The influence of micrometastases on prognosis and survival in stage I-II colon cancer patients: the Enroute⊕ Study

Comparison of Linked Color Imaging and White Light Imaging Colonoscopy for Detection of Colorectal Adenoma Requiring Endoscopic Treatment: A Single-Center Randomized Controlled Trial

BACKGROUND

Linked color imaging (LCI) improves detection of colorectal neoplastic lesions during colonoscopy. However, polyps <5 mm in diameter often do not require resection, and the benefits of LCI are unclear for detection of colorectal polyps ≥5 mm that are indicated for endoscopic resection in clinical practice. This randomized controlled trial compared rates of detection of adenoma polyps, stratified by size, for LCI and white light imaging (WLI).

METHODS

We compared ADR (5 mm-) and PDR (5 mm-), which were defined as the proportion of patients with at least one adenoma or polyp with a diameter of 5 mm or larger in the LCI and WLI groups. Moreover, we estimated ADR and PDR for diameters between 5 and 10 mm (ADR (5-9 mm), PDR (5-9 mm) ) and for diameters larger than 10 mm (ADR (10 mm-), PDR (10 mm-) ).

RESULTS

Data from 594 patients (LCI, n=305; WLI, n=289) were analyzed. ADR (5 mm-) and PDR (5 mm-) were significantly higher in the LCI group than in the WLI group (ADR (5 mm-): P=0.016, PDR (5 mm-): P=0.020). In the assessment of adenoma and polyp size, ADR (5-9 mm) and PDR (5-9 mm) were significantly higher in the LCI group than in the WLI group, although no significant differences were seen in ADR (10 mm-) and PDR (10 mm-) between these groups.

CONCLUSIONS

Polyps ≥5 mm, which are indicated for endoscopic treatment, were more easily visualized with LCI mode than with WLI mode. The improvement in detection rate was obvious for polyps <10 mm, which are easier to miss.

Postoperative Quality Assessment Score Can Select Patients with High Risk for Locoregional Recurrence in Colon Cancer

BACKGROUND

Monitoring surgical quality has been shown to reduce locoregional recurrence (LRR). We previously showed that the arterial stump length (ASL) after complete mesocolic excision (CME) is a reproducible quality instrument and correlates with the lymph-node (LN) yield. We hypothesized that generating an LRR prediction score by integrating the ASL would predict the risk of LRR after suboptimal surgery.

METHODS

502 patients with curative resections for stage I-III colon cancer were divided in two groups (CME vs. non-CME) and compared in terms of surgical data, ASL-derived parameters, pathological parameters, LRR and LRR-free survival. A prediction score was generated to stratify patients at high risk for LRR.

RESULTS

The ASL showed significantly higher values (50.77 mm ± 28.5 mm) with LRR vs. (45.59 mm ± 28.1 mm) without LRR (p < 0.001). Kaplan-Meier survival analysis showed a significant increase in LRR-free survival at 5.58 years when CME was performed (Group A: 81%), in contrast to non-CME surgery (Group B: 67.2%).

CONCLUSIONS

The prediction score placed 76.6% of patients with LRR in the high-risk category, with a strong predictive value. Patients with long vascular stumps and positive nodes could benefit from second surgery to complete the mesocolic excision.

Reg4 and its downstream transcriptional activator CD44ICD in stage II and III colorectal cancer

Reg4 is highly expressed in gastrointestinal malignancies and acts as a mitogenic and pro-invasive factor. Our recent works suggest that Reg4 binds with CD44 and induces its proteolytic cleavage to release intra-cytoplasmic domain of CD44 (CD44ICD). The goal of this study is to demonstrate clinical significance of the Reg4-CD44/CD44ICD pathway in stage II/III colon cancer and its association with clinical parameters of aggression. We constructed a tissue microarray (TMA) of 93 stage II/III matched colon adenocarcinoma patients, 23 with recurrent disease. The TMA was immunohistochemically stained for Reg4, CD44, and CD44ICD proteins and analyzed to identify associations with tumor characteristics, recurrence and overall survival. The TMA data analysis showed a significant correlation between Reg4 and CD44 (r² = 0.23, P = 0.028), CD44 and CD44ICD (r² = 0.36, p = 0.0004), and Reg4 and CD44ICD (r² = 0.45, p ≤ 0.0001). Reg4 expression was associated with larger tumor size (r² = 0.23, p = 0.026). Although, no association was observed between Reg4, CD44, or CD44ICD expression and disease recurrence, Reg4-positive patients had a median survival of 4 years vs. 7 years for Reg4-negative patients (p = 0.04) in patients who recurred. Inhibition of the Reg4-CD44/CD44ICD pathway may be a future therapeutic target for colon cancer patients.

