Clinical importance of intraoperative peritoneal cytology in patients with pancreatic cancer

Use of Diagnostic Laparoscopy and Peritoneal Washings for Pancreatic Cancer

Pancreatic adenocarcinoma is an aggressive malignancy that often presents with advanced disease. Accurate staging is essential for treatment planning and shared decision-making with patients. Staging laparoscopy is a minimally invasive procedure that can detect radiographically occult metastatic disease. Its routine use with the collection of peritoneal washings in patients with pancreatic cancer remains controversial. We, herein, review the current literature concerning staging laparoscopy and peritoneal washings in patients with pancreatic cancer.

Preoperative predictive factors for positive peritoneal cytology results in patients with pancreatic ductal adenocarcinomas: a retrospective study

BACKGROUND

The clinical importance of positive peritoneal cytology results in patients with pancreatic ductal adenocarcinomas remains controversial. We evaluated the prognosis of these patients and the predictive preoperative risk factors for positive peritoneal cytology results.

METHODS

We retrospectively reviewed patients who underwent curative-intent surgery at our institution between May 2010 and June 2020. Preoperative risk factors for positive peritoneal cytology results were identified using logistic regression analysis. A scoring model was constructed using the total number of significant independent predictors for positive peritoneal cytology results.

RESULTS

Of 233 patients, 18 (7.7%) had positive peritoneal cytology results. The recurrence-free survival and cancer-specific survival were markedly worse in patients with positive peritoneal cytology results than in those with negative peritoneal cytology results (recurrence-free survival: 6.0 months vs. 16.6 months, p = 0.050; cancer-specific survival: 19.4 months vs. 47.5 months, p = 0.034). Tumor location (odds ratio: 3.760, 95% confidence interval: 1.099-11.818, p = 0.023), tumor size > 25 mm (odds ratio: 3.410, 95% confidence interval: 1.031-11.277, p = 0.046), preoperative serosal invasion (odds ratio: 5.193, 95% confidence interval: 1.099-24.531, p = 0.038), and preoperative carcinoembryonic antigen level > 5.6 ng/mL (odds ratio: 3.816, 95% confidence interval: 1.248-10.667, p = 0.019) were identified as significant independent predictive factors. Our predictive model's optimal cutoff and positive predictive values for positive peritoneal cytology results were 3 and 27.9%, respectively.

CONCLUSIONS

The indications for curative-intent surgery should be considered carefully in patients with high-risk factors for positive peritoneal cytology results.

Efficacy of staging laparoscopy for resectable pancreatic cancer on imaging and the therapeutic effect of systemic chemotherapy for positive peritoneal cytology

BACKGROUND

The frequency and prognosis of positive peritoneal washing cytology (CY1) in resectable pancreatic ductal adenocarcinoma (R-PDAC) remains unclear. The objective of this study was to identify the clinical implications of CY1 in R-PDAC and staging laparoscopy (SL).

METHODS

We retrospectively analyzed 115 consecutive patients with R-PDAC who underwent SL between 2018 and 2022. Patients with negative cytology (CY0) received radical surgery after neoadjuvant chemotherapy, while CY1 patients received systemic chemotherapy and were continuously evaluated for cytology.

RESULTS

Of the 115 patients, 84 had no distant metastatic factors, 22 had only CY1, and nine had distant metastasis. Multivariate logistic regression revealed that larger tumor size was an independent predictor of the presence of any distant metastatic factor (OR: 6.30, p = .002). Patients with CY1 showed a significantly better prognosis than patients with distant metastasis (MST: 24.6 vs. 18.9 months, p = .040). A total of 11 CY1 patients were successfully converted to CY-negative, and seven underwent conversion surgery. There was no significant difference in overall survival between patients with CY0 and those converted to CY-negative.

CONCLUSION

SL is effective even for R-PDAC. The prognosis of CY1 patients converted to CY-negative is expected to be similar to that of CY0 patients.

LC-1000 flow cytometry system complements intraoperative peritoneal cytology for pancreatic and biliary tract cancer

BACKGROUND

The exfoliative cell analyzer, LC-1000, is medical device that utilizes the principles of flow cytometry, and might provide digital diagnostic information for cytology using a different approach from conventional cytomorphology. In this study, wae examined the usefulness of the LC-1000 as a diagnostic support system for intraoperative peritoneal lavage cytology and its prognostic impact for pancreatic (PC) and biliary tract cancer (BTC).

METHODS

Patients with PC and BTC who underwent surgical treatment were included. First, we identified useful indicators of LC-1000 and established cutoff values to discriminate positive cytology. Next, we verified the validity of these cutoff values.

RESULTS

In the test set (n = 48), of the LC-1000 indicators examined, only MR-CPIx was significantly different between the negative and positive cytology groups, yielding a cutoff value of 0.86. In the validation set (n = 52), the sensitivity, specificity, positive and negative predictive value of the LC-1000 for cytology results was 1.0, 0.49, 0.11 and 1.0, respectively. In patients who had undergone radical resection, recurrence-free survival rate was significantly higher in the LC-1000 negative group than in the positive group in PC, but not in BTC.

CONCLUSION

The LC-1000 was useful as digital support system for peritoneal cytology, and it might have potential as a prognostic factor for PC.

Long-term adjuvant chemotherapy after resection for pancreatic cancer patients with positive peritoneal lavage cytology

PURPOSE

The significance of resection for pancreatic cancer with positive peritoneal lavage cytology (CY +) remains controversial, and the lack of evidence concerning adjuvant chemotherapy (AC) in these patients remains an issue. The aim of the present study was to investigate the prognostic impacts of AC and its duration on the survival outcome in patients with CY + pancreatic cancer.

METHODS

A total of 482 patients with pancreatic cancer who underwent pancreatectomy between 2006 and 2017 were retrospectively analyzed. The overall survival (OS) was compared among the patients with CY + tumors according to the duration of AC.

RESULTS

Among the resected patients, 37 (7.7%) had CY + tumors: 13 received AC for > 6 months, 15 received AC for ≤ 6 months and 9 did not receive AC. The OS of 13 patients with resected CY + tumors who received AC for > 6 months was comparable to that of 445 patients with resected CY- tumors (median survival time 43.0 vs. 33.6 months, P = 0.791), and was significantly better than that of 15 patients with resected CY + tumors who received AC for ≤ 6 months (vs. 16.6 months, P = 0.017). The duration of AC (> 6 months) was an independent prognostic factor in patients with resected CY + tumors (hazard ratio 3.29, P = 0.005).

CONCLUSION

Long-term AC (> 6 months) may improve postoperative survival in pancreatic cancer patients with CY + tumors.

Should Positive Cytology Revealed by Intraoperative Lavage Preclude Radical Resection in Resectable Pancreatic Cancer?: A Systemic Review and Meta-analysis

OBJECTIVES

The aims of this review were to determine whether positive peritoneal lavage cytology (CY+) precludes radical resection in pancreatic cancer and to propose prospections for future studies.

METHODS

MEDLINE, Embase, and Cochrane Central were searched for related articles. Dichotomous variables and survival outcomes were analyzed with the estimation of odds ratio and hazards ratio (HR), respectively.

RESULTS

A total of 4905 patients were included, of which 7.8% were CY+. Positive peritoneal lavage cytology was correlated with poor overall survival (univariate survival analysis [HR, 2.35; P < 0.00001]; multivariate analysis [HR, 1.62; P < 0.00001]), poor recurrence-free survival (univariate survival analysis [HR, 2.50; P < 0.00001]; multivariate analysis [HR, 1.84; P < 0.00001]), and higher initial peritoneal recurrence rate (odds ratio, 5.49; P < 0.00001).

CONCLUSIONS

Although CY+ predicts poor prognosis and a higher risk of peritoneal metastasis after curative resection, it is not sufficient to preclude curative resection based on the current evidence, and high-quality trials should be conducted to assess the prognostic impact of operation among resectable CY+ patients. In addition, more sensitive and accurate methods to detect peritoneal exfoliated tumor cells and more effective comprehensive treatment for resectable CY+ pancreatic cancer patients are clearly warranted.

Prognostic Significance of Intraoperative Peritoneal Lavage Cytology in Patients with Pancreatic Ductal Adenocarcinoma: A Single-Center Experience and Systematic Review of the Literature

BACKGROUND

The prognostic significance of peritoneal lavage cytology (PLC) in patients with pancreatic ductal adenocarcinoma (PDAC) remains controversial. The purpose of this study was to evaluate the prognostic impact of PLC status in PDAC patients.

METHODS

Patients intending to undergo resection for PDAC between 2007 and 2020 were included. Survival was compared among patients who underwent resection with negative or positive PLC status and those who did not undergo resection. Univariable and multivariable analyses were conducted to evaluate the prognostic impact of positive PLC status. A systematic literature review was performed to evaluate the correlation between prognosis and the positive PLC rate.

RESULTS

A total of 480 patients formed the study cohort and were divided as follows: 438 in the negative PLC group, 18 in the positive PLC group, and 24 in the no resection group. Although the median survival time significantly differed between the negative and positive PLC groups (35.7 vs. 13.6 months, P < 0.001), it did not significantly differ between the positive PLC and no resection groups (13.6 vs. 12.2 months, P = 0.605). Multivariable analyses demonstrated that positive PLC status (hazard ratio = 3.54, 95% confidence interval = 1.97-6.38, P < 0.001) was the strongest poor prognostic factor. Based on statistical analyses for the systematic review, the prognostic impact of positive PLC status weakened significantly as the institutional positive PLC rate increased (P = 0.044).

CONCLUSIONS

Resection did not improve the prognosis of patients with positive PLC status in our cohort. The institutional positive PLC rate may be a good reference for surgical indication in these patients.

Intraoperative Cytologic Sampling for Resected Pancreatic and Periampullary Adenocarcinoma with Implications for Locoregional Recurrence-Free Survival

BACKGROUND

We hypothesized that pancreatic and periampullary adenocarcinoma recurrence after surgical resection may be affected by the shedding of malignant epithelial cells during surgical dissection and that this may have implications for disease recurrence and survival.

STUDY DESIGN

In this ongoing, investigator-initiated prospective randomized controlled trial, patients with pancreatic and periampullary adenocarcinoma were randomized intraoperatively, postresection into 3 study arms: peritoneal lavage using 10 L normal saline or distilled water, or control group with no lavage. Peritoneal fluid was sampled for cytologic analysis (cytospin, cellblock, immunohistochemistry-Ber-EP4 antibody) at 4 stages: (1) abdominal entry pre-dissection, (2) resection bed after tumor extirpation, (3) ex vivo resected specimen, and (4) resection bed postlavage.

RESULTS

Between April 2016 and May 2018, 193 patients who underwent randomization for the study also underwent the described cytologic sampling. Of these, 167 patients (86.5%) were ultimately found to have pancreatic or periampullary adenocarcinoma. Before dissection (1) on cytospin analysis, 4.9% were positive, which rose to 10.2% intraoperatively (2), 16.7% ex vivo (3), and decreased to 4.3% (4) after lavage. Lymph node metastasis, margin involvement, and perineural invasion did not correlate with locoregional recurrence (LR). Tumor cells in the ex vivo cytospin (3) correlated with LR (odds ratio 3.8 [95% CI 1.6 to 9.2], p = 0.005) and LR disease-free survival (p = 0.007). Cox regression analysis revealed ex vivo cytospin positivity to be strongly associated with poorer LR disease-free survival (hazard ratio 2.26 [95% CI 1.16 to 4.42], p = 0.017).

CONCLUSIONS

Cytologic sampling from ex vivo specimen irrigation after surgical resection of pancreatic and periampullary adenocarcinoma may have implications for LR, survival, and treatment, suggesting a possible cancer cell shedding phenotype.

Preceding Systemic Chemotherapy for Patients with Pancreatic Ductal Adenocarcinoma with Positive Peritoneal Cytology Provides Survival Benefit Compared with Up-Front Surgery

BACKGROUND

The significance of surgical resection in pancreatic ductal adenocarcinoma (PDAC) with positive peritoneal cytology (PPC) is controversial. This study aimed to evaluate whether preceding chemotherapy could be beneficial for patients with PDAC with PPC.

METHODS

Between 2017 and 2019, 34 consecutive PDAC patients diagnosed with PPC without distant metastasis were retrospectively reviewed. Twenty-three patients did not receive neoadjuvant treatment (NAT) and 11 received NAT. All patients received systemic chemotherapy after PPC was confirmed, and they underwent surgical resection if PPC turned negative. The treatment course, ratio of conversion surgery (CS), and prognosis were evaluated. Moreover, the prognosis of PPC patients who underwent up-front surgery without NAT between 2003 and 2016 was analyzed as a comparative cohort.

RESULTS

The median survival time (MST) of the patients without NAT was 31.4 months. CS was performed in 52.2% of the patients. Patients who underwent CS had better prognoses than those who did not undergo CS (p = 0.005). The CS rate was significantly higher in resectable PDAC (78.5%) than in borderline/unresectable PDAC (11.1%) (p = 0.002). The prognosis of patients with resectable PDAC was improved with preceding chemotherapy compared with up-front surgery (MST 13.0 months; p = 0.016). After NAT, the CS rate was low (27.3%), and the MST was only 14.1 months.

CONCLUSIONS

As an initial treatment for PDAC patients with PPC, chemotherapy may lead to a favorable prognosis. Especially, resectable PDAC is associated with a greater chance of improved prognosis. Future studies are required to ascertain whether up-front surgery or preceding chemotherapy should be performed for these patients.

Predicting positive peritoneal cytology in pancreatic cancer

INTRODUCTION

Positive cytology from peritoneal washings obtained prior to potential resection of pancreatic cancer is associated with grim prognosis, equivalent to M1 disease. We examine our experience with pancreatic cancer patients who underwent pre-resection lavage in an attempt to predict who would have malignant cells on peritoneal cytology.

METHODS

We conducted a retrospective review of patients undergoing pancreatectomy for pancreatic adenocarcinoma at a tertiary care institution from 1995 to 2019 and had pre-resection lavage performed. Demographic and clinicopathologic data were collected. Logistic regression models were used to identify predictors of positive cytology.

RESULTS

Three hundred ninety-nine patients underwent pancreatic resection and had lavage performed. Forty-three (10.8%) had positive peritoneal cytology. Those with positive cytology had higher median Ca19-9 value than those with negative cytology at diagnosis (368.5 vs 200 U/mL, p = 0.007) and after neoadjuvant therapy (100.3 vs 43 U/mL, p = 0.013). After controlling for preoperative therapy received, an initial Ca19-9 greater than 1220 U/mL (OR 2.72, 95% CI 1.07-6.89, p = 0.035), locally advanced disease (OR 4.86, 95% CI 1.31-18.09, p = 0.018), and BMI ≥ 25 kg/m² (OR 2.67, 95% CI 1.04-6.97, p = 0.042) were associated with positive cytology in multivariate logistic regression model. The associated ROC curve had an AUC of 0.7507, suggesting adequate discrimination of those with positive peritoneal cytology.

CONCLUSION

Diagnostic laparoscopy remains an important adjunct to the workup, diagnosis, and staging of pancreatic adenocarcinoma. Patients with locally advanced disease, significantly elevated serum Ca19-9 at diagnosis, and BMI ≥ 25 kg/m² may be at higher risk for positive peritoneal cytology, regardless of whether neoadjuvant therapy is administered.

The impact of peritoneal lavage cytology in biliary tract cancer (KHBO1701): Kansai Hepato-Biliary Oncology Group

Background

Only few studies in literature have analyzed the clinical effects of peritoneal lavage status in biliary tract cancers.

Aim

We aimed to assess the effect of cytology‐positive peritoneal lavage on survival for patients with biliary tract cancer who underwent curative resection.

Methods

The KHBO1701 study was a multi‐institutional retrospective study that assessed the clinical effects of peritoneal lavage cytology in biliary tract cancers. Using clinicopathological data from 11 Japanese institutions, we compared long‐term outcomes between patients with cytology‐positive and cytology‐negative peritoneal lavage.

Results

Of 169 patients who underwent curative resection, 164 were cytology‐negative, and five were cytology‐positive. The incidence of portal invasion and preoperative carbohydrate antigen 19‐9 levels were higher in the cytology‐positive group than in the cytology‐negative group. The incidence of peritoneal metastatic recurrence was also higher, and overall survival tended to be worse in the cytology‐positive group. In contrast, recurrence‐free survival was similar between the cytology‐negative and cytology‐positive groups.

Conclusions

The positive status of peritoneal lavage cytology could moderately affect the survival of patients with biliary tract cancers. Given that surgical resection is the only curative treatment option, it may be acceptable to resect biliary tract cancers without other non‐curative factors, regardless of peritoneal lavage cytology status.

Prognostic impact of intraoperative peritoneal cytology after neoadjuvant therapy for potentially resectable pancreatic cancer

BACKGROUND

Neoadjuvant therapy (NAT) is considered a potential approach to improve survival for patients with pancreatic adenocarcinoma (PA). The objective of this study was to identify the clinical implications of washing peritoneal cytology (CY) status after NAT.

METHODS

Between 2005 and 2016, 151 consecutive patients with resectable (R)/borderline resectable (BR) PA underwent NAT with intention of subsequent resection at our institution. Of them, 13 and 123 patients underwent pancreatectomies with positive (CY+) and negative (CY-) cytology, respectively, while the remaining 15 patients did not undergo resection due to gross metastases at laparotomy. The clinicopathological factors influencing overall survival were clarified by the uni- and multivariate analyses.

RESULTS

The postoperative overall survival (OS) and disease-free survival (DFS) were markedly worse in patients who underwent resection with CY+, compared with those who were CY- (median OS, 14.8 m vs 30.8 m, p = 0.026, and median DFS 6.0 m vs 15.1 m, p = 0.008). According to the resectability by NCCN guidelines, CY+ indicates worse prognosis than CY- in R-PA patients (mOS: 30.1 m vs 71.1 m: p = 0.080). Similarly, in BR-PA patients, CY+ showed the significantly worse prognosis than CY- (mOS: 13.8 m vs 24.5 m: p = 0.048), which prognosis is comparable with patients who did not undergo resection. The multivariate analysis revealed that resectability, CY status and the induction of adjuvant therapy were significant predictors of postoperative OS (p = 0.007: Hazard ratio 2.264, 0.040:2.094 and 0.002:3.246, respectively).

CONCLUSIONS

CY+ is a significant predictor of poorer prognosis in PA patients after NAT. The subsequent pancreatectomies with CY+ after NAT do not contribute to prolonged survival.

Use of imaging as staging and surgical planning for pancreatic surgery

Importance

In the past few decades, there has been rapid advancements in imaging technologies that have become irreplaceable in the pre-operative assessment of patients with pancreatic tumors. Modern imaging modalities, including computed tomography (CT) and endoscopic ultrasound (EUS), can provide critical information of the absence or presence of metastatic disease in pancreatic cancer, as well as details on the local extent and resectability, allowing for the selection of stage appropriate treatments and pre-operatively determined surgical approach.

Objective

The aim of this review is to discuss staging, resectability, and imaging for patients with pancreatic tumors.

Evidence Review

A literature review was performed of articles relevant to the topics of staging, resectability, and imaging of pancreatic tumors. Imaging modalities included CT, EUS, magnetic resonance imaging (MRI), positron emission tomography (PET), antibody-based and narrow band imaging.

Findings

CT pancreas protocol combined with EUS serve as the primary modalities in diagnosis, staging, and surgical planning in patients with pancreatic tumors. MRI is an alternative to CT with near equivalent utility in the pre-operative setting. In some circumstances, PET-CT may be a cost-effective initial study to detect distant disease.

Conclusions and Relevance

Current imaging technologies play a critical role in the evaluation of patients with pancreatic tumors. Advances in the past 3 decades in imaging technologies have revolutionized the process of assessment of stage and resectability in patients with pancreatic tumors. Future imaging technologies will address current limitation in the evaluation of occult metastatic disease.

Peritoneal Lavage Tumor DNA as a Novel Biomarker for Predicting Peritoneal Recurrence in Pancreatic Ductal Adenocarcinoma

BACKGROUND

The clinical role of peritoneal lavage cytology (CY) in pancreatic ductal adenocarcinoma (PDAC) remains controversial, partly due to its low sensitivity. This study aimed to develop a new biomarker, defined as peritoneal lavage tumor DNA (ptDNA), using DNAs extracted from peritoneal lavage samples from patients with PDAC.

METHODS

Samples were collected intraoperatively from 89 PDAC patients who underwent pancreatectomy between 2012 and 2017. Droplet digital polymerase chain reaction (PCR) was used to measure ptDNA for detection of KRAS mutations. The ptDNA status and clinical characteristics were retrospectively evaluated.

RESULTS

Positive ptDNA was found in 41 patients, including all 9 patients positive for CY (CY+) and 32 patients negative for CY (CY-). The mutant allele frequency was significantly higher in the CY+ patients than in the CY- patients. The disease-free survival (DFS) and overall survival (OS) were significantly poorer in the high-ptDNA group than in the low-ptDNA group (median DFS, 11.0 vs. 18.8 months; p = 0.007; median OS, 28.7 vs not reached; p = 0.001). The survival curves of DFS and OS in the CY+ group were almost equal to those in the CY- and high-ptDNA group. In a multivariable analysis, ptDNA was an independent predictive factor for DFS (p = 0.025) and OS (p = 0.047). The estimated cumulative incidence of peritoneal recurrence was 45.5% in the high-ptDNA group. The ptDNA biomarker had a much higher sensitivity for peritoneal recurrence than CY, whereas CY had higher specificity.

CONCLUSIONS

As a promising biomarker, ptDNA may predict poor prognosis and peritoneal recurrence in PDAC, resolving the controversy surrounding CY.

Prognostic indicators in pancreatic cancer patients undergoing total pancreatectomy

PURPOSE

To evaluate the long-term outcomes of total pancreatectomy in a modern cohort of pancreatic cancer patients and to establish whether any factors identified prior to pancreatic resection were related to poor survival.

METHODS

We analyzed, retrospectively, patients who underwent total pancreatectomy for pancreatic cancer between 2007 and 2016. The short- and long-term outcomes were investigated and Cox regression analysis was used to evaluate the prognostic factors identified before resection.

RESULTS

The subjects were 49 patients with a mean age of 65 years, who underwent total pancreatectomy in our hospital during the study period. Peritoneal washing cytology was performed in 48 patients, with positive results in 4 (8.3%). There was no 30-day mortality. The median overall survival was 22.5 months, with a 5-year survival rate of 28.5%. Univariate analyses of the pre-resection variables revealed that overall survival was associated with tumor location, resectability classification, maximum standardized uptake value of positron emission tomography, the preoperative carbohydrate antigen 19-9 level, and peritoneal washing cytology status. Multivariate analysis revealed that positive peritoneal washing cytology status and the maximum standardized uptake value were independent predictors of poor survival.

CONCLUSION

Total pancreatectomy for pancreatic cancer is appropriate for selected patients, but peritoneal washing cytology and positron emission tomography should be performed preoperatively.

Conversion surgery for positive peritoneal washing cytology in pancreatic cancer

Positive peritoneal washing cytology (PPC) of pancreatic carcinoma is defined as distant metastasis in the American Joint Committee on Cancer or Union for International Cancer Control's tumour, node, metastases classification. However, surgical resection was believed to be the only method that prolong survival; thus, many institutions perform pancreatectomy for PPC, despite the unfavourable prognosis. Therefore, a more preferable alternative treatment for PPC is required. A 64-year-old man with resectable pancreatic tail cancer presented to our hospital. PPC was detected at first laparotomy; thus, pancreatectomy was avoided and gemcitabine with nabpaclitaxel (GnP) was administered. After four courses of GnP treatment, PPC converted to negative, as evaluated by abdominal port cytology. Thus, distal pancreatectomy was performed, and R0 resection was achieved. He has been healthy for more than 24 months since the first laparotomy. Initial chemotherapy with the intention of converting the cytological status followed by surgical treatment might become a useful treatment strategy for PPC.

Meta-analysis of recurrence pattern after resection for pancreatic cancer

Background

Initial recurrence mapping of resected pancreatic ductal adenocarcinoma (PDAC) could help in stratifying patient subpopulations for optimal postoperative follow-up. The aim of this systematic review and meta-analysis was to investigate the initial recurrence patterns of PDAC and to correlate them with clinicopathological factors.

Methods

MEDLINE and Web of Science databases were searched systematically for studies reporting first recurrence patterns after PDAC resection. Data were extracted from the studies selected for inclusion. Pooled odds ratios (ORs) and 95 per cent confidence intervals were calculated to determine the clinicopathological factors related to the recurrence sites. The weighted average of median overall survival was calculated.

Results

Eighty-nine studies with 17 313 patients undergoing PDAC resection were included. The weighted median rates of initial recurrence were 20·8 per cent for locoregional sites, 26·5 per cent for liver, 11·4 per cent for lung and 13·5 per cent for peritoneal dissemination. The weighted median overall survival times were 19·8 months for locoregional recurrence, 15·0 months for liver recurrence, 30·4 months for lung recurrence and 14·1 months for peritoneal dissemination. Meta-analysis revealed that R1 (direct) resection (OR 2·21, 95 per cent c.i. 1·12 to 4·35), perineural invasion (OR 5·19, 2·79 to 9·64) and positive peritoneal lavage cytology (OR 5·29, 3·03 to 9·25) were significantly associated with peritoneal dissemination as initial recurrence site. Low grade of tumour differentiation was significantly associated with liver recurrence (OR 4·15, 1·71 to 10·07).

Conclusion

Risk factors for recurrence patterns after surgery could be considered for specific surveillance and treatments for patients with pancreatic cancer.

Intraoperative Peritoneal Washing Cytology on Survival in Pancreatic Ductal Adenocarcinoma With Resectable, Locally Advanced, and Metastatic Disease

OBJECTIVES

The prognostic implications of intraoperative peritoneal washing cytology (IPWC) in patients with pancreatic ductal adenocarcinoma (PDAC) remains incompletely understood.

METHODS

A meta-analysis was conducted to investigate the impact of IPWC status on the clinicopathologic features and survival outcomes in potentially resectable, locally advanced, and metastatic PDAC. Hazard ratio (HR) and 95% confidence interval (CI) were used as the pooled estimates.

RESULTS

A total of 12 studies qualified for inclusion with 3751 PDAC patients. In resectable PDAC, the postoperative 5-year overall survival was significantly better in negative IPWC than in positive IPWC patients, with a pooled HR of 2.47 (95% CI, 1.90-3.21; P < 0.001; I = 69%) in a random-effects model. Likely, combined outcome showed a significantly longer survival benefit in the negative IPWC group (HR, 2.80; 95% CI, 1.94-4.04; P < 0.001) in terms of recurrence-free survival. The presence of positive IPWC did not significantly alter survival outcomes in those PDAC patients with locally advanced or metastatic disease.

CONCLUSIONS

This systematic review and meta-analysis demonstrated that a positive IPWC status in patients with clinically resectable PDAC predicts a poor prognosis. Patients with positive IPWC should be regarded as a specific subgroup, with intensive adjuvant chemotherapy that seems to be warranted for further evaluation.

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.

Prognostic Value of Preoperative Nutritional and Immunological Factors in Patients with Pancreatic Ductal Adenocarcinoma

BACKGROUND

Preoperative nutritional and immunological patient factors have been found to be associated with prognostic outcomes of malignant tumors; however, the clinical significance of these factors in pancreatic ductal adenocarcinoma (PDAC) remains controversial.

OBJECTIVE

The aim of this study was to evaluate the prognostic value of nutritional and immunological factors in predicting survival of patients with PDAC.

METHODS

Retrospective studies of 329 patients who underwent surgical resection for PDAC and 95 patients who underwent palliative surgery were separately conducted to investigate the prognostic impact of tumor-related factors and patient-related factors, including Glasgow Prognostic Score (GPS), modified GPS, Prognostic Nutritional Index (PNI), neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio, and lymphocyte/monocyte ratio.

RESULTS

In multivariate analysis for patients with surgical resection for PDAC, PNI was an independent factor for overall survival (OS) and disease-free survival. The median OS of patients with PNI ≤ 45 was significantly shorter than that of patients with PNI > 45 (17.5 and 36.2 months, respectively; p < 0.001). In multivariate analysis for patients undergoing palliative surgery for PDAC, only NLR was an independent prognosis factor. The median OS of patients with NLR > 5 was significantly shorter than that of patients with NLR ≤ 5 (2.7 and 8.9 months, respectively; p < 0.001).

CONCLUSIONS

PNI in patients with surgical resection and NLR in patients with palliative surgery for PDAC may be useful prognostic factors.