Lymphatic flow in carcinoma of the head of the pancreas

Extranodal extension influences prognosis in pancreatic head cancer: A retrospective cohort study

BACKGROUND

Extranodal extension (ENE) is an established prognostic factor in several gastrointestinal cancers. However, the prognostic impact remains unclear. Here, we investigated the prognostic implications of ENE in patients with surgically resected pancreatic cancer.

METHODS

We retrospectively reviewed 476 surgically resected pancreatic head cancer patients who consecutively underwent upfront pancreaticoduodenectomy for pathologically confirmed pancreatic ductal adenocarcinoma between January 2009 and December 2013. We compared the disease-free survival (DFS) rates of the patients according to ENE status.

RESULTS

Among the 476 patients, patients with ENE had lower DFS rates than those without ENE (N0, 13 months; LN+/ENE-, 7 months; LN+/ENE+, 6 months; P < .001). In addition, even in the same N stage, patients with ENE had lower DFS rates than those without ENE (N0, 13 months; N1/ENE- 8 months; N1/ENE+, 7 months; N2/ENE-, 7 months; N2/ENE+, 4 months, P < .001). However, there was no significant difference in survival rates between patients in the N1/ENE+ group and those in the N2/ENE- group. Additionally, ENE was an independent prognostic factor for pancreatic cancer.

CONCLUSIONS

Extranodal extension significantly predicted a poor prognosis among patients with pancreatic head cancer, especially those with nodal metastasis. Therefore, ENE should be considered a prognostic factor in future editions of the staging system.

Intraoperative frozen section analysis of para-aortic lymph nodes after neoadjuvant FOLFIRINOX: will it soon become useless?

PURPOSE

Positive para-aortic lymph nodes (PALN) (station 16) are commonly detected in the final pathologic examination (ranging from 15 to 26%) among patients who undergo upfront pancreatoduodenectomy for resectable pancreatic ductal adenocarcinoma. However, after neoadjuvant treatment (NAT) the role of positive PALN as a watershed for surgical resection remains unclear. We aimed to determine the incidence of intraoperative detection of PALN after NAT with FOLFIRINOX for pancreatic head adenocarcinoma and its impact on survival, as our policy was to not resect the tumor in such situations.

METHODS

From January 2014 to December 2020, 136 patients with non-metastatic cancer who received neoadjuvant FOLFIRINOX and underwent explorative laparotomy were included.

RESULTS

Intraoperative positive PALN were observed in 7 patients (5%). Patients had resectable (n = 5) or locally advanced (n = 2) disease at the time of surgery, but none of them underwent surgical resection. Positive PALN were significantly associated with a lower median number of FOLFIRINOX cycles (4 vs. 6, P = 0.05). There was no significant difference in overall survival between patients with positive loco-regional lymph nodes after resection and patients with non-resection owing to positive PALN (22 versus 16 months, P = 0.16), Overall survival with positive PALN, carcinomatosis, and liver metastasis was 16, 14, and 10 months, respectively (P > 0.05).

CONCLUSIONS

Our results suggest that NAT may lower PALN involvement. We have modified our policy, positive PALN after NAT are no longer a contraindication to resection, rather a holistic picture of the disease guides management.

Impact of Lymph Node Metastases Around the Superior Mesenteric Artery on Postoperative Outcomes of Pancreatic Head Cancer

BACKGROUND

The neural plexus and lymph nodes around the superior mesenteric artery (LN#14), are the most frequent sites involved by pancreatic head cancer. However the influence of metastases to LN#14 on patients' prognosis has rarely been evaluated.

METHODS

The patients who underwent pancreatectomy for pancreatic head cancer between January 2010 and December 2018 were selected. The patients with nodal metastases were classified into an LN#14 + or LN#14-group according to LN#14 metastasis. Clinical and pathological characteristics and prognosis were compared between the two groups.

RESULTS

In total, 99 patients underwent pancreatectomy. Ninety-four patients were positive for lymph node metastases and 14 and 80 were classified as LN#14 + and LN#14 - , respectively. Postoperative median overall survival (OS) of the LN#14 + and LN#14 - groups was 10.2 and 31.1 months, respectively (P < 0.001). Median OS of the LN#14 + group was worse than that of patients with ≥ 4 metastatic nodes in the LN#14 - group (n = 35, 24.7 months, P = 0.002). In multivariate analysis, LN#14 + (hazard ratio [HR] = 3.89, 95% confidence interval [CI], 1.64-8.86) was one of the independent predictors of worse OS.

CONCLUSION

It might be feasible to recognize LN#14 metastases as an important prognostic factor independently from other regional lymph node metastases.

Differences in the clinicopathological features of pancreatic head carcinoma in dorsal and ventral pancreas: A single institution retrospective review

ABSTRACT

The embryonic development of the pancreas originates from dorsal and ventral anlagen, and the pancreatic cancer arising from dorsal or ventral pancreas may have different clinical pathology features. This study aims to explore whether there are differences in clinicopathological features and prognosis of pancreatic head carcinoma arising from dorsal or ventral pancreas.Between January 2014 and February 2018, 101 patients with resectable pancreatic head cancer who underwent pancreaticoduodenectomy in our institution were retrospectively reviewed. The patients were assigned into 2 groups according to tumor location on preoperative imaging materials (computed tomography/magnetic resonance imaging [CT/MRI]), and the clinicopathological features and prognosis were retrospectively analyzed in view of the embryonic development of the pancreas.Among these patients with pancreatic head cancer, 42 patients had tumors arising from dorsal pancreas (D group) and 59 patients had tumors arising from ventral pancreas (V group). The frequency of lymph node (LN) metastasis around the common hepatic artery (CHA) and hepatoduodenal ligament lymph nodes in the D group was higher than that in the V group (45.2% vs 10.2%, P = .001). And the rate of LN metastasis in the superior mesenteric artery (SMA) region in the V group is higher than that in the D group (32.2% vs 4.8%, P = .002). The D group was more likely to invade the common bile duct (78.6% vs 59.3%, P = .042) and duodenum (71.4% vs 44.1%, P = .006) than the V group. In addition, the survival outcome of V group was better than D group (median overall survival [OS], 15.37 months vs 10.53 months, P = .048, median DFS 9.73 months vs 5.93 months, P = .046).The clinicopathological features of pancreatic head carcinoma arising from dorsal or ventral pancreas are different, and the pancreatic head carcinoma arising from ventral pancreas has a better survival outcome.

Optimal Lymphadenectomy of the Mesopancreas Based on Fluorescence Imaging During Pancreaticoduodenectomy

BACKGROUND

Excision of the mesopancreas with lymphadenectomy is an important component of pancreatoduodenectomy. However, the optimal extent of lymphadenectomy remains unclear. Furthermore, accurate description of the mesopancreatic lymphatic pathways is difficult, probably because of the complex anatomy. Intestinal derotation simplifies the anatomy and facilitates both examination of lymphatic flow and the surgical procedure. The aim of this study was to evaluate lymphatic flow in the mesopancreas using indocyanine green fluorescence imaging with an intestinal derotation technique, and to clarify the optimal extent of mesopancreas excision and lymphadenectomy in pancreatoduodenectomy.

METHODS

Indocyanine green solution (2.5 × 10^-3 mg) was injected into the pancreatic head parenchyma. After intestinal derotation, the spread of indocyanine green was observed using near-infrared imaging.

