Tumour stage and preoperative chemoradiotherapy influence the lymph node yield in stages I-III rectal cancer: results from a prospective nationwide cohort study

Rectal Cancer: Are 12 Lymph Nodes the Limit?

Lymph node dissection is a crucial element of oncologic rectal surgery. Many guidelines regard the removal of at least 12 lymph nodes as the quality criterion in rectal cancer. However, this recommendation remains controversial. This study examines the factors influencing the lymph node yield and the validity of the 12-lymph node limit. Patients with rectal cancer who underwent low anterior resection or abdominoperineal amputation between 2000 and 2010 were analyzed. In total, 20,966 patients from 381 hospitals were included. Less than 12 lymph nodes were found in 20.53% of men and 19.31% of women (p = 0.03). The number of lymph nodes yielded increased significantly from 2000, 2005 and 2010 within the quality assurance program for all procedures. The univariate analysis indicated a significant (p < 0.001) correlation between lymph node yield and gender, age, pre-therapeutic T-stage, risk factors and neoadjuvant therapy. The multivariate analyses found T3 stage, female sex, the presence of at least one risk factor and neoadjuvant therapy to have a significant influence on yield. The probability of finding a positive lymph node was proportional to the number of examined nodes with no plateau. There is a proportional relationship between the number of examined lymph nodes and the probability of finding an infiltrated node. Optimal surgical technique and pathological evaluation of the specimen cannot be replaced by a numeric cut-off value.

Prognostic Implication of Metastatic Lymph Node Ratio in Colorectal Cancers: Comparison Depending on Tumor Location

Background: The proportion of the number of involved lymph nodes (LNs) to the number of examined LNs—defined as metastatic LN ratio (mLNR)—has been considered as a prognostic parameter. This study aims to elucidate the prognostic implication of the mLNR in colorectal cancer (CRC) according to the tumor location. Methods: We evaluated the correlation between prognoses and the involved and examined LNs as well as mLNR according to the tumor location in 266 surgically resected human CRCs. Besides, to evaluate the optimal cutoff for high and low mLNRs, we investigated the correlation between mLNR and survival according to the various cutoffs. Results: LN metastasis was found in 146 cases (54.9%), and colon and rectal cancers were found in 116 (79.5%) and 30 (20.5%) of the cases, respectively. The mean mLNRs were significantly higher in rectal cancer than in colon cancer (0.38 ± 0.28 vs. 0.21 ± 0.24, P = 0.003). Besides this, the number of involved LNs in rectal cancer was significantly high compared to colon cancer (11.83 ± 10.92 vs. 6.37 ± 7.78, P = 0.014). However, there was no significant difference in the examined LNs between the rectal and colon cancers (31.90 ± 12.28 vs. 36.60 ± 18.11, P = 0.181). In colon cancer, a high mLNR was significantly correlated with worse survival for all cutoffs (0.1, 0.2, 0.3, and 0.4). However, rectal cancer only showed a significant correlation between high mLNR and worse survival in the subgroup with a cutoff of 0.2. Conclusions: Our results showed that high mLNR was significantly correlated with worse survival. The number of involved LNs and mLNRs were significantly higher in rectal cancer than in colon cancer. The cutoff of 0.2 can be useful for the differentiation of prognostic groups, regardless of tumor location.

Impact of Surgical Approach on Long-term Survival in Esophageal Adenocarcinoma Patients With or Without Neoadjuvant Chemoradiotherapy

OBJECTIVE

To compare overall survival in patients with esophageal adenocarcinoma who underwent transhiatal esophagectomy (THE) with limited lymphadenectomy or transthoracic esophagectomy (TTE) with extended lymphadenectomy with or without neoadjuvant chemoradiotherapy (nCRT).

BACKGROUND

The application of neoadjuvant therapy might change the association between the extent of lymphadenectomy and survival in patients with esophageal adenocarcinoma. This may influence the choice of surgical approach in patients treated with nCRT.

METHODS

Patients with potentially curable subcarinal esophageal adenocarcinoma treated with surgery alone or nCRT followed by surgery in 7 centers were included. The effect of surgical approach on overall survival, differentiated by the addition or omission of nCRT, was analyzed using a multivariable Cox regression model that included well-known prognostic factors and factors that might have influenced the choice of surgical approach.

