Close collaboration between surgeon and pathologist is essential for accurate staging of early colon cancer

Prognostic role of lymph node micrometastasis in oral and oropharyngeal cancer: A systematic review

BACKGROUND

An estimated 20% of patients with oral and oropharyngeal squamous cell carcinoma (OOSCC) have micrometastases (Mi) or isolated tumor cells (ITC) in the cervical lymph nodes that evade detection by standard histological evaluation of lymph node sections. Lymph node Mi and ITC could be one reason for regional recurrence after neck dissection. The aim of this study was to review the existing data regarding the impact of Mi on the survival of patients with OOSCC.

METHODS

PubMed and the Cochrane Library were searched for articles reporting the impact of Mi and ITC on patient survival. Two authors independently assessed the methodological quality of retrieved studies using the Downs and Black index. Data were also extracted on study type, number of included patients, mode of histological analysis, statistical analysis, and prognostic impact.

RESULTS

Sixteen articles with a total of 2064 patients were included in the review. Among the 16 included studies, eight revealed a statistically significant impact of Mi on at least one endpoint in the Kaplan-Meier and/or multivariate analysis. Three studies regarded Mi as Ma, while five studies found no impact of Mi on survival. Only one study demonstrated an impact of ITC on patient's prognosis in the univariate but not in the multivariate analysis.

CONCLUSION

The majority of cases included in the review were patients with oral cancer. The findings provide low-certainty evidence that Mi negatively impacts survival. Data on ITC were scarcer, so no conclusions can be drawn about their effect on survival. The lower threshold to discriminate between Mi and ITC should be defined for OOSCC since the existing thresholds are based on data from different tumors. The histological, immunohistological, and anatomical characteristics of Mi and ITC in OOSCC as well as the effect of radiotherapy on Mi should be further investigated separately for oral and oropharyngeal carcinomas.

Qualitative and quantitative issues of lymph nodes as prognostic factor in colon cancer

For patients undergoing curative resections for colon cancer, the nodal status represents the strongest prognostic factor, yet at the same time the most disputed issue as well. Consequently, the qualitative and quantitative aspects of lymph node evaluation are thus being scrutinized beyond the blunt distinction between 'node positive' (pN+) and 'node negative' (pN0) disease. Controversy ranges from a minimal or 'least-unit' strategy as exemplified by the 'sentinel node' to a maximally invasive or 'all inclusive' approach by extensive surgery. Ranging between these two extremes of node sampling strategies are factors of quantitative and qualitative value, which may be subject to modification. Qualitative issues may include aspects of lymph node harvest reflected by surgeon, pathologist and even hospital performance, which all may be subject to modification. However, patient's age, gender and genotype may be non-modifiable, yet influence node sample. Quantitative issues may reflect the balance between absolute numbers and models investigating the relationships of positive to negative nodes (lymph node ratio; log odds of positive lymph nodes). This review provides an updated overview of the current controversies and a state-of-the-art perspective on the qualitative and quantitative aspects of using lymph nodes as a prognostic marker in colon cancer.

Prognostic impact of lymph node harvest and lymph node ratio in patients with colon cancer

BACKGROUND

The prognostic impact of the number of lymph nodes and ratio in colon cancer is still debated.

OBJECTIVES

The aim of this study was to evaluate lymph node harvest in patients with colon cancer over time, and to test the hypotheses that investigation of more lymph nodes, and low lymph node ratio in stage III patients, has positive prognostic impact.

DESIGN

This is a prospective, observational study.

SETTINGS

This study was conducted in a single institution treating all patients with colon cancer in a defined catchment area.

PATIENTS

All patients admitted in the period 1993 to 2009 (n = 1481) were included.

MAIN OUTCOME MEASURES

The primary outcomes measured were the number of examined regional lymph nodes according to treatment period, 5-year overall survival and time to recurrence, and univariate (Kaplan-Meier) and multivariate (Cox regression) analyses of prognostic factors.

