Lymph node ratio versus number of affected lymph nodes as predictors of survival for resected pancreatic adenocarcinoma

The Effect of Lymph Node Harvest on Prognosis in Locally Advanced Middle-Low Rectal Cancer After Neoadjuvant Chemoradiotherapy

OBJECTIVE

The purpose of this study was to investigate the relationship between lymph node harvest and the prognosis in locally advanced rectal cancer (LARC) patients after neoadjuvant chemoradiotherapy (nCRT).

METHODS

Patients who were diagnosed with clinical LARC and treated with nCRT and radical surgery between June 2008 and July 2017 were included in this study. The relationship between lymph node retrieval and prognosis was analyzed. Other lymph node-related indicators were explored.

RESULTS

A total of 837 patients with a median follow-up of 61 (7-139) months were included in the study. The five-year DFS and OS rates of all patients were 74.9% and 82.3%, respectively. Multivariate survival analysis suggested that dissection of ≥ 12 lymph nodes did not improve OS or DFS. 7 was selected as the best cutoff value for the total number of lymph nodes retrieved by Cox multivariate analysis (χ2 = 10.072, HR: 0.503, P=0.002). Dissection of ≥ 5 positive lymph nodes (PLNs) was an independent prognostic factor for poorer DFS (HR: 2.104, P=0.004) and OS (HR: 3.471, p<0.001). A positive lymph node ratio (LNR) of more than 0.29 was also an independent prognostic factor for poorer DFS (HR: 1.951, P=0.002) and OS (HR: 2.434, p<0.001).

CONCLUSION

The recommends that at least 7 harvested lymph nodes may be more appropriate for LARC patients with nCRT. PLN and LNR may be prognostic factors for LARC patients with ypN+ after nCRT.

Re-appraising the role of lymph node status in predicting survival in resected distal cholangiocarcinoma - A meta-analysis and systematic review

This systematic review and meta-analysis aimed to confirm the prognostic value of lymph node ratio (LNR), and determine an optimal LNR cut-off for overall survival (OS) in patients with distal cholangiocarcinoma (DCC) undergoing curative surgery. We additionally aimed to provide a consolidated review of current evidence regarding prognostic significance of positive lymph node count (PLNC) and total lymph node count (TLNC). A systematic search of PubMed, EMBASE and Cochrane Library was conducted from inception to October 2020. Studies were included into meta-analysis if there was histological diagnosis, curative surgery, restriction to DCC and relevant LNR results. Quality assessment was performed using the Newcastle Ottawa Scale. Findings for 1228 patients were pooled across 6 studies. Meta-analysis delineated a dose-effect gradient in which higher LNR cut-offs correlated with larger pooled hazard ratios: 0<LNR<0.2 (HR 1.54; 95% CI 1.08-2.20; p = 0.02), LNR>0.2 (HR 3.26; 95% CI 2.07-5.13; p < 0.00001) and LNR>0.4 (HR 3.59; 95% CI 2.31-5.58; p < 0.00001) when compared against a control group of LNR = 0. LNR of 0.2 (HR 2.12; 95% CI: 1.57-2.86; p < 0.0001) was found to be a significant and ideal cut-off for prognostication of poorer OS. A review of current literature reveals an ongoing debate regarding the comparative prognostic value of differing PLNC cut-offs (0/1/3 versus 0/1/4). TLNC of 10-13 is widely reported to be the minimum necessary to ensure improved long term outcomes. PLNC and LNR are strong prognostic factors for OS in DCC. An ideal LNR cut-off of 0.2 is most significantly associated with poorer OS.

Lymph Node Ratio as a Prognostic Marker in Pancreatic Cancer Survival: A Systematic Review and Meta-Analysis

Introduction The lymph node ratio (LNR) is defined as the ratio of number of positive lymph nodes to the total number of lymph nodes harvested during surgery. The objective of this article is to investigate the efficacy of LNR as a prognostic indicator of survival in pancreatic cancer patients who have undergone surgery by meta-analysis. Methods A systematic database search was performed in MEDLINE, Embase, and Google Scholar for relevant studies that reported LNR in pancreatic cancer. Two authors independently screened the relevant articles for selection and to extract data. All studies published in English up to April 2020 were obtained, and a total of 17,128 node-positive patients in 14 studies were included in this meta-analysis. RevMan software 5.3 (Cochrane Collaboration, the Nordic Cochrane Centre, Copenhagen, Denmark) was used for conducting all statistical analyses. Results This meta-analysis demonstrated that LNR > 0.2 significantly correlated with worse survival (hazard ratio [HR]: 1.84; 95% CI: 1.74-1.94; p ≤ 0.00001) in node-positive pancreatic cancer patients. Conclusions Our findings have demonstrated that a higher LNR is a predictor of poor survival and that LNR serves as an independent prognostic marker for assessing survival using a cut-off of 20%.

Prognostic impact of lymph node status in patients after total pancreatectomy for pancreatic ductal adenocarcinoma: A strobe-compliant study

The optimal number of examined lymph nodes (ELN) for staging and impact of nodal status on survival following total pancreatectomy (TP) for pancreatic ductal adenocarcinoma (PDAC) is unclear. The aim of this study was to evaluate the prognostic impact of different lymph node status after TP for PDAC.The Surveillance, Epidemiology, and End Results (SEER) database was used to identify patients who underwent TP for PDAC from 2004 to 2015. We calculated overall survival (OS) of these patients using Kaplan-Meier analysis and Cox proportional hazards model.Overall, 1291 patients were included in the study, with 869 node-positive patients (49.5%). A cut-off points analysis revealed that 19, 19, and 13 lymph nodes best discriminated OS for all patients, node-negative patients, and node-positive patients, respectively. Higher number of ELN than the corresponding cut-off points was an independent predictor for better prognosis [all patients: hazard ratios (HR) 0.786, P = .002; node-negative patients: HR 0.714, P = .043; node-positive patients: HR 0.678, P < .001]. For node-positive patients, 1 to 3 positive lymph nodes (PLN) correlated independently with better survival compared with those with 4 or more PLN (HR 1.433, P = .002). Moreover, when analyzed in node-positive patients with less than 13 ELN, neither the number of PLN nor lymph node ratio (LNR) was associated with survival. However, when limited node-positive patients with at least 13 ELN, univariate analyses showed that both the number of PLN and LNR were associated with survival, whereas multivariate analyses demonstrated that only number of PLN was consistently associated with survival (HR 1.556, P = .004).Evaluation at least 19 lymph nodes should be considered as quality metric of surgery in patients who underwent TP for PDAC. For node-negative patients, a minimal number of 19 lymph nodes is adequate to avoid stage migration. For node-positive patients, PLN is superior to LNR in predicting survival after TP, predominantly for those with high number of ELN.

Microvascular invasion is a major prognostic factor after pancreatico-duodenectomy for adenocarcinoma

BACKGROUND

Microvascular invasion (MVI) has been proved to be poor prognostic factor in many cancers. To date, only one study published highlights the relationship between this factor and the natural history of pancreatic cancer. The aim of this study was to assess the impact of MVI, on disease-free survival (DFS) and overall survival (OS), after pancreatico-duodenectomy (PD) for pancreatic head adenocarcinoma. Secondarily, we aim to demonstrate that MVI is the most important factor to predict OS after surgery compared with resection margin (RM) and lymph node (LN) status.

MATERIALS AND METHODS

Between January 2015 and December 2017, 158 PD were performed in two hepato-bilio-pancreatic (HBP) centers. Among these, only 79 patients fulfilled the inclusion criteria of the study. Clinical-pathological data and outcomes were retrospectively analyzed from a prospectively maintained database.

