**8. Conclusions**

The inflammation and nutrition-based score was elaborated to predict overall survival in patients diagnosed with metastatic gastric cancer. According to this score, patients were classified into favourable, intermediate and high-risk groups exhibiting the median overall survival of 27.6 vs. 13.2 vs. 8.2 months. The respective two-year survival rates were 52% vs. 16% vs. 3%. The ROC curve analysis confirmed that the novel score has higher informativity than

Abbreviations: CRP, C-reactive protein; NLR, neutrophil to lymphocyte ratio; PLR, platelet to lymphocyte ratio; mGPS, modified Glasgow prognostic score; T, local spread of primary gastric cancer by tumour-nodes-metastasis (TNM

/L).

Deng et al. elaborated complex nomograms to predict cancer-specific and cancer-free survival

any of its components [26].

in surgically treated gastric cancer patients [47].

12–20 High risk

0 No high-risk parameters: 1

1 One high-risk parameter:

2 Two high-risk parameters:

Canton score [45]

182 Gastric Cancer

Platelet count and NLR score [29]

Coagulation score [125]

1

Definitions of the score components: Age ≥ 65 scored 3, otherwise scored 0

Grade: G3 scored 5, otherwise scored 0

PLR > 106 scored 3, otherwise scored 0

scored 0

3 Three high-risk parameters: PNI < 48 AND NLR > 1.83

≤ 3

NLR >3

0 No elevated parameters: PLT ≤ 300 × 103

1 One elevated parameter: PLT > 300 × 103

2 Two elevated parameters: PLT > 300 × 103

0 Normal level of D-dimer AND fibrinogen 1 Increased level of either D-dimer OR fibrinogen 2 Increased level of both D-dimer AND fibrinogen

classification), G, grade; PNI, prognostic nutritional index; PLT, platelet count.

PNI = albumin (g/L) + 5 × total lymphocyte count (×10<sup>9</sup>

**Table 7.** The definitions of complex scores.

AND PLT ≤ 3 × 1011/L

AND PLT > 3 × 1011/L

Tumour size ≥ 1.8 cm scored 4, otherwise scored 0

PNI < 48 AND NLR ≤ 1.83 AND PLT ≤ 3 × 1011/L PNI ≥ 48 AND NLR > 1.83 AND PLT ≤ 3 × 1011/L PNI ≥ 48 AND NLR ≤ 1.83 AND PLT > 3 × 1011/L

PNI < 48 AND NLR > 1.83 AND PLT ≤ 3 × 1011/L PNI < 48 AND NLR ≤ 1.83 AND PLT > 3 × 1011/L PNI ≥ 48 AND NLR > 1.83 AND PLT > 3 × 1011/L

Depth of invasion: submucosa scored 3, while mucosa

PNI ≥ 48 AND NLR ≤ 1.83

/mkL AND NLR

/mkL OR NLR >3

/mkL AND

Gastric cancer induces systemic inflammatory reaction. The biological background is complex, involving bone marrow activation, development of immune-suppressing immature myeloid cells, generation of pre-metastatic niches and neutrophil extracellular trap formation from externalised DNA network in bidirectional association with platelet activation. These mechanisms have been demonstrated in general studies of carcinogenesis as well as in animal models and human studies of gastric cancer.

Systemic inflammatory reaction can be easily evaluated by simple, patient friendly and economically non-demanding blood tests practically lacking complications. These tests could be broadly classified as cellular and protein-based. Among cellular tests, neutrophil to lymphocyte ratio is the most widely explored followed by platelet to lymphocyte ratio. Glasgow prognostic score is the prototype of protein-based test.

Although controversies still exist, most researchers have recognised the independent prognostic value of NLR, encompassing overall, cancer-specific, cancer-free or progression-free survival both in early and advanced gastric cancer. NLR can bring significant prognostic information in surgically treated individuals, in case of combined treatment and in patients receiving only chemotherapy.

NLR shows associations with TNM parameters. Thus, it can be incorporated in patient's evaluation for tumour burden. The possibility to predict serosal invasion, peritoneal and/or metastatic spread can be an adjunct to avoid inappropriate attempts of technically impossible gastrectomy. Lymph node status can be predicted as well.

PLR and GPS also possess diagnostic and prognostic information in gastric cancer patients, as well as show correlations with tumour parameters.

The cut-offs for NLR and PLR show significant variability. Mostly, the cut-off levels are identified either based on ROC analysis and Youden Index, or the median is selected for cut-off. Less frequently, the 75th percentile is applied.

Combined scores appear, based on SIR data in complex with patient's characteristics as well as tumour features. The informativity of such scores is generally higher than that of separate components; therefore, wider testing of these scores in different populations should be necessary to bring the promising novel scores to clinical application.
