic characteristics and the expression of these molecules and to evaluate the efficacy of the use of these molecules as prognostic markers for patient survival.

METHODS

We investigated 138 patients who received diagnoses of colorectal cancer and who underwent surgery between January 1995 and December 2000 at the Korea University Hospital. Tissues were obtained from paraffin-embedded blocks of the tumors and studied by tissue microarray analysis. Immunohistochemical staining for L1, beta-catenin, and E-cadherin was performed for each specimen.

RESULTS

L1 expression was found to be correlated with advanced cancer stage (P = .001), distant metastasis (P < .001), and tumor recurrence (P = .006). Survival analysis showed that reduced expression of beta-catenin and E-cadherin, and expression of L1 were statistically significantly related to poor survival. Multivariate analysis revealed that L1 expression was an independent prognostic factor for patient survival.

CONCLUSIONS

L1 expression is associated with tumor progression and poor survival in patients with colorectal cancer and may be clinically useful as a marker for poor prognosis.

The sentinel node procedure in colon carcinoma: a multi-centre study in The Netherlands

BACKGROUND

Lymph node status is the most important predictive factor in colorectal carcinoma. Recurrences occur in 20% of the patients without lymph node metastases. The sentinel lymph node (SLN) biopsy is a tool to facilitate identification of micrometastatic disease and aberrant lymphatic drainage. We studied the feasibility of in vivo SLN detection in a multi-centre setting and evaluated nodal micro-staging using immunohistochemistry (IHC).

MATERIALS AND METHODS

Sub-serosal injection with Patent Blue dye was used in the SLN procedure in 69 patients operated for localized colon cancer in six Dutch hospitals. Each SLN was examined with routine haematoxylin-eosin staining. In tumour-negative SLNs, we performed CK7/8 or 18 IHC.

RESULTS

The procedure was successful in 67 of 69 patients (97%). The SLN was negative in 43 patients. In three cases, it was false negative, resulting in a negative predictive value of 93% and an accuracy of 96%. In 24 of 27 patients with lymph node metastases in a successful SLN procedure, the SLN was positive (sensitivity 89%). In 15 patients, the SLN was the only positive node (21%). In nine patients, we only found micrometastases or isolated tumour cells, resulting in 18% upstaging. Aberrant lymphatic drainage was seen in three patients (4%).

CONCLUSION

The SLN procedure in localized colon carcinoma is reliable in a multi-centre setting. It is helpful to identify patients who would be classified as stage II with conventional staging (18%) and who might benefit from adjuvant treatment.

Potential pathological understaging of pT3 rectal cancer with less than 26 lymph nodes recovered: a prospective study based on a resampling of 50 rectal specimens

The aim of the paper was to establish if the 12 lymph nodes recommended by tumor-node-metastasis (TNM) system are sufficient for a correct staging of rectal cancer. For this purpose, we first compared the mean number of lymph nodes recovered in the same surgical specimen at the routine sampling and at a resampling performed by a second expert gastrointestinal pathologist. The study was performed on 50 cases of pT2N0 and pT3N0 rectal cancers, with a minimum number of 12 lymph nodes recovered at first sampling, histologically negative for metastases. Resampling retrieved a variable number (1 to 24) of nodes missed at first sampling. The final pN0 status was maintained in pT2 patients, whereas in 18.7% of pT3 patients, metastatic lymph nodes were detected if the mean number of lymph nodes increased from 17.8 to 26.8 after the second sampling. Interestingly, all pN1 patients had only a single metastatic lymph node measuring less than 4.9 mm. As we have shown that most (five out of six) missed metastatic lymph nodes were detected in specimens in which a maximum number of 19 lymph nodes had been originally recovered, we strongly suggest a resampling of pT3N0 rectal specimens if less than 20 lymph nodes have been recovered.

Left–right asymmetry in pelvic lymph nodes distribution: Is there a right-side prevalence?

OBJECTIVE

To assess whether pelvic lymph nodes have a left-right asymmetric distribution.

STUDY DESIGN

The oncologic databases of two gynecologic academic departments were used to identify consecutive patients undergoing pelvic systematic lymphadenectomy as part of the treatment for a variety of gynecologic malignancies. All procedures were carried out in a standardized fashion. Lymph node counts were retrieved from pathological reports.

RESULTS

Four hundred and twenty-eight women underwent pelvic lymphadenectomy during the study period. The median lymph node count was higher on the right side than on the left side [10 (0-33) versus 8 (0-29); P<0.0001]. A prevalence of right-sided nodes was found in 265 (61.9%) patients, while in 44 (10.3%) cases pelvic nodes were equally distributed on the two sides. The right-sided prevalence was significantly higher than the expected 50% in each type of malignancy and surgical technique subgroup. The right-sided prevalence was statistically significant even when the analysis was performed for different nodal groups [external iliac nodes: 5 (0-23) versus 4 (0-13), P=0.005; hypogastric and obturator nodes: 6 (0-17) versus 5 (0-19), P=0.04]. Moreover, nodal count was higher on the right than on the left in obese [10 (1-33) versus 8 (1-26), P=0.0002] and nonobese women [10 (0-32) versus 9 (0-29), P<0.0001].

CONCLUSION

Our findings suggest the existence of a left-right asymmetry in pelvic lymph nodes distribution, with right-sided prevalence.

The importance of accurate pathological assessment of lymph node involvement in colorectal cancer

This review presents an up-to-date analysis of the importance of accurate pathological lymph node staging in colorectal cancer. Lymph node staging is reliant on the technique of the surgeon and the pathologist as well as methods employed in the histopathology laboratory, and is vital for determining appropriate therapy. The significance of micrometastatic nodal disease is evaluated and new techniques for pathological evaluation are discussed. Recommendations for evaluation of lymph node status in colorectal cancer are provided based on current scientific evidence, and standardization of pathological dissection and laboratory handling is advocated.

A Dukes/Jass combination--is it more discriminating?

BACKGROUND

In 1987 Jass described a modified staging system for colorectal cancer using two anatomical criteria in common with the Dukes system; extent of spread through the bowel wall and the presence or absence of lymph node involvement. Additionally it used two 'biological' criteria; the nature of the expanding margin of the tumour (pushing or infiltrating), and the presence or absence of lymphocytic infiltration within the tumour. This study aims to determine whether a combination of the Dukes and Jass staging systems provides a better predictor of five year survival in patients with colorectal cancer than Dukes stage alone.

METHOD

The Dukes and Jass stages along with vital status at five years were recorded for all 612 patients undergoing resection for colorectal cancer at the Royal Bolton Hospital and the Beaumont (BMI) Hospital, Bolton between 1991 and 1998. Kaplan-Meier survival curves with log rank test were used to show how survival correlated with Jass group stratified by Dukes stage.