RESULTS

Of the 79 patients in the cohort, MVI was identified in 35 (44.3%). In univariate analysis, MVI (P = .012 and P < .0001), RM (P = .023 and P = .021), and LN status (P < .0001 and P = .0001) were significantly associated with DFS and OS. A less than 1 mm margin clearance did not influence relapse (P = .72) or long-term survival (P = .48). LN ratio > 0.226 had a negative impact on OS (P = .044). In multivariate analysis, MVI and RM persisted as independent prognostic factors of DFS (P = .0075 and P = .0098, respectively) and OS (P < .0001 and P = .0194, respectively). Using the likelihood ratio test, MVI was identified as the best fit to predict OS after PD for ductal adenocarcinomas compared with the margin status model (R0 vs R1) (P = .0014).

CONCLUSION

The MVI represents another major prognostic factor determining long-term outcomes.

A Single-Institution Validation Study of Lymph Node Staging By the AJCC 8th Edition for Patients with Pancreatic Head Cancer: A Proposal to Subdivide the N2 Category

BACKGROUND

According to the revised staging of the American Joint Committee on Cancer, 8th edition (AJCC8), the N category in pancreatic ductal adenocarcinoma is classified as N0 (0), N1 (1-3), and N2 (≥ 4) based on the number of metastatic lymph nodes (LNs). This study aimed to validate this classification and analyze cutoff values of metastatic LN numbers.

METHODS

Patients with pancreatic head ductal adenocarcinoma who underwent pancreaticoduodenectomy at our institution between 2005 and 2016 without preoperative therapy were retrospectively analyzed. The patients were staged by AJCC8, and prognostic analyses were performed. The best cutoff value for the metastatic LN number was determined by the minimum P value approach.

RESULTS

In 228 of 309 patients, LN metastases were found (median number of examined LNs, 41). The median survival time (MST) was 56 months in the N0 group, 34 months in the N1 group, and 20 months in the N2 group (N0 vs N1: P = 0.023; N1 vs N2: P < 0.001). The best cutoff number of metastatic LNs was 4 for patients with LN metastases and 7 for patients with N2 disease. The MST for patients with four to six positive nodes (N2a) was significantly longer than for those with seven or more positive nodes (N2b) (24.0 vs 19.1 months: P = 0.012). For N2b patients, conventional adjuvant chemotherapy did not show survival benefits (P = 0.133), and overall survival did not differ significantly from that for patients with para-aortic LN metastasis (P = 0.562).

CONCLUSION

The N staging of AJCC8 was valid. Clinicians should regard N2b as similar to distant LN metastasis, and more intensive adjuvant therapy may be indicated for this group.

Impact of tumor size on survival of patients with resected pancreatic ductal adenocarcinoma: a systematic review and meta-analysis

Background

The impact of tumor size on prognosis for surgically treated patients with pancreatic ductal adenocarcinoma (PDAC) remains controversial. A systematic review and meta-analysis was performed to evaluate this issue.

Methods

Relevant studies published from January 2000 to June 2017 were identified through EMBASE and PUBMED. Data were pooled for meta-analysis using Review Manager 5.3.

Results

Twenty eight observational studies involving a total of 23,945 patients were included. Tumors > 2 cm was associated with poor prognosis: the pooled hazard ratio (HR) estimate for overall survival was 1.52 (95% confidence interval [CI]: 1.41–1.64; P < 0.0001) by univariate analysis and 1.61 (95% CI: 1.35–1.91; P < 0.0001) by multivariate analysis; the pooled HR estimate for disease-free survival was 1.74 (95% CI: 1.46–2.07; P < 0.0001) by univariate analysis and 1.38 (95% CI: 1.12–1.68; P = 0.002) by multivariate analysis. When compared with patients with tumors ≤2 cm, those with the tumors > 2 cm had higher incidences of lymph node metastasis, poor tumor differentiation, lymph vessel invasion, vascular invasion, perineural invasion, and positive intraoperative peritoneal cytology.

Conclusion

These data demonstrate that PDAC size > 2 cm is an independent predictive factor for poor prognosis after surgical resection and associated with more aggressive tumor biology.

Nomograms predict long-term survival for patients with periampullary adenocarcinoma after pancreatoduodenectomy

BACKGROUND

The prognosis of patients with periampullary adenocarcinoma after pancreatoduodenectomy is diverse and not yet clearly illustrated. The aim of this study was to develop a nomogram to predict individual risk of overall survival (OS) and progression-free survival (PFS) in patients with periampullary adenocarcinoma after pancreatoduodenectomy.

METHODS

A total of 205 patients with periampullary adenocarcinoma after pancreatoduodenectomy were retrospectively included. OS and PFS were evaluated by the Kaplan-Meier method. Two nomograms for predicting OS and PFS were established, and the predictive accuracy was measured by the concordance index (Cindex) and calibration plots.

RESULTS

Lymph node ratio (LNR), carbohydrate antigen 19-9 (CA19-9) and anatomical location were incorporated into the nomogram for OS prediction and LNR, CA19-9; anatomical location and tumor differentiation were incorporated into the nomogram for PFS prediction. All calibration plots for the probability of OS and PFS fit well. The Cindexes of the nomograms for OS and PFS prediction were 0.678 and 0.68, respectively. The OS and PFS survival times were stratified significantly using the nomogram-predicted survival probabilities.

CONCLUSIONS

The present nomograms for OS and PFS prediction can provide valuable information for tailored decision-making for patients with periampullary adenocarcinoma after pancreatoduodenectomy.

ACR Appropriateness Criteria® Resectable Pancreatic Cancer

Management of resectable pancreatic adenocarcinoma continues to present a challenge due to a paucity of high-quality randomized studies. Administration of adjuvant chemotherapy is widely accepted due to the high risk of systemic spread associated with pancreatic adenocarcinoma, but the role of radiation therapy is less clear. This paper reviews literature associated with resectable pancreatic cancer to include prognostic factors to aid in the selection of patients appropriate for adjuvant therapies. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Prognostic Evaluation of Vimentin Expression in Correlation with Ki67 and CD44 in Surgically Resected Pancreatic Ductal Adenocarcinoma

Purpose. Radical surgical resection with adjuvant chemotherapy or chemo-radiotherapy is the most effective treatment for pancreatic ductal adenocarcinoma (PDAC). However, relatively few studies investigate the prognostic significance of biological markers in PDAC. This study aims to look into the expressions of vimentin, Ki67, and CD44 in PDAC surgical specimens and their potential prognostic implications in survival. Method. The study was designed as retrospective, and vimentin, Ki67, and CD44 expressions were evaluated by immunohistochemistry in 53 pancreatic ductal adenocarcinoma cases. Overall survival was assessed by the Kaplan–Meier method. Results. Patients' median age was 68 years. The median survival was 18 months. The tumors were T3-4 in 40/53 (75.5%), and metastases in lymph nodes were found in 42 out of 53 (79.2%) cases. On multivariate analysis, the size of primary tumor (p < 0.001), the surgical resection margin status (p = 0.042), and vimentin expression (p = 0.011) were independently correlated with overall survival. Conclusions. Long-term survival after resection of PDAC is still about 15%. Vimentin expression is a potential independent adverse prognostic molecular marker and should be included in histopathological reports. Also, CD44 expression correlates with high Ki67, vimentin positivity, and N stage and may represent a potential target of novel therapeutic modalities in pancreatic adenocarcinoma patients.

Prognostic impact of nodal statuses in patients with pancreatic ductal adenocarcinoma

BACKGROUND

The present study aimed to clarify the prognostic impact of nodal statuses in pancreatic ductal adenocarcinoma (PDAC) after potentially curative pancreatectomy.