RESULTS

Participants comprised 10 patients who underwent pancreatoduodenectomy for periampullary neoplasms. With indocyanine green fluorescence imaging, 9 of the 10 patients showed lymphatic flow from the pancreatic head to the superior mesenteric artery via the inferior pancreaticoduodenal artery and first jejunal artery (but not via the second and more distant arteries), with eventual drainage into the paraaortic region.

CONCLUSIONS

Lymphatic pathways from the pancreatic head were connected to the superior mesenteric artery via the inferior pancreaticoduodenal artery and first jejunal artery. Excision of the mesopancreas with the inferior pancreaticoduodenal artery and first jejunal artery while preserving the second or more distant arteries appears optimal in pancreatoduodenectomy for periampullary malignancies.

Survival impact based on hepatic artery lymph node status in pancreatic adenocarcinoma: A study of patients receiving modern chemotherapy

BACKGROUND

Chemotherapy for pancreatic adenocarcinoma (PDAC) has significantly improved in recent years. While the involvement of the hepatic artery lymph node (HALN; station 8a lymph node) likely represents advanced disease, a comparison to patients with metastases on modern chemotherapy is lacking.

METHODS

Patients who underwent pancreatoduodenectomy with HALN sent for pathologic review at a single institution from 2003 to 2018 were reviewed. Patients who presented with liver-only metastases at the time of PDAC diagnosis (Stage IV) and received chemotherapy were identified. Multivariate Cox proportional hazards regression modeling was utilized and overall survival (OS) was estimated using Kaplan-Meier analysis.

RESULTS

Of the 112 patients with a HALN sent for analysis, 17 (15%) were positive and 13 (76%) received chemotherapy. Ninety-four stage IV patients were identified and were significantly more likely to have received a multiagent rather than single-agent chemotherapy regimen compared to HALN positive patients (79.8% vs. 38.5%, p < .001). Median OS was significantly longer in all patients who underwent surgical resection, regardless of HALN status, compared to stage IV patients.

CONCLUSIONS

Patients undergoing pancreatoduodenectomy with HALN positivity have significantly improved OS compared to patients with stage IV disease. HALN involvement does not significantly alter survival among resected patients and does not warrant preoperative endoscopic ultrasound-guided biopsy.

Factors associated with metastasis in superior mesenteric vein lymph node in subtotal gastrectomy for gastric cancer: Retrospective case control study

Objective

The revised Japanese treatment guideline for gastric cancer recommends dissection of the superior mesenteric vein lymph node (No. 14v LN) if there is metastasis in infrapyloric lymph node (No. 6 LN). However, it is still controversial whether LN dissection is necessary. The aim of this study was to investigate the factors associated with metastasis in No. 14v LN.

Methods

Patients who underwent D2 lymphadenectomy between 2003 and 2010 were included. We excluded patients who underwent total gastrectomy, had multiple lesions, or had missing data about the status of metastasis in the LNs that were included in D2 lymphadenectomy. Clinicopathologic characteristics and the metastasis in regional LNs were compared between patients with No. 14v LN metastasis (14v+) and those without (14v−).

Results

Five hundred sixty patients were included in this study. Univariate analysis showed that old age, larger tumor size, tumor location, differentiation, lymphatic invasion, venous invasion, perineural invasion, T classification, and N classification were related to metastasis in No. 14v LN. Multivariate analysis showed differentiation (P=0.027) and N classification (P<0.001) were independent related factors. Metastasis in infrapyloric lymph node (No. 6 LN) and proxiaml splenic lymph node (No. 11p LN) was independently associated with metastasis in No. 14v LN.

Conclusions

Differentiation and N classification were independent factors associated with No. 14v LN metastasis, and No. 6 and No. 11p LN metastasis were independent risk factors for No. 14v LN metastasis.

Is the involvement of the hepatic artery lymph node a poor prognostic factor in pancreatic adenocarcinoma?

INTRODUCTION

The aim of this study is to analyze the impact of hepatic artery lymph node (HALN) involvement on the survival of patients undergoing pancreaticoduodenectomy (PD) for pancreatic adenocarcinoma (PA).

METHODS

A single-center retrospective study analyzing patients who underwent PD for PA. Patients were included if, during PD, the HALN was submitted for pathologic evaluation. Patients were stratified by node status: PPLN- (peripancreatic lymph node)/HALN-, PPLN+/HALN- and PPLN+/HALN+. Survival analysis was estimated by the Kaplan-Meier method, and Cox regression was used for risk factors analyses.

RESULTS

Out of the 118 patients who underwent PD for PA, HALN status was analyzed in 64 patients. The median follow-up was 20months (r: 1-159months). HALN and PPLN were negative in 12patients (PPLN-/HALN-, 19%), PPLN was positive and HALN negative in 40patients (PPLN+/HALN-, 62%), PPLN and HALN were positive in 12 patients (PPLN+/HALN+, 19%) and PPLN was negative and HALN positive in 0 patients (PPLN-/HALN+, 0%). The overall 1, 3 and 5-year survival rates were statistically better in the PPLN-/HALN- group (82%, 72%, 54%) than in the PPLN+/HALN- group (68%, 29%, 21%) and the PPLN+/HALN+ group (72%, 9%, 9%, respectively) (P=.001 vs P=.007). The 1, 3 and 5-year probabilities of cumulative recurrence were also statistically better in the PPLN-/HALN- group (18%, 46%, 55%) than in the PPLN+/HALN- group (57%, 80%, 89%) and the PPLN+/HALN+ group (46%, 91%, 100%, respectively) (P=.006 vs P=.021). In the multivariate model, the main risk factor for overall survival and recurrence was lymphatic invasion, regardless of HALN status.

CONCLUSIONS

In pancreatic adenocarcinoma patients with lymph node disease, survival after PD is comparable regardless of HALN status.

Local radicality and survival outcome of pancreatic cancer surgery

Pancreatic cancer remains a therapeutic challenge. Surgical resection in combination with systemic chemotherapy is the only option promising long-term survival and potential cure. However, only about 20% of patients are diagnosed with tumors that are still in a resectable stage. Even after potentially curative resection and modern regimens for adjuvant chemotherapy, the majority of patients develop local and systemic recurrence resulting in median overall survival times of 28-54 months. The predominance of systemic recurrence and its impact on survival may lead to the assumption that surgical radicality and local control play only minor roles in the treatment of pancreatic cancer. This review provides an overview of the recent literature on surgical radicality and survival outcome in pancreatic cancer. The current evidence on the extent of lymphadenectomy, the prognostic impact of the extent of lymph node involvement, and the impact of the resection margin status on postresection survival are reviewed. Data from recent studies performed in the context of modern surgery and adjuvant therapy provide good evidence of a considerable impact of local radicality on survival after pancreatic cancer surgery. Surgical techniques that have been developed to refine oncological resections and to increase local control as well as resectability are highlighted. These techniques include artery-first approaches, level-3 dissection with removal of the periarterial nerve plexus, the triangle operation, and extended resections. Local radicality and quality of surgical resection remain among the most important parameters that determine the chances for survival in patients with non-metastatic pancreatic cancer.