RESULTS

Both the Dukes B and the Dukes C tumours could be divided into groups with significantly different five year survival rates when stratified by Jass group. Five year survival for Dukes stage B, Jass group II tumours was 73.74% compared to Dukes B Jass III tumours whose survival was 51.38% (P = 0.0018). Five year survival for Dukes C Jass III tumours was 43.18% and for Dukes C Jass IV survival was 24.39% (P = 0.0029).

CONCLUSION

By combining the biological criteria of the Jass staging system with the anatomically based Dukes system, both Dukes B and C tumours can be divided into groups with significantly different five year survival figures.

Metastasis-associated protein S100A4--a potential prognostic marker for colorectal cancer

BACKGROUND AND OBJECTIVES

Expression of S100A4, a small calcium-binding protein, in breast, oesophagus and gall bladder cancers is shown to be associated with adverse clinical outcome. We retrospectively examined the correlation of S100A4 expression and outcome in patients with colorectal cancer.

METHODS

Tissue sections from 54 patients with Dukes B, C and D cancers operated on between 1995 and 1998 were stained with anti-S100A4 antibody. The S100A4 expression profile was correlated to the clinico-pathological details.

RESULTS

There were 31 males and 23 females (mean age 65.94 years +/- 12.29). Dukes stage, >4 positive lymph node status and S100A4 expression were significantly associated with poorer survival. The 3 years survival of patients whose tumour stained positive for S100A4 was 62.85% compared to 93.75% for those stained negative (P < 0.012). In patients with <4 involved nodes, S100A4 expression led to poorer survival (57 months vs. 74 months; P < 0.0052). Within a particular Dukes stage, S100A4 expression was associated with poorer outcome. The 5 years survival of Dukes B patients whose tumour stained negative for S100A4 was 92% compared to 54.6% for those with positive tumours.

CONCLUSION

Our results suggest that S100A4 expression is associated with adverse clinical outcome. Inclusion of S100A4 expression status may enhance our accuracy to prognosticate in patients with colorectal cancer.

Cancer staging and survival in colon cancer is dependent on the quality of the pathologists' specimen examination

Correct staging of colon cancer is decisive regarding further oncological treatment, surveillance and prediction of long-term survival. This study investigated the variability in accuracy of pathology reports with focus on differences between pathology departments and their compliance to regional guidelines. Data from the colon cancer register (1997-2002) of the Uppsala/Orebro, Sweden, health care region were analysed and the seven pathology departments in this region were compared. Included were 3735 patients who had undergone resection of a colon cancer. Cumulative 5-year survival was the main end-point. For 64% (n = 2390) of the cases, the number of lymph nodes examined was given (median 8). Survival in stage II was lower when fewer than 12 nodes were examined or when the number of nodes sampled was not given (P = 0.001, log-rank test). In stage III, those with at the most 3 nodes positive (N1) had a better survival than those with 4 or more nodes positive (N2) (P < 0.001, log-rank test). An index of metastases (IM), derived from the number of nodes with metastases divided by the number of nodes examined, was calculated for stage III tumours. Examination of 12 nodes is necessary to assure stage III cases with the median IM (0.32), whereas 20 nodes are necessary to assure 90% of cases with the lower quartile of IM (0.16). Irrespective of the number of nodes investigated, overall survival was better among patients with IM < 0.33 vs. IM > or = 33 (P < 0.001, log-rank test). The prognostic information of the IM was higher than that of the N-stage. Quality of a pathology department, measured by the median number of lymph nodes investigated and by the proportion of reports where the number is given, was determined to indicate correct staging and management of the patient. An index of metastases (IM) is a possible basis for guidance in the choice of adjuvant treatments that appears superior to that of N-stage.

The Reliability of Lymph-node Staging in Rectal Cancer After Preoperative Chemoradiotherapy

AIMS

To determine the prognostic significance of the nodal stage and number of nodes recovered in the surgical specimen after preoperative synchronous chemoradiation (SCRT) and surgery for locally advanced or unresectable rectal cancer.

MATERIALS AND METHODS

One hundred and eighty-two consecutive patients with locally advanced or unresectable (T3/T4) rectal carcinomas were entered on a prospective database and treated in this department with preoperative chemoradiation, followed 6-12 weeks later by surgical resection. Most patients received chemotherapy in the form of low-dose folinic acid and 5-fluorouracil (5-FU) 350 mg/m2 via a 60-min infusion on days 1-5 and 29-33 of a course of pelvic radiotherapy delivered at a dose of 45 Gy in 25 fractions over 33 days to a planned volume. After resection, patients with a positive circumferential margin (< or = 1 mm), extranodal deposits or Dukes' C histology received adjuvant 5-FU-based-chemotherapy (n = 40).

RESULTS

After SCRT, 161 patients underwent resection. Twenty-one patients remained unresectable or refused an exenterative operation. Median follow-up is 36 months. Down-staging was achieved in most patients, with 19 having a complete pathological response (pT0). The median number of lymph nodes recovered for all patients was five (range 0-21). The 3-year survival rate for node-positive patients is 47%, for node-negative patients with less than three lymph nodes recovered is 62% and for node-negative patients with three or more lymph nodes recovered is 70%. Compared with node-positive patients, simple regression models revealed a reduced hazard ratio (HR) of 0.72 (0.36-1.43) for node-negative patients with less than three nodes recovered and 0.48 (0.26-0.89) for node-negative patients with three or more lymph nodes recovered. In a multivariate model, including nodal status, excision status, age and sex only positive excision margins significantly predicted a poor outcome: HR = 3.05 (1.55-5.97).

CONCLUSIONS

The number of nodes found after preoperative chemoradiation is a significant prognostic factor by univariate analysis. In this study, patients with node-negative histology, and at least three nodes recovered, had better long-term survival than patients in whom two or less nodes were recovered or with positive nodes. This effect was attenuated by the inclusion of excision status in multivariate models.

Number of lymph nodes examined and prognosis of TNM stage II colorectal cancer

The diagnosis of a lymph node-negative colorectal carcinoma should imply a good prognosis; however, the outcomes for TNM stage II patients remain variable. Few studies have examined the relationship of the number of lymph nodes examined to the prognosis of this stage. The aim of this study was to determine whether the number of lymph nodes examined has an effect on prognosis of a relatively large sample of patients undergoing curative surgery for stage II colorectal cancer at a single institution. Data on patients who underwent surgery for colorectal cancer between January 1980 and April 2000 were prospectively collected in a database. Patients with TNM stage II or stage III tumours who were treated with curative intent were removed. Patients over 80 years of age were excluded from the survival analysis. Survival comparisons were made using Kaplan-Meier curves and the log-rank test. Multivariate analysis was performed using a Cox regression model. A total of 625 cases of TNM stage II cases and, for comparison purposes, 415 stage III cases, were analysed. Lymph node retrieval in stage II cases was affected by the patient's age (P=0.04) and gender (P=0.02), tumour grade (P<0.0001), tumour site (P<0.0001), and necessity to carry out extended resection (P<0.0001). In stage III cases, lymph node retrieval was affected by patient age (P<0.0001), tumour grade (P=0.02), and tumour site (P=0.002). Decreased lymph node detection was associated with increasing hazard ratios among the 480 TNM stage II patients under 80 years of age, but not among the 345 patients with TNM stage III tumours. Five year survival rate for patients with stage III tumours with only 1-3 positive lymph nodes (52.6%) was similar to that of patients with stage II tumour who had nine or fewer lymph nodes examined (51.3%). These results demonstrate that the prognosis of TNM stage II colorectal cancer is dependent on the number of lymph nodes examined. Patients with few nodes examined have a poorer prognosis. It is possible that a smaller number of lymph nodes examined reflects a diminished immune response. It can be presumed that those patients with stage II tumour with only a few nodes examined should be offered postoperative chemotherapy on a routine basis.

