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

Influence of colectomy type and resected specimen length on number of harvested lymph nodes

BACKGROUND

The optimal (minimal) number of harvested nodes is still a matter of debate. We prospectivly evaluated the relation between specimen length and tumor location to the number of harvested nodes and rate of node positivity.

METHODS

Specimens of right hemicolectomy, left hemicolectomy, and subtotal colectomy were assessed for specimen length, overall number of harvested lymph nodes, and lymph node ratio.

RESULTS

Left hemicolectomies were performed in 106 patients, right hemicolectomies in 90, and subtotal colectomies in 9. The mean number of retrieved lymph nodes was significantly higher in patients with right and subtotal colectomies compared to left colectomies: 33, 44, and 24, respectively. Positive nodes were found in 34% of the patients with right hemicolectomies, 55% in the subtotal group, and 35% in the left hemicolectomy group (not statistically significant). The length of the resected specimen was significantly longer in patients with right and subtotal colectomies compared to left colectomy: 31, 83, and 19 cm, respectively, but the ratio of lymph nodes to the length of the specimen was not statistically different: 1.19, 0.58, and 1.55, respectively.

CONCLUSIONS

It appears that the additional length of resection in right colectomies compared to left colectomies leads to an increase in the average number of resected nodes, a change that did not translate into an increase in the number of positive nodes, nor in the ratio of patients with positive nodes.

Lymph node ratio predicts tumor recurrence in stage III colon cancer

OBJECTIVE

To evaluate the lymph node ratio as a predictor for tumor recurrence in stage III colon cancer patients.

METHODS

Patients with stage III colon cancer who underwent curative resection between January 2005 and December 2010 were retrospectively reviewed. The main outcomes were tumor recurrence and death. The impact of lymph node ratio and other clinicopathological factors on disease-free survival were evaluated by uni- and multivariate analysis. Receiver operator characteristic (ROC) analysis was conducted in order to identify the best cutoff value for lymph node ratio to predict tumor recurrence. Disease-free survival was estimated by the Kaplan-Meier method.

RESULTS

Seventy patients were included in the study (50% male). The mean age was 64 years. Univariate analysis identified four factors for tumor recurrence: carcinoembryonic antigen, N stage, number of positive lymph nodes and lymph node ratio. Lymph node ratio was the one with the greatest magnitude of association. Receiver operator characteristic analyzes identified 0.15 as the best cutoff value. Patients with a lymph node ratio < 0.15 had a disease-free survival of 90% in 3 years (versus 64%, p = 0.011).

CONCLUSION

Lymph node ratio is a strong predictor for tumor recurrence in stage III colon cancer.

Lymph node yield after colectomy for cancer: is absence of mismatch repair a factor?

BACKGROUND

Nodal staging is crucial in determining the use of adjuvant chemotherapy for colon cancer. The number of metastatic lymph nodes has been positively correlated with the number of lymph nodes examined. Current guidelines recommend that at minimum 12 to 14 lymph nodes be assessed. In some studies, mismatch repair deficiency has been associated with lymph node yield.

OBJECTIVE

The purpose of this work was to determine whether mismatch repair-deficient colorectal tumors are associated with increased lymph node yield.

DESIGN

We queried an institutional database to analyze colectomy specimens with immunohistochemistry for mismatch repair genes in patients treated for colorectal cancer between 1999 and 2012. Before 2006, immunohistochemistry was performed at the request of an oncologist or surgeon. After 2006, it was routinely performed for patients <50 years of age. We measured the association of clinical and pathologic features with lymph node quantity. Fourteen predictors and confounders were jointly analyzed in a multivariable linear regression model.

SETTINGS

The study was conducted at a single tertiary care institution.

PATIENTS

Tissue specimens from 256 patients were reviewed.

MAIN OUTCOME MEASURES

The correlation of tumor, patient, and operative variables to the yield of mesenteric lymph nodes was measured.

RESULTS

Of 256 colectomy specimens reviewed, 94 had mismatch repair deficiency. On univariate analysis, mismatch repair deficiency was associated with lower lymph node yield, older patient age, right-sided tumors, and poor differentiation. The linear regression model identified 5 variables with independent relationships to lymph node yield, including patient age, specimen length, lymph node ratio, perineural invasion, and tumor size. A positive correlation was observed with tumor size, specimen length, and perineural invasion. Tumor location had a more complex, nonlinear, quadratic relationship with lymph node yield; proximal tumors were associated with a higher yield than more distal lesions. Mismatch repair deficiency was not independently associated with lymph node yield.

LIMITATIONS

Mismatch repair immunohistochemistry based on patient age, family history, and pathologic features may reduce the generalizability of these results. Our sample size was too small to identify variables with small measures of effect. The retrospective nature of the study did not permit a true assessment of the extent of mesenteric resection.

CONCLUSIONS

Patient age, length of bowel resected, lymph node ratio, perineural invasion, tumor size, and tumor location were significant predictors of lymph node yield. However, when controlling for surgical and pathologic factors, mismatch repair protein expression did not predict lymph node yield.

Prognostic Value of Lymph Node Ratio in Comparison to Lymph Node Metastases in Stage III Colon Cancer

BACKGROUND & OBJECTIVES

Colon cancer is currently of high incidence and mortality rate. Identifying the factors influencing its prognosis can be very beneficial to its clinical treatment. Recent studies have shown that lymph nodes ratio can be considered as an important prognostic factor. The aim of the present study is to investigate the effect of this factor on the prognosis of the patients presenting with stage III colon cancer and to compare the result with the effect of lymph node stage on their prognosis.

MATERIALS

This cross-sectional study was carried out on 66 patients of stage III colon cancer, who met the study inclusion criteria. Patients were categorized into four groups based on Kaplan-Meier plots: LNR1 0-12%, LNR2 13-40%, LNR3 41-84% and LNR4 85-100%. Survival was estimated by Kaplan-Meier method, and differences analyzed by Log-rank test. A Cox proportional hazards model was used for multivariate analysis.

RESULTS

Lymph nodes ratio was a significantly variable both in overall survival ( P <0.0001) and in disease-free survival ( P =0.009). Lymph node stage was significant in overall survival ( P =0.008) but not in disease-free survival ( P =0.05). Multivariable analysis of overall survival showed lymph nodes ratio as the only independent prognostic factor.

CONCLUSION

Lymph node ratio is a more accurate prognostic factor than lymph node stage in overall survival and, in particular, in disease-free survival in patients with stage III colon cancer.

The prognostic value of the number of lymph nodes removed in patients with node-negative colorectal cancer

BACKGROUND

To investigate the prognostic significance of the number of lymph nodes removed in colorectal cancer (CRC) patients with no metastatic lymph node.

PATIENTS AND METHODS

The clinicopathological data of 461 CRC patients was analyzed. In order to compare the survival of patients who had fewer lymph nodes removed versus the survival of patients who had 1-3 metastatic lymph node(s), a separate group of 74 N1 disease patients were also included in the study. All patient data were collected prospectively. Kaplan-Meier method was used for calculation and plotting of the survival curves of the patient groups, and log-rank test was used for the comparison of the survival curves.