METHODS

In 110 patients with >10 examined lymph nodes (ELNs), we investigated how nodal statuses were associated with postoperative survival. Nodal statuses included the number of positive LNs (PLNs); the ratio of PLNs to ELNs (lymph node ratio; LNR); and the location of regional LN metastases, classified as group one (peripancreatic area) and group 2 (outside the peripancreatic area). The maximum χ² value, provided by a Cox proportional hazards model, was used to determine the optimal cutoff value for the number of PLNs and the LNR.

RESULTS

The median numbers of ELNs and metastatic LNs were 33 and 2, respectively. Median survival was longer in patients with ≤3 PLNs (37.5 months), LNR <0.11 (36.1 months), and group 1 LN metastases (37.5 months) compared to in patients with ≥4 PLNs (23.7 months), LNR ≥0.11 (23.9 months), and group 2 LN metastases (22.8 months), respectively. Multivariate analyses revealed that all three investigated nodal statuses were independent factors associated with survival: HR of 2.38 and p = 0.0006 for the location of LN metastases, HR of 1.92 and p = 0.0071 for the number of PLNs, and HR of 1.89 and p = 0.010 for the LNR.

CONCLUSIONS

Three nodal statuses-the number of PLNs, the LNR, and the location of LN metastases-could stratify postoperative survival among PDAC patients with an adequate number of examined LNs after pancreatectomy.

Less than 12 lymph nodes in the surgical specimen after neoadjuvant chemo-radiotherapy: an indicator of tumor regression in locally advanced rectal cancer?

BACKGROUND

The number of lymph node retrieved in the surgical specimen is important for tumor staging and has paramount impact on prognosis in colorectal cancer and imitates the adequacy of lymph node surgical clearance. The paucity of lymph node yields in patients undergoing resection after preoperative chemo radiotherapy (CRT) in rectal cancer has seen. Lower total number of lymph nodes in the total mesoractal excision (TME) specimen after CRT, could a marker of better tumor response.

METHODS

We retrospectively reviewed the prospectively managed data of patients underwent excision for rectal cancer, who treated by neoadjuvant radiotherapy with or without chemotherapy in locally advanced rectal cancer. From 2010 to 2014, 364 patients underwent rectal cancer surgery, of which ninety-one treated with neoadjuvant treatment. Standard surgical and pathological protocols were followed. Patients were categorized into two groups based on the number of total harvested lymph nodes with group 1, having 12 or more nodes harvested, and group 2 including patients who had <12 lymph nodes harvested. The total number of lymph nodes retrieved from the surgical specimen was correlated with grade of tumor regression with neoadjuvant treatment.

RESULTS

Out of 91 patients, 38 patients (42%) had less than 12 lymph nodes examined in specimen. The difference in median number of lymph nodes was observed significantly as 9 (range, 2-11) versus 16 (range, 12-32), in group 2 and 1, respectively (P<0.01). Patients with fewer lymph node group were comparable with respect to age, BMI, pre-operative staging, neoadjuvant treatment. Pathological complete response in tumor pCR was seen with significantly higher rate (40% vs. 26%, P<0.05) in group 2. As per Mandard criteria, there was significant difference in tumor regression grade (TRG) between both the groups (P<0.05). Among patients with metastatic lymph nodes, median LNR was lower in <12 lymph nodes group at 0.167 (range, 0.09-0.45) versus 0.187 (range, 0.05-0.54), difference was not statistically significant (P=0.81).

CONCLUSIONS

Retrieval of fewer than 12 lymph nodes in surgical specimen of rectal cancer who had received neo-adjuvant radiotherapy with or without chemotherapy should be considered as a good indicator of tumor response with better local disease control, and a good prognostic factor, rather than as a pointer of poor diligence of the surgical and pathological assessment.

A systematic review of the prognostic value of lymph node ratio, number of positive nodes and total nodes examined in pancreatic ductal adenocarcinoma

BACKGROUND Pancreatic ductal adenocarcinoma is the most common pancreatic cancer. Five-year overall survival is currently 3.3-6.0%. The aim of this review was to evaluate the prognostic value of lymph node ratio, number of positive nodes and total nodes examined on overall survival rate following pancreatic resection. MATERIALS AND METHODS A literature search was conducted of MEDLINE, EMBASE, the Cochrane Library and Central Register of Controlled Trials and the Cochrane Database of Systematic Review databases, from January 1996 to January 2016. RESULTS Overall, 19 studies including 4,883 patients examined the relationship between lymph node ratio and overall survival. A high lymph node ratio was associated with decreased overall survival in 17 studies. A total of 12 studies examined the relationship between the number of positive nodes and overall survival, and 11 studies revealed that an increase in the number of positive nodes was associated with decreased overall survival. In 15 studies examining the relationship between the total nodes examined and overall survival, there was no association with overall survival in 12 studies. CONCLUSIONS Lymph node ratio and number of positive nodes are factors associated with overall survival in pancreatic ductal adenocarcinoma, but not total nodes examined.

Re-evaluation of classical prognostic factors in resectable ductal adenocarcinoma of the pancreas

Pancreatic ductal adenocarcinoma carries a poor prognosis with annual deaths almost matching the reported incidence rates. Surgical resection offers the only potential cure. Yet, even among patients that undergo tumor resection, recurrence rates are high and long-term survival is scarce. Various tumor-related factors have been identified as predictors of survival after potentially curative resection. These factors include tumor size, lymph node disease, tumor grade, vascular invasion, perineural invasion and surgical resection margin. This article will re-evaluate the importance of these factors based on recent publications on the topic, with potential implications for treatment and outcome in patients with pancreatic cancer.

Preoperative Volume-Based PET Parameter, MTV2.5, as a Potential Surrogate Marker for Tumor Biology and Recurrence in Resected Pancreatic Cancer

This study aims to evaluate the role of volume-based positron emission tomography parameters as potential surrogate markers for tumor recurrence in resected pancreatic cancer. Between January 2008 and October 2012, medical records of patients who underwent surgical resection for pancreatic ductal adenocarcinoma and completed ¹⁸F-fluorodeoxyglucose positron emission tomography/CT as a part of preoperative staging work-up were retrospectively reviewed. Not only clinicopathologic variables but also positron emission tomography parameters such as SUVmax, MTV2.5 (metabolic tumor volume), and TLG (total lesion glycolysis) were obtained. Twenty-six patients were women and 31 were men with a mean age of 62.9 ± 9.1 years. All patients were preoperatively determined to resectable pancreatic cancer except 1 case with borderline resectability. R0 resection was achieved in all patients and 45 patients (78.9%) received postoperative adjuvant chemotherapy with or without radiation therapy. Median overall disease-free survival was 12.8 months with a median overall disease-specific survival of 25.1 months. SUVmax did not correlate with radiologic tumor size (P = 0.501); however, MTV2.5 (P = 0.001) and TLG (P = 0.009) were significantly associated with radiologic tumor size. In addition, MTV2.5 (P < 0.001) and TLG (P < 0.001) were significantly correlated with a tumor differentiation. There were no significant differences in TLG and SUVmax according to lymph node ratio; only MTV2.5 was related to lymph node ratio with marginal significance (P = 0.055). In multivariate analysis, lymph node ratio (Exp [β] = 2.425, P = 0.025) and MTV2.5 (Exp[β] = 2.273, P = 0.034) were identified as independent predictors of tumor recurrence following margin-negative resection. Even after tumor size-matched analysis, MTV2.5 was still identified as significant prognostic factor in resected pancreatic cancer (P < 0.05). However, preoperative neoadjuvant treatment attenuated adverse oncologic impact of high preoperative MTV2.5 (P = 0.210). Preoperatively determined volume-based PET parameter, MTV2.5, can potentially be used as a surrogate marker to estimate tumor biology and tumor recurrence. Individual treatment strategies for pancreatic cancer can be suggested based on patients' preoperative MTV2.5.

