The clinicopathological significance of inferior mesenteric lymph node metastasis in colorectal cancer

The total number of lymph nodes in resected colon cancer specimens is affected by several factors but the lymph node ratio is independent of these

The number of lymph nodes retrieved from the specimen may be a surrogate measure of the adequacy of extensive colon cancer surgery, but many variables may influence the total lymph node yield of any specimen. We examined which variables would be influential both for negative and positive node sampling.The combined results from 428 patients from three hospitals A to C treated in 2007-2009 with single colon cancers having R0 segmental resections were analysed. The surgical technique and pathology staining methods were slightly different between the hospitals.The mean number of lymph nodes was 15.8 (range 1-60). Twelve or more lymph nodes were harvested in 78% of the specimens. In the multivariate Poisson regression analysis of all TNM stages, the factors associated with the total lymph node harvest were age, pathology handling, tumour location and size (p < 0.001), whereas for TNM stage III alone the pathology handling (p < 0.001) and a radical operating technique (p = 0.003) were highly significant. The total number of lymph nodes was the only significant factor for the number of positive lymph nodes (Posln) according to the multivariate negative regression analysis (p = 0.02) but the analysis of the lymph node ratio (LNR) detected no statistically significant variable.Several factors, and especially the specimen processing technique, were important for the total number of harvested lymph nodes. The number of Posln varied between segments and increased with the total number of harvested lymph nodes, but for LNR no variable was important. LNR seemed to abolish the combined effect of tumour location and the total lymph node yield in prognosis assessment.

A nodal positivity constant: new perspectives in lymph node evaluation and colorectal cancer

PURPOSE

To date, associations between the number of lymph nodes evaluated, staging, and survival have been examined in the context of large population-based studies conducted by a small number of investigators. Therefore, although high-quality data are available, perspective is lacking.

METHODS

Studies for this paper were identified by searches of Medline, Scopus, PubMed, and manual searching of references from articles, using the search terms ''colorectal cancer'', ''nodal status'' and ''lymph node''.

RESULTS

It is clear that survival benefit increases with the increasing number of lymph nodes harvested. Despite this observation, there has been no significant increase in the proportion of node-positive cancers over the past two decades.

CONCLUSION

The nodal positivity rate for colorectal cancer consistently approximates 40 % across a wide range of studies internationally, a phenomenon that has not previously been recognized in the literature. We review the evidence and introduce the concept of a nodal positivity constant.

High ligation of the inferior mesenteric artery in rectal cancer surgery

In rectal cancer surgery, it is unclear whether the inferior mesenteric artery (IMA) should be ligated as high as possible, at its origin, or low, below the origin of the left colic artery. We reviewed all relevant articles identified from MEDLINE databases and found that despite a trend of improved survival among patients who underwent high ligation, there is no conclusive evidence to support this. High ligation of the IMA is beneficial in that it allows for en bloc dissection of the node metastases at and around the origin of the IMA, while enabling anastomosis to be performed in the pelvis, without tension, at the time of low anterior resection. High ligation of the IMA does not represent a source of increased anastomotic leak in rectal cancer surgery and postoperative quality of life is improved by preserving the hypogastric nerve without compromising the radicality of the operation. More importantly, high ligation of the IMA improves node harvest, enabling accurate tumor staging. Although the prognosis of patients with node metastases at and around the origin of the IMA is poor, the survival rate of patients with rectal cancer may be improved by performing high ligation of the IMA combined with neoadjuvant and adjuvant therapy.

Distribution of lymph node metastases is an independent predictor of survival for sigmoid colon and rectal cancer

OBJECTIVE

This study evaluated the prognostic significance of the distribution of lymph node metastases (LND) in patients with colorectal cancer.

BACKGROUND

The impact of the LND on survival in colorectal cancer is unknown.