RESULTS

Cancer-specific survival (CSS) rates of patients who had 1-7 lymph node(s) and 8-11 lymph nodes removed were significantly worse than those who had 12 or more lymph nodes removed (p = 0.006 and p = 0.037, respectively), while CSS was not significantly different between those who had 1-7 versus 8-11 lymph node(s) removed (p = 0.647); this grouping had independent prognostic significance in Cox analysis (p = 0.006). CSS of patients with N1 disease was not significantly different from those who had 1-7 and 8-11 lymph node(s) removed (p = 0.312 and p = 0.165, respectively), while it was significantly worse than CSS of patients who had 12 or more lymph nodes removed (p = 0.001).

CONCLUSION

In colorectal cancer patients whose removed lymph nodes are non-metastatic, removal of at least 12 lymph nodes will determine the lymph node status reliably.

Lymph node ratio improves TNM and Astler-Coller's assessment of colorectal cancer prognosis: an analysis of 761 node positive cases

BACKGROUND

Prognosis assessment of node-positive colorectal cancer patients by Astler-Coller (AC) and TNM classifications is suboptimal. Recently, several versions of lymph node ratio (LNR; ratio metastatic/examined nodes) have been proposed but are still mostly unused.

METHODS

The prognostic value of several criteria, including LNR (two classes-LNR1 and LNR2-identified by a 15% cut-off) was studied in 761 consecutive patients, from 2000 through 2010. The relationships between total examined nodes, N, T and LNR were also analysed. LNR1 and LNR2 patients' survival was analysed within AC and TNM subgroups, and then coupled with them.

RESULTS

Age, tumour location and LNR are independent factors predicting survival. The relationships between LNR, N stage and T stage with examined nodes suggest confusing factors. LNR allows for identification of subgroups with different survival within AC and TNM classifications (p < 0.0001). Patients with LNR class discordant from AC stage (LNR1-C2 and LNR2-C1) have a similar 5-year survival (54 and 57%, respectively). LNR2 and TNM stage IIIC define a poor 5-year prognosis (33%).

CONCLUSIONS

LNR is a powerful prognosis predictor, easily integrated with TNM and AC classifications to improve prognosis assessment and facilitate clinical use. Possible confusing factors should be considered in future studies.

Lymph node count and prognosis in colorectal cancer: the influence of examination quality

Colorectal cancer guidelines recommend adjuvant chemotherapy in stage II disease when less than 12 lymph nodes are assessed. The recommendation bases on previous studies showing an association of a low lymph node count and adverse outcome. Compared to current standards, however, the quality of lymph node examination in the studies was low. We, therefore, investigated the prognostic role of <12 lymph nodes in cancers diagnosed adherent to current quality measures. Stage I-IV colorectal cancers from 1,899 patients enrolled into a population-based cohort study were investigated for the prognostic impact of a lymph node count <12. The stage specific share of patients diagnosed with ≥12 nodes (stage I-IV: 62, 85, 85, 78%, respectively) was used to compare lymph node examination quality to other studies. We found no impact of a lymph node count <12 on overall, cancer-specific or recurrence-free survival for any tumour stage. Compared to studies reporting an adverse prognostic impact of a low lymph node count in stages II and III the stage-specific shares of patients with ≥12 nodes were markedly higher in this study (85% vs. 24-58% in previous analyses) and this correlated with increased rates of stage III compared to stage II cancers. In conclusion our data indicate, that the previously reported effect of a low lymph node count on the patients' outcomes is eliminated by improved lymph node examination quality and thus question the general applicability of a 12 lymph node cut off for adjuvant chemotherapy decision making in stage II disease.

Solitary lymph node metastasis is a distinct subset of colon cancer associated with good survival: a retrospective study of surveillance, epidemiology, and end-results population-based data

Background

Colon cancer with lymph node metastases has been considered as advanced stage and to have poor survival. We postulated that patients with solitary lymph node metastasis are a distinct subset with better colon cancer-specific survival than those with multiple lymph node metastases.

Methods

In this retrospective study, we searched Surveillance, Epidemiology, and End-Results (SEER) population-based data and identified 86,674 patients who had been diagnosed with colon cancer without distant metastases and with less than three metastatic nodes between 1991 and 2005. We divided lymph node status into three subgroups: pN0, pN1a, and pN1b and obtained 5-year colon cancer-specific survival for each pT stage. We used Kaplan–Meier and multivariate Cox regression models to assess correlations between risk factors and survival outcomes.

Results

Analysis of SEER data confirmed that patients with solitary lymph node metastases had better 5-year cancer-specific survival than pN1b according to both univariate and multivariate analysis. This finding was confirmed by further analyses in five pT subgroups. Cancer-specific survival of patients with pT1-2N1a was comparable to that of those with pIIA but higher than those with pIIB. In addition, survival of patients with pT3-4aN1a was better than those with pIIC.

Conclusion

Colon cancer patients with solitary lymph node metastasis are a distinct subset with a favorable prognosis; full consideration should be given to this in clinical practice.

Lymph node-independent liver metastasis in a model of metastatic colorectal cancer

Deciphering metastatic routes is critically important as metastasis is a primary cause of cancer mortality. In colorectal cancer (CRC), it is unknown whether liver metastases derive from cancer cells that first colonize intestinal lymph nodes, or whether such metastases can form without prior lymph node involvement. A lack of relevant metastatic CRC models has precluded investigations into metastatic routes. Here we describe a metastatic CRC mouse model and show that liver metastases can manifest without a lymph node metastatic intermediary. Colorectal tumours transplanted onto the colonic mucosa invade and metastasize to specific target organs including the intestinal lymph nodes, liver and lungs. Importantly, this metastatic pattern differs from that observed following caecum implantation, which invariably involves peritoneal carcinomatosis. Anti-angiogenesis inhibits liver metastasis, yet anti-lymphangiogenesis does not impact liver metastasis despite abrogating lymph node metastasis. Our data demonstrate direct hematogenous spread as a dissemination route that contributes to CRC liver malignancy.

Extended lymphadenectomy in colon cancer is crucial

No one doubts that lymph node dissection in colon cancer is necessary, it is just the extent of that dissection that is still under debate. As the individual steps of an oncologic operation cannot be separated from each other, analysis of the significance of lymph node dissection alone is difficult. It has been proven that the T category is directly related to the number and central spread of lymph node metastases. Micrometastases and isolated tumor cells may be detected in lymph nodes by using special staining techniques; their presence may worsen prognosis significantly and approximate it to UICC stage III. The numbers of dissected lymph nodes and the ratio of involved versus dissected lymph nodes have been used as markers for quality of surgery and histopathological evaluation. Recent results underscore the importance of technique and extent of dissection. Dissection must be performed along the embryologic planes of the mesocolon and leave them intact. A high vascular tie with preservation of the central hypogastric nerves must be applied in order to achieve the best oncologic results while preserving quality of life. Extended lymphadenectomy is oncologically relevant only when it is combined with removal of the primary tumor with adequate longitudinal clearance, an intact complete mesocolon, and high vascular tie. It is part of a concept in which the tumor-bearing specimen is harvested as an enveloped package to minimize the risk of tumor cell spillage and local recurrence.