The lymphatic system and pancreatic cancer

This review summarizes current knowledge of the biology, pathology and clinical understanding of lymphatic invasion and metastasis in pancreatic cancer. We discuss the clinical and biological consequences of lymphatic invasion and metastasis, including paraneoplastic effects on immune responses and consider the possible benefit of therapies to treat tumors that are localized to lymphatics. A review of current techniques and methods to study interactions between tumors and lymphatics is presented.

Prognostic value of lymph node ratio in survival of patients with locally advanced rectal cancer

BACKGROUND

The lymph node ratio (LNR) has been shown to be an important prognostic factor in patients with gastric, breast, pancreatic and colorectal cancer. We investigated the prognostic impact of the LNR in addition to TNM classification in patients with locally advanced rectal cancer.

METHODS

We retrospectively analyzed patients who underwent curative resection for locally advanced rectal cancer between July 2005 and December 2010. We determined the LNR cutoff value using a receiver operating characteristic curve. The Kaplan-Meier method was used to estimate survival curves, while Cox regression analyses were used to evaluate the relationship between LNR and survival.

RESULTS

We included 180 patients aged 28-83 years with median follow-up of 41.8 months. The median number of lymph nodes examined and lymph nodes involved were 11.5 and 4, respectively, and the median LNR was 0.366. An LNR of 0.19 (19%) was the cutoff point to separate patients with regard to median overall survival. Median overall survival was 64.2 months for patients with an LNR of 0, 59.1 for an LNR of 0.19 or less and 37.6 for an LNR greater than 0.19 (p = 0.004). The median disease-free survival was 32.9 months for patients with an LNR of 0, 30.4 for an LNR of 0.19 or less and 17.8 for an LNR greater than 0.19 (p = 0.002).

CONCLUSION

Our results suggest that LNR should be considered an additional prognostic factor in patients with locally advanced rectal cancer.

Impact of Lymph Node Ratio on Oncologic Outcomes in ypStage III Rectal Cancer Patients Treated with Neoadjuvant Chemoradiotherapy followed by Total Mesorectal Excision, and Postoperative Adjuvant Chemotherapy

PURPOSE

To evaluate the prognostic impact of the lymph node ratio (LNR) in ypStage III rectal cancer patients who were treated with neoadjuvant chemoradiotherapy (NCRT).

MATERIALS AND METHODS

We retrospectively reviewed the data of 638 consecutive patients who underwent NCRT followed by total mesorectal excision, and postoperative adjuvant chemotherapy for rectal cancer from 2004 to 2011. Of these, 125 patients were positive for lymph node (LN) metastasis and were analyzed in this study.

RESULTS

The median numbers of examined and metastatic LNs were 17 and 2, respectively, and the median LNR was 0.143 (range, 0.02-1). Median follow-up time was 55 months. In multivariate analyses, LNR was an independent prognostic factor for overall survival (OS) (hazard ratio [HR] 2.17, p = 0.041), disease-free survival (DFS) (HR 2.28, p = 0.005), and distant metastasis-free survival (DMFS) (HR 2.30, p = 0.010). When ypN1 patients were divided into low (low LNR ypN1 group) and high LNR (high LNR ypN1 group) according to a cut-off value of 0.152, the high LNR ypN1 group had poorer OS (p = 0.043) and DFS (p = 0.056) compared with the low LNR ypN1 group. And there were no differences between the high LNR ypN1 group and the ypN2 group in terms of the OS (p = 0.703) and DFS (p = 0.831).

CONCLUSIONS

For ypN-positive rectal cancer patients, the LNR was a more effective prognostic marker than the ypN stage, circumferential resection margin, or tumor regression grade after NCRT, and could be used to discern the high-risk group among ypN1 patients.

The Addition of Postoperative Chemotherapy is Associated with Improved Survival in Patients with Pancreatic Cancer Treated with Preoperative Therapy

BACKGROUND

Preoperative/neoadjuvant therapy (NT) is increasingly utilized for the treatment of pancreatic ductal adenocarcinoma (PDAC). However, little data exist regarding information on the use of additional postoperative therapy following NT. The lymph node ratio (LNR) is a prognostic marker of oncologic outcomes after NT and resection. In this study, we evaluated the effectiveness of postoperative therapy following NT, stratified by LNR.

METHODS

A prospective tumor registry database was queried to identify patients with PDAC who underwent resection following NT from 1990 to 2008. Clinicopathologic factors were compared to identify associations with overall survival (OS) and time to recurrence (TTR) based on postoperative chemotherapy status.

RESULTS

Thirty-six (14 %) of the 263 patients received additional postoperative therapy. No differences were observed in the pathologic characteristics between patients who received postoperative chemotherapy and those who did not. The median LNR was 0.12 for patients with N + disease. Following NT, the administration of postoperative therapy was associated with improved median OS (72 vs. 33 months; p = 0.008) for patients with an LNR < 0.15. There was no association between postoperative chemotherapy and OS for patients with LNR ≥ 0.15. Multivariate analysis demonstrated that the administration of postoperative systemic therapy in patients with a low LNR was associated with a reduced risk of death (hazard ratio 0.49; p = 0.02).

CONCLUSION

Postoperative chemotherapy after NT in patients with low LNR is associated with improved oncologic outcomes.

Extent of lymphadenectomy to associate with pancreaticoduodenectomy in patients with pancreatic head cancer for better tumor staging

OBJECTIVES

To define the extent of lymphadenectomy to associate with surgery for pancreatic head cancer.

BACKGROUND

Pancreaticoduodenectomy with extended lymphadenectomy fails to prolong patient survival.

METHODS

Prospective randomized and nonrandomized controlled trials (RCTs and NRCTs), meta-analyses, retrospective reviews, consensus conferences and pre- and intraoperative diagnoses of lymph node (LN) metastases were retrieved. Standard and extended lymphadenectomies were reviewed, including their effects on postoperative complications, mortality rate and long-term survival. The minimum total number of LN examined (TNLE) for adequate tumor staging, and the incidence of metastasis to each LN station were also considered. A pros and cons analysis was performed on the removal of each LN station.

RESULTS

Eleven retrospective studies (2514 patients), five prospective NRCTs (545 patients), and five prospective RCTs (586 patients) described different lymphadenectomies, which obtained similar long-term results. Five meta-analyses showed they did not influence long-term survival. However, N status is an important component of tumor staging. The recommended minimum TNLE is 15. The percent incidence of metastasis to each LN station was calculated considering at least 385 and up to 3725 patients. Preoperative imaging and intraoperative exploration frequently fail to identify metastatic nodes. A pros and cons analysis suggests that lymph node status is better established removing the following LN stations: 6, 8a-p, 12a-b-c, 13a-b, 14a-b-c-d, 16b1, 17a-b. Metastasis to 16b1 LNs significantly worsens prognosis. Their removal and frozen section examination, before proceeding with resection, may contraindicate resection.

CONCLUSION

A standard lymphadenectomy demands an adequate TNLE and removal of the LN stations metastasizing more frequently, without increasing the surgical risk.

The number and ratio of positive lymph nodes affect pancreatic cancer patient survival after neoadjuvant therapy and pancreaticoduodenectomy

AIMS

This study is to examine the significance of the number and ratio of positive nodes in post-neoadjuvant therapy pancreaticoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC).

