Objective

To determine whether mice unable to mount an intact inflammatory response because of a Toll-like receptor (TLR) pathway defect will develop less severe cancer cachexia.

Design

Prospective animal study.

Setting

Academic research center.

Subjects

Six- to eight-week-old, female C3H/HeJ mice (17-18 g) and age-, weight-, and sex-matched wild-type C3H/HeN mice, differing in that the HeJ mice have nonfunctional TLR4 due to a TLR4 double mutation (TLR4(d/d)).

Intervention

The mice were inoculated with equal numbers of SCCF-VII cells and housed in individual cages.

Main outcome measures

Food intake, body weight, pretumor and posttumor body composition, circulating cytokines, and levels of a marker of muscle atrophy were analyzed.

Results

The wild-type HeN mice weighed less on average than the TLR4(d/d) mice (2.6 g vs 4.9 g) (P = .01). They consumed more food, had smaller tumors, and had less lean body mass and fat mass than the TLR4(d/d) mice. Interleukin 1beta level was significantly elevated in the tumor-bearing HeN mice (mean gain of 259 pg/mL) but not in the TLR4(d/d) mice (P = .03). Both mouse strains had evidence of muscle atrophy.

Conclusions

In spite of increased food intake and smaller tumors, the wild-type HeN mice had more severe cachexia than the TLR4(d/d) mice. The impaired ability to secrete proinflammatory cytokines such as interleukin 1beta may protect these animals from developing severe cancer cachexia. This animal model represents a novel system in which the host contributions to cachexia may be further studied.

Background

By the traditional definition of unintended weight loss, cachexia develops in ~80% of patients with pancreatic ductal adenocarcinoma (PDAC). Here, we measure the longitudinal body composition changes in patients with advanced PDAC undergoing 5-fluorouracil, leucovorin, irinotecan, and oxaliplatin therapy.

Methods

We performed a retrospective review of 53 patients with advanced PDAC on 5-fluorouracil, leucovorin, irinotecan, and oxaliplatin as first line therapy at Indiana University Hospital from July 2010 to August 2015. Demographic, clinical, and survival data were collected. Body composition measurement by computed tomography (CT), trend, univariate, and multivariate analysis were performed.

Results

Among all patients, three cachexia phenotypes were identified. The majority of patients, 64%, had Muscle and Fat Wasting (MFW), while 17% had Fat-Only Wasting (FW) and 19% had No Wasting (NW). NW had significantly improved overall median survival (OMS) of 22.6 months vs. 13.0 months for FW and 12.2 months for MFW (P = 0.02). FW (HR = 5.2; 95% confidence interval = 1.5-17.3) and MFW (HR = 1.8; 95% confidence interval = 1.1-2.9) were associated with an increased risk of mortality compared with NW. OMS and risk of mortality did not differ between FW and MFW. Progression of disease, sarcopenic obesity at diagnosis, and primary tail tumours were also associated with decreased OMS. On multivariate analysis, cachexia phenotype and chemotherapy response were independently associated with survival. Notably, CT-based body composition analysis detected tissue loss of >5% in 81% of patients, while the traditional definition of >5% body weight loss identified 56.6%.

Conclusions

Distinct cachexia phenotypes were observed in this homogeneous population of patients with equivalent stage, diagnosis, and first-line treatment. This suggests cellular, molecular, or genetic heterogeneity of host or tumour. Survival among patients with FW was as poor as for MFW, indicating adipose tissue plays a crucial role in cachexia and PDAC mortality. Adipose tissue should be studied for its mechanistic contributions to cachexia.

Purpose

Cancer cachexia is a devastating and understudied illness in patients with head and neck squamous cell carcinoma (HNSCC). The primary objective was to identify clinical characteristics and serum levels of cytokines and cachexia-related factors in patients with HNSCC. The secondary objective was to detect the occurrence of cytokine and cachexia-related factor gene expression in HNSCC tumors.

Experimental design

For the primary objective, cross-sectional data were obtained from prospectively recruited patients identified as cachexia cases and matching cachexia-free controls. For the secondary objective, a retrospective cohort design with matched controls was used.

Results

Clinical characteristics associated with cancer cachexia in HNSCC were T(4) status (P = 0.01), increased C-reactive protein (P = 0.01), and decreased hemoglobin (P < 0.01). Exploratory multiplex analysis of serum cytokine levels found increased interleukin (IL)-6 (P = 0.04). A highly sensitive ELISA confirmed the multiplex result for increased IL-6 in cachectic patients (P = 0.02). Quality of life was substantially reduced in patients with cachexia compared with noncachectic patients (P < 0.01). All tumors of HNSCC patients both with and without cachexia expressed RNA for each cytokine tested and the cachexia factor lipid-mobilizing factor. There were no statistically significant differences between the cytokine and cachexia factor RNA expression of cachectic and noncachectic patients (each P > 0.05). No tumors expressed the cachexia factor proteolysis-inducing factor.

Conclusion

We have identified clinical characteristics and pathophysiologic mechanisms associated with cancer cachexia in a carefully defined population of patients with HNSCC. The data suggest that the acute-phase response and elevated IL-6 are associated with this complex disease state. We therefore hypothesize that IL-6 may represent an important therapeutic target for HNSCC patients with cancer cachexia.