Metastatic lymph node size and colorectal cancer prognosis

BACKGROUND

Colorectal cancer patients with lymph node metastasis constitute a heterogeneous population with variable prognoses. In this study, my colleagues and I propose a simpler lymph node (LN) staging system for colorectal cancer.

STUDY DESIGN

Four-hundred and twenty-three consecutive colorectal cancer patients were studied. Of these, 36 were excluded because another carcinoma was present. The remaining 387 patients entered the TNM staging analysis. In the survival analysis, 76 patients with distant metastasis were excluded and the remaining 311 patients (LN(-) = 204 and LN(+) = 107) were studied. The diameter of the largest metastatic LN (MLN) was measured on histopathological slides. After examination of various cutpoints and survival outcomes, patients with MLNs were classified into n1 (< or = 9 mm) and n2 (> or = 10 mm) groups, according to size of MLNs (n-stage).

RESULTS

Using disease-free survival (DFS) and overall survival (OS) as outcomes, patients were separated into significant prognostic groups by MLN size (univariate, p < 0.0001) (5-year survival, DFS: n0 = 91.5%, n1 = 62.2%, and n2 = 34.4%; OS: n0 = 85.1%, n1 = 63.5%, and n2 = 42.5%) and International Union Against Cancer/American Joint Committee on Cancer (UICC/AJCC) (N-stage) (univariate, p < 0.0001) (5-year survival, DFS: N0 = 91.5%, N1 = 60.5%, and N2 = 36.8%; OS: N0 = 85.1%, N1 = 65.3%, and N2 = 38.0%). But in patients with fewer than 15 LNs examined (n = 31), only the new nodal stage stratified patients into significant groups (OS: p = 0.003 and DFS: p = 0.001). Only the UICC/AJCC N-stage subcategories were further split into significant prognostic groups by MLN size (UICC/AJCC N1: DFS, p = 0.048 and OS, p = 0.11; N2: DFS, p = 0.04 and OS, p = 0.04). n-stage was an independent important factor both in the DFS and OS in multivariable analysis.

CONCLUSIONS

MLN size is a strong prognostic variable in colorectal carcinoma. This new metric may help clinicians treating colorectal cancer patients, but additional studies are required before clinical application.

Lymph Node Evaluation in Colorectal Cancer Patients: A Population-Based Study

BACKGROUND

Adequate lymph node evaluation is required for proper staging of colorectal cancer, and the number of lymph nodes examined is associated with survival. According to current guidelines, the recommended minimum number of lymph nodes examined to ensure adequate sampling is 12. We used data from the National Cancer Institute's Surveillance, Epidemiology, and End Results program to determine the proportion of colorectal cancer patients in the United States who receive adequate lymph node evaluation.

METHODS

For 116,995 adults with colorectal adenocarcinoma, diagnosed from 1988 through 2001, who underwent radical surgery and did not receive neoadjuvant radiation, we evaluated the number of lymph nodes, the likelihood of receiving adequate lymph node evaluation (i.e., at least 12 lymph nodes examined), and the influence of tumor and patient factors on lymph node evaluation. All statistical tests were two-sided.

RESULTS

Among all patients, the median number of lymph nodes examined was nine. Only 37% of all patients received adequate lymph node evaluation. The proportion of patients receiving adequate lymph node evaluation increased from 32% in 1988 to 44% in 2001 (P(trend)<.001, Cochran-Armitage test). Advanced tumor stage was statistically significantly associated with adequate lymph node evaluation (odds ratio [OR] of receiving adequate lymph node evaluation=2.27, 95% confidence interval [CI] = 2.18 to 2.35). Older patients (> or =71 years, OR = 0.45, 95% CI = 0.44 to 0.47) were less likely to receive adequate lymph node evaluation than younger patients, and those with left-sided (OR = 0.45, 95% CI = 0.44 to 0.47) or rectal (OR = 0.52, 95% CI = 0.50 to 0.54) cancers were less likely to receive adequate lymph node evaluation than patients with right-sided cancers. In all analyses, geographic location was an important predictor of adequate lymph node evaluation, which ranged from 33% to 53%, depending on geographic location.

CONCLUSIONS

In 2001, the majority of patients with colorectal cancer still received inadequate lymph node evaluation. The association of demographic variables, particularly patient age and geographic location, with adequate lymph node evaluation indicates that local surgical and pathology practice patterns may affect adequacy of lymph node evaluation.

Sentinel node biopsy in gastrointestinal-tract cancer

Forty three years after Gould's first description of the sentinel lymph node (SN) technique in malignant tumours of the parotid, sentinel lymph node biopsy (SLNB) has become an invaluable tool for the treatment of solid tumours. In some tumour types, it has been shown to reliably reflect the lymph node (LN) status of the tumour-draining LN basin. In melanoma and breast cancers, it has become a widely accepted element in the routine surgical management of these malignant diseases. In gastrointestinal tumours, the technique is currently under intense investigation. First reports on its application in other solid tumours like non-small cell lung cancer, thyroid carcinoma, oropharyngeal carcinoma, vulvar carcinoma, and Merkel Cell carcinoma of the skin were published more recently. In the following review, we will give a synopsis of the fundamentals of the SN concept and will then proceed to an overview of recent advances of SLNB in gastrointestinal cancers.

Sentinel lymph node mapping in colon cancer

BACKGROUND

By systematically reviewing the literature on sentinel lymph node mapping of colon cancers, this study aimed to evaluate this technique as it applies to colon cancers.

METHODS

Human studies on lymphatic mapping for colon cancers were reviewed. Multiple publications of the same studies, abstracts, and case reports were excluded. Current Contents, MEDLINE, EMBASE, and Cochrane Library databases were investigated.

RESULTS

Lymphatic mapping appears to be readily applicable to colon cancers, identifying lymph nodes most likely to harbor metastases. Identification of sentinel lymph nodes varied from 58% to 100% and carried a false-negative rate of approximately 10% in larger studies, but potentially rose 4% to 25% among patients representing a range from node-negative to node-positive (micrometastases) conditions. The prognostic implication of these micrometastases requires further evaluation. Lymphatic mapping in 6% to 29% of cases identified aberrant lymphatic drainage that altered the extent of the lymphadenectomy.