RESULTS

In total, 701 patients were included, of whom 318 had TTE with extended lymphadenectomy and 383 had THE with limited lymphadenectomy. TTE had differential effects on survival (P for interaction = 0.02), with a more favorable prognostic effect in patients who were treated with surgery alone [hazard ratio (HR) = 0.77, 95% confidence interval (CI) 0.58-1.03]. This association was statistically significant in a subgroup of patients with 1 to 8 positive lymph nodes in the resection specimen (HR = 0.62, 95% CI 0.43-0.90). The favorable prognostic effect of TTE over THE was absent in the nCRT and surgery group (HR = 1.16, 95% CI 0.80-1.66) and in the subgroup of nCRT patients with 1 to 8 positive lymph nodes in the resection specimen (HR = 1.00, 95% CI 0.61-1.68).

CONCLUSIONS

Compared to surgery alone, the addition of nCRT may reduce the need for TTE with extended lymphadenectomy to improve long-term survival in patients with esophageal adenocarcinoma.

Lymph node yield and tumour subsite are associated with survival in stage I-III colon cancer: results from a national cohort study

BACKGROUND

It has been suggested that apart from tumour and nodal status, a range of patient-related and histopathological factors including lymph node yield and tumour location seems to have prognostic implications in stage I-III colon cancer. We analysed the prognostic implication of lymph node yield and tumour subsite in stage I-III colon cancer.

METHODS

Data on patients with stage I to III adenocarcinoma of the colon and treated by curative resection in the period from 2003 to 2011 were extracted from the Danish Colorectal Cancer Group database, merged with information from the Danish National Patient Register and analysed.

RESULTS

A total of 13,766 patients were included in the analysis. The 5-year overall survival ranged from 59.3% (95% CI 55.7-62.9%) (lymph node yield 0-5) to 74.0% (95% CI 71.8-76.2%) (lymph node yield ≥ 18) for patients with stage I-II disease (p < 0.0001) and from 36.4% (95% CI 29.8-43.0%) (lymph node yield 0-5) to 59.4% (95% CI 56.6-62.2%) (lymph node yield ≥ 18) for patients with stage III disease (p < 0.0001). The 5-year overall survival for tumour side left/right was 59.3% (95% CI 57.9-60.7%)/64.8% (CI 63.4-66.2%) (p < 0.0001). In the seven colonic tumour subsites, the 5-year overall survival ranged from 56.6% (95% CI 51.8-61.4%) at splenic flexure to 65.8% (95% CI 64.5-67.2%) in the sigmoid colon (p < 0.0001). In a cox regression analysis, lymph node yield and tumour side right/left were found to be prognostic factors. Tumours at the hepatic and splenic flexures had an adverse prognostic outcome.

CONCLUSION

For stage I-III colon cancer, a lymph node yield beyond the recommended 12 lymph nodes was associated with improved survival. Both subsite in the right colon, as well as subsite in the left colon, turned out with adverse prognostic outcome questioning a simple classification into right-sided and left-sided colon cancer.

A Review of Current Challenges in Colorectal Cancer Reporting

Context.—

Pathologic assessment of colorectal cancer resection specimens plays an important role in postsurgical management and prognostication in patients with colorectal cancer. Challenges exist in the evaluation and reporting of these specimens, either because of difficulties in applying existing guidelines or related to newer concepts.

Objective.—

To address challenging areas in colorectal cancer pathology and to provide an overview of the literature, current guidelines, and expert recommendations for the handling of colorectal cancer resection specimens in everyday practice.

Data Sources.—

PubMed (US National Library of Medicine, Bethesda, Maryland) literature review; reporting protocols of the College of American Pathologists, the Royal College of Pathologists of the United Kingdom, and the Japanese Society for Cancer of the Colon and Rectum; and classification manuals of the American Joint Committee on Cancer and the Union for International Cancer Control.

Conclusions.—

This review has addressed issues and challenges affecting quality of colorectal cancer pathology reporting. High-quality pathology reporting is essential for prognostication and management of patients with colorectal cancer.