Exploration of peripancreatic lymphatic pathways in a live porcine model

Pancreatic cancer is associated with a poor prognosis, mainly due to lymph node invasion and lymph node recurrence after surgical resection, even after extended lymphadenectomy. The peripancreatic lymphatic system is highly complex and the specific lymphatic drainage of each part of the pancreas has not been established. The aim of this study was to determine the lymphatic drainage pathways specific to each part of the pancreas on live pigs using Patent Blue. The pancreases of 14 live pigs were injected in different parts of the gland. The technique was efficient and reproducible. The diffusion patterns were similar for each location and were reported. Our results in pigs allowed us to define specific nodal relay stations and lymphatic drainage for each part of the pancreas and confirm that independent anatomical-surgical pancreatic segments can be described. It is interesting to note that lymphatic drainage for the upper part of the proximal part of pancreas (duodenal lobe) occurred on the left side of the portal vein. This suggests that lymph node resection during cephalic duodenopancreatectomy in humans should be extended to the left side of the mesenteric vein, and probably to the right side of the superior mesenteric artery, as recently suggested. These results could help surgeons perform safe anatomical-segmental pancreatic resections with accurate lymphadenectomies and improve survival in patients with pancreatic cancer. Based on these results we will perform an innovative prospective study. Patent Blue will be injected into different parts of the gland in patients operated for pancreatic resection, and lymphatic diffusion of the dye will be recorded in relation to their origin from the theoretical pancreatic segments (ClinicalTrials.gov Identifier: NCT03597230).

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.

Risk factors related to metastasis of para-aortic lymph nodes in pancreatic ductal adenocarcinoma: A retrospective observational study

This study was designed to explore the risk factors related to metastasis of para-aortic lymph node (PALN).Clinicopathologic data of 241 patients with resectable or borderline resectable pancreatic cancer who underwent pancreaticoduodenectomy with extended lymphadenectomy between January 2008 and December 2015 were collected, potential factors related to metastasis of PALN were analyzed.Positive rate of PALN was 19.5% (47/241). Univariate analysis showed that back pain (P = .028), preoperative CA19-9 level (P < .001), tumor size (P < .001), portal vein (PV)/superior mesenteric vein (SMV) invasion (P < .001), superior mesenteric artery (SMA) invasion (P < .001), and diameter > 1.0 cm were in correlation with PALN involvement, multivariate analysis revealed that preoperative CA19-9 level, PV/SMV invasion, SMA invasion and diameter > 1.0 cm were independent risk factors to metastasis of PALN. Patients with LN8+ had a higher positive rate of PALN than with LN8- (38.1% vs 15.6%, P = .001), similar results could be found when LN12+ (35.8% vs 13.2%, P < .001) and LN14+ (41.2% vs 11.0%, P < .001), multivariate analysis showed that LN8+ and LN14+ were closely in correlation with PALN metastasis.Several factors were related to the status of PALN, preoperative CA19-9 level, PV/SMV invasion, SMA invasion and diameter > 1.0 cm were 4 independent risk factors to PALN metastasis. LN8+ and LN14+ were 2 strong predictors of PALN metastasis. A comprehensive analysis covering all possible risk factors related to metastasis of PALN should be given before design of treatment plan whenever involvement of PALN was suspected.

Lymph node 8a as a prognostic marker for poorer prognosis in pancreatic and periampullary carcinoma

OBJECTIVES

An investigation of patients with pancreatic carcinoma aims to identify those who will benefit from surgery. Physical examination, radiology and laboratory findings are helpful. Most prognostic markers, such as lymph node status, micro metastasis and tumour differentiation, are not preoperatively accessible. Metastatic disease in lymph node 8a (Ln8a) in patients operated for pancreatic carcinoma has been reported to be a predictor of shorter overall survival (OS). This lymph node can be assessed preoperatively through resection (possibly even with laparoscopy) and subsequent histopathology. The value of the procedure is disputed. The aim of this study is to investigate whether metastatic disease in Ln8a is a predictor of decreased OS.

MATERIALS AND METHODS

In patients with suspected pancreatic or periampullary carcinoma, who were operated with pancreatoduodenectomy (PD), Ln8a was separately resected and analysed with standard and immuno-histochemical methods. Patients with or without metastasis in Ln8a were compared regarding OS.

RESULTS

Between 2008 and 2011, 122 consecutive patients were eligible and 87 were resected and had LN8a analysed separately. Sixteen patients were Ln8a + and 71 were Ln8a-. Patients with Ln8a + had a significantly reduced median OS as compared to patients with Ln8a- (0.74 (95% CI 0.26-1.26) versus 5.91 years (95% CI 2.91-), p < .001).

CONCLUSION

Ln8a + was associated with a marked reduction of OS, indicating a possible role in the future preoperative workup in patients with a suspicion of pancreatic cancer.

Which patients with para-aortic lymph node (LN16) metastasis will truly benefit from curative pancreaticoduodenectomy for pancreatic head cancer?

In patients with cancer of the pancreatic head, metastasis to para-aortic lymph nodes (LN16) is considered distant metastasis and a poor prognostic marker. However, the incidence of LN16 involvement in pancreatic head cancer is high, and it is unclear whether all such patients have poor surgical outcomes. We investigated the significance of LN16 involvement in resectable pancreatic head cancer by retrospectively analyzing 579 ductal adenocarcinoma patients treated with para-aortic lymph node dissection at two high-volume Chinese centers. Depending upon tumor location, the incidence of LN16 metastasis and the correlation between LN16 involvement and involvement of Group 1 or 2 lymph nodes significantly differed. Metastasis to LN16 indicated a high serum tumor burden and a poor prognosis, though LN16-positive patients with a lymph node ratio (LNR) < 0.25 may still benefit from radical surgery. Survival analysis of LN16-positive patients with resectable pancreatic head cancer revealed that tumor size, tumor differentiation, and tumor location are independent prognostic factors. We also found that preoperative serum CA125 < 18.62 U/ml and the level of JAK2 signaling are both indicators of who may benefit from curative surgical resection for pancreatic head cancer.

MicroRNA Expression in a Readily Accessible Common Hepatic Artery Lymph Node Predicts Time to Pancreatic Cancer Recurrence Postresection

Lymph node involvement in pancreatic adenocarcinoma (PAC) predicts postresection survival, but early lymph node metastasis detection is not easily accomplished. We assessed a panel of microRNAs (miRNAs) in a common hepatic artery lymph node (station 8) that is readily accessible during pancreatoduodenectomy (PD) to determine if increased miRNA levels correlate with postresection recurrence. Station 8 lymph nodes overlying the common hepatic artery collected during PD were assayed for miRNA-10b, miRNA-30c, miRNA-21, and miRNA-155 and cytokeratin-19 (CK19), an epithelial cell marker, using quantitative PCR. Expression was correlated with disease recurrence, recurrence-free survival (RFS), and overall survival (OS). Station 8 lymph nodes from 37 patients (30 periampullary carcinomas (PCs), 2 chronic pancreatitis, 5 other cancers) exhibited increased miRNA-10b levels in 14/30 PCs, and in 10 of these 14 patients, cancer recurred during the study period (2012-2015). High miRNA-10b was also associated with shorter RFS (42.5 vs. 92.4 weeks, p < 0.05) but not OS, whereas miRNA-30c, miRNA-21, and miRNA-155 levels and CK19 mRNA levels in station 8 nodes were variable and did not correlate with RFS or OS. We conclude that elevated miRNA-10b levels in station 8 lymph nodes could be utilized to assess risk for early disease progression in patients with periampullary tumors.

Factors predicting adequate lymph node yield in patients undergoing pancreatoduodenectomy for malignancy

Background

Most pancreatoduodenectomy resections do not meet the minimum of 12 lymph nodes recommended by the American Joint Committee on Cancer for accurate staging of periampullary malignancies. The purpose of this study was to investigate factors affecting the likelihood of adequate nodal yield in pancreatoduodenectomy specimens subject to routine pathological assessment.