Colorectal cancer and lymph nodes: The obsession with the number 12

Lymphadenectomy of colorectal cancer is a decisive factor for the prognostic and therapeutic staging of the patient. For over 15 years, we have asked ourselves if the minimum number of 12 examined lymph nodes (LNs) was sufficient for the prevention of understaging. The debate is certainly still open if we consider that a limit of 12 LNs is still not the gold standard mainly because the research methodology of the first studies has been criticized. Moreover many authors report that to date both in the United States and Europe the number “12” target is uncommon, not adequate, or accessible only in highly specialised centres. It should however be noted that both the pressing nature of the debate and the dissemination of guidelines have been responsible for a trend that has allowed for a general increase in the number of LNs examined. There are different variables that can affect the retrieval of LNs. Some, like the surgeon, the surgery, and the pathology exam, are without question modifiable; however, other both patient and disease-related variables are non-modifiable and pose the question of whether the minimum number of examined LNs must be individually assigned. The lymph nodal ratio, the sentinel LNs and the study of the biological aspects of the tumor could find valid application in this field in the near future.

The learning curve of laparoscopic treatment of rectal cancer does not increase morbidity

INTRODUCTION

The treatment of rectal cancer via laparoscopy is controversial due to its technical complexity. Several randomized prospective studies have demonstrated clear advantages for the patient with similar oncological results to those of open surgery, although during the learning of this surgical technique there may be an increase in complications and a worse prognosis.

OBJECTIVE

Our aim is to analyze how the learning curve for rectal cancer via laparoscopy influences intra- and postoperative results and oncological markers. A retrospective review was conducted of the first 120 patients undergoing laparoscopic surgery for rectal neoplasia. The operations were performed by the same surgical team with a wide experience in the treatment of open colorectal cancer and qualified to perform advanced laparoscopic surgery. We analyzed sex, ASA, tumour location, neoadjuvant treatment, surgical technique, operating time, conversion, postoperative complications, length of hospital stay, number of lymph nodes, stage and involvement of margins.

RESULTS

Significant differences were observed with regard to surgical time (224 min in the first group, 204 min in the second group), with a higher rate of conversion in the first group (22.5%) than in the second (11.3%). No significant differences were noted for rate of conservative sphincter surgery, length of hospital stay, post-surgical complications, number of affected/isolated lymph nodes or affected circumferential and distal margins.

CONCLUSIONS

It is possible to learn this complex surgical technique without compromising the patient's safety and oncological outcome.

Multi-institutional investigation of the prognostic value of lymph nodel yield in advanced-stage oral cavity squamous cell carcinoma

BACKGROUND

Although existing literature provides surgical recommendations for treating occult disease (cN0) in early-stage oral cavity squamous cell carcinoma (SCC), a focus on late-stage oral cavity SCC is less pervasive.

METHODS

The medical records of 162 patients with late-stage oral cavity SCC pN0 who underwent primary neck dissections were reviewed. Lymph node yield as a prognosticator was examined.

RESULTS

Despite being staged pN0, patients that had a higher lymph node yield had an improved regional/distant control rates, disease-free survival (DFS), disease-specific survival (DSS), and overall survival (OS). Lymph node yield consistently outperformed all other standard variables as being the single best prognostic factor with a tight risk ratio range (RR = 0.95-0.98) even when correcting for the number of lymph nodes examined.

CONCLUSION

The results of this study showed that lower regional recurrence rates and improved survival outcomes were seen as lymph node yield increased for advanced T classification oral cavity SCC pN0. This suggests that increasing lymph node yield with an extended cervical lymphadenectomy may result in lower recurrence rates and improved survival outcomes for this advanced stage group.

Occult neoplastic cells in lymph node sinuses and recurrence/metastasis of stage II/III gastric cancer

In the present study, we investigated the correlation between the presence of occult neoplastic cells (ONCs) in lymph node sinuses and recurrence/metastasis of stage II/III gastric cancer in 164 patients who underwent radical curative resection. We calculated the five-year relapse-free survival rate (5Y-RFS) and five-year overall survival rate (5Y-OS) of the ONC(+) and ONC(-) groups. The 5Y-RFS was 71.4% in the ONC(-) group and 47.5% in the ONC(+) group (P=0.003). The 5Y-OS was 68.8 and 48.4%, respectively (P=0.008). ONCs were found in 34.8% of stage II patients and were also detected in 66.7% of stage III patients. For distinguishing between the recurrence and non-recurrence groups, the sensitivity of ONC(+) was 64.5% (40/62; P=0.003), the positive predictive value (PPV) was 49.4% (40/81), the specificity was 59.8% (61/102) and the negative predictive value (NPV) was 73.5% (61/83). This high sensitivity indicates that ONC positivity may be a significant indicator for high-risk patients in the early postoperative period, and a lack of ONCs may be a useful indicator for identifying low-risk patients, as patients without ONCs had a high NPV.

Lymph node evaluation in stage IIA colorectal cancer and its impact on patient prognosis: a population-based study

BACKGROUND

The analysis of regional lymph nodes is particularly relevant in patients with stage II colorectal cancer, in whom the role of adjuvant chemotherapy remains unclear. The aim of this study was to assess the relationship between number of examined lymph nodes and survival in patients with stage IIA (pT3N0M0) colorectal cancer, and to determine the optimal number of lymph nodes that should be examined.

METHODS

The study group included all the surgically-treated colorectal cancer patients in stage IIA (n = 657) who were identified through the population-based Cancer Registry of the Province of Modena (Northern Italy), during the period 2002-2006.

RESULTS

The median number of harvested lymph nodes was 19 (range 1-68). Considering, as a reference point, patients with 12 or less lymph nodes, subjects with n ≥ 20 lymph nodes examined showed, in univariate analysis, a significantly higher cancer specific (p = 0.01) and relapse-free survival (p = 0.003). The results were confirmed by multivariate analysis (Cox model).

CONCLUSION

The result suggests that colorectal cancer patients in stage IIA with n ≥ 20 lymph nodes examined exhibit better survival when compared with subjects in whom fewer lymph nodes were examined. The number of 20 lymph nodes is the essential requirement for an oncologic resection of the large bowel.

Hepatocellular carcinoma in children: epidemiology and the impact of regional lymphadenectomy on surgical outcomes

BACKGROUND

Factors influencing survival in children with HCC have not been studied. The objective of this study was to identify prognostic factors in pediatric HCC, and to determine whether regional lymphadenectomy is associated with improved survival.

METHODS

We performed a retrospective cohort study using the Surveillance, Epidemiology and End Results (SEER) registry. All patients <20 years old diagnosed with HCC from 1973-2009 were included. Disease-specific survival was compared using Kaplan-Meier statistics and Cox proportional-hazards regression.

RESULTS

We identified 238 patients (139 Male: 99 Female). Overall, 112 (47%) received an operation (resection/transplantation). Observed mortality and adjusted hazard of disease-specific death was greater for females (HR=2.07, p=0.013) and older children. Among operative patients, 44% were documented to have a regional lymphadenectomy. Although demographic factors did not differ between lymphadenectomy and non-lymphadenectomy groups, patients who underwent lymphadenectomy had a greater proportion of metastatic disease (24% vs. 15%) and fibrolamellar HCC (53% vs. 31%). Five-year survival for lymphadenectomy patients was superior to non-lymphadenectomy (70% vs. 57%). Adjusted mortality for lymphadenectomy was also improved relative to non-lymphadenectomy (HR=0.26, p=0.013).

CONCLUSIONS

HCC in children is associated with poor survival, especially among children older than 4 years and girls. In surgical candidates, regional lymphadenectomy may be associated with improved survival.