The advantage of one-step nucleic acid amplification for the diagnosis of lymph node metastasis in colorectal cancer patients

Generally, the postoperative examination of lymph nodes (LNs) is based on a microscopic examination of one hematoxylin and eosin (HE)-stained slide; however, an examination of only one part of the LN might lead to incorrect staging of the tumor due to tissue allocation bias. Although multilevel sectioning and the use of immunohistochemistry (IHC) have improved the detection of micrometastases in LNs, this approach is laborious, time-consuming, and costly. A novel molecular technique for the detection of LN metastases of tumors, called one-step nucleic acid amplification (OSNA), is a rapid and semi-quantitative examination quantifying the number of cytokeratin 19 (CK-19) mRNA copies derived from a tumor. OSNA is already in clinical use for the diagnosis of LN metastasis in breast cancer patients; however, the use of OSNA is under investigation with promising results for colorectal cancer (CRC). The present review assessed recent studies on OSNA vs a histopathological examination and its implications for CRC staging and treatment. A total of 16 studies of OSNA in CRC yielded by a PubMed search were reviewed. Among them, seven studies evaluating the diagnostic performance revealed that OSNA had a high specificity (96.8%), high concordance rate (96.0%), and negative predictive value (98.6%) in a pooled assessment. In addition, four studies examining the utility of OSNA in sentinel LNs (SLNs) and two studies focusing on upstaging in pathologically node-negative CRC patients were also reviewed. Multicenter prospective studies with a large cohort of CRC patients are warranted to reveal the benefits of OSNA in the future.

Superior Effect of the Combination of Carbon-Ion Beam Irradiation and 5-Fluorouracil on Colorectal Cancer Stem Cells in vitro and in vivo

Background

The aim of this study was to investigate whether carbon-ion beam irradiation in combination with 5-fluorouracil (5-FU) is superior to carbon-ion beam irradiation alone in targeting colorectal cancer stem-like cells (CSCs).

Materials and Methods

Human colorectal cancer (CRC) cells, HCT116 and HT29, were treated with carbon-ion beam irradiation alone or in combination with 5-FU. Cell viability assay, colony and spheroid formation assay, apoptotic assay, and quantitative real-time PCR analysis of apoptosis- and autophagy-related gene expression were performed.

Results

Carbon-ion beam irradiation dose-dependently decreased CRC cell viability and showed significantly enhanced cell killing effect when combined with 5-FU. Carbon-ion beam irradiation in combination with 5-FU significantly increased the percentage of apoptotic cells. The expression of some apoptotic and autophagy-related genes such as Bax, Bcl2, Beclin1 and ATG7 was significantly induced by carbon-ion beam irradiation alone and was further enhanced when the beam was combined with 5-FU. The spheroid forming capacity of CD133+ cell subpopulations was significantly inhibited by carbon-ion beam in combination with 5-FU. Histopathologically, the combination of carbon-ion beam irradiation and 5-FU destroyed more xenograft tumor cells, and resulted in increased necrosis, cavitation, and fibrosis, compared to carbon-ion beam irradiation alone.

Conclusion

In conclusion, carbon-ion beam treatment combined with 5-FU has the potential to kill CRC cells including CSCs by inducing increased apoptosis and autophagy.

Preoperative endoscopic localization of colorectal cancer and tracing lymph nodes by using carbon nanoparticles in laparoscopy

Background

The objective of this study is to evaluate the effectiveness of preoperative endoscopic localization of colorectal cancer and tracing lymph nodes by carbon nanoparticle tattooing in laparoscopic colorectal cancer surgery.

Methods

From January 2013 to December 2014, 54 patients with colorectal cancer were recruited and divided into experimental (n = 27) and control (n = 27) groups. The patients in the experimental group were localized preoperatively by endoscopic carbon nanoparticle tattooing, whereas patients in the control group were not tattooed.

Results

All injection sites in the experimental group were visible to surgeons. No abdominal pain, fever, diarrhea, and other symptoms of infection were found in the experimental group. The time for detecting the tumor (2.71 ± 2.13 min versus 6.91 ± 5.16 min, p < 0.001), operation time (151.22 ± 30.66 min versus 170.26 ± 33.13 min, p = 0.033), and blood loss during the operation (125.04 ± 29.48 mL versus 147.52 ± 34.35 mL, p = 0.013) were lower in the experimental group than in the control group. Average numbers of dissected lymph nodes in the experimental group exceeded those in the control group (14.41 ± 3.32 versus 8.96 ± 2.90, p < 0.001), and the rate of dissected lymph nodes ≥12 was higher in the experimental group than in the control group (70.37 versus 37.04 %, p < 0.001). Moreover, no difference in postoperative complications was found between the two groups.