RESULTS

Nine hundred fifty (65%) patients underwent curative resection. Median number of examined lymph nodes increased from 7 to 15 (p < 0.001), and the proportion of patients with stage III disease increased from 25% to 33% (p = 0.02) during the study period. In patients with stage I to III disease, time to recurrence (proportion of patients without recurrence or death of colon cancer) improved from 65% to 82% during the period (p < 0.001). An association between lymph node count (<8 compared with ≥ 12) and overall survival was found for patients with stage II disease (57% vs 71%, p = 0.004). Hazard ratio for death within 5 years was 0.7 (p = 0.043) when 8 to 11 nodes were examined and 0.6 (p = 0.001) when ≥ 12 nodes were examined (<8 reference). In patients with stage III disease, increasing lymph node ratio was associated with reduced overall survival and time to recurrence in uni- and multivariate analyses.

LIMITATIONS

This study was limited by the small number of patients in each stage.

CONCLUSIONS

The number of examined lymph nodes increased in the study period. A stage migration was observed, and time to recurrence improved in patients with stage I to III disease. In patients with stage III disease, lymph node ratio was a stronger prognostic factor than the total number of lymph nodes examined.

Sentinel node biopsy in colorectal cancer: Must we believe it?

Lymph node metastasis predicts survival and recurrence in colon cancer (CC), so decisions regarding adjuvant therapy are largely based on nodal status. Chemotherapy is not a routine treatment for node-negative CC because its toxicity and expense exceed its limited benefit in patients without evidence of nodal involvement. The sentinel lymph node (SLN) procedure is a selective sampling technique that can be used to ultrastage regional nodes. The real problem of SLN biopsy in CC is the procedure sensitivity rate. In future, studies concerning SLNs will have to consider issues such as the role of laparoscopy in colorectal resection (which cause technical difficulties in identification of SLNs) and the risk of overstaging of illness as well as the need to exclude T4 CC and, probably, rectal cancer from the studies. Is this the future of correct staging of colorectal cancer? Lymphadenectomy is at the present an integral part of colorectal surgery and surgeons must perform it correctly to improve their results. Nevertheless, for the future another "staging system" is necessary in colorectal cancer which takes into account biologic aspects of the tumor to identify patients with aggresive illness in order to treat them with more effective and less toxic therapies.

Sentinel node biopsy in colorectal cancer: Must we believe it?

April 22, 2013

As Editor-in-Chief of the World Journal of Gastrointestinal Surgery, it has come to my attention that two articles that have published in our journal are very similar to the content of previously published papers.

Specifically, the two articles:

Scabini S, Rimini E, Massobrio A, Romairone E, Linari C, Scordamaglia R, Marini LD, Ferrando V. Primary omental torsion: A case report. World J Gastrointest Surg 2011 Oct 27; 3(10): 153-5. DOI: 10.4240/wjgs.v3.i10.153. PubMed PMID: 22110847; PMCID: PMC3220728 has a number of very common features to the previously published paper Efthimiou M, Kouritas VK, Fafoulakis F, Fotakakis K, Chatzitheofilou K. Primary omental torsion: report of two cases. Surg Today 2009; 39(1): 64-7. DOI: 10.1007/s00595-008-3794-7. Epub 2009 Jan 8. PMID: 19132472.

Scabini S. Sentinel node biopsy in colorectal cancer: Must we believe it World J Gastrointest Surg 2010 Jan 27; 2(1): 6-8. DOI: 10.4240/wjgs.v2.i1.6 PMID: 21160827; PMCID: PMC2999193 has copied entire paragraphs from two papers by Nicholl M, Bilchik AJ. Is routine use of sentinel node biopsy justified in colon cancer Ann Surg Oncol 2008 Jan; 15(1): 1-3. Epub 2007 Oct 11. PubMed PMID: 17929100 and Bilchik AJ, Compton C. Close collaboration between surgeon and pathologist is essential for accurate staging of early colon cancer. Ann Surg. 2007 Jun; 245(6): 864-6. PMID: 17522510; PMCID: PMC1876950.

Based on my review of the aforementioned articles, these two articles are being retracted.

I have also asked the office of the World Journal of Gastrointestinal Surgery to make it a matter of policy to use routinely anti-plagiarism software to screen all submissions to the journal in the future.

Sincerely,

Timothy M. Pawlik, MD, MPH, PhD

Editor-in-Chief World Journal of Gastrointestinal Surgery

Does Specialized Surgical Training Increase Lymph Node Yield in Colon Cancer?