Methods

Six hundred sixty-two patients subject to pancreatoduodenectomy between 1990 and 2013 for pancreatic, ampullary, and common bile duct cancers were reviewed. Predictors of yielding at least 12 lymph nodes were evaluated with a logistic regression model, and a survival analysis was carried out to verify the prognostic implications of nodal counts.

Results

The median number of evaluated nodes was 17 (interquartile range 11 to 25), and less than 12 lymph nodes were reported in surgical specimens of 179 (27 %) patients. Tumor diameter ≥20 mm (odds ratio [OR] 2.547, 95 % confidence interval [CI] 1.225 to 5.329, P = 0.013), lymph node metastases (OR 2.642, 95 % CI 1.378 to 5.061, P = 0.004), and radical lymphadenectomy (OR 5.566, 95 % CI 2.041 to 15.148, P = 0.01) were significant predictors of retrieving 12 or more lymph nodes. Lymph node counts did not influence the overall prognosis of the patients. However, a subgroup analysis carried out for individual cancer sites demonstrated that removing at least 12 lymph nodes is associated with better prognosis for pancreatic cancer.

Conclusions

Few variables affect adequate nodal yield in pancreatoduodenectomy specimens subject to routine pathological assessment. Considering the ambiguities related to the only modifiable factor identified, appropriate pathology training should be considered to increase nodal yield rather than more aggressive lymphatic dissection.

The prognostic impact of para-aortic lymph node metastasis in pancreatic cancer: A systematic review and meta-analysis

PURPOSE

To evaluate by a meta-analytic approach the long-term prognostic impact of para-aortic lymph node (PALN) involvement in resected ductal adenocarcinoma of the pancreas.

METHODS

MEDLINE, Embase, PubMed and the Cochrane Library were searched from January 1990 to June 2015. Trials reporting Kaplan-Meier curves and comparing overall long-term survival of negative and metastatic PALN in patients who underwent resection for pancreatic cancer were included. Lymph nodes were classified according to the Japan Pancreatic Society rules and identified using hematoxylin and eosin staining. Hazard ratios (HRs) and 95%CI were estimated for each trial and pooled in a meta-analysis.

RESULTS

Thirteen eligible studies including 2141 patients (364 positive PALN; 1777 negative PALN) were identified. Most of the studies were retrospective. Heterogeneity among trials was high (I(2) = 98.7%; p < .001). PALN metastasis was associated with increased mortality when compared with patients with negative PALN regardless regional nodal status [HR 1.85, 95%CI 1.48-2.31; p < .001]. Median survival was significantly decreased in patients with positive PALN (WMD = -4.92 months 95%CI -6.40; -3.43; p < .001). Moreover, metastatic PALN affected mortality also when regional lymph nodes were positive [HR 1.67, 95%CI 1.34-2.08; p < .001]. No publication bias was detected.

CONCLUSIONS

PALN metastasis appears to correlate with poor prognosis in patients with pancreatic adenocarcinoma. The assessment of PALN status may be considered for a more accurate staging of the disease and appropriated subgroup survival reporting. However, the definitive avoidance of the resection in case of intraoperative metastatic PALN needs further investigation.

Initial experience in sentinel lymph node detection in pancreatic cancer

BACKGROUND

The local recurrence of pancreatic cancer is around 30% when complete resection can be achieved. Extended lymphatic resections may improve survival, but increases severe morbidity. As accurate patient selection should be mandatory, a new method is presented for pancreatic sentinel lymph node (SLN) detection with lymphoscintigraphy and gamma probe.

MATERIALS AND METHODS

Seven patients with cT2N0M0 pancreatic head cancer were enrolled between 2009 and 2012 in this prospective study. One day prior to surgery, preoperative lymphoscintigraphy with echoendoscopic intratumoural administration of Tc(99m)-labelled nanocolloid was performed, with planar and SPECT-CT images obtained 2h later. Gamma probe detection of SLN was also carried out during surgery.

RESULTS

Radiotracer administration was feasible in all patients. Scintigraphy images showed inter-aortocaval lymph nodes in 2 patients, hepatoduodenal ligament lymph nodes in 1, intravascular injection in 3, intestinal transit in 5, and main pancreatic duct visualisation in 1. Surgical resection could only be achieved in 4 patients owing to locally advanced disease. Intraoperative SLN detection was accomplished in 2 patients, both with negative results. Only in one patient could SLN be confirmed as truly negative by final histopathological analysis.

CONCLUSIONS

This new method of pancreatic SLN detection is technically feasible, but challenging. Our preliminary results with 7 patients are not sufficient for clinical validation.

Pancreatectomy with Para-Aortic Lymph Node Dissection for Pancreatic Head Adenocarcinoma: Pattern of Nodal Metastasis Spread and Analysis of Prognostic Factors

BACKGROUND

This study investigated the prognostic impact of the exact location of nodal metastases in a subgroup of patients who underwent pancreatectomy with extended lymphadenectomy for head adenocarcinoma, with a special focus on station 16b1.

METHODS

Clinical, pathologic, and follow-up details were extracted from our database and analyzed retrospectively. Survival analysis was performed using univariate and multivariate models. We also performed a matched case-control analysis with resected patients who did not receive extended lymphadenectomy and with locally advanced patients.

RESULTS

The study population consisted of 67 patients. The rate of station 16b1 metastases was 20.9%. Station 14a-b metastases (OR = 4.28), G3 tumors (OR = 4.03), and number of PLN ≥ 8 (OR = 4.46) were independently associated with station 16b1 involvement. Among pN1 patients, station 14a-b (HR = 2.60) and station 16b1 metastases (HR = 2.40) were predictors of survival. The median disease-specific survival of 16b1+ patients was 17 months (95% CI 8.47-25.52). In the matched case-control analysis, the survival rates of resected 16b1+ patients was in between pN1/16b1- patients and locally advanced patients.

CONCLUSIONS

Metastases to station 16b1 are associated with a decreased survival in comparison with pN1/16b1- patients, yet longer than in matched locally advanced patients. Station 14 can be considered as a "junctional node" to station 16b1.

Should a standard lymphadenectomy during pancreatoduodenectomy exclude para-aortic lymph nodes for all cases of resectable pancreatic head cancer? A consensus statement by the Chinese Study Group for Pancreatic Cancer (CSPAC)

Understanding and formulating an appropriate strategy for the para-aortic lymph nodes (LN16) during curative surgery for pancreatic head cancer have been controversial for some time. This study intended to provide a recommendation for surgeons to perform an optimal curative surgery on pancreatic cancer patients with or without LN16 involvement. Based on an updated literature search and review, the members of the Chinese Study Group for Pancreatic Cancer (CSPAC) from high-volume centers reached a consensus on the issue of LN16 in pancreatic head cancer. Metastasis to LN16 is quite common in pancreatic head cancer cases. Depending on the location of the tumor, including the ventral and dorsal pancreas, there could be various lymph node drainage pathways whereby LN16 does not necessarily belong to the Group 3 lymph node stations for all cases of pancreatic head cancer. Although LN16 involvement generally indicates a poor prognosis, some cohorts of LN16-involved cases have benefited from a curative surgery, and there is still a lack of level I evidence to convince surgeons to abandon all resectable cases with LN16 positivity. Resection of LN16 combined with a standard lymphadenectomy during pancreatoduodenectomy is recommended by CSPAC, except in patients with both positive LN16 and criteria based on: i) the resectability status of primary tumor; ii) the extent of involved para-aortic lymph nodes; and iii) the serum tumor burden assessed preoperatively.