Conclusions

Tattooing colorectal cancer with carbon nanoparticles in laparoscopic colorectal cancer surgery is safe and useful both in localization and lymph node tracing.

Molecularly determined total tumour load in lymph nodes of stage I-II colon cancer patients correlates with high-risk factors. A multicentre prospective study

Stage I–II (pN0) colorectal cancer patients are surgically treated although up to 25 % will eventually die from disease recurrence. Lymph node (LN) status is an independent prognostic factor in colorectal cancer (CRC), and molecular tumour detection in LN of early-stage CRC patients is associated with an increased risk of disease recurrence and poor survival. This prospective multicentre study aimed to determine the relationship between LN molecular tumour burden and conventional high-risk factors in stage I–II colon cancer patients. A total of 1940 LN from 149 pathologically assessed pN0 colon cancer patients were analysed for the amount of tumour cytokeratin 19 (CK19) messenger RNA (mRNA) with the quantitative reverse transcription loop-mediated isothermal amplification molecular assay One-Step Nucleic Acid Amplification. Patient’s total tumour load (TTL) resulted from the sum of all CK19 mRNA tumour copies/μL of each positive LN from the colectomy specimen. A median of 15 LN were procured per case (IQR 12;20). Molecular positivity correlated with high-grade (p < 0.01), mucinous/signet ring type (p = 0.017), male gender (p = 0.02), number of collected LN (p = 0.012) and total LN weight per case (p < 0.01). The TTL was related to pT stage (p = 0.01) and tumour size (p < 0.01) in low-grade tumours. Multivariate logistic regression showed independent correlation of molecular positivity with gender, tumour grade and number of fresh LN [AUC = 0.71 (95 % CI = 0.62–0.79)]. Our results show that lymph node CK19 mRNA detection correlates with classical high-risk factors in stage I–II colon cancer patients. Total tumour load is a quantitative and objective measure that may help to better stage early colon cancer patients.

Comparing the efficacy of routine H&E staining and cytokeratin immunohistochemical staining in detection of micro-metastasis on serial sections of dye-mapped sentinel lymph nodes in colorectal carcinoma

BACKGROUND

The significance of techniques used for detecting micro-metastasis (MM) or isolated tumor cells (ITCs) is a controversial issue among investigators. We evaluated the different techniques used on sentinel lymph node (SLN) to detect MM/ITCs.

MATERIALS AND METHODS

Ninety-one SLNs of 15 patients underwent serial section with 100 μm interval. In each level, two sections were prepared. One section was stained with H&E and another with anti-cytokeratin antibody (immunohistochemistry). Then the sections were evaluated for detecting MM/ITCs. Results were analyzed by chi-square test.

RESULTS

1656 sections of 91 SLNs of 15 patients were evaluated by a pathologist; MM was found in 1 and ITCs in 1 case. Overall, 2 out of 15 cases (13.3% of the patients) showed MM/ITCs by IHC staining. So, serial section along with using IHC was superior than serial section and routine H&E staining. But it did not affect the 5-year survival of the patients (P = 0.47).

CONCLUSION

Using the combined techniques of serial section and IHC staining could up-stage 13.3% of colon cancer patients who were lymph node negative. In other studies with different combination of serial section, IHC staining, and PCR, investigators were able to find MM/ITCs in 3-39% of the cases. In our study, although serial section and IHC staining could up-stage 13.3% of patients, it could not affect the 5-year survival of the patients.

Influence of extent of lymph node dissection on survival for patients with pT2 colon cancer

PURPOSE

The optimal extent of lymph node dissection for early-stage colon cancer (CC) remains undefined. This study assessed the influence of the extent of lymph node dissection on overall survival (OS) in patients with pT2 CC.

METHODS

We retrospectively examined data from the multi-institutional registry system of the Japanese Society for Cancer of the Colon and Rectum and used a propensity score matching method to balance potential confounders of lymph node dissection. We extracted 463 matched pairs from 1433 patients who underwent major resections for pT2 CC between 1995 and 2004.

