Characterization of low active ghrelin ratio in patients with advanced pancreatic cancer

Diverse and Complementary Effects of Ghrelin and Obestatin

Ghrelin and obestatin are two "sibling proteins" encoded by the same preproghrelin gene but possess an array of diverse and complex functions. While there are ample literature documenting ghrelin's functions, the roles of obestatin are less clear and controversial. Ghrelin and obestatin have been perceived to be antagonistic initially; however, recent studies challenge this dogma. While they have opposing effects in some systems, they function synergistically in other systems, with many functions remaining debatable. In this review, we discuss their functional relationship under three "C" categories, namely complex, complementary, and contradictory. Their functions in food intake, weight regulation, hydration, gastrointestinal motility, inflammation, and insulin secretion are complex. Their functions in pancreatic beta cells, cardiovascular, muscle, neuroprotection, cancer, and digestive system are complementary. Their functions in white adipose tissue, thermogenesis, and sleep regulation are contradictory. Overall, this review accumulates the multifaceted functions of ghrelin and obestatin under both physiological and pathological conditions, with the intent of contributing to a better understanding of these two important gut hormones.

Clinical and Tumor Characteristics of Patients with High Serum Levels of Growth Differentiation Factor 15 in Advanced Pancreatic Cancer

Simple Summary

Growth differentiation factor 15 (GDF-15) is a stress responsive cytokine that mediates food intake, energy consumption, and body weight. We aimed to evaluate whether circulating GDF-15 level could be associated with cachexia symptoms, which include loss of skeletal muscle mass, systemic inflammatory reaction, poor performance status, anorexia, shortened survival time and biological tumor activity in advanced pancreatic cancer (APC). The cut-off for serum GDF-15 was 3356.6 pg/mL, as the mean plus two standard deviations in patients with benign pancreatic disease. APC patients with high serum GDF-15 showed worsened performance, anorexia and elevations of inflammatory and tumor burden, signatures of cachexia, and activation of Akt and JNK in tumor GDF-15-producing pathways. This study identified tumor-driven GDF-15 as a potential cause of cachexia symptoms in APC.

Abstract

We aimed to evaluate the association of circulating growth differentiation factor 15 (GDF-15) with cachexia symptoms and the biological activity of advanced pancreatic cancer (APC). Treatment-naïve patients with liver metastasis of APC or with benign pancreatic disease were retrospectively analyzed. Clinical data, blood samples, and biopsy specimens of liver metastasis were collected prior to anti-cancer treatment. Serum GDF-15 levels and multiple protein expressions in lysates extracted from liver metastasis were measured by enzyme-linked immuno-sorbent assay and reverse-phase protein array, respectively. The cut-off for serum GDF-15 was determined as 3356.6 pg/mL, the mean plus two standard deviations for benign pancreatic disease. The high-GDF-15 group was characterized as showing low Karnofsky performance status (KPS) (p = 0.037), poor Eastern Cooperative Oncology Group performance status (ECOG-PS) (p = 0.049), severe appetite loss (p = 0.011), and high serum levels of carbohydrate antigen 19-9 (p = 0.019) and C-reactive protein (p = 0.009). Tumors of the high-GDF-15 group expressed high levels of phosphorylated (p)JNK (p = 0.007) and pAkt (p = 0.040). APC patients with high serum GDF-15 showed signatures of cachexia and activation of the signaling pathways involving Akt and JNK in the tumor. This study indicated circulating GDF-15 could be associated with cachectic symptoms in APC.

The Benefits of Olanzapine in Palliating Symptoms

OPINION STATEMENT

Olanzapine has become a major drug in the management of chemotherapy-induced nausea and vomiting as a prophylactic agent. In addition, a recent randomized trial has demonstrated its benefits in treating nausea and vomiting associated with advanced cancer. The added benefit to olanzapine is that it also stimulates appetite. As a result, since it treats multiple symptoms associated with advanced cancer, it is likely to become the antiemetic of choice in palliative care at least in the USA. The added benefit of treating insomnia and the avoidance of benzodiazepines should place olanzapine in at the top of the list of drugs to use for patients who do complain of insomnia. There is no good evidence that it potentiates the respiratory depression of opioids unlike benzodiazepines. The evidence is weak that olanzapine in as an adjuvant analgesic. Hopefully, future trials will explore this in greater depth. The benefits of adding olanzapine to potent opioids are that it may reduce craving, drug cues, and opioid misuse. Other symptoms like anxiety and depression may be addressed by the addition of olanzapine to standard antidepressants.