Role of lymph node yield and lymph node ratio in predicting outcomes in non-metastatic colorectal cancer

Background

Lymph node yield (LNY) of 12 or more in resection of colorectal cancer is recommended in current international guidelines. Although a low LNY (less than 12) is associated with poorer outcome in some studies, its prognostic value is unclear in patients with early‐stage colorectal or rectal cancer with a complete pathological response following neoadjuvant therapy. Lymph node ratio (LNR), which reflects the proportion of positive to total nodes obtained, may be more accurate in predicting outcome in stage III colorectal cancer. This study aimed to identify factors correlating with LNY and evaluate the prognostic role of LNY and LNR in colorectal cancer.

Methods

An observational study was performed on patients with colorectal cancer treated at three hospitals in Melbourne, Australia, from January 2010 to March 2016. Association of LNY and LNR with clinical variables was analysed using linear regression. Disease‐free (DFS) and overall (OS) survival were investigated with Cox regression and Kaplan–Meier survival analyses.

Results

Some 1585 resections were analysed. Median follow‐up was 27·1 (range 0·1–71) months. Median LNY was 16 (range 0–86), and was lower for rectal cancers, decreased with increasing age, and increased with increasing stage. High LNY (12 or more) was associated with better DFS in colorectal cancer. Subgroup analysis indicated that low LNY was associated with poorer DFS and OS in stage III colonic cancer, but had no effect on DFS and OS in rectal cancer (stages I–III). Higher LNR was predictive of poorer DFS and OS.

Conclusion

Low LNY (less than 12) was predictive of poor DFS in stage III colonic cancer, but was not a factor for stage I or II colonic disease or any rectal cancer. LNR was a predictive factor in DFS and OS in stage III colonic cancer, but influenced DFS only in rectal cancer.

A statistical tool for risk assessment as a function of the number of lymph nodes retrieved from rectal cancer patients

AIM

Although a minimum of 12 lymph nodes (LNs) has been recommended for examination in colorectal cancer patients there remains considerable debate with regard to rectal cancer. Inadequacy of examined LNs could lead to understaging and inappropriate treatment as a consequence. We describe a statistical tool that allows an estimate of the probability of false-negative nodes.

METHOD

A total of 26 778 patients diagnosed between 2004 and 2013 with rectal adenocarcinoma [tumour stage (T stage) 1-3] who did not receive neoadjuvant therapies and had at least one histologically assessed LN were extracted from the Surveillance, Epidemiology and End Results (SEER) database. A statistical tool using beta-binomial distribution was developed to estimate the probability of missing a positive node as a function of the total number of LNs examined and T stage.

RESULTS

The probability of falsely identifying a patient as node-negative decreased with increasing number of nodes examined for each stage. It was estimated to be 72%, 66% and 52% for T1, T2 and T3 patients, respectively, with a single node examined. To confirm an occult nodal disease with 90% confidence, 5, 9 and 29 nodes need to be examined for patients from stages T1, T2 and T3, respectively.

CONCLUSION

The false-negative rate of the examined LNs in rectal cancer was verified to be dependent preoperatively on the clinical T stage. A more accurate nodal staging score was developed to recommend a threshold for the minimum number of examined nodes with regard to the favoured level of confidence.

Neoadjuvant chemoradiotherapy followed by minimally invasive esophagectomy: is it a superior approach for locally advanced resectable esophageal squamous cell carcinoma?

Background

Few studies reported the outcomes of minimally invasive esophagectomy (MIE) in treating patients with esophageal squamous cell carcinoma (ESCC) after neoadjuvant chemoradiotherapy (nCRT). The aim of the study was to investigate the feasibility and efficacy of nCRT plus MIE (RM) strategy in treating locally advanced resectable ESCC.

Methods

This retrospective study included 175 patients with ESCC undergoing surgical resection after neoadjuvant therapy in our institution from 2010 to 2016. Patients were stratified into three groups: RM, [neoadjuvant chemotherapy (nCT) plus MIE] (CM) and [nCT plus open esophagectomy (OE)] (CO).

