Subclinical cancer cell dissemination in peritoneal lavage fluid detected by reverse-transcription polymerase chain reaction identifies patients at high risk for peritoneal recurrence and consequent impaired survival in the setting of preoperative chemoradiation therapy for pancreatic cancer

Preoperative chemoradiotherapy but not chemotherapy is associated with reduced risk of postoperative pancreatic fistula after pancreatoduodenectomy for pancreatic ductal adenocarcinoma: a nationwide analysis

BACKGROUND

Postoperative pancreatic fistula remains the leading cause of significant morbidity after pancreatoduodenectomy for pancreatic ductal adenocarcinoma. Preoperative chemoradiotherapy has been described to reduce the risk of postoperative pancreatic fistula, but randomized trials on neoadjuvant treatment in pancreatic ductal adenocarcinoma focus increasingly on preoperative chemotherapy rather than preoperative chemoradiotherapy. This study aimed to investigate the impact of preoperative chemotherapy and preoperative chemoradiotherapy on postoperative pancreatic fistula and other pancreatic-specific surgery related complications on a nationwide level.

METHODS

All patients after pancreatoduodenectomy for pancreatic ductal adenocarcinoma were included in the mandatory nationwide prospective Dutch Pancreatic Cancer Audit (2014-2020). Baseline and treatment characteristics were compared between immediate surgery, preoperative chemotherapy, and preoperative chemoradiotherapy. The relationship between preoperative chemotherapy, chemoradiotherapy, and clinically relevant postoperative pancreatic fistula (International Study Group of Pancreatic Surgery grade B/C) was investigated using multivariable logistic regression analyses.

RESULTS

Overall, 2,019 patients after pancreatoduodenectomy for pancreatic ductal adenocarcinoma were included, of whom 1,678 underwent immediate surgery (83.1%), 192 (9.5%) received preoperative chemotherapy, and 149 (7.4%) received preoperative chemoradiotherapy. Postoperative pancreatic fistula occurred in 8.3% of patients after immediate surgery, 4.2% after preoperative chemotherapy, and 2.0% after preoperative chemoradiotherapy (P = .004). In multivariable analysis, the use of preoperative chemoradiotherapy was associated with reduced risk of postoperative pancreatic fistula (odds ratio, 0.21; 95% confidence interval, 0.03-0.69; P = .033) compared with immediate surgery, whereas preoperative chemotherapy was not (odds ratio, 0.59; 95% confidence interval, 0.25-1.25; P = .199). Intraoperatively hard, or fibrotic pancreatic texture was most frequently observed after preoperative chemoradiotherapy (53% immediate surgery, 62% preoperative chemotherapy, 77% preoperative chemoradiotherapy, P < .001).

CONCLUSION

This nationwide analysis demonstrated that in patients undergoing pancreatoduodenectomy for pancreatic ductal adenocarcinoma, only preoperative chemoradiotherapy, but not preoperative chemotherapy, was associated with a reduced risk of postoperative pancreatic fistula.

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.

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.

Levels of tumor markers CEA / CA 19–9 in serum and peritoneal lavage predict postoperative recurrence in patients with pancreatic cancer

Aim

This study aimed to clarify the usefulness of tumor markers from peritoneal lavage in selecting patients with a high risk of recurrence and predicting site‐specific recurrence in patients with pancreatic cancer.

Methods

The levels of serum carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19–9 (sCEA/sCA 19–9) and paired peritoneal lavage CEA and CA 19–9 (pCEA/pCA 19–9) were measured in 90 patients with pancreatic cancer who underwent surgery. Using the cutoff values determined by maximally selected rank statistics for disease‐free survival (DFS), the risk of recurrence and its patterns were evaluated in combination with different markers and different test specimens.

Results

In univariate and multivariate analysis, an elevated pCA 19–9 level (>1.3 U/mL) was an independent prognostic marker for both DFS (hazard ratio [HR], 2.391; P = .018) and overall survival (HR, 3.194; P = .033). Combination analyses contributed to further stratification of a very high risk of recurrence. Of the 58 patients with resectable pancreatic cancer who underwent curative resection, elevated pCA19–9 was also associated with inferior DFS and overall survival (OS). Patients with elevated pCA 19–9 levels were more likely to have an earlier onset of peritoneal recurrence than those with normal pCA 19–9 levels (P = .048, Gehan–Breslow–Wilcoxon test).