RESULTS

Lymph node metastasis was found in 301 (21.0%) of 1433 patients with pT2 CC. In this cohort, significant independent risk factors for lymph node metastasis were lymphatic invasion and venous invasion. Patients who underwent D3 or D2 lymph node dissection did not significantly differ in OS, either among the propensity score-matched cohort (estimated hazard ratio [HR] 0.85, 95% confidence interval [CI] 0.536-1.346, P = 0.484) or in the cohort as a whole (HR 0.720, 95% CI 0.492-1.052, P = 0.089).

CONCLUSIONS

For patients with pT2 CC, D3 lymph node dissection did not add to OS. D2 lymph node dissection may be adequate for pT2 CC.

Determinants of recurrence after intended curative resection for colorectal cancer

Despite intended curative resection, colorectal cancer will recur in ∼45% of the patients. Results of meta-analyses conclude that frequent follow-up does not lead to early detection of recurrence, but improves overall survival. The present literature shows that several factors play important roles in development of recurrence. It is well established that emergency surgery is a major determinant of recurrence. Moreover, anastomotic leakages, postoperative bacterial infections, and blood transfusions increase the recurrence rates although the exact mechanisms still remain obscure. From pathology studies it has been shown that tumors behave differently depending on their location and recur more often when micrometastases are present in lymph nodes and around vessels and nerves. K-ras mutations, microsatellite instability, and mismatch repair genes have also been shown to be important in relation with recurrences, and tumors appear to have different mutations depending on their location. Patients with stage II or III disease are often treated with adjuvant chemotherapy despite the fact that the treatments are far from efficient among all patients, who are at risk of recurrence. Studies are now being presented identifying subgroups, in which the therapy is inefficient. Unfortunately, only few of these facts are implemented in the present follow-up programs. Therefore, further research is urgently needed to verify which of the well-known parameters as well as new parameters that must be added to the current follow-up programs to identify patients at risk of recurrence.

Compositional dynamics of the human intestinal microbiota with aging: implications for health

The human gut contains trillions of microbes which form an essential part of the complex ecosystem of the host. This microbiota is relatively stable throughout adult life, but may fluctuate over time with aging and disease. The gut microbiota serves a number of functions including roles in energy provision, nutrition and also in the maintenance of host health such as protection against pathogens. This review summarizes the age-related changes in the microbiota of the gastrointestinal tract (GIT) and the link between the gut microbiota in health and disease. Understanding the composition and function of the gut microbiota along with the changes it undergoes overtime should aid the design of novel therapeutic strategies to counteract such alterations. These strategies include probiotic and prebiotic preparations as well as targeted nutrients, designed to enrich the gut microbiota of the aging population.

Compositional dynamics of the human intestinal microbiota with aging: implications for health

The human gut contains trillions of microbes which form an essential part of the complex ecosystem of the host. This microbiota is relatively stable throughout adult life, but may fluctuate over time with aging and disease. The gut microbiota serves a number of functions including roles in energy provision, nutrition and also in the maintenance of host health such as protection against pathogens. This review summarizes the age-related changes in the microbiota of the gastrointestinal tract (GIT) and the link between the gut microbiota in health and disease. Understanding the composition and function of the gut microbiota along with the changes it undergoes overtime should aid the design of novel therapeutic strategies to counteract such alterations. These strategies include probiotic and prebiotic preparations as well as targeted nutrients, designed to enrich the gut microbiota of the aging population.

The diagnostic value of one-step nucleic acid amplification (OSNA) for sentinel lymph nodes in colon cancer patients

BACKGROUND

Lymph node status in colon cancer is critical for prognosis estimation and treatment allocation. The purpose of this study was to compare the performance of one-step nucleic acid amplification (OSNA) through detection of cytokeratin 19 mRNA levels with routine pathological examination (RP) and multilevel fine pathological examination (FP) in sentinel lymph nodes (SLN), detected using the ex vivo SLN mapping (SLNM) procedure, in presurgically defined nonmetastatic colon cancer patients.

METHODS

In this prospective study, 325 SLNs of 128 patients from the Jeroen Bosch Hospital in 's-Hertogenbosch and the Leiden University Medical Center were investigated by RP (H&E), FP (H&E and Keratin Pan immunohistochemical staining), and OSNA. The SLNs were harvested by the SLNM procedure, using Patent blue or Indocyanine green. SLNs were divided and separate parts were used for RP, FP, and the OSNA assay.

RESULTS

The diagnostic value of OSNA was 82.1 and 100 % for both FP and combined method (OSNA and FP) compared with RP. An upstaging rate of 20.2 % was obtained with the use of OSNA only and 36.4 % with the use of FP only. An upstaging rate of 46.5 % was obtained by combining the two methods together.

