Background: The aim of this study was to define the association of non-adenocarcinoma pancreatic cancer (NACPC) as a risk factor for postoperative cancer-associated thrombosis (CAT).
Methods: We conducted analysis of prospectively collected data of pancreatic cancer surgery. Randomly collected NACPC cases were matched 1:3 to adenocarcinoma cases (ACPC). Variables included comorbidities, demographics, cancer extension, and preoperative Khorana score (KRS). Primary outcome was CAT, which included deep vein thrombosis and pulmonary embolism confirmed by imaging. Categorical variables are presented as percentages, continuous variables as median and range. SPSS, χ2, Cochran-Armitage, and logistic regression were use for analysis.
Results: The study included 441 patients. Age 65.9±11.5, male 57% (N.=252), 8% (N.=36) had metastasis. IPMN and neuroendocrine were the most common NACPC. Median follow-up was 449 days in which 90 (20%) patients developed CAT. The odds (Odds Ratio [OR] 1.1, 95% Confidence Interval [CI] 0.6- 1.9, P=0.7) and time to venous thromboembolism were not different between NACPC and ACPC. We analyzed for trends of prophylactic strategies by year of surgery; there was no trend for NACPC (P=0.4) or ACPC (P=0.06). KRS was not associated with CAT. In the multivariate analysis, peripheral artery disease (Adjusted Odds Ratio [ORadj] 5.4, 95% CI: 1.7-17.3), ASA class ≥4 (ORadj 3.6; 95% CI: 1.3-10.4), length of stay >9 days (ORadj: 1.9; 1.2-3.2), and cancer vascular invasion (ORadj: 2.9; 95% CI: 1.6-5.3) were associated with CAT.
Conclusions: The rate of VTE in NACPC after surgery was high and not different than ACPC. Histology type should not govern discrimination in thromboprophylaxis selection or extension.