Most colon cancer resections do not meet the 12-lymph node minimum recommended in 2001 National Cancer Institute (NCI) panel guidelines. Previous reports suggest surgical training influences lymph node recovery. We hypothesized that recent trends show improved results for lymphadenectomy regardless of specialty. The cancer registry database at a large community hospital with an academic surgical oncology training program was queried to identify resections performed for colon cancer before (1995 to 2000) and after (2001 to 2006) NCI guideline publication. There were no changes in pathology procedures between 374 early and 411 later procedures. The later period brought increases in mean total lymph nodes (15.4 vs 10.4, P < 0.0001), total positive nodes (1.8 vs 1.2, P = 0.005), and the percentage of procedures yielding 12 or more nodes (overall: 65.9 vs 36.0%, P < 0.0001; Stage II and III disease: 73.0 vs 41.4%, P < 0.003). In addition, mean nodal yield increased (P < 0.0001) for fellowship-trained surgeons (16.7 vs 11.2) and nonfellowship-trained surgeons (14.9 vs 10.2). Single-registry data show that since 2001, most colon resections exceed minimum recommendations for lymph node recovery regardless of surgical training. The increased rate of adequate lymphadenectomy for Stage II and III disease is encouraging because this patient population will benefit most by accurate staging of colon cancer.

Sentinel node biopsy for the individualization of surgical strategy for cure of early-stage colon cancer

INTRODUCTION

The requirement for nodal analysis currently confounds the oncological propriety of focused purely endoscopic resection for early-stage colon cancer and complicates the evolution of innovative alternatives such as natural orifice transluminal endoscopic surgery (NOTES) and its hybrids. Adjunctive sentinel node biopsy (SNB) deserves consideration as a means of addressing this shortfall.

METHODS

Data from two prospectively maintained databases established for multicentric studies of SNB in colon cancer that employed similar methodologies were pooled to establish technique potency selectively in T1/T2 disease (both overall and under optimized conditions) and to project potential clinical impact.

RESULTS

Of 891 patients with T1-4, M0 intraperitoneal colon cancer, 225 had T1/T2 disease. Sentinel nodes were either not found or were falsely negative in 18 patients with T1/T2 cancers (8%) as compared with 17% (112/646) in those with T3/T4 disease (P = 0.001). Negative predictive value (NPV) in the former exceeded 95%, while sensitivity [including immunohistochemistry (IHC)] was 81%. In the 193 patients with T1/T2 disease recruited from those centers contributing >22 patients, sensitivity was 89% and NPV 97%. Thus, in this cohort, SNB could have correctly prompted localized resection (obviating en bloc mesenteric dissection) in 75% (144) of patients, including 59 with T1 lesions potentially amenable to intraluminal resection alone as their definitive treatment. Forty-four patients (23.4%) would still have conventional resection, leaving three patients (1.6% overall) understaged (11% false-negative rate).

CONCLUSION

These findings support the further investigation of SNB as oncological augment for localized resective techniques. Specific prospective study should pursue this goal.

Clinically important aspects of lymph node assessment in colon cancer

There has been considerable discussion in the literature regarding the importance and validity of lymph node retrieval and lymph node count for patients with colon cancer. In this article we summarize the importance of lymph node resection and assessment in contemporary colon cancer care, key clinical determinants of lymph node assessment, and discuss the role of lymph node assessment as a quality marker in colon cancer care.

Johns Hopkins course: 8th annual Current Topics in Gastrointestinal and Liver Pathology

The 8th annual Current Topics in Gastrointestinal and Liver Pathology course was held on the campus of the Johns Hopkins Medical Institutions in Baltimore, MD, USA, on the 8-9 November 2008. Lectures and hands-on microscopy sessions were provided by the Johns Hopkins Division of Gastrointestinal Pathology faculty and a guest faculty member from the University of Michigan (MI, USA). Key topics included newly recognized staging issues, the application of molecular techniques and practical topics for diagnostic pathologists.

Lymphatic mapping and sentinel node biopsy in the colonic mesentery by Natural Orifice Transluminal Endoscopic Surgery (NOTES)

INTRODUCTION

Although intraluminal and transluminal techniques can achieve localized resection of early-stage alimentary tumours, they do not designate the status of the filtering mesenteric lymph nodes. Natural orifice transluminal endoscopic surgery (NOTES) may however effect sentinel node biopsy from within the peritoneum.