CONCLUSIONS

Further follow-up evaluation to assess the prognostic significance of micrometastases for colon cancers is required before the staging benefits of sentinel node mapping can have therapeutic implications. Lymphatic mapping offers the possibility of improving staging by identifying patients with early disseminated disease who should be considered for adjuvant treatment or included in trials of adjuvant treatment to speed up the breakthrough of more effective adjuvant regimens. Large studies are needed to determine whether the sentinel node concept is as valid for colon cancers as studies so far have shown it is for malignant melanoma and breast cancer.

What factors affect lymph node yield in surgery for rectal cancer?

OBJECTIVE

The detection of lymph node metastases is of vital importance in patients undergoing excisional surgery for rectal cancer as it provides important prognostic information and facilitates decision-making with regards to adjuvant therapy. It has been suggested that patients in whom only a small number of nodes are present in the excised specimen have a worse prognosis, presumably due to inadequate lymphadenectomy and consequent understaging of the disease. The aim of this study was to determine which factors affect the yield of lymph nodes.

METHODS

This was a retrospective study of patients who had undergone a resection for histologically proven adenocarcinoma of the rectum. The total number of lymph nodes identified in the excised specimen was recorded in each case. A multivariate analysis was performed to ascertain whether this number was significantly influenced by any of several variables.

RESULTS

A total of 167 patients were studied (M:F ratio 107 : 60, median age 70 years). The median number of lymph nodes contained within the resected specimen was 16 (interquartile range 10-21). On univariate analysis a significantly higher yield of lymph nodes was obtained with tumours in the middle third of the rectum (P=0.007), larger tumours (P < 0.001), more locally advanced tumours according to both pT staging (P=0.001) and Dukes' staging (P=0.020), an increased number of involved nodes (P=0.003) and examination by a specialist histopathologist (P=0.003). On multivariate analysis the only significant variables were tumour size (P=0.021), number of positive nodes (P=0.007) and histopathologist (P=0.021).

CONCLUSIONS

The number of lymph nodes identified within the excised specimen in patients undergoing resection of a rectal cancer positively correlates with the size of the tumour and is also dependent on the examining histopathologist. In addition, in node-positive patients the number of involved nodes increases with increasing lymph node yield.

The impact on nodal staging of lymphatic mapping in carcinoma of the colon and rectum

Although the majority of individuals undergoing apparently curative resection for carcinoma of the colon rectum who are found to be without evidence of metastatic disease in the regional lymph nodes will remain free of disease, approximately 20% to 30% of these individuals will develop recurrent disease and die. This may, in part, be due to understaging of the disease. For this reason, there has been increasing interest in approaches to improving staging of all solid tumors, including carcinoma of the colon and rectum. Lymphatic mapping has revolutionized the management of patients with cutaneous melanoma and breast cancer and has been demonstrated to more accurately stage patients with solid tumors. Our investigations as well as others have taken a number of strategies to improving the staging of individuals of colorectal cancer patients with apparently node-negative disease, including the development of a novel ex vivo lymphatic mapping technique. This article summarizes our and other investigations into improved staging of colorectal cancer with an emphasis on the impact of lymphatic mapping on improving the accuracy of staging of apparently node-negative colorectal cancer patients.

Validation of ex vivo lymphatic mapping in hematoxylin-eosin node-negative carcinoma of the colon and rectum

BACKGROUND

Substantial evidence supports that detailed analysis of the regional lymphatics will identify previously unrecognized micrometastatic disease in colorectal cancer. In order to determine whether the sentinel lymph node(s) (SLNs) harvested by ex vivo lymphatic mapping in node-negative colorectal cancer (CRC) are the most likely node(s) to harbor micrometastatic disease, we examined all nodes in CRC specimens in an identical fashion.

METHODS

One hundred twenty-four specimens from patients with colorectal cancer were delivered to pathology in the fresh state and underwent ex vivo sentinel lymph node mapping. If negative by routine hematoxylin and eosin (H&E) analysis, the SLNs and non-SLNs were subjected to further analysis by level section H&E and immunohistochemical (IHC) analysis.

RESULTS

A mean of 30 nodes were harvested (range, 5-111). Fifty-one patients (41%) were found to be node-positive by routine H&E analysis. SLNs were identified in all but three specimens. A total of 2177 nodes were analyzed from the 66 H&E node-negative specimens (1883 non-SLNs and 294 SLNs). Overall, metastases were identified in 13 of 278 SLNs and in only 5 of 1829 non-SLNs (P <.001). Only 5 of 66 patients (7.5%) had evidence of metastatic disease in non-SLNs when the SLNs were negative. Thirteen apparently node-negative patients (19.3%) were upstaged by IHC analysis of the SLNs (P =.04).

CONCLUSIONS

If the SLN is negative by both H&E and IHC analysis, the probability of finding metastases in a non-SLN is remote. If microstaging is demonstrated to be prognostically relevant, focused examination should be of the SLN(s).

Efficacy of manual dissection of lymph nodes in colon cancer resections

The adequacy of lymph node dissection of colonic resection specimens influences the clinical and pathologic staging, leading to important postsurgical treatment decisions. Although manual lymph node dissection is the current standard at most institutions, recent statistical studies indicate that all lymph nodes, including those measuring 1-2 mm, should be recovered to be assured of lymph node negative status. Thus, we tested the efficacy of gross dissection by submitting the entire residual mesenteric fat. We analyzed 15 randomly chosen colonic resections (2 pT1, 1 pT2, 11 pT3, 1 pT4). After standard gross dissection of lymph nodes and submission of colonic material for diagnosis, the entire remaining mesenteric material was dehydrated over several days by serial washing in alcohol and acetone. All of the mesenteric tissue was submitted for histology. The average number of nodes found by original gross inspection was 20.8, while the average number of additional nodes found after clearing was 68.6. In all, 83% of the additional nodes were 2.0 mm or less in size. There were seven pN0 cases; one was upstaged by additional findings that may have been artifactual. There were four pN1 cases; three were upstaged to pN2 after submission of the mesenteric material. All four pN2 tumors had additional metastases identified. In all, 75% of all positive nodes were under 2.0 mm in size. In this limited sample, standard gross dissection proved sufficient for most pN0 tumors to remain node negative. However, our findings within the pN1 group show that examination of all of the mesenteric material may be necessary to be assured of correct pN status.

How many lymph nodes are necessary to stage early and advanced adenocarcinoma of the sigmoid colon and upper rectum?