Attribution of Ghrelin to Cancer; Attempts to Unravel an Apparent Controversy

Ghrelin is an endogenous peptide hormone mainly produced in the stomach. It has been known to regulate energy homeostasis, stimulate secretion of growth hormone, and mediate many other physiologic effects. Various effects attributed to ghrelin contribute to many aspects of cancer development and progression. Accordingly, a large body of evidence has emerged about the association of ghrelin with several types of cancer in scales of cell-line, animal, and human studies. However, existing data are controversial. This controversy occurs in two main domains: one is the controversial results in local effects of ghrelin on different types of human cancer cell-lines; the second is the apparent disagreement in the results of in-vitro and clinical studies that investigated ghrelin association to one type of cancer. These inconsistencies have hampered the indications to consider ghrelin as a potential tumor biomarker or therapeutic agent in cancer patients. Previous studies have reviewed different parts of current literature about the ghrelin-cancer relationship. Although they have highlighted these controversial results in various ways, no specific recommendations have been given to address it. In this study, we comprehensively reviewed in-vitro, in-vivo, and clinical studies and attempted to use the following approaches to unravel the inconsistencies detected: (a) to distinguish local and systemic effects of ghrelin in interpreting its summary clinical role in each cancer; (b) scrutinizing factors that regulate local effects of ghrelin and could justify different effects of ghrelin on different cancer cell-lines. These approaches could have notable implications for future in-vitro and clinical studies.

A randomized phase II study of nutritional and exercise treatment for elderly patients with advanced non-small cell lung or pancreatic cancer: the NEXTAC-TWO study protocol

Background

Most advanced elderly cancer patients experience fatigue, anorexia, and declining physical function due to cancer cachexia, for which effective interventions have not been established. We performed a phase I study of a new nonpharmacological multimodal intervention called the nutritional and exercise treatment for advanced cancer (NEXTAC) program and reported the excellent feasibility of and compliance with this program in elderly patients with advanced cancer who were at risk for cancer cachexia. We report here the background, hypothesis, and design of the next-step multicenter, randomized phase II study to evaluate the efficacy of the program, the NEXTAC-TWO study.

Methods

Patients with chemo-naïve advanced non-small cell lung cancer or pancreatic cancer, age ≥ 70 years, performance status ≤2, with adequate organ function and without disability according to the modified Katz index will be eligible. In total, 130 participants will be recruited from 15 Japanese institutions and will be randomized into either the intervention group or a control group. Computer-generated random numbers are allocated to each participant. Stratification factors include performance status (0 to 1 vs. 2), site of primary cancer (lung vs. pancreas), stage (III vs. IV), and type of chemotherapy (cytotoxic vs. others). Interventions and assessment will be performed 4 times every 4 ± 2 weeks from the date of randomization. Interventions will consist of nutritional counseling, nutritional supplements (rich in branched-chain amino acids), and a home-based exercise program. The exercise program will include low-intensity daily muscle training and lifestyle education to promote physical activity. The primary endpoint is disability-free survival. It is defined as the period from the date of randomization to the date of developing disability or death due to any cause. This trial also plans to evaluate the improvements in nutritional status, physical condition, quality of life, activities of daily living, overall survival, and safety as secondary endpoints. Enrollment began in August 2017. The study results will demonstrate the efficacy of multimodal interventions for elderly cancer patients and their application for the maintenance of physical and nutritional conditions in patients with cancer cachexia. This work is supported by a grant-in-aid from the Japan Agency for Medical Research and Development.

Discussion

This is the first randomized trial to evaluate the efficacy and safety of a multimodal intervention specific for elderly patients with advanced cancer.

Trial registration

Registered at August 23, 2017. Registry number: UMIN000028801.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5762-6) contains supplementary material, which is available to authorized users.