Cytokeratin-positive cells in the bone marrow from patients with pancreatic, periampullary malignancy and benign pancreatic disease show no prognostic information

Abstract

Background: Pancreatic and periampullary carcinoma are aggressive tumours where preoperative assessment is challenging. Disseminated tumour cells (DTC) in the bone marrow are associated with impaired prognosis in a variety of epithelial cancers. For a cohort of patients with presumed resectable pancreatic and periampullary carcinoma, we evaluated the frequency and the potential prognostic impact of the preoperative presence of DTC, defined as cytokeratin-positive cells detected by immunocytochemistry (ICC). Methods: Preoperative bone marrow samples from 242 patients selected for surgical resection of presumed resectable pancreatic and periampullary carcinoma from 09/2009 to 12/2014, were analysed for presence of CK-positive cells by ICC. The median observation time was 21.5 months. Overall survival (OS) and disease-free survival (DFS) were calculated by Kaplan-Meier and Cox regression analysis. Results: Successful resection of malignant tumours was performed in 179 (74.0%) of the cases, 30 patients resected (12.4%) had benign pancreatic disease based on postoperative histology, and 33 (13.6%) were deemed inoperable during laparotomy due to advanced disease. Overall survival for patients with resected carcinoma was 21.1 months (95% CI: 18.0-24.1), for those with benign disease OS was 101 months (95% CI: 69.4-132) and for those with advanced disease OS was 8.8 months (95% CI: 4.3-13.3). The frequency of CK-positive cells was 6/168 (3.6%) in resected malignant cases, 2/31 (6.5%) in advanced disease and 4/29 (13.8%) in benign disease. The presence of CK-positive cells was not correlated to OS or DFS, neither in the whole cohort nor in the subgroup previously tested negative for circulating tumour cells in blood. Conclusions: The results indicate that CK-positive cells may be present in patients with both malignant and benign diseases of the pancreas. CK-positive cell presence was not associated with differences in prognosis for any patient group. Trial registration: clinicaltrials.gov (NCT01919151)