METHODS AND RESULTS

Our study population consisted of 398 consecutive PDAC patients, who completed neoadjuvant therapy and PD between 1999 and 2012. Lymph node status was classified as ypN0 (node-negative), ypN1 (1-2 positive nodes) and ypN2 (≥3 positive nodes) and correlated with disease-free survival (DFS) and overall survival (OS). The ypN0, ypN1 and ypN2 was present in 183 (46.0%), 117 (29.4%) and 98 (24.6%) patients, respectively. Additionally, 162 (40.7%) had a lymph node ratio (LNR) ≤0.19 and 53 (13.3%) had a LNR >0.19. Patients with ypN1 disease had shorter DFS and OS than those with ypN0 disease, but better DFS and OS than those with ypN2 disease (P < 0.05). Similarly, patients with a LNR ≤ 0.19 had better DFS and OS than those with a LNR > 0.19 (P < 0.001). In multivariate analysis, both the number of positive nodes and LNR were independent prognostic factors for DFS and OS.

CONCLUSIONS

Subclassification of post-therapy node-positive group into ypN1 (1-2 positive nodes) and ypN2 (≥3 positive nodes) should be incorporated into the American Joint Committee on Cancer (AJCC) staging of PDAC patients.

Comparison of Number Versus Ratio of Positive Lymph Nodes in the Assessment of Lymph Node Status in Extrahepatic Cholangiocarcinoma

BACKGROUND

This study aimed to compare the utility of the number of positive lymph nodes with the lymph node ratio (LNR) in predicting survival after resection of extrahepatic cholangiocarcinoma.

METHODS

A retrospective analysis of 142 consecutive patients who underwent radical resection of extrahepatic cholangiocarcinoma was performed. A total of 3066 regional lymph nodes were resected. The median number of nodes per patient was 21. The optimal cutoff values for the number of positive nodes and the LNR were determined using the Chi square scores calculated by the Cox proportional hazards regression model.

RESULTS

Nodal disease was found in 59 patients (42 %). In the subsequent analysis of the impact that nodal status has on survival, 18 patients with R1/2 resection and 6 patients with paraaortic nodal disease who did not survive for more than 5 years after resection were excluded. The optimal cutoff value for the number of positive nodes was 1, and the optimal cutoff value for the LNR was 5 %. Univariate analysis identified both the number of positive nodes (0, 1, or ≥2; P = 0.005) and the LNR (0, 0-5, or >5 %; P = 0.007) as significant prognostic factors. Multivariate analysis identified the number of positive nodes but not the LNR as an independent prognostic factor (P = 0.012). The 5-year survival rates were 64 % for the patients with no positive nodes, 46 % for the patients with one positive node, and 28 % for the patients with two or more positive nodes.

CONCLUSIONS

The number of positive lymph nodes predicts survival better than the LNR after resection of extrahepatic cholangiocarcinoma, provided that nodal evaluation is sufficient.

Impact of lymph node ratio on survival in patients with pancreatic and periampullary cancer

Background

According to some studies, the number of lymph nodes with metastases in relation to the total number of removed lymph nodes, the lymph node ratio (LNR), is one of the most powerful predictors of survival after resection in patients with pancreatic cancer. However, contradictory results have been reported, and small sample sizes of the cohorts and different definitions of a microscopic positive resection margin (R1) hamper the interpretation of data.

Methods

The predictive value of LNR for 3-year survival was assessed using a Cox proportional hazards model. From 1992 to 2012, all patients with pancreatic and periampullary cancer operated on with pancreatoduodenectomy were selected from a database. Clinicopathological characteristics were analysed. Microscopic positive resection margin was defined as the microscopic presence of tumour cells within 1 mm of the margins. A nomogram was created.

Results

Some 760 patients were included. Predictive factors for death in 350 patients with pancreatic ductal adenocarcinoma included in the nomogram were: R1 resection (hazard ratio (HR) 1·55, 95 per cent c.i. 1·07 to 2·25), poor tumour differentiation (HR 2·78, 1·40 to 5·52), LNR above 0·18 (HR 1·75, 1·13 to 2·70) and no adjuvant therapy (HR 1·54, 1·01 to 2·34). The C statistic was 0·658 (0·632 to 0·698), and calibration was good (Hosmer–Lemeshow χ2 = 5·67, P =0·773). LNR and poor tumour differentiation (HR 4·51 and 3·30 respectively) were also predictive in patients with distal common bile duct (CBD) cancer. LNR, R1 resection and jaundice were predictors of death in patients with ampullary cancer (HR 7·82, 2·68 and 1·93 respectively).

Conclusion

LNR is a common predictor of poor survival in pancreatic, distal CBD and ampullary cancer.

Time-related changes in the prognostic significance of the total number of examined lymph nodes in node-negative pancreatic head cancer

BACKGROUND AND OBJECTIVES

The aim of study was to assess time trends in the association between the total number of lymph nodes examined (TNLE) and survival in patients operated for adenocarcinoma of the head of pancreas.

METHODS

Patients operated for node-negative adenocarcinoma of the head of pancreas between 1988 and 2007 were identified from the Surveillance, Epidemiology and End Results (SEER) database. Patients diagnosed between 1988 and 2002 were compared to those diagnosed between 2003 and 2007.

RESULTS

A total of 3,406 patients were included. Although TNLE was associated with survival, the effect was not uniform. Compared to patients with >12 TNLE, survival decreased with lower TNLE (4-12 TNLE: hazard ratio [HR] 1.27, 95% CI 1.10-1.46; <4 TNLE: HR 1.39, 95% CI 1.20-1.60) among patients diagnosed between 1988 and 2002. In contrast, for those diagnosed between 2003 and 2007, while there was decreased survival for those with <4 nodes (HR 1.44, 95% CI 1.22-1.71), no effect was seen for patients with TNLE 4-12 (HR 0.98, 95% CI 0.85-1.14).

CONCLUSION

The prognostic significance of the TNLE in patients operated for adenocarcinoma of the head of the pancreas is not constant over time.

Neoadjuvant therapy is associated with a reduced lymph node ratio in patients with potentially resectable pancreatic cancer

BACKGROUND

The use of neoadjuvant therapy (NAC) for the treatment of potentially resectable pancreatic cancer remains controversial. In this study, we sought to evaluate cancer-specific endpoints in patients undergoing a NAC versus a surgery-first (SF) approach with specific emphasis on lymph node metastases.

METHODS

A total of 222 patients who underwent NAC and 85 patients who underwent SF were identified from 1990 to 2008 and compared for cancer-related endpoints. Peripancreatic lymph nodes from 135 neoadjuvant therapy patients were evaluated for histologic tumor regression.

RESULTS

Patients who underwent NAC followed by surgery had improved overall survival and time to local recurrence compared with the SF approach. NAC patients were less likely to have lymph node metastases (p = 0.001), lymphovascular invasion (LVI), and had smaller tumors. On multivariate analysis, lymph node positivity was associated with SF, tumor size, and the presence of LVI. NAC patients with N0 disease had equivalent outcomes to patients with a low-LNR (0.01-0.15), whereas patients with a LNR >0.15 had reduced survival, and time to local and distant recurrence. Ten of 135 (7.4 %) NAC patients had evidence of tumor regression in at least one lymph node.

CONCLUSIONS

Patients with potentially resectable PDAC selected to undergo NAC had improved survival and longer time to recurrence. Although some of these differences may be related to improvements in multimodality therapy completion rates, tumor regression in lymph node metastases exists and may demonstrate a biologic benefit of NAC compared with a SF approach.

Tricks and tips in pancreatoduodenectomy

Pancreaticoduodenectomy (PD) is the standard surgical treatment for tumors of the pancreatic head, proximal bile duct, duodenum and ampulla, and represents the only hope of cure in cases of malignancy. Since its initial description in 1935 by Whipple et al, this complex surgical technique has evolved and undergone several modifications. We review three key issues in PD: (1) the initial approach to the superior mesenteric artery, known as the artery-first approach; (2) arterial complications caused by anatomic variants of the hepatic artery or celiac artery stenosis; and (3) the extent of lymphadenectomy.

