**7. Conclusions**

Survival studies frequently indicate the independent prognostic value of SIR. Hypothetically, SIR is a characteristic of patient's fight, and not a tumour trait. If so, higher informative value could be obtained through complex scores comprising both NLR and an estimate of tumour burden by cancer markers (such as CA 19-9 or CEA), positron emission tomography findings or clinical characteristics of the tumour, for example, the presence of distant metastases or

In metastatic pancreatic cancer, a combined score of pre-treatment NLR and CA 19-9 was found to be superior to either parameter alone [81]. In resectable pancreatic cancer, the 2-year overall survival rate was significantly lower in those presenting with high preoperative NLR in combination with high CA 19-9 versus the patients having both values in the low range: 37.5 versus 89.9%, respectively [82]. A complex score including NLR along with metabolic activity detected by positron emission tomography (PET) has been found informative [83]. To predict the overall survival of PDAC patients receiving palliative chemotherapy, NLR ≥ 5 was incorporated in a complex score, designated the prognostic index. The other parameters within the framework of this score were performance status, presence of distant metastases or

Similarly to NLR, fibrinogen level has been successfully incorporated in complex scores along with other SIR parameters, for example, GPS, or tumour burden, reflected by stage and/or tumour markers, for example, CA19-9. In cancers of other organs, fibrinogen has also been

In 96 patients who underwent chemoradiotherapy for histologically confirmed, locally advanced PDAC, Glasgow prognostic score (of 2) and fibrinogen (≥400 mg/dL) were independent predictors of worse overall survival and progression free survival. Complex score based

In a large cohort of patients (321 cases) with locally advanced or metastatic pancreatic adenocarcinoma, high plasma fibrinogen was shown to be an independent prognostic factor. It was incorporated in a predictive model along with tumour stage and CA 19-9 level, improving the

Prognostic model for overall survival was elaborated on the basis of independent prognostic factors, identified in 125 PDAC patients by the Cox proportional hazard model. These factors

Carcinomas of different organs differ markedly by their molecular pathogenesis, prognostic factors and involvement of the inflammation in various stages of carcinogenesis. In addition, even cancers of the same organ are heterogeneous, adding complexity to any cancer research. Nevertheless, the keynotes of SIR-based prognostic scores elaborated in cancers other than

comprised plasma fibrinogen, cancer stage and the presence of distant metastasis [19].

**6.5. SIR-based complex scores: Future developments in PDAC**

unresectable tumour. All these approaches have been successfully tested in PDAC.

unresectable tumour, as well as high CEA or CA 19-9 [40].

**6.4. Fibrinogen-based complex scores**

20 Advances in Pancreatic Cancer

assessed along with D-dimer levels or NLR [14].

on fibrinogen and GPS had prognostic value [69].

predictive capability [76].

In conclusion, pancreatic ductal adenocarcinoma is associated with systemic inflammatory reaction. The complex pathogenesis of SIR includes ejection of platelets, neutrophils and myeloid-derived suppressor cells from bone marrow, development of neutrophil extracellular traps and pre-metastatic niches as well as upregulated levels of acute phase proteins and blood clotting factors. Despite the biological complexity, SIR can be easily evaluated by patient friendly and cheap blood tests. NLR and PLR are the most frequently used cellular SIR parameters reflecting the balance between pro-tumourous (neutrophils, platelets) and contra-tumourous (lymphocytes) activities. Glasgow prognostic score, levels of fibrinogen and D-dimers characterise proteins that are involved in SIR and thus—in blood clotting. Significant associations with survival have been demonstrated, mostly regarding NLR in surgically treated and advanced cases. PLR is beneficial to estimate prognosis in advanced cases. Both NLR and PLR can improve the preoperative diagnostics of malignancy in pancreatic cystic tumours, while PLR can be helpful to distinguish between pseudo-tumorous chronic pancreatitis and PDAC. Complex SIR-based scores are developing in order to increase the diagnostic accuracy.
