Background: Unintended weight loss and nutritional problems are often seen in patients with head and neck cancer, but changes in lipid metabolism are poorly studied.

Aim/Objectives: The present study aimed to explore the longitudinal changes in circulating fatty acid (FA) composition in patients with head and neck cancer.

Materials and Methods: This study included 27 patients with head and neck cancer. Treatment consisted of single modality or combined modality treatments. The patients were assessed by repeated blood sampling and body weight assessments before treatment started and on three occasions after the start of treatment. FA profiling included gas chromatography analysis of unsaturated FAs and saturated FAs in serum.

Results: The values of three fatty acids - FA 14:0, FA 18:3n3, and FA 20:3n6 - changed in a specific pattern over the course of the study and the change in FA 14:0 correlated with weight changes.

Conclusions and significance: This study showed altered profiles of both saturated and unsaturated FAs. An improved understanding of the metabolic pathways in patients with head and neck cancer supports the development of better nutritional surveillance and nutritional treatments.

Simple Summary Cancer-associated malnutrition affects nutrient metabolism, including the metabolism of lipids. Toxicities associated with the treatment for head and neck cancer (HNC) may contribute to malnutrition through impaired oral intake and inflammation. Studies on lipid metabolism in patients with HNC are very limited. The anti-inflammatory effect of some fatty acids (FAs) is already proven in other cancers but the results of these studies in HNC are not consistent. This prospective study of 174 patients with HNC contributes to our knowledge of alterations in lipid metabolism following treatment for HNC and serves as basis for future research. Studies on fatty acids (FAs) in patients with head and neck cancer (HNC) are limited. We aimed to investigate the longitudinal changes of circulating FAs in patients with HNC and to examine potential correlations of FA changes with treatment. The secondary aims were to investigate correlations of FAs with cytokines and patient-related factors, and if any FAs correlated with disease recurrence or death. A total of 174 patients with HNC were included before treatment and followed-up at three time points after the start of the treatment through blood sampling and body weight measurements. Serum FA profiling was assessed by gas chromatography. The total follow-up time was 3 years. The levels of almost all FAs changed from baseline to 7 weeks. The change in FA 14:0 was associated with treatment and the change in 18:3n-6 was associated with the patients' pre-treatment BMI. FAs 14:0 and 18:0 were correlated with weight changes from baseline to 7 weeks. IL-6 was correlated with three FAs at 7 weeks and with two FAs at 1 year. Patients with higher levels 20:5n-3 at 3 months had a higher risk of all-cause death within 3 years (HR 2.75, 95% CI 1.22-6.21). Treatment, inflammation, and weight loss contributed in a complex manner to the altered FA profile in the studied cohort. The association between IL-6 and FAs in patients with HNC is in line with earlier studies and suggests the opportunity for regulating inflammation in HNC patients through modulation of FAs.

Aims

To examine the prognostic value of F-18 fluorodeoxyglucose (FDG) uptake in the bone marrow (BM) for disease recurrence and survival in patients with oropharyngeal squamous cell carcinoma (OP-SCC). The secondary aims were to evaluate the prognostic value of PET/CT parameters for the primary oropharyngeal tumor and total tumor burden, and to assess the correlation between FDG uptake variables and serum inflammatory markers.

Methods

This was an observational study of 91 patients with OP-SCC who underwent pretreatment FDG-PET/CT. The patients' blood samples were collected before treatment, and treatment was administered with the intention to cure. The median follow-up time was 40 months. The PET parameters measured were SUVmeanBM for the assessment of BM FDG uptake, SUVmean, SUVmax, total lesion glycolysis (TLG), and metabolic tumor volume (MTV) for the evaluation of primary oropharyngeal tumor and total tumor burden.

Blood samples were analyzed to determine each patient's white cell, red cell, and platelet cell counts, hemoglobin, and C-reactive protein level. In a subgroup of 33 patients, blood serum was analyzed to evaluate the expression of serum immune proteins using a proximity extension assay (Olink Proteomics).

Results

The univariate analysis revealed that SUVmeanBM and tumor-specific parameters (SUVmaxtumor, SUVmeantotal, SUVmaxtotal, MTVtotal, TLGtotal) were significantly associated with recurrence-free survival (RFS). After adjusting for age, sex, and stage only SUVmeanBM remained significantly associated with RFS. Spearman's correlation identified several correlations between PET parameters and inflammatory markers.

Conclusions

Our results show that several FDG-PET/CT parameters may have a prognostic value of treatment outcome in patients with OP-SCC. However, SUVmeanBM was the only independent PET parameter that showed a prognostic value for RFS in the study cohort. Moreover, the study findings might suggest an association between systemic inflammation and the metabolic activity in the BM.