Results

Seventy-six (43.4%), 42 (24%) and 57 (32.6%) patients received RM, CM and CO approach, respectively. Compared with CO approach, RM or CM approach had shorter operation duration (188±39, 185±37 vs. 209±45 minutes, P=0.004, P=0.009) and less blood loss (124±88, 122±79 vs. 166±92 mL, P=0.001, P=0.003). There was a trend with lower risk of postoperative non-surgical complications in RM and CM approach [odds ratio (OR) 0.45, 0.200-1.040; P=0.062; OR 0.41, 0.150-1.160; P=0.093]. There were no differences in 30- and 90-day mortality among all groups. RM approach was more likely to achieve pathological complete regression (27.6% vs. 4.8%, 1.8%, P=0.001, P=0.001) and fewer lymph node metastasis (25.0% vs. 57.1%, 61.4%, P=0.001, P=0.001) than CM or CO approach. Survival analysis revealed a potential trend towards improved overall survival in RM approach compared with CM or CO approach (P=0.098, P=0.166).

Conclusions

RM approach was a safe and efficient strategy in treating locally advanced resectable ESCC.

Multimodality treatment for esophageal adenocarcinoma: multi-center propensity-score matched study

Background

The primary aim of this study was to compare survival from neoadjuvant chemoradiotherapy plus surgery (NCRS) versus neoadjuvant chemotherapy plus surgery (NCS) for the treatment of esophageal or junctional adenocarcinoma. The secondary aims were to compare pathological effects, short-term mortality and morbidity, and to evaluate the effect of lymph node harvest upon survival in both treatment groups.

Methods

Data were collected from 10 European centers from 2001 to 2012. Six hundred and eight patients with stage II or III oesophageal or oesophago-gastric junctional adenocarcinoma were included; 301 in the NCRS group and 307 in the NCS group. Propensity score matching and Cox regression analyses were used to compensate for differences in baseline characteristics.

Results

NCRS resulted in significant pathological benefits with more ypT0 (26.7% versus 5%; P < 0.001), more ypN0 (63.3% versus 32.1%; P < 0.001), and reduced R1/2 resection margins (7.7% versus 21.8%; P < 0.001). Analysis of short-term outcomes showed no statistically significant differences in 30-day or 90-day mortality, but increased incidence of anastomotic leak (23.1% versus 6.8%; P < 0.001) in NCRS patients.

There were no statistically significant differences between the groups in 3-year overall survival (57.9% versus 53.4%; Hazard Ratio (HR)= 0.89, 95%C.I. 0.67-1.17, P = 0.391) nor disease-free survival (52.9% versus 48.9%; HR = 0.90, 95%C.I. 0.69-1.18, P = 0.443). The pattern of recurrence was also similar (P = 0.660). There was a higher lymph node harvest in the NCS group (27 versus 14; P < 0.001), which was significantly associated with a lower recurrence rate and improved disease free survival within the NCS group.

Conclusion

The survival differences between NCRS and NCS maybe modest, if present at all, for the treatment of locally advanced esophageal or junctional adenocarcinoma. Future large-scale randomized trials must control and monitor indicators of the quality of surgery, as the extent of lymphadenectomy appears to influence prognosis in patients treated with NCS, from this large multi-center European study.

Resected irradiated rectal cancers: Are twelve lymph nodes really necessary in the era of neoadjuvant therapy?

BACKGROUND

Our study aims to identify the minimum number of lymph nodes (LN) associated with improved survival in patients who underwent NRT for stage II-III rectal cancer.

METHODS

Adults with clinical stage II and III rectal adenocarcinoma in the National Cancer Data Base were stratified by NRT. Multivariable Cox regression modeling with restricted cubic splines was used to determine the minimum number of LNs associated with improved survival.

RESULTS

Of 38,363 patients, 76% received NRT. After adjustment, a LNY≥12 was associated with improved survival among patients receiving NRT (HR 0.79, p < 0.0001) and those without NRT (HR 0.88, p = 0.04). Among patients receiving NRT, factors independently associated with LNY≥12 were younger age, private insurance, low comorbidity score, a recent year of diagnosis, higher T stage and grade, APR resection, and academic institution.