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.

Structural similarities and differences between the human and the mouse pancreas

Mice remain the most studied animal model in pancreas research. Since the findings of this research are typically extrapolated to humans, it is important to understand both similarities and differences between the 2 species. Beside the apparent difference in size and macroscopic organization of the organ in the 2 species, there are a number of less evident and only recently described differences in organization of the acinar and ductal exocrine tissue, as well as in the distribution, composition, and architecture of the endocrine islets of Langerhans. Furthermore, the differences in arterial, venous, and lymphatic vessels, as well as innervation are potentially important. In this article, the structure of the human and the mouse pancreas, together with the similarities and differences between them are reviewed in detail in the light of conceivable repercussions for basic research and clinical application.

The role of hepatic artery lymph node in pancreatic adenocarcinoma: prognostic factor or a selection criterion for surgery

BACKGROUND

Hepatic artery lymph node (HALN) metastasis in pancreatic adenocarcinoma reportedly confers a survival disadvantage. This has led some authors to propose it as an indicator against pancreaticoduodenectomy (PD).

METHODS

Consecutive patients who underwent PD during 2002-2012 were identified from the University of Louisville prospective hepatopancreaticobiliary database. Overall survival (OS) and disease-free survival (DFS) were estimated using Kaplan-Meier analysis. The log-rank test and multivariate Cox proportional hazards regression were used in further analyses.

RESULTS

A total of 420 patients underwent PD during the period of study, of whom 197 had lymph node (LN) metastasis. Among these, 41 (20.8%) patients had disease-positive HALNs. The HALN was the only site of LN metastasis in only three of the 247 patients (1.2%). Median follow-up was 18.5 months (interquartile range: 4.1-28.2 months). Median OS and DFS were 22.7 months [95% confidence interval (CI) 19.0-26.3] and 12.6 months (95% CI 10.2-15.2). There was no significant difference in median OS between HALN-positive patients (18.4 months, 95% CI 12.3-24.0) and HALN-negative patients (19.7 months, 95% CI 16.7-22.6) (P = 0.659). On multivariate analysis, the hazard ratio (HR) of death was highest among patients with an LN ratio of >0.2 (HR 1.2, 95% CI 1.1-1.29; P = 0.012) followed by those with poorly differentiated histology (HR 1.09, 95% CI 1.04-1.11; P = 0.029).

CONCLUSIONS

In pancreatic adenocarcinoma patients with LN disease, survival after PD is comparable regardless of HALN status. Therefore, HALN-positive disease should not preclude the performance of PD.

Extended lymphadenectomy in pancreatic cancer is crucial

Lymph node metastasis is considered one of the most significant factors associated with postoperative prognosis in patients with pancreatic cancer. Some prospective studies found no significant differences in survival between patients who underwent pancreatic cancer surgery with extended lymphadenectomy and those who underwent surgery with standard lymphadenectomy. However, recent reports, such as those describing the significance of the metastatic to examined lymph node ratio, suggest the need for some degree of lymphadenectomy. This review describes the findings of published studies and discusses the usefulness of LN dissection in patients with pancreatic cancer.

Hepatic arterial nodal metastases in pancreatic cancer: is this the node of importance?

BACKGROUND

The hepatic artery lymph node (HALN) is frequently sampled during pancreaticoduodenectomy (PD). Data suggest that survival in the setting of HALN metastases is similar to that of stage IV pancreatic ductal adenocarcinoma (PDAC). The objectives of this study were to describe the prognostic significance of HALN metastases and to assess the predictive performance of HALN compared to peripancreatic lymph node status.

METHODS

Patients undergoing PD for PDAC from January 2000-October 2010 were identified from a prospectively maintained database. Patients were included if during PD the HALN was submitted for pathologic evaluation. Patients were excluded if margins were macroscopically positive, if pathology was found to be consistent with a diagnosis other than PDAC. Overall (OS) and disease-free survival (DFS) were estimated by Kaplan-Meier methods.

RESULTS

Of the 671 patients who underwent PD for PDAC, HALN status was analyzed for 147 patients. HALN was positive in 23 patients (16 %), 38 were peripancreatic lymph node (PPLN) and HALN negative, and 86 were PPLN+/HALN-. Median follow-up for survivors was 10 months. In a multivariable model, lymph node status and tumor differentiation predicted OS and DFS. Hazard of death and relapse/death were highest among the HALN+ patients (hazard ratio [HR] 2.94; p = 0.017 and HR 2.66; p = 0.011, respectively). Kaplan-Meier analysis revealed significant differences in OS (p = 0.017) and DFS (p = 0.013) based on lymph node status.

CONCLUSIONS

OS and DFS are significantly reduced in patients with a positive HALN. Differentiation and lymph node status were predictors of OS and DFS. In the multivariate models, differentiation and lymph node status remain independent predictors of OS and DFS.

Clinical target volume delineation including elective nodal irradiation in preoperative and definitive radiotherapy of pancreatic cancer

BACKGROUND

Radiotherapy (RT) is widely used in the treatment of pancreatic cancer. Currently, recommendation has been given for the delineation of the clinical target volume (CTV) in adjuvant RT. Based on recently reviewed pathologic data, the aim of this study is to propose criteria for the CTV definition and delineation including elective nodal irradiation (ENI) in the preoperative and definitive treatment of pancreatic cancer.

METHODS

The anatomical structures of interest, as well as the abdominal vasculature were identified on intravenous contrast-enhanced CT scans of two different patients with pancreatic cancer of the head and the body. To delineate the lymph node area, a margin of 10 mm was added to the arteries.

RESULTS

We proposed a set of guidelines for elective treatment of high-risk nodal areas and CTV delineation. Reference CT images were provided.

CONCLUSIONS

The proposed guidelines could be used for preoperative or definitive RT for carcinoma of the head and body of the pancreas. Further clinical investigations are needed to validate the defined CTVs.

Clinicopathologic assessment of pancreatic ductal carcinoma located at the head of the pancreas, in relation to embryonic development

OBJECTIVES

Pancreaticoduodenectomy is performed for pancreatic head cancer that originated from the dorsal or ventral primordium. Although the extent of lymph node (LN) dissection is the same irrespective of the origin, the lymphatic continuities may differ between the 2 primordia.

METHODS

Between March 2003 and September 2010, 152 patients underwent pancreaticoduodenectomy for pancreatic cancer. One hundred six patients were assigned into 2 groups according to tumor location on preoperative computed tomography, and their clinical and pathological features were retrospectively analyzed in view of the embryonic development of the pancreas.

RESULTS

Sixty of 106 patients were classified with tumors that were derived from the dorsal pancreas (D group) and 46 from the ventral pancreas (V group). The frequency of LN involvement around the middle colic artery (LN 15) in the D group was higher than in the V group (P = 0.008). The rate of additional resection of the pancreas tended to be higher in the D group (P = 0.067).

CONCLUSIONS

The present study showed the detailed pattern of spread of pancreatic ductal carcinoma to the LNs and provided important information for determining the optimal surgical strategy.