CONCLUSIONS

OSNA and FP appeared to be promising tools for the detection of lymph node micro- and macrometastases in SLNs after SLNM. The performances of OSNA and FP in this study were superior to RP. Because OSNA allows analysis of the whole lymph node, sampling bias can be avoided. OSNA therefore may improve tumor staging.

The role of sentinel lymph node in colon cancer evolution

INTRODUCTION

The aim of this study is to evaluate the sentinel lymph node mapping (SLNM) with methylene blue staining "ex vivo" in colon cancer, as well as calculate the upstaging obtained by the determination of micrometastases and its correlation with the evolution of the disease.

METHODS

Between 2008 and 2011, 101 patients with colon cancer undergoing resection were studied prospectively with SLNM and detection of micrometastases. The correlation of SLN micrometastases with the disease evolution was evaluated in patients with a follow-up of more than one year.

RESULTS

The SLNM rate was 92 cases (91%). Only SLN was positive for micrometastases in 9 cases, with a 14% upstaging. The incidence of false negatives was 9 patients (10%). Mean follow of N0 patients (n=74) was 38 months. The SLN- (negative) group (65 patients) had a recurrence rate of 4 patients (7%), whereas this rate was 2 patients (22%) in the group of SLN+(positive) (9 patients), but without significant differences. No differences in survival were observed.

CONCLUSIONS

SLNM is a reproducible technique without significant increase in time and costs. Upstaging was obtained in 14% of patients staged as N0 by conventional technique. At follow-up of N0 patients with SLN+there seems to be a higher rate of recurrence, which could change the guidelines of adjuvant treatment, but we must interpret the results it with caution because the sample is small.

The prognostic value of micrometastases and isolated tumour cells in histologically negative lymph nodes of patients with colorectal cancer: a systematic review and meta-analysis

INTRODUCTION

Detection of occult tumour cells in lymph nodes of patients with stage I/II colorectal cancer is associated with decreased survival. However, according to recent guidelines, occult tumour cells should be categorised in micrometastases (MMs) and isolated tumour cells (ITCs). This meta-analysis evaluates the prognostic value of MMs and of ITCs, separately.

METHODS

PubMed, Embase, Biosis and the World Health Organization International Trials Registry Platform were searched for papers published until April 2013. Studies on the prognostic value of MMs and ITCs in lymph nodes of stage I/II colorectal cancer patients were included. Odds ratios (ORs) for the development of disease recurrence were calculated to analyse the predictive value of MMs and ITCs.

RESULTS

From five papers, ORs for disease recurrence could be calculated for MMs and ITCs separately. In patients with colorectal cancer, disease recurrence was significantly increased in the presence of MMs in comparison with absent occult tumour cells (OR 5.63; 95%CI 2.4-13.13). This was even more pronounced in patients with colon cancer (OR 7.25 95% CI 1.82-28.97). In contrast, disease recurrence was not increased in the presence of ITCs (OR 1.00 95% CI 0.53-1.88).

CONCLUSION

Patients with stage I/II colorectal cancer and MMs have a worse prognosis than patients without occult tumour cells. However, ITCs do not have a predictive value. The distinction between ITCs and MMs should be made if the detection of occult tumour cells is incorporated in the clinical decision for adjuvant treatment.

Excellent prognosis of node negative patients after sentinel node procedure in colon carcinoma: a 5-year follow-up study

AIM

Investigate the prognostic impact and clinical relevance of the sentinel node (SN)-procedure in colon carcinoma.

PATIENTS AND METHODS

Between May 2002 and January 2004, the SN-procedure was performed in 55 patients that underwent elective resection for clinically non-advanced colon carcinoma. A control group of 110 patients was identified from a cohort between January 2000 and April 2002. All lymph nodes were analysed by conventional haematoxylin-eosin staining. All negative SNs underwent in-depth analysis using immunohistochemical-staining and automated microscopy with the Ariol-system. Patients with positive lymph nodes were offered adjuvant chemotherapy. All patients were routinely monitored at 6-month intervals and follow-up was more than 5 years.

RESULTS

The SN was successfully identified in 98% of the patients, with 94% sensitivity. In-depth analysis with immunohistochemistry and automated microscopy (Ariol-system) upstaged 3 and 4 patients respectively. When only node-negative patients were analysed, overall 5-year-survival was significantly better in the SN group (91% vs. 76%, p = 0.04). Cancer-specific-mortality was even 0% (vs. 8%, p = 0.08). Disease-free-survival was significantly improved to 96% (vs. 77%, p < 0.01).