METHODS

A total of 1205 consecutive patients who underwent potentially curative surgery for sigmoid colon or rectal cancer with high ligation of the inferior mesenteric artery (IMA) from January 1997 to February 2008 were assigned to 4 groups based on LND: LND0, no lymph node metastases-615 patients (51.0%); LND1, metastases in the pericolic nodes-324 patients (26.9%); LND2, metastases in the intermediate nodes-172 patients (14.3%); and LND3, node metastases at the origin of the IMA-94 patients (7.8%).

RESULTS

The 5-year overall survival rates of patients with LND0, LND1, LND2, and LND3 were 83%, 63%, 52%, and 28%, respectively (P < 0.001). The 5-year disease-free survival rates of patients with LND0, LND1, LND2, and LND3 were 83%, 54%, 43%, and 21%, respectively (P < 0.001). On multivariate analysis, LND was an independent prognostic factor for both overall survival and disease-free survival. However, the 5-year local recurrence-free survival rate was not inversely related to the LND. On a subset analysis that compared stage III disease with stage IV disease, the 5-year overall survival and disease-free survival rates were 45% and 31% for the patients with stage IV disease compared with 40% and 32% for the patients with stage III, LND3 disease, respectively (P = 0.761 and 0.704). For the patients with pN1 tumors, the overall survival and disease-free survival did not differ significantly according to the LND (P = 0.471 and 0.347, respectively). However, for patients with pN2 tumors, the overall survival and disease-free survival curves among the LND groups significantly differed (P < 0.001 and <0.001, respectively).

CONCLUSION

LND is an independent predictor of survival for colorectal cancer patients, but it does not predict local recurrence. The N categorization including LND may enhance the prognostic value of the TNM staging system for patients with node-positive sigmoid colon or rectal cancer.

Apical-node metastasis in sigmoid colon or rectal cancer: is it a factor that indicates a poor prognosis after high ligation?

PURPOSE

The prognostic significance of apical-node metastasis around the inferior mesenteric artery (IMA) remains unclear. We investigated the oncological relevance of apical-node metastasis detected after high ligation of the IMA in stage III sigmoid colon or rectal cancer.

METHODS

Between May 2003 and December 2007, 229 consecutive patients with stage III sigmoid colon or rectal cancer, who had undergone curative resection with high ligation, were analyzed. Cox proportional regression model was used to identify the prognostic factors for disease-free survival.

RESULTS

Thirty-one patients (13.5%) had apical-node metastases: 0% with T0-1, 3.8% with T2, 11.5% with T3, and 29.3% with T4 disease (p = 0.017). Additionally, the factors related to apical-node metastasis were tumor size, number of metastatic lymph nodes, lymph-node ratio, and N-stage. Multivariate analysis showed that the lymph-node ratio (odds ratio (OR) = 40.53, 95% confidence interval (CI) = 8.41-195.22, p < 0.001) was an independent prognostic factor for disease-free survival but that apical-node metastasis was not a factor that predicted a poor outcome (OR = 1.53, 95% CI = 0.81-2.91, p = 0.192). Apical-node metastasis was not a prognostic factor for disease-free survival on multivariate analysis of the subgroups based on tumor location (sigmoid colon cancer: OR = 1.42, 95% CI = 0.42-1.82, p = 0.577; rectal cancer: OR = 1.82, 95% CI = 0.82-4.06, p = 0.141).

CONCLUSIONS

This study suggests that apical-node metastasis is not a poor prognostic factor for stage III sigmoid colon or rectal cancer after high ligation.

Prognostic significance of distribution of lymph node metastasis in advanced mid or low rectal cancer

BACKGROUND

Few studies have focused on distribution of lymph node metastasis. The aim of this study is to evaluate the prognostic significance of the location of involved lymph nodes in patients with advanced mid or low rectal cancer.

METHODS

We defined proximal lymph node involvement (PLNp) as superior rectal and inferior mesenteric lymph node metastasis along the trunks of the supplying vessel, and mesorectal lymph node involvement (MLNp) as lymph node metastasis located within the mesorectum.