The lymph-node yields in specimens resected for colorectal adenocarcinoma show considerable variations, raising the question whether the minimum lymph-node number recommended by the UICC (International Union Against Cancer) for pN0 classification represents an appropriate quality standard for specimen work-up. The number of pericolic lymph nodes recovered from 568 archival surgical colorectal carcinoma specimens located in the sigmoid or upper rectum showed a highly statistically significant correlation with both the pT category and the presence of metastases ( P<0.0005). The median lymph-node yield in standardized (i.e., resembling in size surgically removed cancer specimens) tumor-free specimens obtained during autopsies was 13 lymph nodes, compared with 20.5 when diverticula were present and more than 30 in specimens with chronic inflammation or from patients with systemic infections. In 48 pT2 and pT3 carcinoma specimens prospectively dissected in the same way, median numbers of 18 (pT2) and 23 (pT3) lymph nodes were detected (range between 8 and 39 nodes). The lymph-node numbers recommended in previous studies and by the UICC often seem to be too low to declare a specimen free of metastases. Although the great variation in lymph-node counts requires the recovery of all lymph nodes for pN0 classification, recommendations considering the pT status and additional factors like diverticula and inflammatory changes can be useful as a quality standard for specimen work up.

Sentinel lymph node mapping in colorectal cancer

BACKGROUND

Ultrastaging, by serial sectioning combined with immunohistochemical techniques, improves detection of lymph node micrometastases. Sentinel lymph node mapping and retrieval provides a representative node(s) to facilitate ultrastaging. The impact on staging of carcinoma of the colon and rectum in all series emphasizes the importance of this technique in cancer management. Now the challenge is to determine the biological relevance and prognostic implications.

METHODS

The electronic literature (1966 to present) on sentinel node mapping in carcinoma of the colon and rectum was reviewed. Further references were obtained by cross-referencing from key articles.

RESULTS

Lymphatic mapping appears to be readily applicable to colorectal cancer and identifies those lymph nodes most likely to harbour metastases. Sentinel node mapping carries a false-negative rate of approximately 10 per cent in larger studies, but will also potentially upstage a proportion of patients from node negative to node positive following the detection of micrometastases. The prognostic implication of these micrometastases requires further evaluation.

CONCLUSION

Further follow-up to assess the prognostic significance of micrometastases in colorectal cancer is required before the staging benefits of sentinel node mapping can have therapeutic implications.

Nodal staging of colorectal carcinomas and sentinel nodes

This review surveys the staging systems used for the classification of colorectal carcinomas, including the TNM system, and focuses on the assessment of the nodal stage of the disease. It reviews the quantitative requirements for a regional metastatic work up, and some qualitative features of lymph nodes that may help in the selection of positive and negative lymph nodes. Identification of the sentinel lymph nodes (those lymph nodes that have direct drainage from the primary tumour site) is one such qualitative feature that is claimed to allow the upstaging of colorectal carcinomas via an oriented, enhanced pathological work up. Current evidence in favour of a change in the requisite of assessing as may lymph nodes as is possible, and concentrating the efforts on only a selected number of lymph nodes, is weak.

Accuracy of determining nodal negativity in colorectal cancer on the basis of the number of nodes retrieved on resection

BACKGROUND

Correct determination of nodal status is pivotal to accurate staging and predicting survival.

METHODS

This is a secondary analysis of INT0089, an intergroup trial of adjuvant chemotherapy for high-risk stage II and III colon cancer. A subset of patients was studied who underwent right or left hemicolectomy and from whom at least 10 lymph nodes were examined. A mathematical model was created to estimate the probability of a true negative result on the basis of the number of nodes examined. The number of nodes needed to predict nodal negativity with 85%, 50%, and 25% probability on the basis of tumor stage was calculated.

RESULTS

In this analysis, 1585 patients were studied. The average number of nodes removed at surgery was comparable between treatment groups at 18.5 (median of 16 in all groups). With this model, when 18 nodes are removed at resection, there is a <25% probability of true node negativity in T1/T2 tumors, whereas <10 nodes need to be examined in T3 and T4 tumors to achieve the same probability.

CONCLUSIONS

Tumor stage and the number of nodes retrieved at resection influence the accuracy of determining nodal status in colon cancer. Most patients are understaged. Underestimating nodal stage may influence decisions regarding adjuvant therapy, as well as overall prognosis.

Colorectal cancer in 2003: old principles, new strategies

In the last two decades the prognosis of colorectal cancer has improved for two reasons: (i) the proportion of patients with localized disease has increased and treatment has been standardized, and (ii) new chemotherapeutic agents have led to a longer life expectancy for patients with advanced disease. In this review the current insights in disease etiology and treatment of localized and disseminated colorectal cancer are discussed.

Influence of obesity on lymph node recovery from rectal resection specimens

Careful lymph node dissection from colorectal resection specimens is important procedure for cancer staging. Present study intended to assess the impact of surgical technique and patient's obesity on this process. Number of lymph nodes harvested by manual dissection from resection specimens of 141 patients with rectal cancer and the rate of nodal metastases were analyzed and compared in different groups of patients selected by length of resection specimen and body mass index. The median and mean number of lymph nodes found per patient were 6 and 6.7. The shorter resection specimens (<16 cm after formalin fixation) yielded significantly lower number of nodes than those with length > 16 cm (5.7 versus 7.9). Most significant reduction in mean number of lymph nodes was observed in obese patients with short specimens (4.8). This subset of patients presented the lowest rate of nodal metastases (38%). The surgical technique seems to be an important factor for lymph node recovery from rectal resections specimens. The patient's obesity had an unfavourable impact on this procedure. Standardized surgery and histopathological examination are needed even in non-specialized centers to harvest adequate number of lymph nodes.

Is there a minimum number of lymph nodes that should be histologically assessed for a reliable nodal staging of T3N0M0 colorectal carcinomas?

BACKGROUND AND OBJECTIVES

Because of the existing controversy, we searched for a cutoff value for the number of lymph nodes (LNs) to be examined in order to establish a reliable node-negative stage in colorectal carcinomas (CRCs).

METHODS

From the SEER database, 8,574 T3N0M0 first, single, histologically confirmed, surgically treated CRCs, with at least 1 LN examined histologically, were considered. As a first approach, the relationships between number of examined LNs and 5- and 10-year overall survival (OS) rates, computed by the Kaplan-Meier method, were assessed. Next, multivariate analysis was performed; a proportional hazards model was fitted to the data and used to obtain a smoothed plot of the martingale residuals vs. the number of negative LNs.

RESULTS

Both OS rates displayed an improvement with an increase of number of LNs examined. The smoothed plot of the martingale residuals against the number of negative LNs was reasonably linear.

CONCLUSIONS

Both approaches suggest that there is no cutoff value for the number of LNs to be examined for an adequate nodal staging; for a reliable pN0 staging, as many LNs should be assessed as possible. However, qualitative features of lymph nodes (e.g., those identified by sentinel lymphadenectomy) may alter this recommendation.

The influence of nodal size on the staging of colorectal carcinomas

AIMS

The reliable identification of node negative colorectal carcinomas (CRCs) has often been linked to the histological examination of a minimum number of lymph nodes. The sizes of the lymph nodes, their metastatic status, and their number were investigated to establish whether these parameters are related, and whether their relation could help in determining the adequacy of staging.