Identification of the lymphatic drainage pathways from the pancreatic head guided by indocyanine green fluorescence imaging during pancreaticoduodenectomy

AIMS

We identified the lymphatic drainage pathways from the pancreatic head guided by indocyanine green (ICG) fluorescence imaging to analyze optimal lymphadectomy for pancreatic cancer.

METHODS

The lymphatic pathways in 20 patients undergoing pancreaticoduodenectomy were analyzed. We injected ICG into the parenchyma in the anterior (n = 10) or posterior surface (n = 10) of the pancreas head and observed the intraoperative lymphatic flows by ICG fluorescence imaging.

RESULTS

The seven main lymphatic drainage pathways were identified: (1) along the anterior or posterior pancreaticoduodenal arcade, (2) running obliquely down behind the superior mesenteric vein (SMV), (3) reaching the left side of the superior mesenteric artery (SMA), (4) running longitudinally upward between the SMV and SMA, (5) along the middle colic artery toward the transverse colon, (6) reaching the paraaortic (PA) region, and (7) reaching the hepatoduodenal ligament. The lymphatic pathway reaching the left side of the SMA was observed in 4 patients (20%), while that reaching the PA region in 17 patients (85%). The mean time to reach around the SMA was longer than that to reach the PA region.

CONCLUSIONS

We found that several lymphatic drainage routes were observed from the pancreatic head, suggesting that a lymphadectomy around the SMA might have a similar oncological impact as that of the PA region.

Proposing the lymphatic target volume for elective radiation therapy for pancreatic cancer: a pooled analysis of clinical evidence

Background

Radiation therapy is an important cancer treatment modality in both adjuvant and definitive setting, however, the use of radiation therapy for elective treatment of regional lymph nodes is controversial for pancreatic cancer. No consensus on proper selection and delineation of subclinical lymph nodal areas in adjuvant or definitive radiation therapy has been suggested either conclusively or proposed for further investigation. This analysis aims to study the pattern of lymph node metastasis through a pooled analysis of published results after radical tumor and lymph nodal resection with histological study in pancreatic cancer.

Methods

Literature search using electronic databases including MEDLINE, EMBASE, and CANCERLIT from January 1970 to June 2009 was performed, supplemented by review of references. Eighteen original researches and a total of 5954 pancreatic cancer patients underwent radical surgical resection were included in this analysis. The probability of metastasis in regional lymph nodal stations (using Japan Pancreas Society [JPS] Classification) was calculated and analyzed based on the location and other characteristics of the primary disease.

Results

Commonly involved nodal regions in patients with pancreatic head tumor include lymph nodes around the common hepatic artery (Group 8, 9.79%), posterior pancreaticoduodenal lymph nodes (Group 13, 32.31%), lymph nodes around the superior mesenteric artery (Group 14, 15.85%), paraaortic lymph nodes (Group 16, 10.92%), and anterior pancreaticoduodenal lymph nodes (Group 17, 19.78%); The probability of metastasis in other lymph nodal regions were <9%.

Commonly involved nodal regions in patients with pancreatic body/tail tumor include lymph nodes around the common hepatic artery (Group 8, 15.07%), lymph nodes around the celiac trunk (Group 9, 9.59%), lymph nodes along the splenic artery (Group 11, 35.62%), lymph nodes around the superior mesenteric artery (Group 14, 9.59%), paraaortic lymph nodes (Group 16, 16.44%), and inferior body lymph nodes (Group 18, 24.66%). The probability of metastasis in other lymph nodal regions were <9%.

Conclusions

Pancreatic cancer has a high propensity of regional lymphatic metastases; however, clear patterns including the site and probability of metastasis can be identified and used as a guide of treatment in patients with resectable pancreatic cancer. Further clinical investigation is needed to study the efficacy of elective treatment to CTV defined based on these patterns using high-dose conformal or intensity-modulated radiation therapy.

Evaluation of the prognostic factors and significance of lymph node status in invasive ductal carcinoma of the body or tail of the pancreas

OBJECTIVE

We evaluated prognostic indicators for distal pancreatectomy with regional lymph node dissection in pancreatic body or tail carcinoma.

METHODS

Between 1993 and 2008, 50 patients with ductal carcinoma of the body or tail of the pancreas who underwent distal pancreatectomy with regional lymph node dissection were retrospectively analyzed. Clinicopathological factors associated with patient survival were evaluated.

RESULTS

No in-hospital deaths occurred among the study patients. The overall 5-year survival rate was 19.3%, and median survival was 22.6 months. Univariate analysis revealed that lymph node metastasis, intrapancreatic neural infiltration, peripancreatic nerve plexus infiltration, and tumor differentiation affected patient survival significantly. Multivariate analysis validated lymph node metastasis as an independent prognostic factor. Moreover, the lymph nodes attached to the pancreas were the most frequent metastatic nodes, and the number of metastasis in the lymph nodes attached to the pancreas was significantly associated with survival after surgical resection.

CONCLUSIONS

Lymph node metastasis was a significant and independent prognostic factor for the surgically resected pancreatic body or tail carcinoma. Furthermore, the lymph nodes attached to the pancreas were the most frequent metastatic nodes, and these lymph nodes were potential indicators predicting both tumor extension and survival after surgery for pancreatic body or tail carcinoma.

Surgical management of carcinoma of the head of pancreas: extended lymphadenectomy or modified en bloc resection?

Pancreatoduodenectomy for the treatment of periampullary cancer was described over 70 years ago. The technique has evolved in an attempt to improve the dismal prognosis for patients with pancreatic cancers. Radical regional resection has been proposed to decrease the incidence of local recurrence as well as to improve survival. These extended resections have failed to show a significant survival benefit in prospective randomized controlled studies. Furthermore, extended pancreatic resections may be associated with increased morbidity. The concept of modified en bloc resection has been advocated and is soundly based on anatomical and pathological principals. This procedure is a modification of the radical regional resection previously described. It involves resection of the peripancreatic retroperitoneal tissue and lymph nodes en bloc with the head of pancreas, in order to achieve an R0 resection but without the morbidity associated with an extended lymphadenectomy. Conceptually, this procedure may be the most appropriate technique for the management of pancreatic head cancers although the ultimate effect on long-term survival can only be judged after further clinical studies.

The nature of neural invasion by pancreatic cancer

OBJECTIVES

Neural invasion is one of the most important modes of tumor extension in pancreatobiliary tract cancer. However, the precise pattern of neural invasion and the relationship between neural invasion and nodal involvement are unknown.

METHODS

Using 8 surgical specimens from patients with pancreatic cancer, 4973 sections were created and examined histopathologically. A total of 961 sections of VX2 tumor grown in the retroperitoneum of rabbits also were examined histologically. The precise mechanism by which neural invasion occurs and the relationship between nerve fascicle and lymph node involvement were determined by histological examination of serial sections.

RESULTS

Histological evaluation of the surgical specimens revealed continuity between the cancer cells between the inside and the outside of the perineurium. Tumor cells grew mainly in a continuous fashion along the branches of nerves. An advancing tip of the tumor cells was identified. The pattern of tumor spread in the experimental study was similar to that in the clinical study. Continuity was found between the cancer cells inside some lymph nodes and the cancer cells within the perineural space. This finding suggests that neural invasion might be a pathway to lymphatic involvement.

CONCLUSIONS

Neural invasion is a common, but not a specific, feature of pancreatic cancer. Tumor cells in the perineural space grow in a continuous fashion and may be responsible for some cases of lymphatic spread.