CONCLUSIONS

This study describes the prognostic impact of the SN-procedure in colon carcinoma after 5-year-follow-up. Only one patient had recurrent disease after a negative SN procedure (disease-free-survival 96%). These results indicate that the SN-procedure is of prognostic relevance and might be useful to select patients for adjuvant chemotherapy. Patients that are lymph node negative after an SN-procedure have an excellent prognosis and do not need adjuvant treatment.

Prognostic significance of histologically detected lymph node micrometastases of sizes between 0.2 and 2 mm in colorectal cancer

PURPOSE

Minimal lymph node involvement is a potential prognostic factor in colorectal cancer. The International Union Against Cancer defined tumour deposits between 0.2 and 2 mm as micrometastases and clusters and single-cell infiltrations below this cutoff as isolated tumour cells. Nevertheless, only a minority of studies discriminated metastatic involvements according to this definition.

METHODS

In order to investigate the prognostic significance of micrometastases (0.2-2 mm), we performed a retrospective study enrolling 44 routinely diagnosed micrometastatic cases within 15 years which represent about 1% of our cases. These cases have been re-evaluated.

RESULTS

Seven of the micrometastatic cases turned out to be macrometastases after step sectioning. Complete follow-up was available in 33 remaining cases. Collections of node-negative and macrometastatic cases served as control groups. The Kaplan-Meier curves of macro- and micrometastatic cases showed a similar adverse course (p = 0.830) especially during the first 40 months. The 5-year-survival rates were 51, 60 and 64 months for macro-, micrometastatic and node-negative cases, respectively. The difference in overall survival, however, reached only a statistical trend and was not significant (p = 0.137). After re-evaluation with step sections and cytokeratin immunohistochemistry out of an initial 91 node-negative cases, 11 (12%) cases were identified with isolated tumour cells and one (1%) case with a micrometastasis.

CONCLUSIONS

Our data show that micro- and macrometastatic colorectal cancers show very similar survival rates. Therefore, efforts to improve the detection of lymph node micrometastases seem to be justified.

[Sentinel lymph node biopsy technique in colon cancer. Experience in 125 cases]

INTRODUCTION

The level of lymph node involvement is the most important factor in staging colorectal cancer without metastasis. Sentinel lymph node mapping identifies the node(s) that most accurately reflect the lymph node status of patients, and intensive techniques that improve staging can be focused on these nodes. The aim of this study was to assess the efficacy of ex vivo sentinel lymph node mapping in the staging of colon cancer.

MATERIALS AND METHODS

A prospective study was conducted on 125 patients from the Alava-Txagorritxu University Hospital Health Region (Alava), who were diagnosed prior to surgery with colon cancer without distant metastasis from September 2009 to December 2011. Ex vivo sentinel lymph node mapping with methylene blue was use in these patients to study the sentinel nodes with multiple slices using immunohistochemical techniques and haematoxylin-eosin staining. A comparative study was also performed based on a control group of 170 patients staged with conventional techniques, and involving a single slice and haematoxylin-eosin staining.

RESULTS

The sentinel lymph node identification rate was 98%, with 5.6% false negatives. Upstaging occurred in 14.2% of cases compared to the group studied using conventional techniques (P=.006).

CONCLUSIONS

Ex vivo sentinel lymph node mapping with methylene blue accurately reflects the lymph node status of patients with colon cancer. This approach upstages patients classified as stages i and ii by conventional techniques to stage iii, indicating chemotherapy that may improve their prognosis.

Ex vivo sentinel node mapping in colon cancer combining blue dye staining and fluorescence imaging

BACKGROUND

The sentinel lymph node procedure has been proposed to improve nodal staging in colon cancer patients. The aim of this study was to assess the added value of near-infrared (NIR) fluorescence imaging to conventional blue dye staining for ex vivo sentinel lymph node mapping.

MATERIALS AND METHODS

We included 22 consecutive patients undergoing surgery for colon cancer. After tumor resection, we submucosally injected a premixed cocktail of the near-infrared lymphatic tracer HSA800 and blue dye around the tumor for detection of sentinel lymph nodes. We used the Mini-FLARE imaging system for fluorescence imaging.

RESULTS

In 95% of patients, we identified at least one sentinel lymph node. Overall, a total of 77 sentinel lymph nodes were identified, 77 of which were fluorescent (100%) and 70 of which were blue (91%). Sentinel lymph nodes that were located deeper in the mesenteric fat could easily be located by NIR fluorescence. In four of five patients with lymph node metastases, tumor cells were present in at least one of the sentinel lymph nodes.