CONCLUSIONS

A minimum LNY of 12 confers a survival benefit for rectal cancer patients regardless of receiving neoadjuvant radiation therapy.

The number of retrieved lymph nodes needed for accurate staging differs based on the presence of preoperative chemoradiation for rectal cancer

The aim of this study is to investigate if retrieval of 12 lymph nodes (LNs) is sufficient to avoid stage migration as well as to evaluate the prognostic impact of insufficient LN retrieval in different treatment settings of rectal cancer, particularly in the case of preoperative chemoradiotherapy (pCRT).The data of all patients with biopsy proven rectal adenocarcinoma who underwent curative surgery between January 2005 and December 2012 were analyzed. Univariate and multivariate analyses for oncologic outcomes were performed in LN metastasis or no LN metastasis (LN-) group. Subgroup analyses were performed according to whether a patient had received pCRT.A total of 1825 patients were enrolled into the study. The maximal Chi-square method revealed the minimum number of harvested LNs required to be 12. Univariate and multivariate analyses found LNs ≥ 12 to be an independent prognostic factor for both overall survival (OS) (hazard ratio [HR] = 0.5, 95% confidence intervals [CIs]: 0.3-0.8; P = 0.002) and disease-free survival (DFS) (HR = 0.6, 95% CI: 0.4-0.7; P < 0.001) in the LN- group. In the LN- group, LNs ≥ 12 continued to be a significant prognostic factor both for OS and DFS in the subgroup of patients who did not undergo pCRT. However, in the subgroup of the LN- patients who underwent pCRT, LN ≥ 8 was significant for DFS and OS.Retrieval of LNs ≥ 12 and LNs ≥ 8 should be achieved to obtain accurate staging and optimal treatment for the non-pCRT and pCRT groups in rectal cancer, respectively.

Lymph node ratio and surgical quality are strong prognostic factors of rectal cancer: results from a single referral centre

AIM

Nodal stage is a strong prognostic factor of oncological outcome of rectal cancer. To compensate for the variation in total number of harvested nodes, calculation of the lymph node ratio (LNR) has been advocated. The aim of the study was to compare the impact, on the long-term oncological outcome, of the LNR with other predictive factors, including the quality of total mesorectal excision (TME) and the state of the circumferential resection margin.

METHOD

Consecutive patients having elective surgery for nonmetastatic rectal cancer were extracted from a prospectively maintained database. Retrospective uni- and multivariate analyses were performed based on patient-, surgical- and tumour-related factors. The prognostic value of the LNR on overall survival (OS) and on overall recurrence-free survival (ORFS) was assessed and a cut-off value was determined.

RESULTS

From 1998 to 2013, out of 456 patients, 357 with nonmetastatic disease were operated on for rectal cancer. Neoadjuvant radiochemotherapy was administered to 66.7% of the patients. The mean number of lymph nodes retrieved was 12.8 ± 8.78 per surgical specimen. A lower lymph node yield was obtained in patients who received neoadjuvant chemoradiotherapy (11.8 vs 14.2; P = 0.014). The 5-year ORFS was 71.8% and the 5-year OS was 80.1%. Multivariate analysis confirmed LNR, the quality of TME and age to be independent prognostic factors of OS. LNR, age and perineural infiltration were independently associated with ORFS. Low- and high-risk patients could be discriminated using an LNR cut-off value of 0.2.

CONCLUSION

LNR is an independent prognostic factor of OS and ORFS. In line with the principles of optimal surgical management, the quality of TME and lymph node yield are essential technical requirements.

Comparative analysis focusing on surgical and early oncological outcomes of open, laparoscopy-assisted, and robot-assisted approaches in rectal cancer patients

PURPOSE

Because there are few comparative studies of open, laparoscopy-assisted (LA), and robot-assisted (RA) total mesorectal excision (TME) for rectal cancer, we aimed to compare these three procedures in terms of sphincter-saving operation (SSO) achievement, surgical complications, and early oncological outcomes.

METHODS

The short-term outcomes of 2114 patients with rectal cancer consecutively enrolled between July 2010 and February 2015 at Asan Medical Center (Seoul, Korea) were retrospectively evaluated. Patients underwent either open, LA, or RA TME (n = 1095, 486, and 533, respectively) performed by experienced surgeons.

