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

Staging error does not explain the relationship between the number of lymph nodes in a colon cancer specimen and survival

BACKGROUND

Survival in colon cancer is greater in those patients who have more lymph nodes identified at resection and may be due to stage migration, confounding by treatment, social, or clinical characteristics. Identifying factor(s) responsible for the effect may represent an opportunity to improve quality of care for patients with colon cancer by increasing node counts in specimens.

METHODS

Cox proportional hazards models were created to analyze survival of 11,399 patients with stage I-III colon cancer from the Surveillance, Epidemiology and End Results (SEER)-Medicare database. The primary predictor variable was the number of lymph nodes identified. The models allowed adjustment for patient factors, use of chemotherapy, surgical specialty, and the average number of nodes identified by surgeon and hospital pathologist.

RESULTS

The number of nodes identified was related to survival. Compared to those with less than 7 nodes, patients with 7 to 11 nodes had a 13% lesser risk of death (hazard ratio [HR], 0.87; 95% confidence interval [CI], 0.76-0.99; P = .037). Patients with more than 12 nodes had a 17% lesser risk (HR, 0.83; 95% CI, 0.73-0.95; P = .005). Adjusting for selected patient demographic characteristics, receipt of chemotherapy, surgical specialty, and the average number of nodes identified per specimen by the surgeon or hospital did not significantly alter the relationship between number of nodes and survival.

CONCLUSION

These findings argue against understaging or confounding as the explanation for the inferior survival observed in patients with fewer nodes identified. National initiatives to increase the number of nodes identified in colon cancer specimens may not improve substantially the cancer-specific outcomes.

Nodal staging score: a tool to assess adequate staging of node-negative colon cancer

PURPOSE

Adequate nodal staging of colon cancer has been defined as pathologic examination of at least 12 lymph nodes. We sought to refine this definition by quantifying the likelihood that a pathologically node-negative patient has, indeed, no positive nodes.

PATIENTS AND METHODS

Patients with stage I-III adenocarcinoma of the colon between 1994 and 2005 and had at least one lymph node pathologically examined were identified from the Surveillance, Epidemiology and End Results (SEER) database (n = 131,953). We estimated the sensitivity of the pathologic staging of locoregional spread using a beta-binomial model and developed the nodal staging score (NSS), which is the probability that a patient is correctly staged as node negative. NSS is a function of T stage and the number of examined nodes.

RESULTS

The probability of missing a positive node that is in fact truly present is 29.7% if five nodes are examined, 20.0% if eight are examined, and drops to 13.6% for 12 nodes are examined. An NSS of 90% can be achieved by examining a single node for T1 and four nodes for T2 tumors. To maintain similar levels of NSS for T3, 13 nodes need to be examined and for T4 lesions, 21 nodes need to be examined. Graphical and tabular tools are provided to facilitate calculation of NSS and treatment decision making in practice.

CONCLUSION

The minimum number of examined nodes for adequate staging depends on the T stage. The score we developed indicates the adequacy of nodal staging for patients with no positive nodes and can assist clinical decision making in the patient without nodal metastasis.

Metastatic lymph node ratio is a more precise predictor of prognosis than number of lymph node metastases in stage III colon cancer

OBJECTIVE

The objective of this study is to assess the value of metastatic lymph node ratio (LNR) in predicting disease-free survival (DFS) in patients with stage III adenocarcinoma of the colon.

MATERIALS AND METHODS

From 1995 to 2003 inclusively, a total of 624 patients featuring stage III adenocarcinoma of the colon underwent curative resection. Of the 624 patients, an adequate number of lymph nodes (n > or = 12) had been harvested in 490 patients. These patients were stratified into LNR groups 1 (LNR < or = 0.4), 2 (0.4 < LNR < or = 0.7), and 3 (LNR > 0.7). Kaplan-Meier survival curve and log-rank test were used to evaluate the prognostic value of LNR. A Cox regression model was used for multivariate analyses.

RESULTS

The 5-year DFS rate was 66.7% for patients with LNR1, 35.1% for those with LNR2, and 0% for patients with LNR3 (p < 0.0001). In T3/4LNR1 patients (n = 411), there was no difference in survival between those with N1 stage and those with N2 stage. Cox proportional hazards regression analysis revealed that N stage (number of positive lymph nodes) was not a significant factor when LNR was taken into consideration.

CONCLUSIONS

LNR is a more precise predictor of 5-year DFS than number of positive lymph nodes (N stage) in patients with stage III colon cancer.

Lymphocytic reaction to colorectal cancer is associated with longer survival, independent of lymph node count, microsatellite instability, and CpG island methylator phenotype

PURPOSE

Host immune response to tumor may be an important prognostic factor for colon cancer patients. However, little is known on prognostic significance of histopathologic lymphoid reaction to tumor, independent of the number of lymph nodes examined and tumoral molecular alterations, including microsatellite instability (MSI) and the CpG island methylator phenotype (CIMP), both of which are associated with lymphocytic reaction and clinical outcome.

EXPERIMENTAL DESIGN

Using 843 colorectal cancer patients in two independent prospective cohorts, we examined patient prognosis in relation to four components of lymphocytic reaction (i.e., Crohn's-like reaction, peritumoral reaction, intratumoral periglandular reaction, and tumor-infiltrating lymphocytes) and overall lymphocytic score (0-12). CIMP was determined using eight markers including CACNA1G, CDKN2A (p16), CRABP1, IGF2, MLH1, NEUROG1, RUNX3, and SOCS1. Cox proportional hazard models computed hazard ratio for mortality, adjusted for covariates including tumor stage, body mass index, lymph node count, KRAS, BRAF, p53, cyclooxygenase-2 (PTGS2), MSI, CIMP, and LINE-1 methylation.