RESULTS

PLNp was identified in 67 patients (8.4%) of total 797 patients. Age <60 years (P=0.02), poorly differentiated/mucinous histologic type (P=0.011), and positive perineural invasion (P<0.001) were risk factors of PLNp in patients with node positive rectal cancer. Patients with PLNp had poorer oncologic outcomes than those without PLNp in terms of overall survival (P<0.001). For patients with node-positive rectal cancer, there was significant difference in the overall survival rate between PLNp and MLNp groups, regardless of N stage (P=0.025 for N1, P=0.009 for N2).

CONCLUSIONS

Our results suggest that PLNp is associated with adverse oncologic outcomes and has prognostic significance in patients with node positive mid or low rectal cancer.

Lymph node harvest in colon cancer specimens depends on tumour factors, patients and doctors, but foremost on specimen handling

There are good indications that the number of lymph nodes found in the specimen after resections for colon cancer somehow has a bearing on prognosis. Many factors have been reported in the literature to influence lymph node retrieval. We wanted to assess these closer with special focus on the pathology handling process in our own practice. A range of international literature was reviewed to study what has been found to influence lymph node harvest. A questionnaire was sent to 13 renowned national and international institutions to explore their handling of the colon cancer specimens to obtain a histological diagnosis. A retrospective, hospital audit was undertaken to examine if the number of lymph nodes and staging after examinations of the specimens varied between individual pathologists. In the literature, tumour and patient characteristics, as well as the surgeon and the pathologist, are found to be influential, but it is difficult to ascertain which ones are truly essential. Fat solvents were found by several to increase the lymph node yield, although some also opposed this finding. Our questionnaire showed some variations in the routines of each Department. A junior pathologist was more likely to inspect the specimen first hand and not more than half employed specific lymph node detection strategies while three of 13 did not seek a minimum number of lymph nodes. Still every department had implemented a standard procedure for such examinations. The internal audit showed without doubt that the devotion of the pathologist secured significantly more lymph nodes from the specimen and this may also have detected more stage III cancers. Several tumour and individual patient characteristics, surgical approach and specimen handling may influence lymph node yield and theoretically, TNM staging. Our investigation specifically suggests that tissue handling by pathologists may be a prominent factor in lymph node harvest from colon cancer specimens.

Prognostic impact of inferior mesenteric artery lymph node metastasis in colorectal cancer

AIM

The aims of this study are to identify the natural course of inferior mesenteric artery (IMA) lymph node metastasis, and to evaluate the prognostic impact of IMA lymph node metastasis in the sigmoid colon and rectal cancer.

PATIENTS AND METHODS

From our prospectively collected database, a total of 625 patients who underwent resection with curative intent for stage III adenocarcinoma of the sigmoid colon and rectal cancer between June 1995 and June 2007 were selected. Patients were divided into the IMA-positive group (n = 33) and the IMA-negative group (n = 592) according to IMA lymph node metastasis status. Clinicopathological features, recurrence patterns, and 5-year disease-free survival rates were compared between the two groups.

RESULTS

Following curative resection, 5-year disease-free survival rate was 31.9% in the IMA-positive group and 69.4% in the IMA-negative group (p < 0.001). Cox regression analysis revealed that rectal cancer, pathologic stage, and presence of IMA lymph node metastasis were independently associated with disease-free survival. Systemic recurrence rate was significantly higher in the IMA-positive group than in the IMA-negative group (48.5 vs. 20.8%, respectively, p = 0.001). Para-aortic nodal recurrence showed significant association with presence of IMA lymph node metastasis on multivariate analysis (hazard ratio 11.8; 95% confidence interval 2.7-52.2, p = 0.001).

CONCLUSION

Presence of IMA lymph node metastasis should be considered as a predictive factor for high systemic recurrence, and should be treated and followed up with caution for para-aortic nodal recurrence.