Impact of Schwartz enhanced visualization solution on staging colorectal cancer and clinicopathological features associated with lymph node count

BACKGROUND

Stage-specific survival for colon cancer improves when more lymph nodes are reported in the surgical specimen. This has led to a minimum standard of identifying 12 lymph nodes as a quality indicator.

OBJECTIVE

The aim of this study was to determine whether the addition of Schwartz solution increases node yield and impacts pathologic staging.

DESIGN

This is a prospective cohort study.

SETTING

The study was conducted in an academic medical center.

PATIENTS

Included were 104 consecutive patients with colorectal cancer.

MAIN OUTCOME MEASURES

Lymph node counts before and after specimen treatment with Schwartz solution and incidence of upstaging were measured.

RESULTS

An additional 20 minutes (interquartile range, 15-40 minutes) was spent searching for lymph nodes, increasing the median number of nodes from 22.5 to 29.0 nodes. However, only 1 patient was upstaged. Schwartz solution decreased the number of specimens with less than 12 lymph nodes from 15 to 6. The following factors were associated with Schwartz solution leading to the detection of additional nodes: number of nodes detected initially with formalin only (p < 0.000), mesenteric fat volume (p < 0.000), mesenteric fat weight (p < 0.000), length of specimen (p < 0.016), tumor greatest dimension (p < 0.016), patient body surface area (p < 0.034), and patient age (p < 0.003).

LIMITATIONS

Clinical data for this study were obtained retrospectively and were not available for all of the patients.

CONCLUSIONS

Although Schwartz solution increased the number of nodes detected in 95% of patients and improved compliance with the 12-node standard for colon resection, there was minimal impact on cancer staging. Upstaging is unlikely to explain the increase in overall survival in patients with higher lymph node counts, casting doubt on the validity of this process measure as a meaningful quality indicator. Rather, the lymph node count may be a reflection of inherent tumor biology or host-related factors.

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.

What does absence of lymph node in resected specimen mean after neoadjuvant chemoradiation for rectal cancer

Background

The effect of insufficient node sampling in patients with rectal cancer managed by neoadjuvant chemoradiation followed by surgery has not been clearly determined. We evalulated the impact of insufficient sampling or even abscence of lymph nodes in the specimen on survival in patients at high-risk (T3, T4 or node positive) for rectal cancer.

Methods

We conducted a single institution, retrospective analysis of all patients who underwent surgical rectal resection following neoadjuvant chemoradiation for treatment of mid to lower rectal cancer between 1997 and 2009. ypNX was defined as the absence of lymph nodes retrieved in the resected specimen.

Results

A total of 132 patients underwent resection for treatment of rectal cancer following neoadjuvant chemoradiation. Ninety four patients (71.2%) were considered as having node-negative disease, including ypNx and ypN0. In 38 patients (28.8%), the primary tumor was associated with regional lymph node metastases (ypNpos). The mean number of retrieved nodes per specimen was 14.2, respectively. The five-year overall survival from initial operation for the ypNx group was 100%, respectively. The estimated five-year overall survival for ypN0 and ypNpos was 84.0% and 60.3%, respectively (P =0.001). No significant differences in overall survival were observed between the ypNx and ypN0 group (P =0.302).

Conclusion

Absence of recovered LN in resected specimens after neoadjuvant chemoradiation was observed in 7.6% of specimens. Absence of LN should not be regarded as a risk factor for poor survival or as a sign of less radical surgery.

Number of examined lymph nodes and nodal status assessment in pancreaticoduodenectomy for pancreatic adenocarcinoma

BACKGROUND

The accuracy of the assessment of the nodal status in resected cephalic pancreatic adenocarcinoma (PA) depends on the number of examined lymph nodes (NELN). This study assesses the impact of the NELN on N staging and survival and propose a minimal number of examined lymph nodes (MNELN) ensuring reliability of the pN status determination.

METHODS

188 consecutive patients treated by pancreaticoduodenectomy (PD) for PA. Correlations between NELN and survivals of pN0 and pN1 groups and with the rate of pN1 patients were studied. A probability model based on the binomial law was built to estimate the MNELN able to detect pN1 patients with a sensitivity ≥ 95%.

RESULTS

Overall and disease free 5-year survivals were 27.2% and 24.6% respectively. 135 patients (71.8%) were staged pN1. The median NELN was 17 (range 0-68). Overall and disease free survivals of pN1 patients were not related to NELN. The influence of NELN on survival in pN0 patients due to stage migration did not reach significance. The probability model showed that a MNELN of 16 nodes was required to detect pN1 patients with a sensitivity of 95%.

CONCLUSION

A MNELN of 16 is required to assess pN status and should be considered as a quality criterion in future studies and trials on PD for PA.

D3 Lymph Node Dissection in Right Hemicolectomy with a No-touch Isolation Technique in Patients With Colon Cancer

BACKGROUND

The role of lymph node dissection in the management of right-sided colon cancer remains controversial.

OBJECTIVE

The aim of this study was to investigate the surgical treatment of curable right-sided colon cancer by using D3 lymphadenectomy with a no-touch isolation technique and to determine the extent of lymph node dissection optimal for the prognosis of right-sided colon cancer.

DESIGN

This research is a retrospective cohort study from a prospectively collected database.

SETTING

The investigation took place in a specialized colorectal surgery department.

PATIENTS

: Data on 370 consecutive patients who underwent D3 lymph node dissection for right-sided colon cancer with a no-touch isolation technique were identified.

MAIN OUTCOME MEASURES

The survival of patients with involvement of main nodes at the roots of colonic arterial trunks along superior mesenteric vessels through intermediate nodes in the right mesocolon was determined.

RESULTS

The 5-year overall survival of patients with stage I (n = 73, 19.7%), II (n = 155, 41.9%), and III (n = 142, 38.4%) cancer were 94.5%, 87.6%, and 79.2%. The 5-year disease-specific survival of patients with stages I, II, and III cancer were 100.0%, 94.5%, and 85.0%. Eleven patients (3.0%) had metastatic involvement of main lymph nodes, whereas 49 (13.2%) had metastases to intermediate lymph nodes. The 5-year overall survival and disease-specific survival of patients with metastases to main lymph nodes were 36.4% for both, and 5-year overall survival and disease-specific survival of patients with metastases to intermediate lymph nodes were 77.6% and 83.5%.

LIMITATIONS

This study was limited by its nonrandomized retrospective design.

CONCLUSIONS

D3 lymphadenectomy with a no-touch isolation technique allows curative resection and long-term survival in a cohort of patients with cancer of the right colon.

Does geography influence the treatment and outcomes of colorectal cancer? A population-based analysis

Background

The Canadian province of Manitoba covers a large geographical area but only has one major urban center, Winnipeg. We sought to determine if regional differences existed in the quality of colorectal cancer care in a publicly funded health care system.

Methods

This was a population-based historical cohort analysis of the treatment and outcomes of Manitobans diagnosed with colorectal cancer between 2004 and 2006. Administrative databases were utilized to assess quality of care using published quality indicators.

Results

A total of 2,086 patients were diagnosed with stage I to IV colorectal cancer and 42.2% lived outside of Winnipeg. Patients from North Manitoba had a lower odds of undergoing major surgery after controlling for other confounders (odds ratio (OR): 0.48, 95% confidence interval (CI): 0.26 to 0.90). No geographic differences existed in the quality measures of 30-day operative mortality, consultations with oncologists, surveillance colonoscopy, and 5-year survival. However, there was a trend towards lower survival in North Manitoba.