METHODS

A transgastric NOTES technique was utilized in six pigs. A conventional double-channel gastroscope created both the 12mm anterior gastrotomy and the pneumoperitoneum and enabled peritoneoscopy. The sigmoid colon was fully exposed by an intracolonic magnet under extracorporeal control. Colonoscopy facilitated submucosal injection of methylene blue dye (3 ml) at the apex of the sigmoid loop under direct transgastric vision. The mesocolon was searched for blue-stained lymph channels and nodes, the latter being resected and retrieved by the intraperitoneal endoscope. At procedure end, three pigs underwent immediate laparotomy for scrutiny of the operation site while three were survived for forensic laparotomy on postoperative day 14.

RESULTS

Each procedure was a technical success. Gastrotomy, pneumoperitoneum, peritoneoscopy and sigmoid exposure were promptly achieved (mean 9.2 min). Post-injection, blue lymphatics identifying specific nodes were immediately appreciable and these could be dissected cleanly and retrieved intact per oram. Mean lymphadenectomy time was 19 (range 12-32) min. All survival animals thrived during convalescence. At laparotomy, there was neither mesentery penetration, bowel ischemia nor mesenteric hematoma/hemorrhage in any pig and no residual blue stained nodes in those sacrificed early.

CONCLUSION

Sentinel node biopsy can be performed without abdominal wall transgression. Thus potentially the oncological proprietary of local resectional techniques may be augmented while preserving their ideals and dividends.

Could lymphatic mapping and sentinel node biopsy provide oncological providence for local resectional techniques for colon cancer? A review of the literature

BACKGROUND

Endoscopic resectional techniques for colon cancer are undermined by their inability to determine lymph node status. This limits their application to only those lesions at the most minimal risk of lymphatic dissemination whereas their technical capacity could allow intraluminal or even transluminal address of larger lesions. Sentinel node biopsy may theoretically address this breach although the variability of its reported results for this disease is worrisome.

METHODS

Medline, EMBASE and Cochrane databases were interrogated back to 1999 to identify all publications concerning lymphatic mapping for colon cancer with reference cross-checking for completeness. All reports were examined from the perspective of in vivo technique accuracy selectively in early stage disease (i.e. lesions potentially within the technical capacity of endoscopic resection).

RESULTS

Fifty-two studies detailing the experiences of 3390 patients were identified. Considerable variation in patient characteristics as well as in surgical and histological quality assurances were however evident among the studies identified. In addition, considerable contamination of the studies by inclusion of rectal cancer without subgroup separation was frequent. Indeed such is the heterogeneity of the publications to date, formal meta-analysis to pool patient cohorts in order to definitively ascertain technique accuracy in those with T1 and/or T2 cancer is not possible. Although lymphatic mapping in early stage neoplasia alone has rarely been specifically studied, those studies that included examination of false negative rates identified high T3/4 patient proportions and larger tumor size as being important confounders. Under selected circumstances however the technique seems to perform sufficiently reliably to allow it prompt consideration of its use to tailor operative extent.

CONCLUSION

The specific question of whether sentinel node biopsy can augment the oncological propriety for endoscopic resective techniques (including Natural Orifice Transluminal Endoscopic Surgery [NOTES]) cannot be definitively answered at present. Study heterogeneity may account for the variability evident in the results from different centers. Enhanced capacity (perhaps to the level necessary to consider selective avoidance of en bloc mesenteric resection) by its confinement to only early stage disease is plausible although not proven. Specific study of the technique in early stage tumors is clearly essential before proffering this approach.

What’s wrong with sentinel node mapping in colon cancer?

Despite near-universal embrace of the concept and clinical relevance of lymphatic mapping for sentinel node identification and analysis for cancers of the breast and integument, the same technique has struggled to a find a role in gastrointestinal cancers in general and, perhaps, in colon cancer in particular. Despite many studies demonstrating its feasibility in malignancies of the large bowel, concern is continually aroused by the variable and often unacceptably low sensitivity rates. Additionally, many confess uncertainty as to what benefit it could ever confer to patients even if it were proven sufficiently accurate given that standard surgical resection incorporates mesenteric resection anyway. However, the huge impact sentinel node mapping has had on clinical practice in certain cancers means that each of these aspects merit careful reconsideration, from very first principles.