Predicting positive peritoneal cytology in pancreatic cancer

• Published in: Journal of cancer research and clinical oncology Vol. 147; no. 6; pp. 1825 - 1832
• Main Authors: O’Halloran, Eileen A., Board, Tamsin, Lefton, Max, Devarajan, Karthik, Dotan, Efrat, Meyer, Joshua, Reddy, Sanjay S.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-06-2021; Springer Nature B.V
• Subjects: Adenocarcinoma; Cancer Research; Cellular biology; Cytology; Diagnosis; Hematology; Internal Medicine; Laparoscopy; Medicine; Medicine & Public Health; Oncology; Original Article – Clinical Oncology; Pancreatic cancer; Peritoneum; Regression analysis; Pancreatic adenocarcinoma; Peritoneal lavage; Positive cytology
• ISSN: 0171-5216; 1432-1335
• DOI: 10.1007/s00432-020-03471-9

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/m
2
(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/m
2
may be at higher risk for positive peritoneal cytology, regardless of whether neoadjuvant therapy is administered.