Conclusion

We found minimal differences by geography. However, overall compliance with quality measures is low and there are concerning trends in North Manitoba. This study is one of the few to evaluate population-based benchmarks for colorectal cancer therapy in Canada.

Evaluation of preoperative C-reactive protein aids in predicting poor survival in patients with curative colorectal cancer with poor lymph node assessment

Lymph node status is the most significant prognostic factor of colorectal cancer. However, there is a risk of disease understaging if the extent of lymph node assessment is sub-optimal. Preoperative C-reactive protein (CRP) is known to be a useful tool in predicting postoperative outcomes in patients with colorectal cancer. We retrospectively evaluated whether CRP adds to prognosis information in stage I-III colorectal cancer patients with poor lymph node assessment. In stages I-III, multivariate analysis revealed that CRP-positive status and advanced T-stage were factors that independently affected survival. In stage III, univariate analysis revealed that lymph node number retrieval and lymph node ratio were factors that affected survival. However, CRP positivity was the only independent factor for survival. CRP positivity did not predict poor prognosis in stage II or III patients with adequate lymph node retrieval. By contrast, the prognosis of CRP-positive patients was poorer than that of CRP-negative patients in stage II and III, with inadequate lymph node retrieval. CRP is an independent prognostic marker in patients with stage I-III, II or III colorectal cancer. The evaluation of CRP may provide useful information on prognosis in curative patients with an inadequate examination of lymph nodes.

Lymph node evaluation for resected colorectal cancer

SUMMARY The negative impact of regional lymph node metastasis on survival from nonmetastatic colorectal cancers is proportional to the number of nodes harvested. A thorough lymph node examination by the pathologist is essential for accurate staging. Recommendations in the USA and Europe stipulate that a minimum of 12–15 lymph nodes must be examined to accurately predict regional node negativity. The prognostic separation for stage III colorectal cancer obtained by the lymph node ratio is superior to that of the absolute number of positive nodes. The extent of mesenteric resection, pathologic technique, age or tumor location may influence lymph node yield. In the future, biological significance and clinical impact on outcome of very small amounts of tumor in regional nodes could help in staging patients. The current data are considered insufficient to recommend either the routine examination of multiple tissue levels of paraffin blocks or the use of special/ancillary techniques.

Elevated preoperative carcinoembryonic antigen (CEA) and Ki67 is predictor of decreased survival in IIA stage colon cancer

BACKGROUND

The present study was designed to investigate the prognostic factors of stage IIA (pT3N0M0) colon cancer.

METHODS

We retrospectively reviewed consecutive patients with stage IIA colon cancer treated with curative surgery alone from January 2004 to June 2008 in Peking University Cancer Hospital. Patient demographics, and clinical, histopathologic, and laboratory data were analyzed. Univariate and multivariate analyses were carried out to identify prognostic factors associated with 3-year disease-free survival (DFS).

RESULTS

For the 84 valid cases reviewed in this study, the 3-year DFS was 88.1 %. That for a group with elevated CEA was 77.1 % and for a group with a normal CEA level, it was 95.9 %, with statistical difference (p = 0.007). Multivariate analysis demonstrated that CEA level (p = 0.012, OR = 8.013, 1.573-40.817), expression of Ki67 (p = 0.099, OR = 3.298, 0.799-3.610), male gender (p = 0.024, OR = 7.212, 1.293-40.237), and anemia (p = 0.011, OR = 6.461, 1.537-27.151) were the independent prognostic factors for 3-year DFS. Stratified analysis revealed that an elevated CEA level combined with high expression of Ki67 was associated with poorer prognosis (3-year DFS 70 %).

CONCLUSIONS

An elevated preoperative serum level of CEA and high expression of Ki67 in tumor tissue were predictors of poor prognosis for patients with stage IIA colon cancer. These patients should therefore be considered candidates for receiving intensive surveillance. Future clinical trials using multicenter patient cohorts should be prospectively performed to evaluate whether these high-risk patients could benefit from adjuvant chemotherapy to improve prognosis.

Impact of age on the quality of lymphadenectomy for colorectal cancer

The aim of this study was to evaluate the impact of patient age on the number of lymph nodes dissected during surgery for colorectal cancer. Clinical and histopathological data of 231 consecutive patients who underwent elective surgery for colorectal cancer were reviewed retrospectively. Patients were divided into those aged ≤70 years and >70 years. Our findings suggest that patient's age influences the number of lymph nodes detected in surgical specimens; this number was lower in patients aged >70 years and decreased with further aging.

Does body mass index impact the number of LNs harvested and influence long-term survival rate in patients with stage III colon cancer?

BACKGROUND

The aim of this study is to evaluate whether different body mass index (BMI) values affect lymph node (LN) retrieval and whether such variations influence long-term survival in Asian patients.

METHOD

From January 1995 to July 2003, 645 stage III colon cancer patients were enrolled in our study. Patients were stratified into four groups: Obese (BMI ≧ 27 kg/m(2)), overweight (24 ≤ BMI < 27 kg/m(2)), normal (18.5 ≤ BMI < 24 kg/m(2)), and underweight (BMI < 18.5 kg/m(2)).

RESULTS

Mean BMI in the cohort was 23.3 kg/m(2). Mean number of LNs harvested was 23.1, 19.5, 19.8 and 28.1 in the normal, overweight, obese and underweight groups, respectively. There was a significant difference in the mean number of LNs harvested when comparing the overweight and underweight groups to the normal group (p = 0.013 and p = 0.04, respectively). Females were overrepresented in the underweight group (p = 0.011), and patients who had proximal colon cancers were more frequently underweight (p = 0.018). The mean number of LNs harvested varied by cases of right hemicolectomy (p = 0.009) and proximal cancer location (p = 0.009) for different BMI groups. Multivariate analysis showed that underweight, proximal colon cancer, well- or moderately differentiated adenocarcinoma and stage IIIC cancer were significant variables for adequate LN recovery. BMI was not significantly associated with relapse-free survival (p = 0.523) or overall survival (p = 0.127).

CONCLUSION

BMI is associated with LN harvest but is not an independent variable in stage III colon cancer survival.

The relationship of lymph node evaluation and colorectal cancer survival after curative resection: a multi-institutional study

BACKGROUND

Esophagectomy remains the mainstay treatment for clinical T1bN0M0 esophageal cancer because pathologic lymph node metastases in these patients are not negligible. Recently, chemoradiotherapy (CRT), which can preserve the esophagus, has been reported to be a promising therapeutic alternative to esophagectomy. However, to our knowledge, no comparative studies of esophagectomy and CRT have been reported in clinical T1bN0M0 esophageal cancer.

METHODS

A total of 173 patients with clinical T1bN0M0 squamous cell carcinoma of the thoracic esophagus were enrolled in this study, 102 of whom were treated with radical esophagectomy (S group) and 71 with definitive CRT (CRT group). Treatment results of both groups were retrospectively compared.

RESULTS

No statistically significant difference was found in overall survival, but the S group displayed significantly better progression-free survival than the CRT group. Disease recurrence was observed in 12 S group patients and 20 CRT group patients. The incidence of distant recurrence was similar, while local recurrence and lymph node recurrence were significantly more frequent in the CRT group. In the S group, 20 patients had pathologic lymph node metastasis. The progression-free survival of patients with pathologic lymph node metastasis did not differ from those without nodal metastasis. In the CRT group, local recurrence could be controlled by salvage esophagectomy, but treatment results of lymph node recurrence were poor; only 4 of 12 patients with lymph node recurrences were cured.