RESULTS

Increasing overall lymphocytic reaction score including tumor-infiltrating lymphocytes was associated with a significant improvement in colorectal cancer-specific and overall survival (log-rank P < 0.003). These findings remained significant (adjusted hazard ratio estimates, 0.49-0.71; P(trend) < 0.009) in multivariate models that adjusted for covariates, including body mass index, MSI, CIMP, LINE-1 hypomethylation, and cyclooxygenase-2. The beneficial effect of tumoral lymphocytic reaction was consistent across strata of clinical, pathologic, and molecular characteristics.

CONCLUSIONS

Lymphocytic reactions to tumor were associated with improved prognosis among colorectal cancer patients, independent of lymph node count and other clinical, pathologic, and molecular characteristics.

The assessment of prognosis of surgically resected oesophageal cancer is dependent on the number of lymph nodes examined pathologically

AIMS

The prognosis in surgically resected oesophageal carcinoma (OC) is dependent on the number of regional lymph nodes (LN) involved, but no guidance exists on how many LNs should be examined histopathologically to give a reliable pN status. The aim of this study was to determine whether the number of LNs examined after OC resection has a significant effect on the assessment of prognosis.

METHODS AND RESULTS

Routinely generated pathology reports from 237 consecutive patients undergoing oesophagectomy for OC were examined and analysed in relation to survival. The main outcome measure was survival from date of diagnosis. Lymph node count (LNC) correlated strongly with survival; a plateau was reached after a count of 10. Median and 2-year survival was 30 months and 42%, respectively, if <10 nodes were examined (n = 88), compared with 51 months and 61% if >10 nodes were examined (P = 0.005). This effect was greatest in pN0 cases. The prognostic value of the absolute number of LN metastases (<4) and LN ratio (<0.4) was strongly dependent on a LNC of >10.

CONCLUSIONS

These results demonstrate the importance of careful pathological examination and lymph node retrieval after OC resection. At least 10 nodes should be examined to designate an OC as pN0.

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

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

Factors affecting number of lymph nodes harvested in colorectal cancer

BACKGROUND

Lymph node involvement is a highly important prognostic factor in colorectal cancer staging. Examination of a minimum of 12 nodes is recommended for accurate staging. The purpose of this study was to identify factors affecting the number of lymph nodes harvested in colorectal cancer specimens.

MATERIALS AND METHODS

Retrospective review of all patients undergoing colectomy for colorectal cancer at our VA hospital from 2002 to 2007 was done. Statistical analysis was done using univariate as well as multivariate analysis. One hundred eighty-three patients were analyzed.

RESULTS

Average number of nodes retrieved was 14.9 with 92 (51%) containing fewer than 12 lymph nodes. Median number of nodes was 11. The only two factors found to have an effect on nodes harvested were pathologist P<0.05 and surgeon experience P=0.01. Factors not found to have an impact on number of nodes harvested were age of patient, previous operation, T stage of tumor, type of colectomy, bowel prep, laparoscopic versus open technique, or BMI. Multivariate analysis confirmed pathologist and surgeon experience as independent factors associated with number of nodes retrieved P<0.05.

CONCLUSIONS

Operating surgeon and examining pathologist were the only factors found to have a significant impact on number of nodes harvested. Meticulous dissection both in and outside of the operating room are indicated.

Lymph node evaluation of colon cancer and its association with improved staging and survival in the Department of Defense Health Care System

BACKGROUND

Improved survival is associated with an increased number of lymph nodes (LNs) examined. The aim of this study was to assess whether the examination of >or=12 LNs is associated with more accurate colon cancer staging.

METHODS

We queried the Department of Defense Automated Central Tumor Registry database for stage I-III colon cancer patients. Logistic regression analysis was performed to determine whether the examination of >or=12 LNs is associated with increased rates of LN-positive colon cancer. Kaplan-Meier and Cox proportional hazard analysis was performed to evaluate the effect of number of LNs examined on survival.

RESULTS

The rate of LN-positive colon cancer is significantly higher with increasing number of LNs examined (1-3 LNs examined: 31% vs. >12 LNs examined: 41%, P<.001). Logistic regression analysis adjusting for patients, tumor, and hospital characteristics showed that examination of >or=12 LNs is associated with a >30% increase in detecting a LN-positive colon cancer (odds ratio, 1.350; 95% confidence interval, 1.175-1.511). The evaluation of >or=12 LNs is associated with improved survival in LN-negative colon cancer patients (P<.001).

CONCLUSIONS

Our study demonstrates that the proportion of LN-positive colon cancer is far higher when >or=12 LNs are examined. Examination of >or=12 LNs may improve staging accuracy and outcome with optimal use of systemic chemotherapy.

Prognostic significance of peritoneal tumour cells identified at surgery for colorectal cancer

BACKGROUND

The prognostic significance of intraperitoneal tumour cells (IPCs) in colorectal cancer is not clear. This study aimed to determine whether detection of IPCs could be used a prognostic marker for selecting patients at high risk of recurrence.

METHODS

The study included 226 patients with colorectal cancer who underwent elective resection. Clinical variables, including the presence of IPCs, were analysed for their prognostic significance.

RESULTS

Thirty-three patients (14.6 per cent) were positive for IPCs. Univariable analysis indicated that the presence of IPCs was a significant prognostic factor in patients with stage III colorectal cancer; the 5-year disease-specific survival rate was 14 per cent in IPC-positive patients versus 79 per cent in those without IPCs (P < 0.001). Multivariable analysis showed that IPC positivity was the most robust prognostic factor in stage III disease (hazard ratio 2.2; P = 0.003), whereas nodal category (N1 or N2) showed no significant association with prognosis. In addition, IPCs were associated with haematogenous recurrence (P = 0.004) rather than peritoneal or local recurrence (P = 0.077) in patients with stage III disease.