CONCLUSIONS

This study shows the successful use and added value of the NIR fluorescence tracer HSA800 to conventional blue dye for the ex vivo sentinel lymph node procedure in colon cancer.

The complexity of the count: considerations regarding lymph node evaluation in colorectal carcinoma

In patients with colorectal carcinoma, studies have reported improved survival with increasing numbers of retrieved lymph nodes. These findings are puzzling, as increased node sampling was not correlated with significant change in disease staging. Although the physiologic processes underlying this correlation between number of lymph nodes sampled and survival remain unknown, the reported correlation has caused modifications to clinical and non-clinical practices. Herein, we review the literature and discuss potential etiologies responsible for the observed increased survival statistics. Literature regarding colorectal lymph node anatomy, molecular aspects of colorectal cancer, changes in tumor characteristics and utilization of lymph node sample numbers are evaluated. In addition, we present the mathematical concepts available for probabilistic prediction of diagnostic confidence based upon sample size. From evaluation of the aggregate literature, certain facts emerge which are not easily identified within the individual studies. Colorectal carcinoma appears to encompass a number of individual disease entities with different physiologic characteristics and likelihoods of metastasis. In addition, it appears the improved survival is likely multifactorial including effects from intrinsic tumor biology and tumor-host interactions along with ever changing clinical practices. Finally, because lymph node count is dependent on a number of variables and is correlated, but unlikely to be causally associated with survival, use of this number as a quality indicator is unwarranted. Based on statistical considerations, the current recommended goal of 12-15 recovered lymph nodes without evidence of metastatic disease provides approximately 80% negative predictive value for colorectal carcinoma metastasis.

Colorectal carcinoma grading by quantifying poorly differentiated cell clusters is more reproducible and provides more robust prognostic information than conventional grading

The most widely used system to define the histological grade of colorectal carcinoma (CRC) is based on the degree of gland formation. This system suffers from significant interobserver variability which may limit its prognostic value and consequently better standardized criteria for the assessment of histological grading of CRC are needed. The present study aims to evaluate and to compare, in a cohort of postsurgical pTNM stage I CRC, conventional histological grading, and a novel grading system based on the number of poorly differentiated clusters of neoplastic cells, in terms of interobserver reproducibility, prognostic significance on progression-free survival, and association with other clinicopathological characteristics. Grading with both systems was performed by two pathologists independently and blinded to the clinicopathological data. Interobserver agreement was higher when grade was assessed by counting poorly differentiated clusters than by assessing the relative proportion of the glandular component. Contrary to conventional grading, the novel system provided significant prognostic information in terms of progression-free survival and was significantly associated with budding, invasive growth, lymphatic invasion, and occult nodal metastases of CRC. In conclusion, our findings suggest that a tumor grading system based on the number of poorly differentiated clusters is more reproducible and provides better prognostic stratification of pTNM stage I CRC patients than conventional grading.

[Lymph node staging in gastrointestinal cancer. Combination of methylene blue-assisted lymph node dissection and ex vivo sentinel lymph node mapping]

The histopathological lymph node staging is of crucial importance for the prognosis estimation and therapy stratification in gastrointestinal cancer. However, the recommended numbers of lymph nodes that should be evaluated are often not reached in routine practice. Methylene blue assisted lymph node dissection was introduced as a new, simple and efficient technique to improve lymph node harvest in gastrointestinal cancer. This method is inexpensive, causes no delay and needs no toxic substances. All studies performed revealed a highly significantly improved lymph node harvest in comparison to the conventional technique. Moreover, this technique can be combined with a new ex vivo sentinel lymph node mapping that for the first time is based on histological sentinel lymph node detection. The success rate of this method is similar to conventional techniques and it enables an efficient application of extended investigation methods, such as immunohistochemistry or the polymerase chain reaction.

The effect of colonoscopic tattooing on lymph node retrieval and sentinel lymph node mapping

BACKGROUND

In colorectal cancer (CRC), colonoscopic tattooing is performed to mark the tumor site before laparoscopic surgery.

OBJECTIVE

To determine whether colonoscopic tattooing can be used to refine staging accuracy by increasing the lymph node (LN) yield per specimen and to determine its accuracy as a sentinel LN procedure.

DESIGN

Retrospective, case-control study. All LNs were microscopically examined for the presence of carbon particles.

SETTING

A university hospital and a teaching hospital.

PATIENTS

A consecutive series of 95 tattooed patients who had surgery for CRC between 2005 and 2009. A series of 210 non-tattooed patients who had surgery in the same time period served as controls.