Prognostic assessment of different lymph node staging methods for pancreatic cancer with R0 resection: pN staging, lymph node ratio, log odds of positive lymph nodes

BACKGROUND AND AIMS

Survival after surgical resection of pancreatic adenocarcinoma is poor. Several prognostic factors such as the status of the resection margin, lymph node status, or tumour grading have been identified. The aims of the present study were to evaluate and compare the prognostic assessment of different lymph nodes staging methods: standard lymph node (pN) staging, metastatic lymph node ratio (LNR), and log odds of positive lymph nodes (LODDS) in pancreatic cancer after pancreatic resection.

MATERIALS AND METHODS

Data were retrospectively collected from 143 patients who had undergone R0 pancreatic resection for pancreatic ductal adenocarcinoma. Survival curves (Kaplan-Meier and Cox proportional hazard models), accuracy, and homogeneity of the 3 methods (LNR, LODDS, and pN) were compared to evaluate the prognostic effects.

RESULTS

Multivariate analysis demonstrated that LODDS and LNR were an independent prognostic factors, but not pN classification. The scatter plots of the relationship between LODDS and the LNR suggested that the LODDS stage had power to divide patients with the same ratio of node metastasis into different groups. For patients in each of the pN or LNR classifications, significant differences in survival could be observed among patients in different LODDS stages.

CONCLUSION

LODDS and LNR are more powerful predictors of survival than the lymph node status in patients undergoing pancreatic resection for ductal adenocarcinoma. LODDS allows better prognostic stratification comparing LNR in node negative patients.

Prognostic value of the lymph node ratio after resection of periampullary carcinomas

BACKGROUND

Data have indicated that the lymph node ratio (LNR) may be a better prognostic indicator than lymph node status in pancreatic cancer.

OBJECTIVES

To analyse the value of the LNR in patients undergoing resection for periampullary carcinomas.

METHODS

A cut off value of 0.2 was assigned to the LNR in accordance with published studies. The impact of histopathological factors including a LNR was analysed using Kaplan-Meier and Cox regression methods.

RESULTS

In total, 551 patients undergoing a resection (January 2000 to December 2010) were analysed. The median lymph node yield was 15, and 198 (34%) patients had a LNR > 0.2. In patients with a LNR of > 0.2, the median overall survival (OS) was 18 versus 33 months in patients with an LNR < 0.2 (P < 0.001). Univariate analysis demonstrated a LNR > 0.2, T and N stage, vascular or perineural invasion, grade and resection margin status to be significantly associated with OS. On multivariate analysis, only a LNR > 0.2, vascular or perineural invasion and margin positivity remained significant. In N1 disease, a LNR was able to distinguish survival in patients with a similar lymph node burden, and correlated with more aggressive tumour pathological variables.

CONCLUSION

A LNR > 0.2, and not lymph note status, is an independent prognostic factor for OS indicating the LNR should be utilized in outcome stratification.

Clinical and pathologic features influencing survival in patients undergoing pancreaticoduodenectomy for pancreatic adenocarcinoma

OBJECTIVE

The aim of the study was to determine the clinicopathological features that influence survival in patients with resected pancreatic ductal adenocarcinoma (PDA).

METHODS

The study used a single institution retrospective review of patients undergoing pancreaticoduodenectomy (PD) for PDA from 1993 to 2010.

RESULTS

Two hundred forty-six consecutive cases of resected PDA were identified: 128 males (52 %), median age 68 years. Median hospital length of stay was 8 days and 30-day mortality rate was 2.4 %. There were 101 (41.1 %) postoperative complications, 77 % of which were Dindo-Clavien Grade 3 or less. Overall survival was 85, 63, 25, and 15 % at 6 months, 1 year, 3 years, and 5 years, respectively, with a median survival of 17 months. Multivariate Cox proportional hazard modeling demonstrated lymph node ratio was negatively correlated with survival at all time points. Preoperative hypertension was a poor prognostic factor at 6 months, 3 years, and 5 years. The absence of postoperative complications was protective at 6 months whereas pancreatic leaks were associated with worse survival at 6 months. Abdominal pain on presentation, operative time, and estimated blood loss were also associated with decreased survival at various time points.

CONCLUSION

The strongest prognostic variable for short- and long-term survival after PD for PDA is lymph node ratio. Short-term survival is influenced by the postoperative course.

Revisiting the concept of lymph node metastases of pancreatic head cancer: number of metastatic lymph nodes and lymph node ratio according to N stage

BACKGROUND

Some suggest that metastatic lymph node ratio (LNR) may be prognostic of survival in patients with pancreatic cancer. However, this phenomenon was confused by inclusion of node-negative patients in the analysis. The present study was designed to evaluate the prognostic impact of metastatic LNR and the absolute number of metastatic LNs in patients resected for pancreatic cancer.

METHODS

Data were collected from 398 patients who underwent curative surgery for pancreatic head cancer at Seoul National University Hospital. Long-term survival was analyzed according to LNR and absolute number of metastatic LNs.

RESULTS

Of the patients, 227 (57.0 %) had LN metastasis. The mean numbers of total retrieved and metastatic LNs were 19.5 and 1.9, respectively, and the mean LNR was 0.11. Median overall survival (OS) of patients was significantly higher in N0 than in N1 patients after curative resection (25.4 vs. 14.8 months, p < 0.001). Median OS was significantly lower in patients with 1 than in those with 0 positive LNs (17.3 vs. 25.4 months, p = 0.001). Among N1 patients, those with 0 < LNR ≤ 0.2 had comparable prognosis than those with >0.2 LNR (median OS 17.2 vs. 12.8 months, p = 0.096), and the number of metastatic LNs did not correlate with median OS (p = 0.365).

CONCLUSIONS

The presence of a single positive metastatic LN was associated with significantly poorer OS in patients with pancreatic cancer. When LN metastasis was present, the number of metastatic LNs and LNR had limited prognostic relevance.

Redefining the R1 resection for pancreatic ductal adenocarcinoma: tumour lymph nodal burden and lymph node ratio are the only prognostic factors associated with survival

INTRODUCTION

The presence of positive nodal disease (LND) and the number of lymph nodes involved (LNB) are known to be significant prognostic markers for resected adenocarcinoma of the pancreas. In addition, the ratio of the number of involved nodes to the number of nodes resected known as the lymph node ratio (LNR) is emerging as an important prognostic marker. The role of the resection margin (RM) as presently defined (R1 ≤ 1 mm) is unclear as results differ based on the dataset. The aim of this study was to assess the impact of nodal disease and a redefined RM on outcome.

MATERIAL AND METHODS

Retrospective analysis of pancreatic head resections for adenocarcinomas from 2003-2009. The RM was re-analysed based on tumour clearance and categorized into: histopathological evidence of a tumour; ≤ 0.5 mm, ≤ 1 mm, ≤ 1.5 mm, or ≤ 2.0 mm of the actual surgical resection margin. The impact of histopathological variables on cancer-specific survival (CSS) and disease-free survival (DFS) was analysed.

RESULTS

LND, LNB and LNR were independent prognostic markers for CSS (P = 0.048, 0.003, 0.016) but, did not influence DFS. A LNR < 0.143 was associated with a higher CSS [38.16 ± 4.69 versus 20.59 ± 2.20 months, P = 0.0042, hazard ratio (HR) 3.74 (95% confidence interval (CI) 1.52-9.23)]. An R1 RM was not associated with CSS or DFS on multivariate analysis, irrespective of the distance. LNB and LNR maintained independent significance irrespective of the size of the RM.