CONCLUSION

The presence of IPCs is a significant prognostic factor in patients with stage III colorectal cancer.

Improving lymph node detection in colon cancer in community hospitals and their pathology department in southern Netherlands

AIM

The aim was to investigate whether a set of measures directed at increasing lymph node (LN) detection among colon cancer patients led to clinically relevant changes in LN detection rate.

METHODS

Data of all patients with curative colon cancer (pT(any) N(any) M0) diagnosed in 1999-2007 whose resection specimens were evaluated by the Institute for Pathology and Medical Microbiology in Eindhoven (n=1501) were included. Feedback to specialists, increased fixation time, and ex-vivo injection of the specimen with Patent blue V dye were used to increase LN detection rate. Trends in the proportion of patients with insufficient LNs examined were investigated; moreover, the Patent blue-stained patients (n=86) were compared with a group of unstained patients (n=84). Based on the decrease in the proportion of high-risk node-negative patients, a calculation of chemotherapy-related costs saved was made.

RESULTS

The proportion of patients with <12 LNs examined decreased from 87% in 1999 to 48% in 2007 (p(trend)<0.0001). In the stained group this was 37%, versus 56% for the unstained group (p=0.010). In 1999, 79% of stage II patients were high-risk compared to 55% in 2007, which translates to a saving of almost 1,000,000 euro based on 92 stage II patients diagnosed in 2007.

CONCLUSION

A diverse set of measures increased the number of examined lymph nodes among patients with colon cancer. Large savings can be made due to the reduced proportion of high-risk node-negative patients who would otherwise have received adjuvant chemotherapy.

Identification of 12 or more lymph nodes in resected colon cancer specimens as an indicator of quality performance

BACKGROUND

: Identification of > or =12 lymph nodes in resected colon cancer specimens has been endorsed as a quality indicator.

METHODS

: The Hoag Hospital cancer registry was used to identify patients diagnosed with colon cancer. The proportion of colon cancer specimens for which > or =12 lymph nodes were identified was determined by anatomic location, stage of disease, patient age, and operating surgeon. Survival was correlated with stage and with whether > or =12 lymph nodes were identified.

RESULTS

: Pathology procedural changes in 1998 were associated with an increase in the average number of lymph nodes identified from 8.0 to 14.5 (P < .0001); therefore, analysis was limited to 574 patients who underwent surgical resection of colon adenocarcinoma during 1998 to 2005. Identification of > or =12 lymph nodes varied from 57% to 83% by 7 anatomic locations (P < .0001), from 65% to 75% by 5 age cohorts (P = .027), from 59% to 73% by 4 general stages of disease (P = .004), and from 53% to 80% among 12 surgeons who performed at least 17 resections (P = .014). The proportion of resections in which > or =12 lymph nodes were identified was higher for 3 colorectal fellowship-trained surgeons compared with the other 9 surgeons (77% vs 63%, P = .0007), and with 30 surgeons who each performed <10 resections (77% vs 51%, P < .0001). Identification of > or =12 lymph nodes was associated with better survival for patients with stage I (P = .016) and stage II (P = .021) disease.

CONCLUSIONS

: Anatomic location, colorectal surgical training, and case volume were strongly correlated with the number of lymph nodes identified. Cancer 2009. (c) 2009 American Cancer Society.

Does a laparoscopic approach affect the number of lymph nodes harvested during curative surgery for colorectal cancer?

BACKGROUND

This study aimed to assess the number of lymph nodes (LNs) harvested after laparoscopic and open colorectal cancer resections.

METHODS

Between 1996 and 2007, 431 colorectal cancer patients underwent laparoscopic resection. During the periods of 1996-1997, 2002-2003, and 2006-2007, 243 patients undergoing laparoscopic colorectal cancer resection were matched 1-2 by age, operation, gender, operation date, body mass index (BMI), and tumor stage (TNM) to 486 patients undergoing open surgery. The numbers of examined and involved LNs were compared according to tumor location and year of surgery.

RESULTS

Colorectal cancer resections (243 laparoscopic and 486 open procedures) were performed for 729 patients (447 men) with a mean age of 66.2 +/- 12.3 years and a mean BMI of 28.5 +/- 7.3. The mean number of LNs per case was 24.8 +/- 20.6. The number of LNs retrieved did not differ between laparoscopic and open surgery (p = 0.4). A significant difference was observed between the number of involved LNs retrieved laparoscopically (2.2 +/- 3.8) and the number retrieved by open surgery (1.6 +/- 4; p = 0.03). There were significant differences between the numbers of LNs retrieved from the right colon (28.1 +/- 14.6), left colon (24.5 +/- 17.6), and rectum (19.1 +/- 15.1) (p < 0.001). There were significantly fewer examined LNs in laparoscopic than in open cases during 2002 and 2003 (p = 0.003).

CONCLUSION

Laparoscopic resection of colorectal cancer can achieve lymph node retrieval similar to that achieved by the open approach. In this era of new technology, laparoscopic lymph node harvest is becoming more optimized.

Lymph node ratio predicts disease-specific survival in melanoma patients

BACKGROUND

The objectives of this analysis were to compare various measures associated with lymph node (LN) dissection and to identify threshold values associated with disease-specific survival (DSS) outcomes in patients with melanoma.

METHODS

Patients with lymph node-positive melanoma who underwent therapeutic LN dissection of the neck, axilla, and inguinal region were identified from the SEER database (1988-2005). We performed Cox multivariate analyses to determine the impact of the total number of LNs removed, number of negative LNs removed, and LN ratio on DSS. Multivariate cut-point analyses were conducted for each anatomic region to identify the threshold values associated with the largest improvement in DSS.