MAIN OUTCOME MEASUREMENTS

Total number of LNs retrieved, detection rate, and sensitivity of tattooing as a sentinel node procedure.

RESULTS

A higher LN yield was observed in patients with preoperative tattooing, median (interquartile range) 15 (10-20) versus 12 (9-16), (P = .014). In multivariable analysis, the presence of carbon-containing LNs was an independent predictive factor for a higher LN yield (P = .002). The detection rate was 71%, with a median of 5 carbon-containing LNs per specimen. If preoperative tattooing was used for sentinel node mapping, the overall accuracy of predicting LN status was 94%. In the 24 N1 cases, there were 4 false-negative procedures (sensitivity 83%).

LIMITATIONS

Retrospective series.

CONCLUSION

After tattooing of CRC, the LN yield was higher than in a control group, and it could be used as a sentinel node procedure with acceptable accuracy rates. Because LN yield and sentinel node mapping are associated with improved diagnostic accuracy of LN involvement, preoperative tattooing can refine staging.

Correlation between expression of CK20 mRNA in peripheral blood and clinicopathological features and prognosis in patients with colorectal cancer

AIM: To investigate the clinical significance of cytokeratin 20 (CK20) mRNA expression in peripheral venous blood of patients with colorectal carcinoma.

METHODS: The expression of CK20 mRNA was detected by RT-PCR in peripheral venous blood samples from 20 healthy volunteers, 10 patients with colorectal polyps, and 61 patients with colorectal cancer.

RESULTS: The positive rate of CK20 mRNA in peripheral venous blood of patients with colorectal cancer was 41.0% (25/61). CK20 mRNA expression in peripheral venous blood was associated with TNM stage, local lymph node metastasis, distant metastasis, and depth of invasion (all P < 0.05). The expression of CK20 mRNA was not detected in peripheral venous blood of healthy volunteers and patients with colorectal polyps. Seventeen cases died during the follow-up period, of whom 10 had positive expression of CK20 in peripheral blood.

CONCLUSION: CK20 is a specific marker for blood micrometastasis of colorectal cancer. The expression of CK20 mRNA in the blood of patients with colorectal cancer is related with the invasion and metastasis of colorectal cancer. Detection of CK20 mRNA in peripheral blood seems to be of relevance for prognosis in colorectal cancer.

Ex vivo localization and immunohistochemical detection of sentinel lymph node micrometastasis in patients with colorectal cancer can upgrade tumor staging

BACKGROUND

It is not clear if sentinel lymph node (SLN) mapping can improve outcomes in patients with colorectal cancers. The purpose of this study was to determine the prognostic values of ex vivo sentinel lymph node (SLN) mapping and immunohistochemical (IHC) detection of SLN micrometastasis in colorectal cancers.

METHODS

Colorectal cancer specimens were obtained during radical resections and the SLN was identified by injecting a 1% isosulfan blue solution submucosally and circumferentially around the tumor within 30 min after surgery. The first node to stain blue was defined as the SLN. SLNs negative by hematoxylin and eosin (HE) staining were further examined for micrometastasis using cytokeratin IHC.

RESULTS

A total of 54 patients between 25 and 82 years of age were enrolled, including 32 males and 22 females. More than 70% of patients were T3 or above, about 86% of patients were stage II or III, and approximately 90% of patients had lesions grade II or above. Sentinel lymph nodes were detected in all 54 patients. There were 32 patients in whom no lymph node micrometastasis were detected by HE staining and 22 patients with positive lymph nodes micrometastasis detected by HE staining in non-SLNs. In contrast only 7 SLNs stained positive with HE. Using HE examination as the standard, the sensitivity, non-detection rate, and accuracy rate of SLN micrometastasis detection were 31.8% (7/22), 68.2% (15/22), and 72.2%, respectively. Micrometastasis were identified by ICH in 4 of the 32 patients with HE-negative stained lymph nodes, resulting in an upstaging rate 12.5% (4/32). The 4 patients who were upstaged consisted of 2 stage I patients and 2 stage II patients who were upstaged to stage III. Those without lymph node metastasis by HE staining who were upstaged by IHC detection of micrometastasis had a significantly poorer disease-free survival (p = 0.001) and overall survival (p = 0.004).

CONCLUSION

Ex vivo localization and immunohistochemical detection of sentinel lymph node micrometastasis in patients with colorectal cancer can upgrade tumor staging, and may become a factor affecting prognosis and guiding treatment.

Superstaging in colorectal cancer

Should be used to refine current management strategies