CONCLUSION

LNB and LNR are the only prognostic factors for CSS in patients with pancreatic head adenocarcinoma, but do not predict recurrence. Microscopic RMs does not seem to influence the outcome even when redefined. Further prospective studies are indicated to substantiate these findings.

Tumor-positive resection margins reflect an aggressive tumor biology in pancreatic cancer

BACKGROUND

Resection margin status has been shown to impact outcomes for pancreatic adenocarcinoma (PAC), yet it remains unknown whether margin status is a reflection of tumor biology or surgical technique.

METHODS

Two hundred eighty-three consecutive patients with pancreatic adenocarcinoma were identified in a prospectively maintained database. Only patients with R0 (n = 207) or R1 (n = 76) tumors were included. Each operative surgeon's first 50 cases were excluded to control for technical inexperience. Univariable and multivariable analyses of clinicopathologic and intra-operative factors were performed.

RESULTS

The median follow-up for the cohort was 30.3 months with a median overall survival (OS) of 19.0 months. The R1 group had a higher rate of lymph node ratio >0.2 (41% vs. 25%; P = 0.013), and more microvascular invasion (64% vs. 44%; P = 0.007). R0 resections had both improved overall survival (22.7 months vs. 15.0 months, P = 0.004) and disease free survival (13.5 months vs. 10.7 months, P = 0.026). Factors independently associated with overall survival were microvascular invasion (HR 2.26; P = 0.001), pre-existing pulmonary disease (HR 2.18, P = 0.043), and cardiac disease (HR 1.78, P = 0.033).

CONCLUSION

Factors associated with an R1 resection reflect a biologically more aggressive tumor, with a higher likelihood of microvascular invasion and increased positive lymph node ratio.

N0/N1, PNL, or LNR? The effect of lymph node number on accurate survival prediction in pancreatic ductal adenocarcinoma

INTRODUCTION

We evaluated the prognostic accuracy of LN variables (N0/N1), numbers of positive lymph nodes (PLN), and lymph node ratio (LNR) in the context of the total number of examined lymph nodes (ELN).

METHODS

Patients from SEER and a single institution (MGH) were reviewed and survival analyses performed in subgroups based on numbers of ELN to calculate excess risk of death (hazard ratio, HR).

RESULTS

In SEER and MGH, higher numbers of ELN improved the overall survival for N0 patients. The prognostic significance (N0/N1) and PLN were too variable as the importance of a single PLN depended on the total number of LN dissected. LNR consistently correlated with survival once a certain number of lymph nodes were dissected (≥13 in SEER and ≥17 in the MGH dataset).

CONCLUSIONS

Better survival for N0 patients with increasing ELN likely represents improved staging. PLN have some predictive value but the ELN strongly influence their impact on survival, suggesting the need for a ratio-based classification. LNR strongly correlates with outcome provided that a certain number of lymph nodes is evaluated, suggesting that the prognostic accuracy of any LN variable depends on the total number of ELN.

A high positive lymph node ratio is associated with distant recurrence after surgical resection of ampullary carcinoma

BACKGROUND

For ampullary carcinoma (AC), the lymph node ratio (LNR) has been associated with overall survival. However, the use of the LNR to predict distant recurrence risk remains unknown. The purpose of this study was to determine if the LNR is associated with distant recurrence risk.

METHODS

One hundred forty three patients with AC who underwent pancreaticoduodenectomy between 1989 and 2011 were identified from a single-institution prospective database. Data on clinicopathologic factors and recurrence were analyzed.

RESULTS

At a median follow-up of 43 months (62 months for survivors), 55 patients (38 %) had developed recurrent disease, with a median time to recurrence of 13 months. Patients with a LNR ≥ 0.15 were more likely to have T3/4 tumors, advanced stage lymphovascular (LVI), or perineural invasion (PNI) and develop recurrent disease. Univariate analysis demonstrated that T-stage, lymph node status, AJCC stage, LVI, PNI, and LNR were significantly associated with decreased time to distant recurrence (TTDR). In multivariate stepwise regression, only LNR and LVI were significantly associated with decreased TTDR.

CONCLUSIONS

A high positive LNR is associated with distant recurrence after surgical resection of AC. Given the high risk of disease recurrence, consideration for adjuvant therapy is warranted in patients with a LNR ≥ 0.15.

Factors influencing the number of pelvic and para-aortic lymph nodes removed in surgical treatment of endometrial and ovarian cancer

OBJECTIVE

This study aimed to determine the number of lymph nodes (LNs) removed in patients who underwent abdominal complete systematic pelvic and para-aortic lymphadenectomy and to identify factors that contribute to disparity in the number of LNs removed.

METHODS

We retrospectively reviewed 260 patients with endometrial cancer and ovarian cancer between 1997 and 2011. All pelvic and para-aortic LNs were submitted as 25 separate packets. The correlations of the number of LNs with age, year of surgery, the operating surgeon, pathologist, body mass index (BMI), histology, clinical stage, operating time, blood loss, and lymph node metastasis were investigated.

RESULTS

The median number of LNs removed was 45 pelvic (17-92) and 25 para-aortic (6-69) LNs. Among pelvic LNs, the common iliac nodes were the most frequently removed followed by the obturator nodes. The median number of the left upper para-aortic LNs between the left renal vein and the inferior mesenteric artery was highest among para-aortic LNs. There were significant correlations between the total number of LNs removed and age (P = 0.036), histology (clear vs serous; P = 0.015), and BMI (P < 0.0001) in ovarian cancer. Features associated with higher LN count on multivariate linear regression analysis included younger patients (P = 0.038) and higher BMI (P = 0.012).

CONCLUSIONS

Age and BMI are independently associated with higher LN counts during LN dissection in ovarian cancer. The present study results may be important when using LN counts as a surrogate for adequate lymphadenectomy.

Prognostic relevance of number and ratio of metastatic lymph nodes in resected pancreatic, ampullary, and distal bile duct carcinomas

BACKGROUND

Lymph node ratio (LNR) may be more useful than nodal (N) status in prognostic subclassification of adenocarcinomas after pancreatoduodenectomy. Ampullary (AC), biliary (DBC), and pancreatic (PC) adenocarcinomas are biologically distinct, and nodal involvement may have different prognostic importance among these separate cancers.

METHODS

We included 179 consecutive pancreatoduodenectomies for PC, AC, or DBC, and performed standardized histopathologic evaluation, including prospective registration and retrospective reevaluation of the cancer origin. Associations between histopathologic variables and LNR, N status, and number of metastatic nodes were evaluated. Unadjusted and adjusted survival analysis was performed.

RESULTS

Overall 5 year survival was 6% for PC (n=72), 26% for DBC (n=46), and 46% for AC (n=61). Lymph node involvement was more frequent in PC (75%) than in AC (48%) and DBC (57%). In PC, N status did not discriminate between prognostic groups (N1 vs. N0; p=0.31). However, increasing LNR was associated with poorer survival in unadjusted analysis, as well as when adjusting for margin involvement, degree of differentiation, and tumor diameter (p=0.032; hazard ratio 1.87, 95% confidence interval 1.06-3.31). In AC and DBC, N status clearly discriminated between subgroups of patients with different long-term survival in unadjusted and adjusted survival analysis (N1 vs. N0; p<0.001), whereas number of metastatic nodes and LNR did not predict survival among node-positive resections.

CONCLUSIONS

The predictive value of nodal involvement depends on the type of cancer within the pancreatic head. In AC and DBC, N status adequately discriminates between good and poor prognosis. In PC, LNR may be more powerful in prognostic subclassification.