RESULTS

The LN ratio was significantly associated with DSS for all LN regions. The LN ratio thresholds resulting in the greatest difference in 5-year DSS were .07, .13, and .18 for neck, axillary, and inguinal regions, respectively, corresponding to 15, 8, and 6 LNs removed per positive lymph node. After adjustment for other clinicopathologic factors, the hazard ratios (HRs) were .53 (95% confidence interval [CI], .40 to .71) in the neck, .52 (95% CI, .42 to .65) in the axillary, and .47 (95% CI, .36 to .61) in the inguinal regions for patients who met the LN ratio threshold.

CONCLUSIONS

Among the prognostic factors examined, LN ratio was the best indicator of the extent of LN dissection, regardless of anatomic nodal region. These data provide evidence-based guidelines for defining adequate LN dissections in melanoma patients.

Number of lymph nodes examined and associated clinicopathologic factors in colorectal carcinoma

CONTEXT

Nodal metastasis is one of the most important prognostic factors in colorectal carcinoma. The number of lymph nodes recovered and examined in resection specimens has been recently shown to be critical for proper staging and is associated with survival.

OBJECTIVE

To assess the clinicopathologic factors that may be associated with the number of lymph nodes harvested from surgical resections.

DESIGN

Clinicopathologic factors of 434 consecutive cases of colorectal cancers treated by surgical resection from a single tertiary medical center were retrospectively reviewed and correlated with number of lymph nodes recovered.

RESULTS

Our data show that patient age, tumor location, and length of resected bowel segment were associated with number of lymph nodes harvested in surgical resections of colorectal cancer. The average number of lymph nodes was 18.2 and 17.8 for patients younger than 50 years and aged 50 through 60 years, respectively, whereas it was 14.4, 15.1, and 14.9 for patients aged 61 through 70 years, 71 through 80 years, and 80 years and older, respectively. More lymph nodes were present in resection specimens of cecum/ascending colon and descending colon cancers than in those of transverse colon, sigmoid colon, and rectal cancers. There was a linear increase in number of lymph nodes examined with increasing length of bowel resection specimens. In multivariate regression analysis, the factors that remained independent predictors of removal of 12 or more lymph nodes from resection specimens were tumor location and length of resected bowel segment.

CONCLUSIONS

The number of lymph nodes obtained in resection specimens for colorectal cancer was significantly associated with the length of resected segments of bowel, patient age, and location of the tumor.

Should total number of lymph nodes be used as a quality of care measure for stage III colon cancer?

OBJECTIVE

To assess whether TNODS is an independent prognostic factor after adjusting for the lymph node ratio (LNR).

SUMMARY BACKGROUND DATA

The medical literature has suggested that the TNODS is associated with better survival in stage II and III colon cancer. Thus TNODS was endorsed as a quality measure for patient care by American College of Surgeons, National Quality Forum. There is, however, little biologic rationale to support this linkage.

METHODS

: A total of 24,477 stage III colon cancer patients were identified from Surveillance, Epidemiology, and End Results cancer registry and categorized into 4 groups, LNR1 to LNR4, according to LNR interval: <0.07, 0.07 to 0.25, 0.25 to 0.50, and >0.50. Patients were also stratified according to TNODS into high TNODS (> or = 12) and low TNODS (<12) groups. The method of Kaplan-Meier was used to estimate the 5-year survival and the log-rank test was used to test the survival difference among the different groups.

RESULTS

Patients with high TNODS have better survival compared with those with low TNODS (5-year survival 51.0% vs. 45.0%, P < 0.0001). However, after stratifying by LNR status, there was no significant survival difference between patients with high TNODS and those with low TNODS within strata LNR2 (5-year survival 56.3% vs. 56.0%, P = 0.26). Ironically, patients with high TNODS had significantly worse survival than those with low TNODS within strata LNR3 (5-year survival 41.2% vs. 47.4%, P = 0.0009) and LNR 4 (5-year survival 22.0% vs. 32.1%, P < 0.0001).

CONCLUSIONS

The previously reported prognostic effect of TNODS on node-positive colon cancer was confounded by LNR. This observation calls into question the use of TNODS as a quality measure for colon cancer patients' care.

Standardized surgery for colonic cancer: complete mesocolic excision and central ligation--technical notes and outcome

OBJECTIVE

Total mesorectal excision (TME) as proposed by R.J. Heald more than 20 years ago, is nowadays accepted worldwide for optimal rectal cancer surgery. This technique is focused on an intact package of the tumour and its main lymphatic drainage. This concept can be translated into colon cancer surgery, as the mesorectum is only part of the mesenteric planes which cover the colon and its lymphatic drainage like envelopes. According to the concept of TME for rectal cancer, we perform a concept of complete mesocolic excision (CME) for colonic cancer. This technique aims at the separation of the mesocolic from the parietal plane and true central ligation of the supplying arteries and draining veins right at their roots.

METHOD

Prospectively obtained data from 1329 consecutive patients of our department with RO-resection of colon cancer between 1978 and 2002 were analysed. Patient data of three subdivided time periods were compared.

RESULTS

By consequent application of the procedure of CME, we were able to reduce local 5-year recurrence rates in colon cancer from 6.5% in the period from 1978 to 1984 to 3.6% in 1995 to 2002. In the same period, the cancer related 5-year survival rates in patients resected for cure increased from 82.1% to 89.1%.

CONCLUSION

The technique of CME in colon cancer surgery aims at a specimen with intact layers and a maximum of lymphnode harvest. This is translated into lower local recurrence rates and better overall survival.