TNM staging system of colorectal carcinoma: a critical appraisal of challenging issues

CONTEXT

Colorectal cancer is the leading cause of morbidity and death among gastrointestinal tumors and ranks fourth after lung, breast, and ovarian cancers. Despite a continuous refinement of the T (tumor), N (node), and M (metastasis) staging system to express disease extent and define prognosis, and eventually to guide treatment, the outcome of patients with colorectal cancer may vary considerably even within the same tumor stage. Therefore, the need for new factors, either morphologic or molecular, that could more precisely stratify patients into different risk categories is clearly warranted.

OBJECTIVES

To present the state of the art with regard to the colorectal cancer staging system and to discuss confusing and/or challenging issues, including the assessment of peritoneal membrane involvement, vascular invasion, tumor deposits, and pathologic tumor response to neoadjuvant chemoradiotherapy.

DATA SOURCES

Literature review of relevant articles indexed in PubMed (US National Library of Medicine) and primary material from the authors' institutions.

CONCLUSIONS

Two emerging needs exist for the TNM system, namely, further stratification of patients with the same tumor stage and incorporation of nonanatomic factors, the latter including molecular and treatment factors. The identification and classification of morphologic features encountered in the pathologic examination of colorectal cancer specimens may be difficult and a source of subjective variability. Enhanced pathologic analysis, agreed-upon standard protocols, and standardization should improve the completeness and accuracy of pathology reports.

[Not Available]

F. Leblanc, C. Laurent E. Rullier Lymph node dissection is a standard part of surgical resection of rectal cancer which helps to avoid local recurrence and allows for accurate staging of the disease. Three types of lymph node dissection have been considered. Mesorectal lymphadenectomy should remove the mesorectum systematically and should extend at least 5cm distal to the tumor. Inferior mesenteric lymphadenectomy should extend at least to the origin of the left colic artery. Lateral lymphadenectomy removing iliac and obturator nodes results in complications and has not been shown to improve survival; it is not routinely recommended. Omission of lymph node dissection is only proposed for the smallest T1 tumors with favorable histology.

[Not Available]

F. Leblanc, C. Laurent E. Rullier Lymph node dissection is a standard part of surgical resection of rectal cancer which helps to avoid local recurrence and allows for accurate staging of the disease. Three types of lymph node dissection have been considered. Mesorectal lymphadenectomy should remove the mesorectum systematically and should extend at least 5cm distal to the tumor. Inferior mesenteric lymphadenectomy should extend at least to the origin of the left colic artery. Lateral lymphadenectomy removing iliac and obturator nodes results in complications and has not been shown to improve survival; it is not routinely recommended. Omission of lymph node dissection is only proposed for the smallest T1 tumors with favorable histology.

ASCO 2006 Update of Recommendations for the Use of Tumor Markers in Gastrointestinal Cancer

Purpose

To update the recommendations for the use of tumor marker tests in the prevention, screening, treatment, and surveillance of gastrointestinal cancers.

Methods

For the 2006 update, an update committee composed of members from the full Panel was formed to complete the review and analysis of data published since 1999. Computerized literature searches of Medline and the Cochrane Collaboration Library were performed. The Update Committee's literature review focused attention on available systematic reviews and meta-analyses of published tumor marker studies.

Recommendations and Conclusion

For colorectal cancer, it is recommended that carcinoembryonic antigen (CEA) be ordered preoperatively, if it would assist in staging and surgical planning. Postoperative CEA levels should be performed every 3 months for stage II and III disease for at least 3 years if the patient is a potential candidate for surgery or chemotherapy of metastatic disease. CEA is the marker of choice for monitoring the response of metastatic disease to systemic therapy. Data are insufficient to recommend the routine use of p53, ras, thymidine synthase, dihydropyrimidine dehydrogenase, thymidine phosphorylase, microsatellite instability, 18q loss of heterozygosity, or deleted in colon cancer (DCC) protein in the management of patients with colorectal cancer. For pancreatic cancer, CA 19-9 can be measured every 1 to 3 months for patients with locally advanced or metastatic disease receiving active therapy. Elevations in serial CA 19-9 determinations suggest progressive disease but confirmation with other studies should be sought. New markers and new evidence to support the use of the currently reviewed markers will be evaluated in future updates of these guidelines.