Significance of Common Hepatic Artery Lymph Node Metastases During Pancreaticoduodenectomy for Pancreatic Head Adenocarcinoma

BACKGROUND

Common hepatic artery lymph nodes (CHALN) are frequently sampled during pancreaticoduodenectomy for adenocarcinomas of the head of the pancreas. In some institutions, if metastatic disease is detected intraoperatively in these lymph nodes, the tumor is considered unresectable and a curative operation is not performed. No solid data exist to support this practice.

METHODS

A retrospective review of a prospectively collected database was conducted of the records of all patients who underwent a pancreaticoduodenectomy for pancreatic adenocarcinoma between September 1991 and April 2005. Clinical and pathologic factors were analyzed to determine their influence on survival.

RESULTS

Fifty-five of 175 patients had CHALN separately identified and evaluated; these patients constituted the study population. Thirty-eight patients (69%) had one or more lymph nodes with metastatic involvement; 10 of these had disease in CHALN. The median overall survival for patients with node-negative, node-positive (but CHALN-negative), and CHALN-positive disease were 22.9, 16.1, and 14.7 months, respectively. The 5-year overall survival rates for the respective groups were 22%, 17%, and 0%.

CONCLUSIONS

CHALN metastases correlate with poor prognosis and no long-term survival. Further studies examining CHALN status are indicated and could lead to modifications of pancreatic cancer staging and management.

Resection of the mesopancreas (RMP): a new surgical classification of a known anatomical space

Background

Prognosis after surgical therapy for pancreatic cancer is poor and has been attributed to early lymph node involvement as well as to a strong tendency of cancer cells to infiltrate into the retropancreatic tissue and to spread along the peripancreatic neural plexuses. The objective of our study was to classify the anatomical-surgical layer of the mesopancreas and to describe the surgical principles relevant for resection of the mesopancreas (RMP). Immunohistochemical investigation of the mesopancreatic-perineural lymphogenic structures was carried out with the purpose of identifying possible routes of metastatic spread.

Methods

Resection of the mesopancreas (RMP) was performed in fresh corpses. Pancreas and mesopancreas were separated from each other and the mesopancreas was immunohistochemically investigated.

Results

The mesopancreas strains itself dorsally of the mesenteric vessels as a whitish-firm, fatty tissue-like layer. Macroscopically, in the dissected en-bloc specimens of pancreas and mesopancreas nerve plexuses were found running from the dorsal site of the pancreatic head to the mesopancreas to establish a perineural plane. Immunohistochemical examinations revealed the lymphatic vessels localized in direct vicinity of the neuronal plexuses between pancreas and mesopancreas.

Conclusion

The mesopancreas as a perineural lymphatic layer located dorsally to the pancreas and reaching beyond the mesenteric vessels has not been classified in the anatomical or surgical literature before. The aim to ensure the greatest possible distance from the retropancreatic lymphatic tissue which drains the carcinomatous focus can be achieved in patients with pancreatic cancer only by complete resection of the mesopancreas (RMP).

Full-dose gemcitabine and concurrent radiotherapy for unresectable pancreatic cancer

PURPOSE

Full-dose gemcitabine and concurrent radiotherapy is a promising treatment approach in unresectable pancreatic cancer. This study was conducted to assess the pattern of failure and toxicity associated with the use of conformal treatment volumes, omitting prophylactic lymph node irradiation.

METHODS AND MATERIALS

Seventy-four patients with locally advanced pancreatic cancer were treated between 1997 and 2005 with full-dose (1000 mg/m(2), Days 1, 8, and 15) gemcitabine and concurrent radiotherapy (36 Gy [median] in 15 daily fractions). The planning target volume (PTV) was limited to the gross tumor volume (GTV) plus 1-cm margin. Patient computed tomography (CT) scans were systematically reviewed to determine the pattern of failure. Kaplan-Meier and Cox-regression models were used to analyze freedom from local progression (FFLP), distant failure, overall survival (OS), and toxicity.

RESULTS

With a median follow-up of 10.6 months (20.6 months in living patients), the 1-year and 2-year FFLP rates were 64% and 38%, respectively. Four patients (5%) failed in the peripancreatic lymph nodes (3 in-field and 1 marginal failure). Median OS was 11.2 months. Analyzed as a time-dependent covariate, local failure was a significant predictor of OS (p = 0.0074). Sixteen patients (22%) had significant gastrointestinal (GI) toxicity (> or = Grade 3). PTV correlated with significant GI toxicity (p = 0.007).

CONCLUSIONS

Freedom from local progression in unresectable pancreatic cancer is suboptimal. In conjunction with full-dose gemcitabine, the use of conformal fields encompassing only the GTV helps reduce toxicity and does not result in marginal failures. Our findings provide rationale for intensification of local therapy in conjunction with more effective systemic therapy.

Oncological problems in pancreatic cancer surgery

Despite the development of more sophisticated diagnostic techniques, pancreatic carcinoma has not yet been detected in the early stage. Surgical resection provides the only chance for cure or long-term survival. The resection rate has increased due to recent advances in surgical techniques and the application of extensive surgery. However, the postoperative prognosis has been poor due to commonly occurring liver metastasis, local recurrence and peritoneal dissemination. Recent molecular-biological studies have clarified occult metastasis, micrometastasis and systemic disease in pancreatic cancer. Several oncological problems in pancreatic cancer surgery are discussed in the present review.

Survival of patients with periampullary carcinoma is predicted by lymph node 8a but not by lymph node 16b1 status

BACKGROUND

The aim of this study was to assess the impact of metastatic disease in lymph nodes 8a and 16b1 (as defined by the Japanese Pancreas Society) on survival in patients with periampullary malignancy.

METHODS

Patients undergoing resection for primary pancreatic ductal adenocarcinoma or intrapancreatic bile duct adenocarcinoma were identified from a prospective database (September 1997-May 2003).

RESULTS

Thirteen of 54 and ten of 44 evaluable patients had metastatic involvement of lymph nodes 8a and 16b1 respectively. Metastatic involvement of lymph node 8a was associated with a significantly shorter median survival (197 versus 470 days; P = 0.003) but metastatic involvement of lymph node 16b1 did not affect survival (457 versus 503 days; P = 0.185). Multivariate analysis showed lymph node 8a status to be the strongest predictor of outcome (P = 0.006). Median survival of those with metastatic lymph node 8a was not significantly different from that of 81 patients with overt metastatic periampullary cancer at the time of diagnosis (98 days; P = 0.072)

CONCLUSION

Lymph node 8a was an independent prognostic factor in patients with periampullary malignancy, but lymph node 16b1 was not. Survival in those with metastatic lymph node 8a was not significantly different from that in patients with metastatic disease at presentation. Preoperative determination of lymph node 8a status may have important implications in selecting patients for treatment.

Current standards of surgery for pancreatic cancer

Background

Pancreatic cancer carries a dismal prognosis but there has been a vast increase in evidence on its management in the past decade.

Methods

An electronic and manual search was performed for articles on the surgical treatment of pancreatic cancer published in the past 10 years.

Results

Six major areas of advancement were identified. Groups at high risk of developing pancreatic cancer, notably those with chronic pancreatitis and hereditary pancreatitis, have been defined, raising the need for secondary screening. Methods of staging pancreatic cancer for resection have greatly improved but accuracy is still only 85–90 per cent. Pylorus-preserving partial pancreatoduodenectomy without extended lymphadenectomy is the simplest procedure; it does not compromise long-term survival. Adjuvant chemotherapy significantly improves long-term survival. Patients who are free from major co-morbidity have better palliation by surgery (with a double bypass) than by endoscopy. High-volume centres improve the results of surgery for all outcome measures including long-term survival.