Conclusion

pCA 19–9 is a reliable marker for predicting postoperative recurrence in patients with pancreatic cancer after surgery. Further risk stratification can be achieved by using combination assays. The combination of pCA 19–9 and sCA19–9 also serves as a predictor of recurrence site‐specific recurrence.

Impact of Tumor-Derived DNA Testing in Peritoneal Lavage of Pancreatic Cancer Patients with and Without Occult Intra-Abdominal Metastases

BACKGROUND

The fractional abundance of tumor-derived DNA in body fluids depends on the metastatic sites and the degree of expansion. We aimed to assess the clinical significance of tumor-derived DNA testing in the peritoneal lavage of patients with pancreatic cancer.

METHODS

The prevalence and abundance of tumor-derived DNA was assessed in 204 subjects with ascites by peritoneal lavage (AS) and the evaluable paired plasma (PL) from 149 pancreatic cancer patients undergoing abdominal exploration. Genetic profiles were evaluated by next-generation sequencing, and prognostic impact was assessed using Cox proportional hazard models.

RESULTS

Of 204 subjects, AS samples from patients with peritoneal dissemination (PER+) and positive cytology (CY+) showed significantly higher prevalence and abundance of tumor-derived DNA than those with negative counterparts. Tumor-derived DNA prevalence and abundance in AS were more likely to be higher than in paired PL in a subgroup of patients with PER+ and CY+, respectively. Next-generation sequencing revealed concordant or discrepant mutational patterns between the AS and PL samples. Multivariate analysis showed that both tumor-derived DNA in AS (hazard ratio [HR] 3.940, p = 0.009) and PL (HR 2.936, p = 0.026) were independently associated with poor survival in treatment-naïve patients. In patients who underwent resection, tumor-derived DNA positivity in the AS was more predictive of early recurrence than in PL.

CONCLUSIONS

Tumor-derived DNA in AS can serve as characterizing the genetic profiles of tumor cells attributable to the development of PER+ and predicting the minimal residual disease and early recurrence in patients with pancreatic cancer.

Insight into PCR testing for surgeons

The most commonly used molecular diagnostic technique is the polymerase chain reaction (PCR). PCR detects a short section of genetic code of interest, a cancer gene, human mRNA or a pathogen's genome. It is used by every specialty in medicine and surgery, with increasing frequency and importance. In this article, the history, steps of the cycle, uses, forms, advantages and disadvantages of PCR are discussed. With the SARS coronavirus-2 pandemic having such an enormous impact on the delivery of elective surgery, decisions to proceed or defer are made by surgeons on a daily basis, based on PCR results. An understanding of these results is provided, what they tell us, what they do not and what other information is required to make these decisions. It is imperative to also look beyond PCR results, seeing the patient within the context of their symptoms, other pathology and imaging results, with the assistance of a medical virologist or microbiologist, in complex cases.

Survival equivalence in patients treated for borderline resectable and unresectable locally advanced pancreatic ductal adenocarcinoma: a systematic review and network meta-analysis

BACKGROUND

The clinical relevance of subdivision of non-metastatic pancreatic ductal adenocarcinoma (PDAC) into locally advanced borderline resectable (LA-BR) and locally advanced unresectable (LA-UR) has been questioned. We assessed equivalence of overall survival (OS) in patients with LA-BR and LA-UR PDAC.

METHODS

A systematic review was performed of studies published January 1, 2009 to August 21, 2019, reporting OS for LA-BR and LA-UR patients treated with or without neoadjuvant therapy (NAT), with or without surgical resection. A frequentist network meta-analysis was used to assess the primary outcome (hazard ratio for OS) and secondary outcomes (OS in LA-BR, LA-UR, and upfront resectable (UFR) PDAC).

