Velda Gonzalez

Abstract

Radiotherapy treatment-induced intestinal injury and gut microbial perturbation/dysbiosis have been implicated in the pathobiology of cancer-related fatigue. The objective of this brief review was to explore the available evidence of the relationship between intestinal injury and self-reported fatigue, especially among cancer patients. The scientific evidence-including our own-linking gut mucosal barrier dysfunction and gut microbial perturbation/dysbiosis induced by cancer treatment with worsening of cancer related fatigue (perhaps through the gut-brain axis) is limited but promising. Emerging data suggest that lifestyle interventions and the administration of specific probiotics may favorably modulate the gut microbiota and potentially mediate beneficial effects leading to improvements in fatigue.

Abstract

Purpose: To examine a) whether there are significant differences in the severity of symptoms of fatigue, sleep disturbance, or depression between patients with rectal cancer who develop co-occurring symptoms and those with no symptoms before and at the end of chemotherapy and radiation therapy (CRT); b) differences in gut microbial diversity between those with co-occurring symptoms and those with no symptoms; and c) whether before-treatment diversity measurements and taxa abundances can predict co-occurrence of symptoms. Methods: Stool samples and symptom ratings were collected from 31 patients with rectal cancer prior to and at the end of (24–28 treatments) CRT. Descriptive statistics were computed and the Mann-Whitney U test was performed for symptoms. Gut microbiome data were analyzed using R’s vegan package software. Results: Participants with co-occurring symptoms reported greater severity of fatigue at the end of CRT than those with no symptoms. Bacteroides and Blautia2 abundances differed between participants with co-occurring symptoms and those with no symptoms. Our random forest classification (unsupervised learning algorithm) predicted participants who developed co-occurring symptoms with 74% accuracy, using specific phylum, family, and genera abundances as predictors. Conclusion: Our preliminary results point to an association between the gut microbiota and co-occurring symptoms in rectal cancer patients and serves as a first step in potential identification of a microbiota-based classifier.

Abstract

Purpose: To examine a) whether there are significant differences in gut microbial diversity and in the abundance of gut microbial taxa; and b) differences in predicted functional pathways of the gut microbiome between those participants with high co-occurring symptoms and those with low co-occurring symptoms, prior to neoadjuvant chemotherapy and radiation therapy (CRT) for rectal cancer. Methods: Rectal cancer patients (n = 41) provided stool samples for 16 S rRNA gene sequencing and symptom ratings for fatigue, sleep disturbance, and depressive symptoms prior to CRT. Descriptive statistics were computed for symptoms. Gut microbiome data were analyzed using QIIME2, LEfSe, and the R statistical package. Results: Participants with high co-occurring symptoms (n = 19) had significantly higher bacterial abundances of Ezakiella, Clostridium sensu stricto, Porphyromonas, Barnesiella, Coriobacteriales Incertae Sedis, Synergistiaceae, Echerichia-Shigella, and Turicibacter compared to those with low co-occurring symptoms before CRT (n = 22). Biosynthesis pathways for lipopolysaccharide, L-tryptophan, and colanic acid building blocks were enriched in participants with high co-occurring symptoms. Participants with low co-occurring symptoms showed enriched abundances of Enterococcus and Lachnospiraceae, as well as pathways for β-D-glucoronosides, hexuronide/hexuronate, and nicotinate degradation, methanogenesis, and L-lysine biosynthesis. Conclusion: A number of bacterial taxa and predicted functional pathways were differentially abundant in patients with high co-occurring symptoms compared to those with low co-occurring symptoms before CRT for rectal cancer. Detailed examination of bacterial taxa and pathways mediating co-occurring symptoms is warranted.

Abstract

Background: Home-based exercise interventions might be a desirable long-term option for breast cancer survivors to enhance compliance and long-term health benefits. Purpose: To assess the effectiveness of a home-based intervention aimed at helping survivors of breast cancer meet the physical activity guidelines of the American College of Sports Medicine. Methods: Eighty-nine women (age: 55.4 ± 10 years; body mass index: 31 ± 6.5 kg/m2) from 2 cancer centers serving Hispanic women participated in this study. Women underwent a baseline assessment of cardiorespiratory fitness, muscle endurance and strength, flexibility, range of motion, and extremity disability. After baseline measures, women were randomized into a control or exercise group. The exercise intervention consisted of a walking program, elastic band strengthening, and flexibility exercises performed at home. The outcome measures were reassessed 16 weeks after baseline measures. Results: The intervention showed a strong effect of time on muscle strength and shoulder range of motion, and time and group for self-reported disability. There were no differences in sedentary behavior, physical fitness, and disability measures across intervention groups, including both exercise groups combined and changes over time between intervention groups. Conclusion: It appears that a home-based intervention affects only upper-body strength and related disability, indicating that other components might need closer monitoring for significant changes to occur across time.