Ductal adenocarcinoma of the pancreatic head: A focus on current diagnostic and surgical concepts

Complete surgical resection still remains the only possibility of curing pancreatic cancer, however, only 10% of patients undergo curative surgery. Pancreatic resection currently remains the only method of curing patients, and has a 5-year overall survival rate between 7%-34% compared to a median survival of 3-11 mo for unresected cancer. Pancreatic surgery is a technically demanding procedure requiring highly standardized surgical techniques. Nevertheless, even in experienced hands, perioperative morbidity rates (delayed gastric emptying, pancreatic fistula etc.) are as high as 50%. Different strategies to reduce postoperative morbidity, such as different techniques of gastroenteric reconstruction (pancreatico-jejunostomy vs pancreatico-gastrostomy), intraoperative placement of a pancreatic main duct stent or temporary sealing of the main pancreatic duct with fibrin glue have not led to a significant improvement in clinical outcome. The perioperative application of somatostatin or its analogues may decrease the incidence of pancreatic fistulas in cases with soft pancreatic tissue and a small main pancreatic duct (< 3 mm). The positive effects of external pancreatic main duct drainage and antecolic gastrointestinal reconstruction have been observed to decrease the rate of pancreatic fistulas and delayed gastric emptying, respectively. Currently, the concept of extended radical lymphadenectomy has been found to be associated with higher perioperative morbidity, but without any positive impact on overall survival. However, there is growing evidence that portal vein resections can be performed with acceptable low perioperative morbidity and mortality but does not achieve a cure.

Multi-institutional analysis of pancreatic adenocarcinoma demonstrating the effect of diabetes status on survival after resection

BACKGROUND

The effect of diabetes on survival after resection pancreatic ductal carcinoma (PDAC) is unclear. The present study was undertaken to determine whether pre-operative diabetes has any predictive value for survival.

METHODS

A retrospective review from seven centres was performed. Metabolic factors, tumour characteristics and outcomes of patients undergoing resection for PDAC were collected. Univariate and multivariable analyses were performed to determine factors associated with disease-free (DFS) and overall survival (OS).

RESULTS

Of the 509 patients in the present study, 31.2% had diabetes. Scoring systems were devised to predict OS and DFS based on a training set (n= 245) and were subsequently tested on an independent set (n= 264). Pre-operative diabetes (P < 0.001), tumour size >2 cm (P= 0.001), metastatic nodal ratio >0.1 (P < 0.001) and R1 margin (P < 0.001) all correlated with DFS and OS on univariate analysis. Scoring systems were devised based on multivariable analysis of the above factors. Diabetes and the metastatic nodal ratio were the most important factors in each system, earning two points for OS and four points for DFS. These scoring systems significantly correlated with both DFS (P < 0.001) and OS (P < 0.001).

CONCLUSION

Pre-operative diabetes status provides useful information that can help to stratify patients in terms of predicted post-operative OS and DFS.

Double inferior vena cava does not complicate para-aortic nodal dissection for the treatment of pancreatic carcinoma

Duplication of the inferior vena cava (IVC) involves large veins on both sides of the aorta that join anteriorly at the level of the renal arteries to become the suprarenal IVC. We report CT scan and intraoperative images of a patient with duplication of the IVC who underwent pancreaticoduodenectomy with para-aortic lymphadenectomy for carcinoma of the pancreatic head: nodal dissection along the left caval vein was not carried out. The anatomical background of the lymphatic flow to the para-aortic lymph nodes and the theoretic basis for lymph node dissection of the para-aortic area in cases of double IVC are highlighted. Lymphadenectomy along the left caval vein is not necessary in patients with double IVC who undergo pancreaticoduodenectomy with extended lymphadenectomy for carcinoma of the pancreatic head in the absence of preoperative appearance of para-aortic disease.

Robotic versus open pancreaticoduodenectomy: a comparative study at a single institution

BACKGROUND

Minimally invasive pancreaticoduodenectomy (PD) remains one of the most challenging abdominal procedures, and its application is poorly reported in the literature so far. To date, few data are available comparing a minimally invasive approach to open PD. The aim of the present study is to compare the robotic and open approaches for PD at a single institution.

METHODS

Data from 83 consecutive PD procedures performed between January 2002 and May 2010 at a single institution were retrospectively reviewed. Patients were stratified into two groups: the open group (n = 39; 47%) and the robotic group (n = 44; 53%).

RESULTS

Patients in the robotic group were statistically older (63 years of age versus 56 years; p = 0.04) and heavier (body mass index: 27.7 vs. 24.8; p = 0.01); and had a higher American Society of Anesthesiologists (ASA) score (2.5 vs. 2.15; p = 0.01) when compared to the open group. Indications for surgery were the same in both groups. The robotic group had a significantly shorter operative time (444 vs. 559 min; p = 0.0001), reduced blood loss (387 vs. 827 ml; p = 0.0001), and a higher number of lymph nodes harvested (16.8 vs. 11; p = 0.02) compared to the open group. There was no significant difference between the two groups in terms of complication rates, mortality rates, and hospital stay.

CONCLUSIONS

The authors present one of the first studies comparing open and robotic PD. While it is too early to draw definitive conclusions concerning the long-term outcomes, short-term results show a positive trend in favor of the robotic approach without compromising the oncological principles associated with the open approach.

Multivariate analysis of immunohistochemical evaluation of protein expression in pancreatic ductal adenocarcinoma reveals prognostic significance for persistent Smad4 expression only

Background

Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis with a 5-year survival rate of <5% and an average survival of only 6 months. Although advances have been made in understanding the pathogenesis of PDAC in the last decades, overall survival has not changed. Various clinicopathological and immunohistological variables have been associated with survival time but the exact role that these variables play in relation to survival is not clear.

Methods and results

To examine how the variables affected survival independently, multivariate analysis was conducted in a study group of 78 pancreatic ductal adenocarcinomas. The analysis included clinicopathological parameters and protein expression examined by immunohistochemistry of p53, Smad4, Axl, ALDH, MSH2, MSH6, MLH1 and PMS2. Lymph node ratio <0.2 (p = 0.004), tumor free resection margins (p = 0.044) and Smad4 expression (p = 0.004) were the only independent prognostic variables in the multivariate analysis. Expression of the other proteins examined was not significantly related to survival.

Conclusions

Discrepancies with other studies in this regard are likely due to differences in quantification of immunohistochemical staining and the lack of multivariate analysis. It underscores the importance to standardize the methods used for the application of immunohistochemistry in prognostic studies.

Which is the most suitable classification for colorectal cancer, log odds, the number or the ratio of positive lymph nodes?

Objective

The aim of the current study was to investigate which is the most suitable classification for colorectal cancer, log odds of positive lymph nodes (LODDS) classification or the classifications based on the number of positive lymph nodes (pN) and positive lymph node ratio(LNR) in a Chinese single institutional population.

Design

Clinicopathologic and prognostic data of 1297 patients with colorectal cancer were retrospectively studied. The log-rank statistics, Cox's proportional hazards model, the Nagelkerke R² index and a Harrell's C statistic were used.

Results

Univariate and three-step multivariate analyses identified that LNR was a significant prognostic factor and LNR classification was superior to both the pN and LODDS classifications. Moreover, the results of the Nagelkerke R² index (0.130) and a Harrell's C statistic (0.707) of LNR showed that LNR and LODDS classifications were similar and LNR was a little better than the other two classifications. Furthermore, for patients in each LNR classification, prognosis was homologous between those in different pN or LODDS classifications. However, for patients in pN1a, pN1b, LODDS2 and LODDS3 classifications, significant differences in survival were observed among patients in different LNR classifications.

Conclusions

For patients with colorectal cancer, the LNR classification is more suitable than pN and LODDS classifications for prognostic assessment in a Chinese single institutional population.