CONCLUSIONS

Selection of patients at high risk of pathologic lymph node metastasis is essential when formulating treatment decisions for clinical T1bN0M0 esophageal cancers.

Better retrieval of lymph nodes in colorectal resection specimens by pathologists' assistants

BACKGROUND

Errors in surgical pathology are partly due to the increasing workload of pathologists. To reduce this workload, 'pathologists' assistants' (PAs) have been trained to take over some of the pathologists' recurrent tasks. One of these tasks is the precise examination of ≥10 lymph nodes (LNs), which is of paramount importance to reduce the risk of understaging of colorectal cancer patients.

AIMS

To evaluate the role of PAs in harvesting LNs in colorectal resection specimens and, by doing so, in improving patient safety.

METHODS

LN harvest was retrospectively reviewed in 557 pathology reports on colorectal resection specimens collected in two Dutch hospitals from 2008 until 2011.

RESULTS

PAs sampled ≥10 LNs in significantly more cases than pathologists did (83.2% vs 60.9% in hospital A and 79.2% vs 67.6% in hospital B) and recovered on average significantly more LNs than pathologists did (18.5 vs 12.2 in hospital A and 16.6 vs 13.2 in hospital B). PAs harvested a significantly higher percentage of LNs <5 mm than pathologists did (64.2% vs 53.7%). The percentages of colon cancer patients eligible for adjuvant chemotherapy due to inadequate LN sampling alone were significantly higher for cases dissected by pathologists than for those dissected by PAs (17.3% vs 1.1% in hospital A and 13.1% vs 3.4% in hospital B) CONCLUSIONS: PAs contribute to patient safety since they recover more and, in particular, smaller LNs from colorectal resection specimens than pathologists do. Moreover, they help to reduce costs and morbidity by reducing the number of patients eligible for adjuvant chemotherapy due to inadequate LN sampling alone.

Application of the Western-based adjuvant online model to Korean colon cancer patients; a single institution experience

Background

Adjuvant Online (AOL) is web-accessible risk-assessment model that predicts the mortality and the benefits of adjuvant therapy (http://www.newadjuvantonline.com). AOL has never been validated for Asian colon cancer patients.

Methods

Using the Yonsei Tumor Registry database, patients who were treated within the Yonsei University Health System between 1990 and 2005 for T1-4, N0-2, and M0 colon cancer were included in the calculations for survival. Observed and predicted 5-year overall survival was compared for each patient.

Results

The median age of the study population of 1431 patients was 60 years (range, 15–87 years), and the median follow-up duration was 7.9 years (range, 0.06–19.8 years). The predicted 5-year overall survival rate (77.7%) and observed survival (79.5%) was not statistically different (95% Confidential interval, 76.3–81.5) in all patients. Predicted outcomes were within 95% confidential interval of observed survival in both stage II and III disease, including most demographic and pathologic subgroups. Moreover, AOL more accurately predicted OS for patients with stage II than stage III.

Conclusions

AOL tended to offer reliable prediction for 5-year overall survival and could be used as a decision making tool for adjuvant treatment in Korean colon cancer patients whose prognosis is similar to other Asian patients.

Time-dependent trends in lymph node yield and impact on adjuvant therapy decisions in colon cancer surgery: an international multi-institutional study

BACKGROUND

Lymph node yield (LNY) and accuracy of nodal assessment are critical to staging and treatment planning in colon cancer (CC). A nationally agreed upon 12-node minimum is a quality standard in CC. The impact of this quality measure on LNY and impact on therapeutic decisions are evaluated in two international, multi-center, prospective trials comprising a well-characterized cohort assembled over 8 years (2001-2009) with long-term follow-up.

HYPOTHESIS

Quality adherence through increased LNY improves staging accuracy and impacts adjuvant therapy decisions.

METHODS

Retrospective analysis of prospective data to assess time-dependent LNY, the dependent variable in multivariate linear regression analysis adjusted for age, gender, body-mass-index (BMI), tumor size/stage/grade, anatomic location and surgery date.

RESULTS

Two-hundred-forty-five patients with non-metastatic CC, median age 70 years, BMI 26 kg/m(2), tumor size 4.0 cm, and LNY 17 nodes were studied. Seventy-two percent had T3 (70 %)/T4 (2 %) tumors. Adherence to the 12-node minimum was 70 %(2001-2002), 81 % (2003-2004), 90 % (2005-2006), 94 % (2007-2008). LNY significantly increased over time (Median LNY: 2001-2004 = 15 vs. 2005-2008 = 17; P < 0.001) on multivariate analysis controlling for tumor size (P < 0.001), and right-sided tumor location (P < 0.001). Adjuvant therapy administration and indication for chemotherapy according to LNY (<12 vs. 12 + LNs = 33 % vs. 39 %; P = 0.48) and time period (2001-2004 vs. 2005-2008 = 39 % vs. 37 %; P = 0.89) remained unchanged.

CONCLUSIONS

Despite the independent predictors of nodal yield (tumor location and size), year of study still had a significant impact on nodal yield. Despite increased quality adherence and LNY over time, there appears to be a delayed impact on adjuvant therapy decisions once quality standard adherence takes effect.

Application of Petersen Index score for Dukes'B colorectal cancer in a population of 103 consecutive resected patients

Dukes' B colorectal cancer (CRC) represents a wide spectrum of disease from early penetration through the bowel wall to aggressive and extensive tumours with extramural venous spread and involvement of the serosa, surgical margins or adjacent organs. Among Dukes' B cancers, Petersen Index allows stratification to identify those patients whom chemotherapy may benefit. One hundred and three resected patients with CRC Dukes' B were included prospectively in a database and considered in the present study. According to Petersen Index, a score (from 0 to 4) for each patient was calculated on the basis of peritoneal and margin involvement, venous invasion and tumour perforation. Twenty-four out of 103 tumours were located in the rectum and 79 in the colon. According to PI score 59 patients had a score of 0, 30 of 1 and 14 of ≥2. The overall R0 resection was achieved in 95.1 % of cases and the majority of patients with PI score of ≥2 were R1-2. The mean of harvested lymph nodes was 23.6 (±10.7) with no difference according to the PI score. Patients in the high-risk group had a worse 5-year survival rate (66.3 %) compared with the other group (P < 0.009). Multivariate analysis validated the PI score as a significant independent factor (P = 0.017). Both high-quality pathology and adequate harvested lymph nodes are needed for a proper staging. Even though the influence of PI score on survival is confirmed as it leads to an additional rate of colorectal cancer being considered for adjuvant therapy, we underline that a comparison with additional clinical and histological prognostic factors should be needed.

High lymph node yield is related to microsatellite instability in colon cancer

BACKGROUND

Lymph node (LN) yield in colon cancer resection specimens is an important indicator of treatment quality and has especially in early-stage patients therapeutic implications. However, underlying disease mechanisms, such as microsatellite instability (MSI), may also influence LN yield, as MSI tumors are known to exhibit more prominent lymphocytic antitumor reactions. The aim of the present study was to investigate the association of LN yield, MSI status, and recurrence rate in colon cancer.