Positive lymph node retrieval ratio optimises patient staging in colorectal cancer

Alternative lymph node (LN) parameters have been proposed to improve staging in colorectal cancer. This study compared these alternative parameters with conventional TNM staging in predicting long-term survival in patients undergoing curative resection. A total of 295 consecutive patients (mean age 70 years; range 39–95; s.d. 10.4) underwent resection for colorectal cancer from 2001 to 2004. Age, sex, primary tumour site, TNM stage and chemotherapy/radiotherapy were recorded. Patients with colon and rectal cancers were analysed separately for LN parameters: LN total; adequate LN retrieval (⩾12) and inadequate (<12); total number of negative LN; total number of positive LN and the ratio of positive LN to total LN (pLNR). Univariate and multivariate survival analysis was performed. The median number of LN retrieved was 10 (1–57) with adequate LN retrieval in 147 cases (49.8%). For each T and N stage, inadequate LN retrieval did not adversely affect long-term survival (P>0.05). On multivariate analysis, only pLNR was an independent predictor of overall survival in both colon and rectal cancers (HR 11.65, 95% CI 5.00–27.15, P<0.001 and HR 13.40, 95% CI 3.64–49.10, P<0.001, respectively). Application of pLNR subdivided patients into four prognostic groups. Application of the pLNR improved patient stratification in colorectal cancer and should be considered in future staging systems.

Reduced lymph node yield in rectal carcinoma specimen after neoadjuvant radiochemotherapy has no prognostic relevance

BACKGROUND

In colorectal surgery UICC/AJCC criteria require a yield of 12 or more locoregional lymph nodes for adequate staging. Neoadjuvant radiochemotherapy for rectal carcinoma reduces the number of lymph nodes in the resection specimen; the prognostic impact of this reduced lymph node yield has not been determined.

METHODS

One hundred two patients with uT3 rectal carcinoma who were receiving neoadjuvant radiochemotherapy were compared with 114 patients with uT3 rectal carcinoma who were receiving primary surgery followed by adjuvant radiochemotherapy. Total lymph node yield and number of tumor-positive lymph nodes were determined and correlated with survival.

RESULTS

After neoadjuvant radiochemotherapy both total lymph node yield (12.9 vs. 21.4, p < 0.0001) and number of tumor-positive lymph nodes (1.0 vs. 2.3, p = 0.014) were significantly lower than after primary surgery plus adjuvant radiochemotherapy. Reduced total lymph node yield in neoadjuvantly treated patients had no prognostic impact, with overall survival of patients with 12 or more lymph nodes the same as that of patients with less than 12 lymph nodes. Overall survival of neoadjuvantly treated patients was significantly influenced by the number of tumor-positive lymph nodes with 5-year-survival rates of 88, 63, and 39% for 0, 1-3, and more than 3 positive lymph nodes (p < 0.0001).

CONCLUSION

The UICC/AJCC criterion of a total lymph node yield of 12 or more should be revised for rectal carcinoma patients.

Factors that influence 12 or more harvested lymph nodes in early-stage colorectal cancer

BACKGROUND

The number of lymph nodes required for accurate staging is a critical component in early-stage (stage A and B) colorectal cancer (CRC). Current guidelines demand at least 12 lymph nodes to be retrieved. Results of previous studies were contradictory in factors, which influenced the number of harvested lymph nodes. This study was designed to determine the factors that influence the number of harvested lymph nodes (> or =12) in early-stage CRC in a single institution.

METHODS

Between 2003 and 2007, data on patients who underwent surgery for early-stage CRC were analyzed retrospectively. Data for a total of 470 patients were collected and all the tumor-bearing specimens were fixed with node identification performed. Several possible factors that influence 12 or more harvested lymph nodes were investigated and classified into four aspects: (1) operating surgeon, (2) examining pathologist, (3) patient (age, sex, and body mass index), and (4) disease (maximal length of tumor, length of specimen, tumor localization, tumor cell differentiation, Dukes stage, type of resection, and type of tumor).

RESULTS

A total of 289 patients (61.5%) with 12 or more harvested lymph nodes and 181 patients (38.5%) with < 12 lymph nodes were analyzed. The results demonstrate that within a single institution the maximal length of tumor, tumor localization, and depth of tumor invasion according to Dukes stage were independent influencing factors of 12 or more harvested lymph nodes. Maximal length of tumor was associated with more harvested lymph nodes (P < 0.001). Neither the operating surgeon nor the examining pathologist had significant influence on the number of harvested lymph nodes.

CONCLUSIONS

The number of harvested lymph nodes was highly variable in patients who underwent resection of early-stage CRC. Neither the operating surgeon nor the examining pathologist had significant influence on the number of harvested lymph nodes. Therefore, from the viewpoint of the surgeons, disease itself is the most important factor influencing the number of harvested lymph nodes.

Clinically important aspects of lymph node assessment in colon cancer

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

Is lymph node count an ideal quality indicator for cancer care?

Although lymph node count has substantial appeal as a quality indicator because of the ease of measurement, the presence of variation in the population, the association with survival for many cancers, and the previous success of quality intervention programs, improvements in patient outcome by increasing lymph node counts have not yet been demonstrated. This article discusses potential pitfalls in the use of lymph node count as a quality indicator.

Survival in stage III colon cancer is independent of the total number of lymph nodes retrieved

BACKGROUND

Retrieval of >/= 12 lymph nodes has been set as a marker of quality for surgical resection for colon cancer. The aim of our study was to determine if increasing the number of lymph nodes recovered in stage III colon cancer results in improved survival and if it does represent a reasonable quality metric.