Conclusion

The surgical management of pancreatic cancer has undergone a significant change in the past decade. It has moved away from no active treatment. The standard of care can now be defined as potentially curative resection in a specialist centre followed by adjuvant systemic chemotherapy.

Lysophosphatidic acid (LPA) in malignant ascites stimulates motility of human pancreatic cancer cells through LPA1

Cytokines and growth factors in malignant ascites are thought to modulate a variety of cellular activities of cancer cells and normal host cells. The motility of cancer cells is an especially important activity for invasion and metastasis. Here, we examined the components in ascites, which are responsible for cell motility, from patients and cancer cell-injected mice. Ascites remarkably stimulated the migration of pancreatic cancer cells. This response was inhibited or abolished by pertussis toxin, monoglyceride lipase, an enzyme hydrolyzing lysophosphatidic acid (LPA), and Ki16425 and VPC12249, antagonists for LPA receptors (LPA1 and LPA3), but not by an LPA3-selective antagonist. These agents also inhibited the response to LPA but not to the epidermal growth factor. In malignant ascites, LPA is present at a high level, which can explain the migration activity, and the fractionation study of ascites by lipid extraction and subsequent thin-layer chromatography indicated LPA as an active component. A significant level of LPA1 receptor mRNA is expressed in pancreatic cancer cells with high migration activity to ascites but not in cells with low migration activity. Small interfering RNA against LPA1 receptors specifically inhibited the receptor mRNA expression and abolished the migration response to ascites. These results suggest that LPA is a critical component of ascites for the motility of pancreatic cancer cells and LPA1 receptors may mediate this activity. LPA receptor antagonists including Ki16425 are potential therapeutic drugs against the migration and invasion of cancer cells.

Can intestinal innervation be preserved in pancreatoduodenectomy for cancer? Results of an anatomical study

Twenty dissections were carried out, in all of which the splanchnic nerves, celiac plexuses, capital pancreatic plexus and superior mesenteric plexus were identified and traced. The capital pancreatic plexus was formed from two bundles, the first taking its origin from the right celiac plexus, the second from the superior mesenteric plexus. These two bundles joined together just behind the head of the pancreas. Two preganglionic bundles, a ganglion and two postganglionic bundles composed the superior mesenteric plexus. Postganglionic bundles received fibers from both right and left celiac plexuses. In small cancers a thin layer of nervous tissue around the superior mesenteric artery might be spared in order to avoid diarrhea from intestinal denervation. This study has provided anatomical evidence that a part of the mesenteric plexus, which receives fibers from both left and right celiac plexuses, maintains a sufficient intestinal innervation.

Results of pancreaticoduodenectomy for pancreatic cancer: extended versus standard procedure

In Western experience, the long-term survival benefit after extended pancreaticoduodenectomy (EPD) in patients with pancreatic ductal adenocarcinoma is still controversial. The aim of this work was to evaluate weather EPD for pancreatic ductal adenocarcinoma prolongs long-term survival compared to standard pancreaticoduodenectomy (SPD). From November 1992 to September 1996, we performed pancreatic resections in 30 patients affected by stage I-III pancreatic ductal adenocarcinoma: 13 patients underwent SPD and 17 patients underwent EPD, consecutively. The two groups of patients were similar for all the demographic, clinical, and pathological characteristics, and all the intraoperative factors considered except the number of resected lymph nodes (mean number per case = 34.2 +/- 15.5 in the EPD group versus 12.8 +/- 3.6 in the SPD group, p <0.001) and the operative time (median time per case = 375 minutes in the EPD group versus 270 minutes in the SPD group, p = 0.009). Patients in the two groups experienced a similar postoperative course. The estimated survival probability at 1 and 3 years after operation was 0.76 (95% confidence interval [CI]: 0.49 to 0.90) and 0.24 (95% CI: 0.07 to 0.45) in the EPD group; 0.31 (95% CI: 0.09 to 0.55) and 0.08 (95% CI: 0.00 to 0.29) in the SPD group (p = 0.014). According to a Cox model, the treatment was associated with R0 patients' long-term survival (SPD versus EPD: hazard ratio (HR) = 4.82, 95% CI: 1.66 to 14.00, p = 0.004). Grading of tumor differentiation was confirmed to be a relevant prognostic factor (poor versus moderate: HR = 4.33, 95% CI: 1.49 to 12.61, p = 0.007), whereas type of resection had no significant effect (pylorus-preserving versus hemigastrectomy: HR = 1.49, 95% CI: 0.56 to 3.95, p = 0.42). The proportion of R0 patients with local recurrence was lower in the EPD group (20.0% versus 70.0%, p = 0.034).

Analysis of paraaortic lymph node involvement in pancreatic carcinoma: a significant indication for surgery?

BACKGROUND

Lymph node status is a key prognostic factor for pancreatic carcinoma. The paraaortic lymph nodes are the highest level of lymph nodes that can be resected safely in the abdomen for pancreatic and other gastrointestinal tumors. The pattern of paraaortic lymph node involvement and its relation with other lymph node groups were analyzed and the significance of this information relative to surgical therapy examined.

METHODS

Between 1974-1996, 99 patients with invasive ductal carcinoma of the pancreas underwent pancreatectomy at the study institution. The pattern of lymph node involvement, particularly paraaortic, was evaluated by careful pathologic review of extended lymphadenectomy specimens. RESULTS. Fifty-eight of 76 patients (76%) with carcinoma in the pancreatic head (Ph) and 19 of 23 patients (83%) with carcinoma of the pancreatic body and tail (Pbt) had lymph node involvement. Fourteen patients with Ph disease (18%) and 4 with Pbt disease (17%) had paraaortic lymph node involvement. Tumor size did not correlate with paraaortic lymph node involvement. A correlation was found between Group 13 (posterior pancreaticoduodenal lymph nodes), Group 14 (lymph nodes surrounding the superior mesenteric artery), and the paraaortic lymph nodes for Ph disease. All paraaortic lymph node metastases were located in the 16M region (the region between the celiac trunk and the inferior mesenteric artery). For patients with Pbt disease, the distribution of paraaortic lymph node metastases was the same as for those with Ph disease. Only 33% of cases of paraaortic lymph node metastases were suspected preoperatively or perioperatively. The longest survival for a patient with paraaortic lymph node metastases was 36 months and 17 months, respectively, for patients with Ph and Pbt disease.

CONCLUSIONS

The paraaortic lymph nodes are frequent sites of metastasis from pancreatic carcinoma, and are difficult to evaluate preoperatively or perioperatively. This situation mandates paraaortic lymph node dissection, at least in the 16M region.

Problems in pancreatic cancer surgery

Despite the development of more sophisticated diagnostic techniques, it remains difficult to detect pancreatic carcinoma in the early stage. However, the resection rate has been increasing due to recent advances in surgical techniques and the application of extensive surgery. In 1995, statistics of the Pancreatic Cancer Register Committee of Japan Pancreas Society showed a 44.5% rate of resection. Further, according to Japan Pancreas Society staging, the 5-year survival rate of Stage I, II, III, and IV after surgical resection was 46.3, 27.5, 20.4, and 8.3%, respectively. This paper will review the Japanese experience of pancreatic carcinoma and several problems in pancreatic cancer surgery.