RESULTS

Thirty-nine studies, comprising 14,065 patients in a network of eight unique treatment subgroups were analysed. Overall survival was better for LA-BR than LA-UR patients following surgery both with and without NAT. Neoadjuvant therapy prior to surgery was associated with longer OS for UFR, LA-BR, and LA-UR tumours, compared to upfront surgery.

CONCLUSION

Survival between the LA-BR and LA-UR subgroups was not equivalent. This subdivision is useful for prognostication, but likely unhelpful in treatment decision making. Our data supports NAT regardless of initial disease extent. Individual patient data assessment is needed to accurately estimate the benefit of NAT.

MicroRNA-593-3p Expression in Peritoneal Lavage Fluid as a Prognostic Marker for Pancreatic Cancer Patients Undergoing Staging Laparoscopy

BACKGROUND

Some presumed resectable pancreatic cancer patients harbor radiographically occult metastases that are incidentally identified at the time of abdominal exploration. This study aims to identify novel diagnostic or predictive microRNA (miRNA) markers for subclinical peritoneal dissemination in patients with pancreatic cancer undergoing abdominal exploration.

METHODS

Peritoneal lavage fluid samples were harvested from 74 patients with pancreatic cancer at the time of staging laparoscopy. Microarray analysis was performed using peritoneal lavage fluids with positive and negative cytology. Candidate microRNA expression was quantified and validated by droplet-digital PCR assays.

RESULTS

In the miRNA array analysis, miR-593-3p showed significant upregulation in peritoneal lavage fluids with positive cytology. Of the 74 patients validated, peritoneal lavage fluids with positive cytology had significantly higher expression of miR-593-3p than those with negative cytology (P < 0.001). Even in cases with no peritoneal dissemination and negative cytology, multivariate analysis revealed that elevated miR-593-3p expression was significantly correlated with worse overall survival than those with low expression (hazard ratio: 3.474, P = 0.042). Of the 48 patients who underwent pancreatectomy, multivariate analysis also demonstrated that higher expression of miR-593-3p in peritoneal lavage was the only significant poor prognostic marker influencing both overall survival (hazard ratio: 23.38, P = 0.005) and recurrence-free survival (hazard ratio: 5.700, P = 0.002).

CONCLUSIONS

Elevated miR-593-3p expression in peritoneal lavage suggests the presence of subclinical micrometastasis even in cases with localized pancreatic cancer, and miR-593-3p could be a useful prognostic predictor for pancreatic cancer patients undergoing staging laparoscopy.

Pathological complete response (pCR) with or without the residual intraductal carcinoma component following preoperative treatment for pancreatic cancer: Revisiting the definition of "pCR" from the prognostic standpoint

BACKGROUND AND AIM

There are no previous reports describing the prognostic significance of the residual intraductal carcinoma component (carcinoma in situ [CIS]) following preoperative treatment for pancreatic ductal adenocarcinoma (PDAC). The aim of the present study was to investigate the prognostic significance of a minimal residual CIS in cases with complete absence of an invasive component after preoperative treatment for PDAC.

METHODS

Eighty-one of 594 PDAC patients with preoperative treatment and subsequent surgery in our institute showed remarkable remission in the invasive component, which included 48 patients with the minimal residual invasive component (Min-inv group) and 33 with absence of an invasive component (No-inv group). We assessed the survival of these patients in association with the presence or absence of an invasive component and intraductal CIS.

RESULTS

Five-year overall survival in the No-inv group patients was significantly better than that of the Min-inv group patients (82%/66%, P = .041). Among the 33 patients in the No-inv group, residual CIS was observed in 16 patients (CIS-positive group), and the remaining 17 patients had no residual CIS (CIS-negative group). There was no significant difference in survival between patients in the CIS-positive and CIS-negative groups (92%/78%, P = .31).

CONCLUSIONS

Residual CIS in the absence of an invasive component after preoperative treatment does not yield a prognostic impact after receiving perioperative treatment for PDAC. It might be reasonable to define pathological complete response (pCR) from the prognostic standpoint as follows: pCR is the complete absence of an invasive carcinoma component regardless of residual CIS.