Immunologically-based nutritional status assessment amongst preoperative colorectal cancer patients - does it link to TNM stage.

Introduction: Disease-related malnutrition can develop in colorectal cancer (CRC) patients, negatively affecting postoperative clinical outcomes. Nutritional status should be assessed using standardised tools and laboratory parameters to identify malnourished patients and introduce personalised, targeted dietary interventions based on epigenetics, immunologically-related aspects, and gut microbiome. The primary aim of this study is to analyse the immunonutritional status of CRC patients in the preoperative period. The secondary aim is to assess the link between albumin-to-globulin ratio (AGR), prognostic nutritional index (PNI), and TNM staging. Patients and methods: This study initially included 21 patients with histopathological confirmation of CRC qualified for surgical resection of the tumour. Immunologically-related nutritional status parameters, i.e., AGR and PNI, were calculated for selected 12 patients. The optimal cut-off value of PNI was determined, allowing patients to be divided into two independent groups: PNI-low and PNI-high. The link between AGR, PNI, and TNM was analysed. Results: TNM classification of the 12 selected participants revealed that most participants classified as T3 (67%), lymph node metastasis was identified in 50% of patients, and there were no distant metastases. Among selected patients, the analysis of mean values of immunological laboratory tests showed that they were within the normal range, except for lymphocyte levels, which were reduced (22.03 ± 7.31%). The optimal cut-off value was set at 51.74 for PNI; thus, patients were accordingly divided into PNI-low and PNI-high groups (<51.74, 34% of cases; ≥51.74, 66%, respectively). PNI-low was initially associated with more advanced cases (based on T assessment) compared to PNI-high (100% versus 75%; respectively); however, it failed to reach statistical significance (p = 0.515; effect size 0.2889; CI 95%, CI = 0.0110-7.5681). Therefore, this finding should be interpreted with caution. Lymph node metastasis was found more often in the PNI-high group than in the PNI-low group. Conclusions: Overall concentrations of albumin and total protein were not decreased in CRC patients; however, these parameters allow calculation of AGR and PNI. The link between PNI-low and locally advanced cases of CRC based on T assessment can potentially exist; nevertheless, it should be confirmed with more clinical data. Lymph node metastasis was more often observed in the PNI-high group. This status is also related to higher levels of AGR. A PNI-low value is more related to local than distant pathological processes associated with CRC.