STUDY DESIGN

Data from patients with stage III colon cancer from 1996 to 2001 were analyzed. Outcomes after operation (cancer-specific survival, disease-free survival, and overall survival) with or without adjuvant therapy were evaluated in 3 categories: the entire cohort, patients with N1, and patients with N2 disease. These categories were then classified into subgroups by the number of nodes (</= 12 versus >12) retrieved per specimen and whether they had 5-FU-based chemotherapy or not.

RESULTS

Three hundred twenty-nine patients, with a median followup of 5 years with stage III colon cancer, were identified. Five-year cancer-specific and disease-free survival was 67.2% and 59.7%, respectively. A positive correlation between number of positive lymph nodes and overall survival was found (p < 0.05). No significant association was observed between the total number (> 12 versus </= 12) of lymph nodes removed either in the entire cohort or in patients with N1 (249 patients) and N2 (80 patients) disease.

CONCLUSION

Accurate staging requires an appropriate operation and a concerted pathologic effort to identify lymph nodes in the colon specimen. The total number of lymph nodes analyzed for stage III colon cancer is not a prognostic indicator of cancer-specific and disease-free survival.

D3 lymphadenectomy using a medial to lateral approach for curable right-sided colon cancer

BACKGROUND AND AIMS

The extended D3 lymphadenectomy using a medial to lateral (MtL) approach for the treatment of curable right-sided colon cancer is performed with a view to improving oncologic surgery outcomes. However, the feasibility and safety of this procedure has not been fully examined. The present study investigated the feasibility and safety of D3 lymphadenectomy using the MtL approach for curable right-sided colon cancers.

METHODS

Between January 2005 and May 2007, 42 patients underwent a curative-intent right (25) or extended right (17) hemicolectomy including D3 lymphadenectomy using the MtL approach performed by the same single surgeon. The extent of the D3 lymphadenectomy followed the recommendations of the Japanese Society for Cancer of the Colon and Rectum.

RESULTS

There were 27 male and 15 female patients, with a mean age of 59.2 years (range, 30-83). The mean operation time was 172.5 min (range, 55-274) and the mean blood loss was 128.3 ml (range, 50-500). All procedures were successful and no conversions to open surgery were required in laparoscopic cases (32 patients, 76.2%). The mean number of harvested lymph nodes was 45 (range, 18-92). There was no surgical mortality or morbidity, except one case of postoperative ileus which was conservatively managed. The mean postoperative hospital stay was 8.6 days (range, 6-15).

CONCLUSION

The findings indicate that a D3 lymphadenectomy using the MtL approach is a feasible and safe procedure for the treatment of curable right-sided colon cancer.

Are 12 nodes needed to accurately stage T1 and T2 colon cancers?

Evaluation of 12 lymph nodes has been mandated to prevent colon cancer understaging. Given that the probability of node metastases is largely associated with T-stage, are <12 nodes substandard for T1 and T2 lesions? We evaluated if survival for T1 and T2 tumors varies by nodes examined. In SEER, 61,237 patients undergoing colon cancer resection were identified. For each T-stage, 5-year survival rates were compared for node-negative cancers by using stepwise node cut-point comparisons (4 nodes, <4, etc.). Survival impact was determined by log-rank test and hazard regression. For T1 tumors, 4 nodes had 24% lower hazard of death compared to <4. For T2 tumors, 10 nodes had the biggest survival impact, 15% lower hazard of death. In conclusion, the number of nodes to stage T1 and T2 lesions may be <12.

Lymph node examination as a predictor of long-term outcome in Dukes B colon cancer

BACKGROUND

Mortality from cancer recurrence in Dukes B patients is approximately 25-30%. Outcome in Dukes B patients improves in direct relation to the number of lymph nodes examined. Examining fewer lymph nodes risks understaging and also such patients are less likely to receive chemotherapy. The aim of this study was to assess the impact of the number of lymph nodes examined on recurrence and mortality in Dukes B colon cancers.

MATERIALS AND METHODS

A retrospective database was constructed of 328 consecutive patients who underwent resection for Dukes B colorectal cancer between January 1993 and December 2001 at Middlemore Hospital. Patients with incomplete data, previous colorectal cancer, or perioperative deaths were excluded as were cases of rectal cancer. Data for the remaining 216 patients was subjected to multivariate and logistic regression analysis with 'patient death' or 'cancer recurrence' (CRec5) within 5 years as endpoints. A graph was constructed depicting CRec5 as broken down by lymph node strata. Receiver operator characteristic (ROC) curves were constructed for mortality and CRec5.

RESULTS

The mean number of lymph nodes examined was 16.0 (median 14; range 2-48). The mean number of lymph nodes examined in those who died within 5 years was 12.8 vs. 17.5 in those who remained alive (p = 0.0027). The mean number of lymph nodes examined in those with evidence of recurrence within 5 years was 11.8 vs. 17.1 in those without recurrence (p = 0.0007). Analysis at various lymph node strata showed a sharp and statistically significant drop in the recurrence rate after the 16th node mark. The ROC curve for CRec5 showed that examination of 12 lymph nodes provided maximum sensitivity (0.60) and specificity (0.64).

CONCLUSION

Examination of more than 16 lymph nodes is associated with a significant reduction in cancer recurrence. This supports the current clinical practice of harvesting and analysing as many nodes as possible during surgical resection and pathological analysis.

Decreased expression of monocyte chemoattractant protein-1 predicts poor prognosis following curative resection of colorectal cancer

PURPOSE

The significance of monocyte chemoattractant protein-1 in colorectal cancer is not well understood. The aim of this study was to investigate the significance of monocyte chemoattractant protein-1 expression in colorectal cancer patients undergoing potentially curative surgery.