METHODS

Clinicopathological data and tumor samples were collected from 332 stage II and III colon cancer patients. DNA was isolated and PCR-based MSI analysis performed. LN yield was defined as "high" when 10 or more LNs were retrieved and "low" in case of fewer than 10 LNs.

RESULTS

Tumors with high LN yield were significantly associated with the MSI phenotype (high LN yield: 26.3% MSI tumors vs low LN yield: 15.1% MSI tumors; P=.01), mainly in stage III disease. Stage II patients with high LN yield had a lower recurrence rate compared with those with low LN yield. Patients with MSI tumors tended to develop fewer recurrences compared with those with MSS tumors, mainly in stage II disease.

CONCLUSIONS

In the present study, high LN yield was associated with MSI tumors, mainly in stage III patients. Besides adequate surgery and pathology, high LN yield is possibly a feature caused by biologic behavior of MSI tumors.

Improved lymph node harvest from resected colon cancer specimens did not cause upstaging from TNM stage II to III

BACKGROUND

The number of lymph nodes retrieved and examined from a resected colon cancer specimen may be crucial for correct staging. We examined if efforts to increase the lymph node harvest to more than 12 lymph nodes per specimen would upstage some patients from TNM stage II to III.

METHODS

Three hospitals compared results from 2000 with those of 2007 in 421 resected patients with stage II and III colon cancer. Hospital A endeavored to improve the surgical procedure while the pathologists enhanced the quality of lymph node sampling. Hospital B did not make any marked changes, while hospital C introduced the GEWF lymph node solvent (glacial acetic acid, ethanol, distilled water, and formaldehyde) in their pathology method.

RESULTS

In 2000, 12 or more lymph nodes were harvested in 39.6, 45.0, and 21.1% of the specimens from the three hospitals, while the figures for 2007 were 85.7, 42.0, and 90.3%, respectively. The significant increase in lymph node harvest in two of the hospitals in 2007 compared to 2000 (p < 0.001) did not affect the share of patients with stage III in 2007 (38.7%) compared to 2000 (44.1%) (p = 0.260). The number of positive lymph nodes and the lymph node ratio (LNR) decreased from 2000 to 2007. A lymph node yield of 12 or more was not associated with an increased probability of positive lymph nodes in a multivariable logistic regression analysis.

CONCLUSION

More radical surgery and dedicated pathologists and the use of the GEWF solvent significantly increased the lymph node yield but did not upstage patients from TNM stage II to III.

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.

Microsatellite instability status does not predict total lymph node or negative lymph node retrieval in stage III colon cancer

The relationship between higher total lymph node resection number in colorectal cancer resection specimens and improved overall survival is well known. Recent studies describe an association between a high rate of microsatellite instability and a high total lymph node count in colorectal cancer. Higher lymph node retrieval may potentially explain the improved survival seen in cancers with microsatellite instability. We investigate whether these associations can be validated in a cohort of American Joint Committee on Cancer stage III colon cancers. Medical records from 200 cases of stage III colon cancer resection specimens were reviewed, and sufficient tissue was available for 168. Expression of DNA mismatch repair proteins was determined by immunohistochemistry, and microsatellite status, by polymerase chain reaction. The mean total lymph node count in cases with microsatellite instability versus microsatellite stable tumors (15.9 versus 16.9; P = .664) and the mean number of negative lymph nodes in each respective category (12.2 versus 13.6; P = .522) were not significantly different. There was no difference between microsatellite stable cases and cases with microsatellite instability when total lymph node counts (P = .953) or negative lymph node counts (P = .381) were analyzed with respect to percentage of cases above and below the medians. This cohort of stage III colon cancers does not support a significant relationship between microsatellite status and a higher retrieval of total or negative lymph nodes. Although microsatellite instability is associated with improved overall survival in our cohort (P = .026), the reason for this does not appear to be related to higher numbers of retrieved lymph nodes.

Lymph node harvest in colon and rectal cancer: Current considerations

The prognostic significance of identifying lymph node (LN) metastases following surgical resection for colon and rectal cancer is well recognized and is reflected in accurate staging of the disease. An established body of evidence exists, demonstrating an association between a higher total LN count and improved survival, particularly for node negative colon cancer. In node positive disease, however, the lymph node ratios may represent a better prognostic indicator, although the impact of this on clinical treatment has yet to be universally established. By extension, strategies to increase surgical node harvest and/or laboratory methods to increase LN yield seem logical and might improve cancer staging. However, debate prevails as to whether or not these extrapolations are clinically relevant, particularly when very high LN counts are sought. Current guidelines recommend a minimum of 12 nodes harvested as the standard of care, yet the evidence for such is questionable as it is unclear whether an increasing the LN count results in improved survival. Findings from modern treatments, including down-staging in rectal cancer using pre-operative chemoradiotherapy, paradoxically suggest that lower LN count, or indeed complete absence of LNs, are associated with improved survival; implying that using a specific number of LNs harvested as a measure of surgical quality is not always appropriate. The pursuit of a sufficient LN harvest represents good clinical practice; however, recent evidence shows that the exhaustive searching for very high LN yields may be unnecessary and has little influence on modern approaches to treatment.

Comparative analysis of various prognostic nodal factors, adjuvant chemotherapy and survival among stage III colon cancer patients over 65 years: an analysis using surveillance, epidemiology and end results (SEER)-Medicare data

AIM

The prognostic effects of chemotherapy and various lymph node measures [positive nodes, total node count and the positive lymph node ratio (PLNR)] have been established. It is unknown whether the cancer-specific survival benefit of chemotherapy differs across these nodal prognostic categories.

METHOD

This retrospective analysis of linked Surveillance, Epidemiology and End Results (SEER) data and Medicare data (SEER-Medicare)included patients ≥ 65 years of age with a diagnosis of stage III colon cancer between 1997 and 2002. We grouped patients according to the number of positive nodes (N1 and N2), total node count (≥ 12 and < 12 total nodes) and PLNR (below the 75th percentile and at least at the 75th percentile of the PLNR). The end point was colon cancer-specific mortality.

RESULTS

Fifty-one per cent (3701) of the 7263 patients received adjuvant therapy during the time period 1997-2002. The mean (standard deviation) number of total nodes examined was 13 (9) and the number of positive nodes identified was 3 (3). Patients with N2 disease, < 12 total nodes examined and a high PLNR had a worse survival at 2, 3 and 5 years following colectomy. Utilization of chemotherapy demonstrated a colon cancer-specific survival benefit (hazard ratio at median follow up = 0.7; P < 0.001) that was consistent and statistically significant across the three nodal prognostic categories examined.

CONCLUSION

The benefit of chemotherapy did not vary based on N stage, total node count or PLNR. The results favour a broad-based approach towards increasing the chemotherapy treatment rates in stage III patients of ≥ 65 years of age, rather than an approach that targets clinical subgroups.

Salvage colectomy for endoscopically removed malignant colon polyps: is it possible to determine the optimal number of lymph nodes that need to be harvested?

AIM

The total number of lymph nodes examined after salvage colectomy for endoscopically removed malignant polyps was evaluated and an attempt was made to determine whether there was an optimal number of lymph nodes that should be harvested.

METHOD

From 2000 to 2009, 531 patients underwent segmental resection for non-metastatic colon cancer. Of these, 22 underwent a salvage colectomy for an endoscopically removed malignant polyp, the main indication for which was a resection margin of < 1 mm. The surgical procedure was identical to that used for all colon cancers.