Abstract

Background. The role of alterations in gut microbiota composition (termed dysbiosis) has been implicated in the pathobiology of depressive symptoms; however, evidence remains limited. This cross-sectional pilot study is aimed at exploring whether depressive symptom scores changed during neoadjuvant chemotherapy and radiation therapy to treat rectal cancer, and if gut microbial taxa abundances and predicted functional pathways correlate with depressive symptoms at the end of chemotherapy and radiation therapy. Methods. 40 newly diagnosed rectal cancer patients (ages 28-81; 23 males) were assessed for depressive symptoms using the Hamilton Rating Scale for Depression (HAM-D) and provided stool samples for 16S rRNA sequencing. Gut microbiome data were analyzed using QIIME2, and correlations and regression analyses were performed in R. Results. Participants had significantly higher depressive symptoms at the end as compared to before CRT. The relative abundances of Gemella, Bacillales Family XI, Actinomyces, Streptococcus, Lactococcus, Weissella, and Leuconostocaceae were positively correlated (Spearman’s rho=0.42 to 0.32), while Coprobacter, Intestinibacter, Intestimonas, Lachnospiraceae, Phascolarctobacterium, Ruminiclostridium, Ruminococcaceae (UCG-005 and uncultured), Tyzzerella, and Parasutterella (Spearman’s rho=−0.43 to−0.31) were negatively correlated with HAM-D scores. Of the 14 predicted MetaCyc pathways that correlated with depressive symptom scores at the end of CRT, 11 (79%) were associated with biosynthetic pathways. Conclusions. Significant bacterial taxa and predicted functional pathways correlated with depressive symptoms at the end of chemotherapy and radiation therapy for rectal cancer which warrants further examination and replication of our findings.

Abstract

Context: Although microbial-mediated disturbance of intestinal mucosal homeostasis (dysbiosis) is believed to contribute to the pathogenesis of chemotherapy and radiotherapy (CRT)–related fatigue, potential differences in the gut microbial diversity and in the abundance of gut microbial taxa between fatigued and non-fatigued patients have not been adequately examined, particularly in the rectal cancer population. Purpose: In this cross-sectional study, we aim to examine the differences in (a) gut microbial diversity and gut microbial abundances and (b) predicted functional pathways of the gut microbiome between rectal cancer participants with and without fatigue at the end of CRT. Methods: Rectal cancer patients (n = 50) provided stool samples for 16S rRNA gene sequencing and symptom ratings for fatigue at the end of CRT. Gut microbiome data were analyzed using QIIME2, LEfSe, and the R statistical package. Results: Fatigued (n = 35) participants showed enriched bacterial abundances of Eubacterium, Streptococcus, Adlercreutzia, and Actinomyces, as well as enriched abundances of the microbial sucrose degradation pathway, compared to non-fatigued patients at the end of CRT (n = 15). Conclusions: Differentially abundant microbial taxa were identified in fatigued and non-fatigued rectal cancer participants at the end of CRT. However, the exact role of these taxa (and identification of species) in the biology of CRT-related fatigue remains to be examined.

Abstract

Purpose: This article aims to provide perspectives on the establishment of a consortium for nurse scientists with similar career trajectories interested in cancer-related symptoms (CRS) research. Hereby, we describe the development of and recent outcomes from the CRS consortium, the lessons learned in establishing the consortium, and future directions to advance the science of CRS. Model and Methods: New and innovative strategies are needed to address the complexity of CRS research. A CRS consortium was created to allow a mechanism for oncology nurse scientists with varying expertise to collaborate to advance CRS research. The National Institutes of Health (NIH) Symptom Science Model (SSM) guides the research of the CRS Consortium. Discussion and Conclusions: A need for improved CRS assessment and management has been identified. The CRS consortium was created as a collaborative think tank to begin to address this need. