Prognostic value of occult tumor cells obtained by peritoneal lavage in patients with resectable pancreatic cancer and no ascites: A systematic review

Clinical impact of high-quality testing for peritoneal lavage cytology in pancreatic cancer

In pancreatic ductal adenocarcinoma (PDAC) patients, the importance of peritoneal lavage cytology, which indicates unresectability, remains controversial. This study sought to determine whether positive peritoneal lavage cytology (CY+) precludes pancreatectomy. Furthermore, we propose a novel liquid biopsy using peritoneal lavage fluid to detect viable peritoneal tumor cells (v-PTCs) with TelomeScan F35, a telomerase-specific replication-selective adenovirus engineered to express green fluorescent protein. Resectable cytologically or histologically proven PDAC patients (n = 53) were enrolled. CY was conducted immediately following laparotomy. The resulting fluid was examined by conventional cytology (conv-CY; Papanicolaou staining and MOC-31 immunostaining) and by the novel technique (Telo-CY; using TelomeScan F35). Of them, 5 and 12 were conv-CY+ and Telo-CY+, respectively. All underwent pancreatectomy. The two double-CY+ (conv-CY+ and Telo-CY+) patients showed early peritoneal recurrence (P-rec) postoperatively, despite adjuvant chemotherapy. None of the three conv-CY+ Telo-CY- patients exhibited P-rec. Six of the 10 Telo-CY+ conv-CY- patients (60%) relapsed with P-rec. Of the remaining 38 double-CY- [conv-CY-, Telo-CY-, conv-CY± (Class III)] patients, 3 (8.3%) exhibited P-rec. Although conv-CY+ status predicted poor prognosis and a higher risk of P-rec, Telo-CY was more sensitive for detecting v-PTC. Staging laparoscopy and performing conv-CY and Telo-CY are needed to confirm the indication for pancreatectomy.

Clinical impact of multimodal treatment including chemoradiotherapy, conversion surgery and postoperative chemotherapy for borderline resectable and unresectable locally advanced pancreatic cancer without disease progression after gemcitabine plus nab-paclitaxel

BACKGROUND

The purpose of this study was to investigate treatment outcomes of chemoradiotherapy (CRT) using S-1 with or without conversion surgery after gemcitabine plus nab-paclitaxel (GnP) for borderline resectable (BR) and unresectable locally advanced (UR-LA) pancreatic cancer.

METHODS

From 2016 to 2020, patients without disease progression after GnP for BR or UR-LA pancreatic cancer underwent CRT with S-1. If distant metastasis was not detected after CRT, conversion surgery and oral administration of S-1 as postoperative adjuvant chemotherapy for at least 6 months was performed.

RESULTS

Forty patients were included in the present study. The median number of cycles of GnP was 6. Surgery was performed after CRT in 25 patients. The median progression-free survival (PFS) and overall survival (OS) periods from the start of radiotherapy were 24.6 and 27.4 months, respectively. The OS periods from the start of radiotherapy in patients who underwent conversion surgery and those who did not undergo conversion surgery were 41.3 and 16.8 months, respectively. The PFS periods from the start of radiotherapy in patients who underwent surgery and those who did not undergo surgery were 28.3 and 8.6 months, respectively. Patients who were able to receive S-1 after conversion surgery for more than 6 months had better OS than those who were not (p = 0.039), although there was no significant difference of PFS (p = 0.365).

CONCLUSIONS

In BR/UR-LA pancreatic cancer without disease progression after GnP, multimodal treatment including CRT, conversion surgery and the scheduled postoperative chemotherapy may be effective.

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.

Effect of omega-3 supplementation on the nutritional status of patients with pancreatic cancer: A protocol for systematic review of clinical trials

BACKGROUND

Globally, pancreatic cancer is the seventh most common cause of cancer-related death in both sexes, accounting for 466,003 deaths and 495,773 new cases in 2020. The purpose of this study was to synthesize and evaluate evidence on the effects of omega-3 supplementation on the nutritional status of patients with pancreatic cancer.

METHODS

This systematic review protocol will be guided by Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols. Five databases will be searched: MEDLINE/PubMed, CENTRAL Cochrane, EMBASE, Web of Science, and SCOPUS, with no restrictions on the publication date nor language. The internal validity and risk of bias of randomized controlled trials will be assessed using the revised Cochrane Risk-Of-Bias tool for randomized trials (RoB 2), whereas the risk of bias in non-randomized studies of interventions will be evaluated using the ROBINS-I. The heterogeneity among the studies will be assessed using the I2 statistic. Based on the results of this test, we will verify whether the meta-analysis would be feasible. If feasibility would be confirmed, a random-effect model analysis will be performed. For data analysis, the calculation of the pooled effect estimates will have a 95% confidence interval, while the alpha will be set to 0.05 using the R statistical software version 4.0.4. All methodological steps of this review will be performed independently by two reviewers and will be conducted and managed in the EPPI-Reviewer Software™.

RESULTS

This review may be of particular interest to researchers and clinicians, given the low survival and overall burden of patients with pancreatic cancer. Furthermore, the results of this systematic review may contribute to the development of new nutritional interventions in these patients.

CONCLUSION

To the best of our knowledge, this will be the first study to critically assess the scientific evidence and estimate the effect of omega-3 supplementation on the nutritional status of patients with pancreatic cancer. The review will perform a rigorous approach, adhering to the PRISMA Statement 2020 using a comprehensive and systematic search strategy in five databases and additional sources with no time period nor language restrictions.

Clinical significance of immunocytochemical staining for peritoneal lavage cytology in pancreatic cancer

BACKGROUND

Peritoneal lavage cytology for pancreatic ductal adenocarcinoma is conducted with both an intraoperative rapid diagnosis by Papanicolaou staining (cytology-rapid) and a final diagnosis by immunocytochemical staining at a later date (cytology-final) in our hospital. However, the clinical significance of cytology-final has not yet been elucidated.

METHODS

A total of 675 pancreatic ductal adenocarcinoma patients who underwent pancreatectomy and cytology between 2002 and 2018 were retrospectively reviewed. Diagnostic results of cytology-rapid and cytology-final and survival outcomes were analyzed.

RESULTS

A total of 43 patients (6.4%) were diagnosed as cytology-rapid (+), and all of them were ultimately diagnosed as cytology-final (+). Among the 632 patients with cytology-rapid (-), 19 (3.0%) were eventually diagnosed as cytology-final (+). The overall survival of patients with cytology-rapid (+) and that of patients with cytology-rapid (-) did not differ to a statistically significant extent (median survival time 26.4 vs 32.9 months; P = .106). In contrast, the overall survival of patients who were diagnosed as a false-negative result by cytology-rapid was significantly worse than that of patients diagnosed as a true negative (18.7 vs 34.8 months; P = .031). The overall survival of patients with cytology-final (+) was significantly worse than that of patients with cytology-final (-) (23.6 vs 34.8 months; P = .012). A multivariate analysis showed that cytology-final (+) was an independent prognostic factor for the OS (hazard ratio = 1.43; P = .049), whereas cytology-rapid (+) was not.

CONCLUSION

Immunocytochemical staining may be a useful complement to a diagnosis of cytology by conventional Papanicolaou staining in pancreatic ductal adenocarcinoma 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.

Prognostic Value of Peritoneal Lavage Cytology in Patients with Pancreatic Ductal Adenocarcinoma Stratified by the Resectability Status

BACKGROUND

The prognostic value of peritoneal lavage cytology (CY) for pancreatic ductal adenocarcinoma (PDAC) remains controversial. We assessed the prognostic impact of CY status stratified by resectability in PDAC patients treated with surgical resection.

METHODS

Clinical data from 440 patients with PDAC who underwent surgical resection were retrospectively analyzed to examine the association of CY status with clinicopathological factors and survival.

RESULTS

Positive CY status (CY+) was found in 30 patients (7%). These patients had significantly worse overall survival in both the resectable (R) (P = 0.002) and borderline resectable (BR) (P < 0.001) groups. The median survival time of CY+ patients in the R and BR groups was 25.6 and 6.7 months, respectively. Multivariate analysis revealed that CY+ was an independent prognostic factor in the BR group (P < 0.001) but not in the R group (P = 0.08). In the R group, CY+ patients who received adjuvant chemotherapy had significantly longer overall survival than those without adjuvant chemotherapy (34.3 vs. 9.8 months, respectively; P < 0.001).

CONCLUSIONS

The prognosis of CY+ patients in the BR group was extremely poor. In the R group, surgical resection combined with adjuvant chemotherapy may improve the prognosis of CY+ patients.

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.

Predictors of distant metastasis on exploration in patients with potentially resectable pancreatic cancer

BACKGROUND

Patients with potentially resectable pancreatic ductal adenocarcinoma (PDAC) are frequently found to be unresectable on exploration due to small distant metastasis. This study was to investigate predictors of small distant metastasis in patients with potentially resectable PDAC.

METHODS

Patients who underwent surgical exploration for potentially resectable PDAC from 2013 to 2014 were reviewed retrospectively and divided into two groups according to whether distant metastases were encountered on exploration. Then, univariate and multivariate logistic regression analyses were used to identify predictors of distant metastasis. A scoring system to predict distant metastasis of PDAC on exploration was constructed based on the regression coefficient of a multivariate logistic regression model.

RESULTS

A total of 235 patients were included in this study. Mean age of the study population was 61.7 ± 10.4 years old. Upon exploration, distant metastases were found intraoperatively in 62 (26.4%) patients, while the remaining 173 were free of distant metastases. Multivariate logistic regression analysis identified that age ≤ 62 years old (p < 0.001), male sex (p = 0.011), tumor size ≥4.0 cm (p < 0.001), alanine aminotransferase level (ALT) < 125 U/L (p < 0.001), and carbohydrate antigen (CA19-9) level ≥ 385 U/mL (p < 0.001) were independent risk factors for occult distant metastasis of PDAC. A preoperative scoring system (0-8 points) for distant metastasis on exploration was constructed using these five factors. The receiver operating characteristic curves showed that the area under the curve of this score was 0.85. A score of 6 points was suggested to be the optimal cut-off value, and the sensitivity and specificity were 85% and 69%, respectively.

CONCLUSIONS

Distant metastasis is still frequently encountered on exploration for patients with potentially resectable PDAC. Younger age, male sex, larger tumor size, low ALT level and high CA19-9 level are independent predictors of unexpected distant metastasis on exploration.

A Therapeutic Strategy for Resectable Pancreatic Cancer Based on Risk Factors of Early Recurrence

OBJECTIVES

The aim of this study was to identify risk factors for early recurrence and assess the prognostic benefit of neoadjuvant therapy (NAT) for resectable pancreatic cancer.

METHODS

Patients with radiographically resectable pancreatic cancer according to the National Comprehensive Cancer Network guidelines were enrolled. We regarded recurrence within 6 months after surgery as early recurrence.

RESULTS

This study involved 115 patients (80 who underwent upfront surgery and 35 who received NAT). Serum carbohydrate antigen 19-9 greater than 85 U/mL and p53 expression in 0 or more than 80% of tumor cells were independent risk factors for early recurrence after upfront surgery. We classified patients into a high-risk group (1 or 2 risk factors) and a low-risk group (no risk factors). In the high-risk group, the median overall survival time of patients with NAT was significantly longer than that of patients without NAT (P = 0.028). By contrast, the median overall survival time was not different according to NAT in the low-risk group.

CONCLUSIONS

Serum carbohydrate antigen 19-9 and p53 expression of the primary tumor could be predictors of early recurrence in patients with resectable pancreatic cancer. The prognosis of patients with a high risk of early recurrence may be improved using NAT.

Tumor manipulation during pancreatic resection for pancreatic cancer induces dissemination of tumor cells into the peritoneal cavity: a systematic review

BACKGROUND

Intraoperative tumor manipulation may induce the dissemination of occult peritoneal tumor cells (OPTC) into the peritoneal cavity.

METHODS

A systematic review was performed in the PubMed, Embase and Cochrane databases from inception to March 15, 2017. Eligible were studies that analyzed the presence of OPTC in peritoneal fluid, by any method, both before and after resection in adults who underwent intentionally curative pancreatic resection for histopathologically confirmed pancreatic ductal adenocarcinoma in absence of macroscopic peritoneal metastases.

RESULTS

Four studies with 138 patients met the inclusion criteria. The pooled rate of OPTC prior to tumor manipulation was 8% (95% CI 2%-24%). The pooled detection rate of OPTC in patients in whom OPTC became detectable only after tumor manipulation was 33% (95% CI 15-58%). Only one study (28 patients) reported on survival, which was worse in patients with OPTC (median 11.1 months versus 30.3 months; p = 0.030).

CONCLUSION

This systematic review suggests that tumor manipulation induces OPTC in one third of patients with pancreatic cancer. Since data on survival are lacking, future studies should determine the prognostic consequences of tumor manipulation, including the potential therapeutic effect of 'no-touch' and minimally invasive resection strategies.

Evaluation of the 8th AJCC staging system for pathologically versus clinically staged pancreatic adenocarcinoma: A time to revisit a dogma?

BACKGROUND

The 8th edition of the American Joint Committee on Cancer (AJCC) staging system for pancreatic exocrine adenocarcinoma has been released. The current study seeks to assess the 7th and 8th editions among patients registered within the surveillance, epidemiology and end results (SEER) database.

METHODS

SEER database (2010-2013) has been accessed through SEER*Stat program and AJCC 8th edition stages were reconstructed utilizing the collaborative stage descriptions. Kaplan-Meier analysis of overall survival and pancreatic cancer-specific survival analyses (according to both 7th and 8th editions and according to whether pathological or clinical staging were conducted) has been performed. Multivariate analysis of factors affecting pancreatic cancer-specific survival was also conducted through a Cox proportional hazard model.

RESULTS

A total of 18  948 patients with pancreatic adenocarcinoma were identified in the period from 2010-2013. Pancreatic cancer-specific survival among pathologically staged patients and according to the 8th edition showed significant differences for all pair wise comparisons among different stages (P < 0.0001) except for the comparison between stage IA and stage IB (P = 0.307) and the comparison between stage IB and stage IIA (P = 0.116). Moreover, P value for stage IA vs IIA was 0.014; while pancreatic cancer-specific survival according to the 7th edition among pathologically staged patients showed significant differences for all pair wise comparisons among different stages (P < 0.0001) except for the comparison between IA and IB (P = 0.072), the comparison between stage IIA and stage IIB (P = 0.065), the comparison between stage IIA and stage III (P = 0.059) and the comparison between IIB and III (P = 0.595). Among clinically staged patients (i.e. those who did not undergo initial radical surgery), the prognostic performance of both 7th and 8th stages for both overall survival and pancreatic cancer-specific survival was limited.

CONCLUSION

There is clearly a need to have two staging systems for pancreatic adenocarcinoma: pathological and clinical staging systems.

Prognostic value of site-specific metastases in pancreatic adenocarcinoma: A Surveillance Epidemiology and End Results database analysis

AIM

To evaluate the prognostic value of site-specific metastases among patients with metastatic pancreatic carcinoma registered within the Surveillance, Epidemiology and End Results (SEER) database.

METHODS

SEER database (2010-2013) has been queried through SEER*Stat program to determine the presentation, treatment outcomes and prognostic outcomes of metastatic pancreatic adenocarcinoma according to the site of metastasis. In this study, metastatic pancreatic adenocarcinoma patients were classified according to the site of metastases (liver, lung, bone, brain and distant lymph nodes). We utilized chi-square test to compare the clinicopathological characteristics among different sites of metastases. We used Kaplan-Meier analysis and log-rank testing for survival comparisons. We employed Cox proportional model to perform multivariate analyses of the patient population; and accordingly hazard ratios with corresponding 95%CI were generated. Statistical significance was considered if a two-tailed P value < 0.05 was achieved.

RESULTS

A total of 13233 patients with stage IV pancreatic cancer and known sites of distant metastases were identified in the period from 2010-2013 and they were included into the current analysis. Patients with isolated distant nodal involvement or lung metastases have better overall and pancreatic cancer-specific survival compared to patients with isolated liver metastases (for overall survival: lung vs liver metastases: P < 0.0001; distant nodal vs liver metastases: P < 0.0001) (for pancreatic cancer-specific survival: lung vs liver metastases: P < 0.0001; distant nodal vs liver metastases: P < 0.0001). Multivariate analysis revealed that age < 65 years, white race, being married, female gender; surgery to the primary tumor and surgery to the metastatic disease were associated with better overall survival and pancreatic cancer-specific survival.

CONCLUSION

Pancreatic adenocarcinoma patients with isolated liver metastases have worse outcomes compared to patients with isolated lung or distant nodal metastases. Further research is needed to identify the highly selected subset of patients who may benefit from local treatment of the primary tumor and/or metastatic disease.