METHODS

We studied 101 colorectal cancer patients who underwent potentially curative surgery. The concentration of monocyte chemoattractant protein-1 in the tumor and normal mucosa were measured. The expression of monocyte chemoattractant protein-1 was also evaluated immunohistochemically.

RESULTS

The tissue concentration of monocyte chemoattractant protein-1 in the tumor was significantly higher than that in the normal mucosa. The decreased monocyte chemoattractant protein-1 cancer/normal ratio was associated with lymph node involvement and could predict poor prognosis. On univariate analysis, the decreased monocyte chemoattractant protein-1 ratio, carcinoembryonic antigen levels, and serosal invasion were the significant factors for poor prognosis. Multivariate analysis showed that monocyte chemoattractant protein-1 ratio was the only independent risk factor predictive of a poor prognosis. Immunohistochemically, monocyte chemoattractant protein-1 was expressed in the cytoplasm.

CONCLUSION

The decreased monocyte chemoattractant protein-1 ratio was an independent factor predicting poor prognosis in patients undergoing potentially curative surgery. Monocyte chemoattractant protein-1 deficiency may present a new therapeutic approach for colorectal cancer.

[Not Available]

F. Pagès, A. Berger, F. Zinzindohoué, A. Kirilovsky, J. Galon, W.-H. Fridman Lymph node dissection is an integral part of the surgical resection of colon cancers; it completes the wide regional resection of tumor and it allows prognostic evaluation through accurate staging. Studies have demonstrated an immune reaction to the tumoral site which attests to an ongoing dialog between the tumor and systemic defenses. The regional lymph nodes constitute an important first line of immune defense where initial host response is initiated or, inversely, they may participate in a local state of immunosuppression. This article reviews current knowledge on intra-tumoral and nodal immune status in colorectal cancers and attempts to evaluate the potential immunologic implications of lymph node dissection.

[Not Available]

F. Lacaine Lymph node metastasis carries enormous prognostic weight in the evaluation of colon cancer and raises the question of how extensive a lymph node dissection should be. Lymph node dissection has several goals: 1) staging of the cancer at the time of intervention; 2) improving the chances for complete resection and cure; 3) evaluating the thoroughness and quality of a particular surgical procedure. The prognostic value of lymphadenectomy is evident from the direct practical decisions it entails: evidence-based recommendations (Level A) have proposed adjuvant chemotherapy for all patients with Stage III colon cancer since 1990. Studies have shown a statistically significant correlation between the number of nodes examined in an operative specimen and long-term survival in patients with Stage II disease. The more closely lymph nodes are examined, the more metastasis is found; one can then see the aberrations of stage migration described as the "Will Rogers Phenomenon." Without randomized studies, it is impossible to say whether resection of a larger number of lymph nodes actually improves the prognosis or whether that number is simply a marker of better surgical management including the quality of the surgical gesture, the careful pathologic examination of the specimen, and subsequent choices for adjuvant chemotherapy. The recovery of 12 lymph nodes correlates with a better global prognosis. At the very least, it is an effective marker for the quality of the surgical resection and can be used in the evaluation of professional practice.

[Not Available]

F. Pagès, A. Berger, F. Zinzindohoué, A. Kirilovsky, J. Galon, W.-H. Fridman Lymph node dissection is an integral part of the surgical resection of colon cancers; it completes the wide regional resection of tumor and it allows prognostic evaluation through accurate staging. Studies have demonstrated an immune reaction to the tumoral site which attests to an ongoing dialog between the tumor and systemic defenses. The regional lymph nodes constitute an important first line of immune defense where initial host response is initiated or, inversely, they may participate in a local state of immunosuppression. This article reviews current knowledge on intra-tumoral and nodal immune status in colorectal cancers and attempts to evaluate the potential immunologic implications of lymph node dissection.

[Not Available]

F. Lacaine Lymph node metastasis carries enormous prognostic weight in the evaluation of colon cancer and raises the question of how extensive a lymph node dissection should be. Lymph node dissection has several goals: 1) staging of the cancer at the time of intervention; 2) improving the chances for complete resection and cure; 3) evaluating the thoroughness and quality of a particular surgical procedure. The prognostic value of lymphadenectomy is evident from the direct practical decisions it entails: evidence-based recommendations (Level A) have proposed adjuvant chemotherapy for all patients with Stage III colon cancer since 1990. Studies have shown a statistically significant correlation between the number of nodes examined in an operative specimen and long-term survival in patients with Stage II disease. The more closely lymph nodes are examined, the more metastasis is found; one can then see the aberrations of stage migration described as the "Will Rogers Phenomenon." Without randomized studies, it is impossible to say whether resection of a larger number of lymph nodes actually improves the prognosis or whether that number is simply a marker of better surgical management including the quality of the surgical gesture, the careful pathologic examination of the specimen, and subsequent choices for adjuvant chemotherapy. The recovery of 12 lymph nodes correlates with a better global prognosis. At the very least, it is an effective marker for the quality of the surgical resection and can be used in the evaluation of professional practice.

Prognostic significance of the number of lymph nodes removed at lobectomy in stage IA non-small cell lung cancer

BACKGROUND

Lobectomy with mediastinal lymph node dissection is the standard of care in stage IA non-small cell lung cancer (NSCLC). We investigated whether the number of lymph nodes removed influences survival in stage IA NSCLC patients who underwent lobectomy.

METHODS

2545 stage IA NSCLC patients in the California Cancer Registry who underwent lobectomy between 1999 and 2003 were analyzed. Cox proportional hazards regression was used to identify independent prognostic factors.