Preoperative concurrent radiotherapy with capecitabine before total mesorectal excision in locally advanced rectal cancer

PURPOSE

Capecitabine is an attractive radiosensitizer which can be tumor specific. This study was undertaken to evaluate the toxicity and efficacy of oral capecitabine when used with preoperative radiation therapy.

METHODS AND MATERIALS

We conducted a prospective Phase II trial to assess the pathologic response, sphincter preservation effect, and acute toxicity of preoperative chemoradiation (CRT) in locally advanced (uT3-4/N +) but resectable adenocarcinoma of the lower two-thirds of the rectum. The radiation dose was 50 Gy over 5 weeks (46 Gy to whole pelvis + 4 Gy boost), and capecitabine was administered daily at a dose of 1650 mg/m(2) during the entire course of radiation therapy. Surgery was performed with standardized total mesorectal excision 4 to 6 weeks after completion of CRT and followed by four cycles of capecitabine (2500 mg/m(2)/day for 14 days).

RESULTS

Ninety-five patients were entered into this study; their median age was 55 (range, 31-75 years). Ninety (95%) patients completed preoperative CRT as planned, and complete resection was achieved in 92 of 94 resected cases (98%). Downstaging rate was 71% (56/79) on endorectal ultrasonography, and it was 76% (71/94) on pathology finding. No tumor cell was observed in the specimens of 11 patients (12%). Among the 54 whose tumor was located within 5 cm from the anal verge, 40 patients (74%) underwent sphincter-preserving procedures. Elevation of the distal tumor margin from the anal verge by preoperative CRT was 0.8 +/- 1.3 cm. Grade 3 toxicities were rare (diarrhea in 3% and neutropenia in 1%).

CONCLUSION

Preoperative CRT using capecitabine achieved encouraging rates of tumor downstaging and sphincter preservation with a low toxicity profile.

Prospective phase II study of preoperative chemoradiation with capecitabine in locally advanced rectal cancer

PURPOSE

Capecitabine is an attractive oral chemotherapeutic agent that has a radiosensitizing effect and tumor-selectivity. This study was performed to evaluate the efficacy and toxicity of preoperative chemoradiation therapy, when used with oral capecitabine, for locally advanced rectal cancer.

MATERIALS AND METHODS

A prospective phase II trial of preoperative chemoradiation for locally advanced adenocarcinomas of the lower two-thirds of the rectum was conducted. A radiation dose of 50 Gy over five weeks and a daily dose of 1650 mg/m(2) capecitabine in two portions was administered during the entire course of radiation therapy. Surgery was performed with standardized total mesorectal excision four to six weeks after completion of the chemoradiation.

RESULTS

Between January 2002 and September 2003, 61 patients were enrolled onto this prospective phase II trial. The pretreatment clinical stages were T3 in 64% (n=39), T4 in 36% (n=22) and N1-2 in 82% (n=50) of these patients. Fifty-six (92%) patients completed the chemoradiation as initially planned and a complete resection performed in 58 (95%). Down-staging was observed in 45 patients (74%) and a pathologic complete response in 6 (10%). Among the 37 patients with tumors located within 5 cm from the anal verge on colonoscopy, 27 (73%) underwent a sphincter-preserving procedure. No grade 3 and 4 proctitis or hematological toxicities were observed.

CONCLUSION

Preoperative chemoradiation therapy with capecitabine achieved encouraging rates of tumor downstaging and sphincter preservation, with a low toxicity profile. This combined modality can be regarded as a safe and effective treatment for locally advanced rectal cancer.