METHODS

One thousand three hundred and thirty four negative lymph nodes, 189 metastatic lymph nodes, and 43 pericolonic/perirectal tumour deposits measuring > or = 3 mm from 60 node positive and from 63 node negative patients with CRC were assessed for size.

RESULTS

The mean size (SD) of these structures was 4.5 (2.7) mm. The lymph nodes were significantly larger in the CRCs with metastatic nodes (4.7 v 4.3 mm). Involved nodes were significantly larger than negative nodes (6.3 v 4.2 mm), despite the fact that the largest node was < or = 5 mm in one third of node positive CRCs. The examination of the seven largest nodes could have adequately staged 97% of node positive CRCs and 98% of all CRCs.

CONCLUSIONS

The nodal staging of CRCs is dependent not only on the number of lymph nodes investigated, but also on qualitative features of the lymph nodes assessed, including their size. Lymph nodes are not equivalent and any study neglecting this fact will give grounds for error in the recommendation of a minimum number of nodes for the reliable determination of node negative CRCs. Although pathologists should aim to recover all nodes, a negative nodal status based on only seven nodes can be reliable.

Prognostic evaluation of stage B colon cancer patients is improved by an adequate lymphadenectomy: results of a secondary analysis of a large scale adjuvant trial

OBJECTIVE

To determine if the extent of lymphadenectomy (number of recovered lymph nodes) was associated with long-term outcome in patients operated on for stage B and C colon cancer.

SUMMARY BACKGROUND DATA

Lymphatic spreading is the main prognostic indicator in colon cancer patients, although the optimal extent of lymphadenectomy and its prognostic impact are still unknown.

METHODS

In 3,648 patients (median follow-up 3.6 years) enrolled in two consecutive INTACC multicentric trials on adjuvant therapy for colon cancer, we studied the association of the number of recovered nodes with overall survival and relapse free survival by means of univariate and Cox regression analysis.

RESULTS

The worst overall survival was related to ages > 65 (risk ratio [RR] = 1.30), higher grading (RR = 1.96). Better overall survival was related to female gender (RR = 0.80) and to higher number of recovered nodes (8-12 nodes, RR = 0.46, 13-17 nodes, RR = 0.76, nodes > or = 18, RR = 0.79). The same pattern was observed for relapse free survival. Longer overall and relapse free survival were related to a higher number of recovered nodes with P =.034 and P =.003 respectively (stratified analysis for absence or presence of positive nodes). Stage B patients with fewer than 7 nodes in the specimen had both shorter overall survival (P =.0000) and relapse free survival (P =.0016) than the other B patients. Outcome of stage C patients was not related to the number of recovered nodes (P =.28 and 0.12 respectively). The interaction test between stage of disease and number of recovered nodes was statistically significant (P =.017).

CONCLUSIONS

Stage B patients with a small number of examined nodes may be understaged. Thus, these patients might be considered for adjuvant therapy because of their poorer life expectancy than other stage B patients. For stage C patients, the number of recovered nodes does not seem to affect long-term outcome.

Adjuvant therapy in rectal cancer: analysis of stage, sex, and local control--final report of intergroup 0114

PURPOSE

The gastrointestinal Intergroup studied postoperative adjuvant chemotherapy and radiation therapy in patients with T3/4 and N+ rectal cancer after potentially curative surgery to try to improve chemotherapy and to determine the risk of systemic and local failure.

PATIENTS AND METHODS

All patients had a potentially curative surgical resection and were treated with two cycles of chemotherapy followed by chemoradiation therapy and two additional cycles of chemotherapy. Chemotherapy regimens were bolus fluorouracil (5-FU), 5-FU and leucovorin, 5-FU and levamisole, and 5-FU, leucovorin, and levamisole. Pelvic irradiation was given to a dose of 45 Gy to the whole pelvis and a boost to 50.4 to 54 Gy.

RESULTS

One thousand six hundred ninety-five patients were entered and fully assessable, with a median follow-up of 7.4 years. There was no difference in overall survival (OS) or disease-free survival (DFS) by drug regimen. DFS and OS decreased between years 5 and 7 (from 54% to 50% and 64% to 56%, respectively), although recurrence-free rates had only a small decrease. The local recurrence rate was 14% (9% in low-risk [T1 to N2+] and 18% in high-risk patients [T3N+, T4N]). Overall, 7-year survival rates were 70% and 45% for the low-risk and high-risk groups, respectively. Males had a poorer overall survival rate than females.

CONCLUSION

There is no advantage to leucovorin- or levamisole-containing regimens over bolus 5-FU alone in the adjuvant treatment of rectal cancer when combined with irradiation. Local and distant recurrence rates are still high, especially in T3N+ and T4 patients, even with full adjuvant chemoradiation therapy.

Lymph node recoveries from 2427 pT3 colorectal resection specimens spanning 45 years: recommendations for a minimum number of recovered lymph nodes based on predictive probabilities

This study investigates the relationship between the number of recovered lymph nodes and lymph node metastases in colorectal resection specimens. All of the slides from 2427 pT3 colorectal resection specimens from patients operated on at William Beaumont Hospital during the 45 years from 1955 through 2000 were reviewed. Lymph node metastases were present in 333 of 1499 (22.2%) specimens with fewer than 15 recovered lymph nodes, compared with 789 of 928 (85.0%) specimens with 15 or greater recovered lymph nodes (p <0.01). The proportion of lymph node metastases increased as a function of the number of recovered lymph nodes (p <0.01). Similarly, in patients without lymph node metastases, survival increased as a function of the number of recovered lymph nodes. Among these patients, the 5-year overall survival rate was 62.2% among patients with seven or fewer recovered lymph nodes and 75.8% among patients with 18 or more recovered lymph nodes (p = 0.018). Statistical analysis found the predictive probability of identifying the single lymph node metastasis in a theoretical specimen with a single lymph node metastasis is 0.25 if 12 lymph nodes are recovered and 0.46 if 18 lymph nodes are recovered. The predictive probability increased as the number of recovered lymph nodes increased, suggesting there is no minimum number that reliably or accurately stages all patients. Thus, all palpable lymph nodes should be recovered, including those that are 1 or 2 mm.

Detection of lymph node metastases in colorectal carcinoma

The detection of lymph node metastases is the single most important prognostic factor for patients with colorectal cancer. This review outlines the difficulties and methods of detecting positive lymph node metastases in this disease. An outline of traditional diagnostic methods including preoperative ultrasound and cross sectional imaging techniques are evaluated alongside newer modalities including immunoscintography and PET scanning and intraoperative radioguided imaging. Pathological methods of detecting positive nodal disease using standard histopathological staging, enhanced lymph node harvesting and determination of micrometastases are also discussed.

Anatomic study of the lymph nodes of the mesorectum

PURPOSE

Lymph node involvement is the most important prognostic factor when staging patients with colorectal cancer. The probability of detecting metastasis grows with the number of nodes examined. However, the number of nodes found in surgical specimens varies substantially. We have therefore determined the number and distribution of lymph nodes in the mesorectum by cadaveric dissection.