RESULTS

RA TME was a significant determinant of SSO in multivariate analysis that included potential variables such as tumor location and T4 category (odds ratio, 2.458; 95 % confidence interval, 1.497-4.036; p < 0.001). The cumulative rates of 3-year local recurrence, overall survival, and disease-free survival did not differ among the three groups: 2.5-3.4, 91.9-94.6, and 82.2-83.1 % (p = 0.85, 0.352, and 0.944, respectively). Early general surgical complications occurred more frequently in the open group than in the LA and RA groups (19.3 versus 13.0 versus 12.2 %, p < 0.001), specifically ileus and wound infection.

CONCLUSIONS

There were no significant differences in 3-year survival outcomes and local recurrence among open, LA, and RA TME. RA TME is useful for SSO achievement, regardless of advanced stage and location of rectal cancer. The open procedure had a slightly but significantly higher incidence of postoperative complications than LA and RA.

The prognostic value of lymph node ratio in a national cohort of rectal cancer patients

OBJECTIVE

To analyze the prognostic implications of the lymph node ratio (LNR) in curative resected rectal cancer.

SUMMARY BACKGROUND DATA

It has been proposed that the LNR has a high prognostic impact in colorectal cancer, but the lymph node ratio has not been evaluated exclusively for rectal cancer in a large national cohort study.

METHODS

All 6793 patients in Denmark diagnosed with stage I to III adenocarcinoma of the rectum, and so treated in the period from 2003 to 2011, were included in the analysis. The cohort was divided into two groups according to whether or not neo-adjuvant treatment had been given.

RESULTS

In a multivariate analysis the pN status, ypN status and lymph node yield were found to be independent prognostic factors for overall survival, irrespective of neo-adjuvant therapy. The LNR was also found to be a significant prognostic factor with a Hazard Ratio ranging from 1.154 (95% CI: 0.930-1.432) (LNR: 0.01-0.08) to 2.974 (95% CI: 2.452-3.606) (LNR > 0.5) in the group of patients who had surgery to begin with and from 1.381 (95% CI: 0.891-2.139) (LNR: 0.01-0.08) to 2.915 (95% CI: 2.244-3.787) (LNR > 0.5) in the group of patients who had neo-adjuvant treatment.

CONCLUSIONS

The LNR reflects the influence on survival from N-status and the lymph node yield and since LNR was shown to be a significant prognostic predictor for overall survival in patients with curatively resected stage III rectal cancer irrespective of neo-adjuvant therapy we recommend that the introduction of LNR should be considered for rectal cancer in a revised TNM classification.

Impact of Total Lymph Node Count on Staging and Survival After Neoadjuvant Chemoradiation Therapy for Rectal Cancer

PURPOSE

Current guidelines recommend that a minimum of 12 lymph nodes (LNs) be dissected to accurately stage rectal cancer patients. Neoadjuvant chemoradiation therapy (CRT) decreases the number of LNs retrieved at surgery. The purpose of this study was to assess the impact of the number of LNs dissected on overall survival (OS) for localized rectal cancer patients treated with neoadjuvant CRT.

METHODS

Treatment data were obtained on all patients treated for rectal cancer (2000-2013) in the National Oncology Data Alliance™, a proprietary database of merged tumor registries. Eligible patients were treated with neoadjuvant CRT followed by surgery and had complete data on number of positive LNs, number of LNs examined, and treatment dates (n = 4565).

RESULTS

Hazard ratios for OS decreased sequentially with increasing number of LNs examined until a maximum benefit was achieved with examination of eight LNs. On multivariate analysis, age, sex, race, marital status, grade, ypT stage, ypN stage, type of surgery, margin status, presence of pathologically confirmed metastasis at surgery, and number of LNs examined were significant predictors of OS.

CONCLUSIONS

Examination of eight or more LNs in rectal cancer patients treated with neoadjuvant CRT resulted in accurate staging and assignment into prognostic groups with an ensuing improvement in OS by stage. This study suggests that eight LNs is the threshold for an adequate lymph node dissection after neoadjuvant CRT.