Our results demonstrated that a higher CRP/alb ratio together with a higher age, male sex, poor differentiation grade and positive para-aortic lymph node(s) was associated with a lower overall survival. A CRP/alb ratio above 0.2 is associated with a decreased overall survival in patients with PDAC after curative pancreatic resection. In accordance with Haruki et al., the CRP/alb ratio was an independent prognostic factor for overall survival in patients after resection for PDAC.(RW.ERROR - Unable to find reference:doc:5da7252ee4b03d8801e716e2) This has also been demonstrated in patients with advanced pancreatic cancer.(3) In addition, previous studies have shown the prognostic value of the mGPS on overall survival of patients with PDAC.(19–21) In our cohort, however, the mGPS was not an independent prognostic factor for overall survival, which was consistent with some previous studies,(RW.ERROR - Unable to find reference:doc:5db2b004e4b02d4c96af2fee) although a prognostic trend was present. This might indicate that the CRP/alb ratio, being a continuous variable, may be a superior predictor if it is not condensed into a score. Furthermore, both high CRP and low albumin were associated with poor survival, but only CRP was an independent prognostic factor for overall survival, indicating that the prognostic value of CRP/alb is mainly driven by CRP. There is increasing understanding of the mechanism of the relation between the CRP/alb ratio and survival in patients with cancer. C-reactive protein is a marker of inflammation, and an elevated serum level might be caused by tumour necrosis or local tissue damage.(13) In addition, an elevated CRP could be a marker for a beneficial environment for the origin and growth of metastases. An elevated CRP gives an upregulation of the vascular endothelial growth factor, which promotes the growth and proliferation of tumours.(11) In addition, CRP is produced in response to elevated interleukin-6 levels.(12) Interleukin-6 promotes tumour growth by inducing multiple signalling pathways, including proliferation, angiogenesis and metabolism.(22) Hypoalbuminemia is often thought to reflect malnutrition in patients. However, emerging evidence shows that a low albumin level may also be a reflection of an inflammatory state.(23, 24) The exact cause of low albumin levels in patients with cancer is unclear. The literature suggests that it is a combination of several mechanisms. One explanation is that high interleukin-6 levels produced by cancer cells inhibit the synthesis of albumin.(25) Alternatively, it may be the result of an increase in vascular permeability, which causes a redistribution of albumin, leading to lower serum levels and high extra vascular fluid levels.(26, 27) In accordance with the literature, men had a lower overall survival than women did.(28–30) It is well known that pancreatic cancer occurs more frequently in men. The underlying cause remains unclear. Possible explanations include differences in environmental or occupational risk-factors, but other lifestyle factors, such as heavy smoking and high alcohol intake in men, may also contribute.(2) Alternatively, undiscovered genetic factors may play a role. These possible factors were assumed to also contribute to a higher mortality risk. In a recent review of clinical prediction models for survival after pancreatic cancer surgery, it was found that tumour size, lymph node status, resection margin and differentiation grade were most often included in the final prediction models.(6) In this study, all these variables were analysed, and the multivariate analysis showed that, of these variables, only differentiation grade and para-aortic lymph node status were significantly associated with overall survival. In the same review, it was also suggested to include neo-adjuvant therapy in the analyses. In our study, neo-adjuvant therapy had no significant predictive value, probably due to the small number (n = 6) of patients receiving neo-adjuvant therapy. However, the role of neo-adjuvant therapy is currently being investigated in the PREOPANC II trial and the CRP/alb ratio in these patients could be the subject of research in the near future. Moreover, Strijker and others have recommended to include the location of the tumour in the pancreas as a variable, since previous studies have demonstrated differences in tumour biology between tumours in the head and corpus/tail.(31, 32) In our study, no statistical difference in overall survival was observed between head or distal pancreatic resections. The authors of the review have also commented that to objectively predict the outcome for pancreatic tumours, a distinction between different types of pancreatic and periampullary tumours should be made. Our study had several important strengths: we included only PDACs; we made a distinction between tumour locations; and we confirmed patients’ survival status using the national Personal Records Database. Our study was limited, however, by its retrospective nature, which among other consequences, resulted in the limited availability of laboratory results and confounding factors like preoperative pancreatitis, cholangitis or biliary drainage. Since biliary drainage might influence CRP, it may have been appropriate to include this variable. We did, however, include in the analyses the bilirubin level, which had no significant association with overall survival and did not influence the outcome. Over the last decades, variables used to assess the immune system and inflammation have gained interest as prognostic biomarkers for the prediction of outcomes for pancreatic cancer.(3, 7–11) Since immunotherapy may play an important role in the future treatment of pancreatic cancer, our study and future research concerning prognostic systemic inflammatory variables could be of significant value.(33) In conclusion, this study showed that an elevated CRP/alb ratio was independently and significantly associated with decreased overall survival in patients with PDAC after pancreatic resection. The CRP/alb ratio may therefore be of additional value to current prediction models and may be helpful in clinical decision-making.