METHODS

Twenty formalin-fixed cadaveric pelvises were dissected (13 males). The search for lymph nodes was performed in a systematic way, from the division of the superior rectal artery following the smallest visible branches to the level of the anorectal ring.

RESULTS

A total of 168 lymph nodes were found in 20 mesorectal blocks, with a mean (standard deviation) number per specimen of 8.4 (4.45). Lymph node size ranged from 2 to 10 mm. Distribution of lymph nodes in mesorectum was as follows: 120 nodes (71.4 percent) were found around the branches of the superior rectal artery proximal to the peritoneal reflection, and 48 nodes (28.6 percent) were found distal to the peritoneal reflection. Fourteen specimens (70 percent) had lymph nodes at the division of the superior rectal artery.

CONCLUSIONS

The mean number of lymph nodes found in the mesorectum distal to the superior rectal artery division was 8.4. Most of these lymph nodes were proximal to the peritoneal reflection. The range found in the number of lymph nodes per case should be considered for use in the formulation of guidelines in anatomicopathologic studies of surgical specimens obtained after mesorectal excision.

Clinical significance of E-cadherin-catenin complex expression in metastatic foci of colorectal carcinoma

BACKGROUND AND OBJECTIVES

Reduced expressions of cell adhesion molecules (E-cadherin, alpha-catenin, and beta-catenin) has been reported to be associated with tumor metastasis. However, the clinical significance of such adhesion molecules in the metastatic foci remains unclear. In this study, we evaluated the prognostic significance of E-cadherin, alpha-catenin, and beta-catenin expressions in the metastatic foci of patients with colorectal carcinoma.

METHODS

The expressions of E-cadherin, alpha-catenin, and beta-catenin were detected immunohistochemically in 105 primary tumors, in 30 metastatic lymph nodes, and 13 metastatic liver tumors from consecutive patients with colorectal carcinoma.

RESULTS

Reduced normal expression of E-cadherin, alpha-catenin, and beta-catenin in comparison with normal epithelium was detected in 78 primary tumors, respectively. Patients who had tumors with reduced expression of adhesion molecules showed unfavorable prognosis and the reduced expression of adhesion molecules was detected as one of the independent prognostic factors for patients with colorectal carcinoma. In 30 patients with lymph node metastasis, the increased expression of adhesion molecules in metastatic lymph nodes compared with primary tumors was detected in 13 patients. The prognosis of these 13 patients was poorer than that of remaining 17 patients (P = 0.0296). Also, in 13 patients with liver metastasis, even no significant difference was observed, the mean survival time of 6 patients who had metastatic liver tumors with increased expression of adhesion molecules (10 months) was shorter than that of the remaining 7 patients (16 months; P = 0.1718).

CONCLUSIONS

These results suggest that increased expression of the cadherin-catenin cell-cell adhesion system in metastatic foci may play an important role in progression of metastatic colorectal carcinomas.

The role of sentinel lymph node mapping in staging of colon and rectal cancer

PURPOSE

Nodal metastasis is the best predictor of survival for patients with colon cancer. Statistical models based on random distribution of positive lymph nodes suggest that to correctly classify nodal status with 95 percent confidence, 20 nodes are needed for T1 lesions, 17 nodes for T2, and 15 nodes for T3. The mean number of nodes identified in American patients is 8, suggesting that they might not be accurately staged. Patients in our tumor registry staged as "node-negative" had a short survival when they had < or =10 lymph nodes evaluated when compared with patients with >10 lymph nodes evaluated (p < 0.01). We hypothesized that the use of sentinel lymph node may assist in the staging of colon cancer.

METHODS

Thirty-eight consecutive patients with colon lesions were prospectively enrolled into this trial between February 1998 and November 1999. Thirty-one patients met criteria for analysis. During surgery, Lymphazurin blue dye was injected subserosally into the area around the tumor. Routine nodal evaluation, with extra cuts of all sentinel nodes, was undertaken.

RESULTS

At least one sentinel lymph node was found in 18 of 31 patients (58 percent). Sensitivity of 67 percent, specificity and positive predictive value of 100 percent, and negative predictive value of 94 percent were found when sentinel lymph nodes were identified. In 2 of these 18 patients, the sentinel lymph node was the only positive lymph node found.

CONCLUSIONS

Application of the sentinel lymph node technique to colon cancer may make it easier to identify lymph nodes most likely to contain metastatic disease, potentially "down-staging" more patients. This may have implications in postoperative care.

Tumor growth pattern and thymidine phosphorylase expression are related with the risk of hematogenous metastasis in patients with Astler Coller B1/B2 colorectal carcinoma

BACKGROUND

The benefit of adjuvant chemotherapy appears to be limited for patients with Astler Coller B1/B2 colorectal carcinoma but may be better in a subgroup of patients with a high recurrence risk. In the current case-control analysis, the authors evaluated whether patients with a high risk of hematogenous metastasis could be identified by means of a thorough histologic and immunohistochemical examination of the resection specimens.

METHODS

A database was built for all patients treated in a general teaching hospital for colorectal carcinoma between 1985 and 1995. From this database, all patients with an Astler Coller B1 or B2 tumor who subsequently had developed hematogenous metastases were taken as cases. For each case, three matched controls (age, Astler Coller, year of diagnosis) without metachronous metastases were selected. The resection specimens of cases and controls were blindly examined by two observers for the following: World Health Organization (WHO) classification; differentiation grade; growth pattern; lymphocytic, fibroblastic, and eosinophilic reaction; angioinvasion; number of lymph nodes examined; expression of E-cadherin, vascular endothelial growth factor and thymidine phosphorylase (TP); P53; microvessel density.

RESULTS

Twenty-two cases and 65 controls were included in the analysis. Tumor growth pattern and tumor TP expression both independently contributed to recurrence risk. With these 2 variables, 4 subgroups could be identified with a recurrence risk ranging from 0% to 42%.

CONCLUSIONS

Tumor growth pattern and degree of TP expression both appear to be related to the recurrence risk. Prospective trials should point out whether these variables can be implemented in the decision making concerning adjuvant chemotherapy.

GEWF solution

BACKGROUND

Lymph node status is an important prognostic factor in the staging of colorectal carcinoma. Several adjunctive solutions have been used to increase the yield of pericolic lymph nodes from colorectal cancer resection specimens.

METHODS

During 1998 at the Grey Bruce Regional Health Centre (Owen Sound, Ontario), 67 colonic resections were performed for colorectal cancer. Lymph nodes were identified using GEWF solution (glacial acetic acid, ethanol, distilled water, and formaldehyde) in 35 cases, and by the conventional method of sectioning, inspection, and palpation in 32 cases.