RESULTS

The mean number of lymph nodes examined was 11.6 ± 7.6 for the 22 patients with an endoscopically removed malignant polyp and 26.2 ± 13.9 for the remaining 509 patients (P = 0.0006). Fewer than 12 lymph nodes were examined in 62 (12%) of the 509 patients and in 13 (59%) of the 22 patients with an endoscopically removed malignant polyp (P < 0.0001). In the group of 22 patients who underwent a salvage colectomy, the total number of lymph nodes examined ranged from 2 to 33. At a mean follow up of 41 ± 15.6 months, no local or distant recurrence was observed in the 22 patients.

CONCLUSION

The total number of lymph nodes examined after colectomy for endoscopically removed malignant polyps varies and is less than the recommended number of 12 in most cases: this does not appear to have long-term prognostic significance. There is no biological reason to explain this clinical observation.

Long-term survival results of surgery alone versus surgery plus UFT (Uracil and Tegafur)-based adjuvant therapy in patients with stage II colon cancer

BACKGROUND

It is well established that adjuvant chemotherapy with 5-fluouracil and leucovorin (5-FU/LV) improves survival for patients with resected colon cancer; however, the benefits of oral uracil and tegafur (UFT) chemotherapy in these patients are still uncertain.

METHODS

All patients enrolled in this retrospective study with stage II disease who were treated with surgery or surgery plus UFT were examined to determine the overall survival and disease-free interval. Time-to-event by treatment group was examined using Kaplan-Meier estimates and multivariable Cox regression analysis.

RESULTS

There were 456 eligible patients-217 (47.5%) patients had surgery and 239 (52.5%) patients had surgery plus UFT. In patients aged ≧65 years, deeper tumor depth and fewer nodes observed were associated with lower survival. The 5-year survival rate was 84.2% in the surgery group and 89.1% in the surgery plus UFT group (P = 0.006). Treatment with UFT after surgery was associated with improved outcome compared with surgery alone: overall survival (HR = 0.611, P = 0.018) and disease-free survival (HR = 0.590, P = 0.032).

CONCLUSIONS

Oral fluoropyrimidines improve the disease-free rate and the overall survival of patients after resection of stage II colon cancer. These observations support the use of these agents following surgery as it provides a benefit over surgery alone.

Prognostic factors for survival after curative resection of Dukes' B colonic cancer

AIM

Data on the prognostic factors for survival in patients with locally advanced, node-negative colon cancer are limited. This study aimed to determine which factors might predict survival in patients with Dukes' B (T3 or T4, N0) colon cancer.

METHOD

One hundred and eighty (93 male; median age 75 [range, 38-96] years) consecutive patients who had resection of a primary Dukes' B (on final histopathological analysis) colonic cancer between 1998 and 2003 were studied. No patient received neoadjuvant chemotherapy. Multivariate Cox regression modelling was used to assess the prognostic value of variables. Median follow up was 85 (60-125) months.

RESULTS

Thirteen (7%) patients had a perforation at presentation. The median distance from tumour to the nearest longitudinal resection margin was 6 (0.3-27) cm. One hundred and twenty-four (69%) patients had a lymph node yield of 12 or more nodes. Actual 5-year survival was 59%. On multivariate regression analysis, tumour perforation (perforation vs no perforation, 5-year survival, 23%vs 61%; hazard ratio (HR), 3.7; 95% confidence interval (CI), 1.6-8.4; P = 0.002), tumour-to-margin distance (< 5 cm vs ≥ 5 cm, 48%vs 65%; HR, 1.7; 95% CI, 1.1-2.7; P = 0.039) and older age (≥ 75 years vs < 75 years, 45%vs 72%; HR, 3; 95% CI, 1.8-5; P < 0.001) were independent significant variables.

CONCLUSION

A lymph node yield of 12 or more nodes is not a significant prognostic factor for survival after resection of Dukes' B colonic cancer. Patients with tumour perforation or limited resection have worse prognosis.

Lymph node retrieval from colorectal resection specimens for adenocarcinoma: is it worth the extra effort to find at least 12 nodes?

AIM

Retrieval of a minimum of 12 lymph nodes has been recommended for adequately staging a node-negative colorectal cancer (CRC). This study was designed to determine whether the extra effort expended to recover more nodes for histological examination improves the accuracy of staging.

METHOD

Pathology reports, histology worklists, and haematoxylin and eosin (H&E) slides of 334 CRC resections were reviewed. The total number of nodes and the number of positive nodes harvested from the first and additional searches were recorded for each patient.

RESULTS

The number of nodes retrieved from the 334 resections at the first search ranged from 0 to 57 (mean: 14.2), with 195 patients (58.4%) having ≥ 12 nodes. Nodal metastasis was found in 122 (33.6%) patients. Additional searches were performed on 115 patients, including 91 with < 12 nodes. The mean number of nodes recovered in these patients increased significantly, from 9.1 to 14.2 (P < 0.0001). Thirty-one additional positive nodes were found in 19 patients following the further searches, and 12 (63.2%) of the 19 patients were upstaged using the American Joint Committee on Cancer (AJCC) 6th edition (2002) staging criteria. The total number of nodes retrieved and the probability of obtaining ≥ 12 nodes correlated negatively with the age of the patient and the rectosigmoid location of the tumours, but positively with the specimen length, the pericolic/perirectal fat width, female gender and tumour size.

CONCLUSION

Although a number of patient and specimen variables influence the number of lymph nodes retrieved, our observations support the importance of a thorough search for nodes in CRC specimens in order to achieve accurate tumour staging.

Number of lymph nodes retrieved is an important determinant of survival of patients with stage II and stage III colorectal cancer

OBJECTIVE

The number of lymph nodes retrieved is recognized to be a prognostic factor of Stage II colorectal cancer. However, the prognostic significance of the number of lymph nodes retrieved in Stage III colorectal cancer remains controversial.

METHODS

The relationship between the number of lymph nodes retrieved and clinical and pathological factors, and significance of the number of lymph nodes retrieved for prognosis of Stage II and III colorectal cancer were investigated. A total of 16 865 patients with T3/T4 colorectal cancer who had R0 resection were analysed.

RESULTS

The arithmetic mean of the number of lymph nodes retrieved of all cases was 20.0. The number of lymph nodes retrieved were varied according to several clinical and pathological variables with significant difference, and the greater difference was observed in scope of nodal dissection. Survival of Stages II and III was significantly associated with the number of lymph nodes retrieved. Five-year overall survival of the patients with ≤ 9 of the number of lymph nodes retrieved and those with >27 differed by 6.4% for Stage II colon cancer, 8.8% for Stage III colon cancer, 12.5% for Stage II rectal cancer and 10.6% for Stage III rectal cancer. With one increase in the number of lymph nodes retrieved, the mortality risk was decreased by 2.1% for Stage II and by 0.8% for Stage III, respectively. The cut-off point of the number of lymph nodes retrieved was not obtained.

CONCLUSIONS

The number of lymph nodes retrieved was shown to be an important prognostic variable not only in Stage II but also in Stage III colorectal cancer, and it was most prominently determined by the scope of nodal dissection. A cut-off value for the number of lymph nodes retrieved was not found, and it is necessary to carry out appropriate nodal dissection and examine as many lymph nodes as possible.