RESULTS

Increasing number of lymph nodes removed was associated with statistical significant improvements in overall survival (OS) (p = 0.0001) and lung cancer-specific survival (LCSS) (p = 0.0309) of stage IA NSCLC patients who underwent lobectomy. The number of lymph nodes removed remained an independent favorable prognostic factor for OS (ptrend = 0.0001) and LCSS (ptrend = 0.0095) even after adjustment for other independent prognostic factors including age, sex, histology, histologic grade, socioeconomic status, and marital status in the Cox proportional regression analyses. Removal of 11 to 15 lymph nodes conferred the lowest hazard ratio for death [versus none; hazard ratio = 0.52; 95% confidence interval: 0.36-0.75].

CONCLUSIONS

The number of lymph nodes removed in stage IA NSCLC patients who underwent lobectomy is an independent prognostic factor for OS and LCSS.

A cohort study of tumoral LINE-1 hypomethylation and prognosis in colon cancer

Genome-wide DNA hypomethylation plays has an important role in genomic instability and colorectal carcinogenesis. However, the relationship between cellular DNA methylation level and patient outcome remains uncertain. Using 643 colon cancers in two independent prospective cohorts, we quantified DNA methylation in repetitive long interspersed nucleotide element-1 (LINE-1) elements using pyrosequencing, which is a good indicator of global DNA methylation level. We used Cox proportional hazard models to calculate hazard ratios (HRs) of colon cancer-specific and overall mortality, adjusting for patient and tumoral features, including CpG island methylator phenotype (CIMP). Statistical tests were two-sided. LINE-1 hypomethylation was linearly associated with a statistically significant increase in colon cancer-specific mortality (for a 30% decrease in LINE-1 methylation: multivariable HR = 2.37, 95% confidence interval [CI] = 1.42 to 3.94; P(trend) < .001) and overall mortality (multivariable HR = 1.85, 95% CI = 1.25 to 2.75; P(trend) = .002). The association was consistent across the two independent cohorts and strata of clinical and molecular characteristics, including sex, age, tumor location, stage, and CIMP, microsatellite instability, KRAS, BRAF, p53, and chromosomal instability status. In conclusion, tumoral LINE-1 hypomethylation is independently associated with shorter survival among colon cancer patients.

Prognostic relevance of occult nodal micrometastases and circulating tumor cells in colorectal cancer in a prospective multicenter trial

PURPOSE

Nodal micrometastasis and circulating tumor cells detected by multimarker quantitative real-time reverse transcription-PCR (qRT-PCR) may have prognostic importance in patients with colorectal cancer.

EXPERIMENTAL DESIGN

Paraffin-embedded sentinel lymph nodes from 67 patients and blood from 34 of these patients were evaluated in a prospective multicenter trial of sentinel lymph node mapping in colorectal cancer. Sentinel lymph nodes were examined by H&E staining and cytokeratin immunohistochemistry. Sentinel lymph nodes and blood were examined by a four-marker qRT-PCR assay (c-MET, melanoma antigen gene-A3 family, beta1-->4-N-acetylgalactosaminyltransferase, and cytokeratin-20); qRT-PCR results were correlated with disease stage and outcome.

RESULTS

In H&E-negative sentinel lymph node patients that recurred, cytokeratin immunohistochemistry and qRT-PCR detected metastasis in 30% and 60% of patients, respectively. Disease-free survival differed significantly by multimarker qRT-PCR upstaged sentinel lymph node (P = 0.014). qRT-PCR analysis of blood for circulating tumor cells correlated with overall survival (P = 0.040).

CONCLUSION

Molecular assessment for micrometastasis in sentinel lymph node and blood specimens may help identify patients at high risk for recurrent colorectal cancer, who could benefit from adjuvant therapy.

Does Obesity Influence Lymph Node Harvest among Patients Undergoing Colectomy for Colon Cancer?

Adequate lymph node harvest among patients undergoing colectomy for cancer is critical for staging and therapy. Obesity is prevalent in the American population. We investigated whether lymph node harvest was compromised in obese patients undergoing colectomy for cancer. Medical records of patients who had undergone colectomy for colon cancer were reviewed. We correlated the number of lymph nodes with body mass index (BMI) and compared the number of lymph nodes among patients with BMI less than 30 kg/m2 to those with BMI of 30 kg/m2 or greater (“obese”). Among all 191 patients, the correlation coefficient was 0.04 (P > 0.2). The mean number of nodes harvested from 122 nonobese patients was 12.4 ± 6 and that for 69 obese patients 12.8 ± 6 (P > 0.2). Among 130 patients undergoing right colectomy and 35 patients undergoing sigmoid colectomy, the correlation coefficients were 0.02 (P > 0.2) and 0.16 (P > 0.2), respectively. There was not a statistically significant difference in lymph node harvest between obese and nonobese patients (14.1 ± 7 vs 13.8 ± 6, P > 0.2; and 11.8 ± 6 vs 8.6 ± 5, P > 0.2), respectively. Obesity did not compromise the number of lymph nodes harvested from patients undergoing colectomy for colon cancer.

Lymph node evaluation in early-stage colon cancer

Accurate nodal staging is of crucial importance in patients with nonmetastatic colon cancer, because it affects patient prognosis and delivery of adjuvant chemotherapy. In this article, we review the role of 2 controversial aspects of lymph node staging in colon cancer: the number of lymph nodes evaluated and sentinel lymph node (SLN) biopsy. Although it is clear that the number of lymph nodes assessed correlates with patient survival, the underlying mechanisms are far more uncertain, and thus, more research is warranted to determine whether interventions to increase nodal assessment will lead to improved patient outcomes. Sentinel lymph node biopsy does not appear to have the same advantages in the treatment of patients with colon cancer as in the treatment of patients with breast cancer or melanoma. Also, it might not improve colon cancer staging above standard pathology, and should be restricted to use in research settings.