RESULTS

There were no significant differences between GEWF and non-GEWF cases with respect to patient age, length of resection, size of tumor, tumor histologic type, tumor differentiation, or depth of tumor penetration into the bowel wall. Use of GEWF led to a significant increase in the number of lymph nodes found (10.2 +/- 4.9 per case) compared with non-GEWF cases (6.8 +/- 3.9 per case) (P =.002). In GEWF cases 358 lymph nodes were identified, 82 with metastases, whereas in the non-GEWF cases 218 lymph nodes were found, 41 with metastases. The size of positive lymph nodes in the GEWF group (0.5 +/- 0.2 cm) was significantly smaller than in the non-GEWF group (0.7 +/- 0.4 cm) (P =.046). A greater percentage of positive lymph nodes in the GEWF cases (49/82, 60%) were 0.5 cm or smaller compared with the non-GEWF cases (17/41, 41%).

CONCLUSIONS

GEWF increases the yield of lymph nodes recovered from colorectal cancer specimens and may lead to improved staging of this cancer; it is inexpensive and simple to use.

Fluorouracil plus leucovorin as effective adjuvant chemotherapy in curatively resected stage III colon cancer: results of the trial adjCCA-01

PURPOSE

Adjuvant postoperative treatment with fluorouracil (5-FU) and levamisole in curatively resected stage III colon cancer significantly reduces the risk of cancer recurrence and improves survival. Biochemical modulation of 5-FU with leucovorin has resulted in increased remission rates in metastatic colorectal cancer, thus reflecting an increased tumor-cell kill. The impact of 5-FU plus leucovorin on survival and tumor recurrence was analyzed in comparison with the effects of 5-FU plus levamisole in the prospective multicentric trial adjCCA-01.

PATIENTS AND METHODS

Patients with a curatively resected International Union Against Cancer stage III colon cancer were stratified according to T, N, and G category and randomly assigned to receive one of the two adjuvant treatment schemes: 5-FU 400 mg/m(2) body-surface area intravenously in the first chemotherapy course, then 450 mg/m(2) x 5 days; 12 cycles, plus leucovorin 100 mg/m(2) (arm A), or 5-FU plus levamisole (Moertel scheme; arm B).

RESULTS

Six hundred eighty (96.9%) of 702 patients enrolled onto this study were eligible. After a median follow-up time of 46.5 months, the 5-FU plus leucovorin combination significantly improved disease-free survival (P =.037) and significantly decreased overall mortality (P =.0089) in comparison with 5-FU plus levamisole. In a multivariate proportional hazards model, adjuvant chemotherapy emerged as a significant prognostic factor for survival (P =.0059) and disease-free survival (P =.03). Adjuvant treatment with 5-FU plus levamisole as well as with 5-FU plus leucovorin was generally well tolerated; only a minority of patients experienced grade 3 and 4 toxicities.

CONCLUSION

After a curative resection of a stage III colon cancer, adjuvant treatment with 5-FU plus leucovorin is generally well tolerated and significantly more effective than 5-FU plus levamisole in reducing tumor relapse and improving survival.

Impact of number of nodes retrieved on outcome in patients with rectal cancer

PURPOSE

We postulated that the pathologic evaluation of the lymph nodes of surgical specimens from patients with rectal cancer can have a substantial impact on time to relapse and survival.

PATIENTS AND METHODS

We analyzed data from 1,664 patients with T3, T4, or node-positive rectal cancer treated in a national intergroup trial of adjuvant therapy with chemotherapy and radiation therapy. Associations between the number of lymph nodes found by the pathologist in the surgical specimen and the time to relapse and survival outcomes were investigated.

RESULTS

Patients were divided into groups by nodal status and the corresponding quartiles of numbers of nodes examined. The number of nodes examined was significantly associated with time to relapse and survival among patients who were node-negative. For the first through fourth quartiles, the 5-year relapse rates were 0.37, 0.34, 0.26, and 0.19 (P: = .003), and the 5-year survival rates were 0.68, 0.73, 0.72, and 0.82 (P: = .02). No significant differences were found by quartiles among patients determined to be node-positive. We propose that observed differences are primarily related to the incorrect determination of nodal status in node-negative patients. Approximately 14 nodes need to be studied to define nodal status accurately.

CONCLUSION

These results suggest that the pathologic assessment of lymph nodes in surgical specimens is often inaccurate and that examining greater number of nodes increases the likelihood of proper staging. Some patients who might benefit from adjuvant therapy are misclassified as node-negative due to incomplete sampling of lymph nodes.

Histopathological detection of lymph node metastases from colorectal carcinoma

AIM

To evaluate whether the assessment of multiple sections from retrieved nodes yields an increased number of metastases compared with the number that would be detected by the commonly applied method of microscopy of a single section of lymph node only.

METHODS

A prospective study of 72 colorectal carcinoma resection specimens. Lymph node sampling was based on the current guidelines for the detection of breast cancer metastases in axillary nodes. Lymph nodes up to approximately 5 mm in maximum extent were processed in entirety, without prior sectioning, and assessed histologically at three levels; larger lymph nodes were processed in entirety as multiple sections and histologically assessed at one level.

RESULTS

From a total of 72 carcinomas, eight were Dukes's A, 26 were Dukes's B, and 38 were Dukes's C. The mean and median numbers of nodes identified were 13 and 12, respectively (range, three to 44). Of the Dukes's C cases, four contained lymph node metastases identified by our method that might have gone undetected by the current, generally applied method. In one case, this led to the detection of the only nodal metastasis present and therefore "upstaged" the tumour from Dukes's B to C. On average, six extra tissue blocks were processed for each case in applying this method.

CONCLUSION

The assessment of multiple sections of lymph nodes from colorectal specimens leads to the detection of only a small number of additional nodal metastases. The method involves increased workload for pathologists and laboratory staff.

Number of nodes examined and staging accuracy in colorectal carcinoma

PURPOSE

The objective of this study was to determine the number of nodes that need to be examined to accurately reflect the histology of the regional lymphatics in colorectal carcinoma.

PATIENTS AND METHODS

Patients undergoing curative resection for T2 and T3 colorectal cancer between 1992 and 1996 were reviewed. Pathologic data from these patients were entered into a computerized database for storage, retrieval, and analysis. The major outcome measured was the number of nodes that need to be examined to achieve a node-positive rate consistent with that reported in the National Cancer Data Base (NCDB) report.

RESULTS

The number of nodes examined ranged from 0 to 78 (mean, 17 nodes). Node-negative patients had fewer nodes examined (mean, 14 nodes) than node-positive patients (mean, 20 nodes; P =.003). The entire sample had a node-positive rate of 38.8% (95% confidence interval [CI], 32% to 45.5%), not statistically different from that in the NCDB report. When at least 14 nodes were examined, the percent of patients with at least one positive node was 33.3% (95% CI, 24.6% to 42.3%), not statistically different from the NCDB report.

CONCLUSION

In a sample of patients statistically similar to the sample in the NCDB report, the examination of at least 14 nodes after resection of T2 or T3 carcinoma of the colon and rectum will accurately stage the lymphatic basin.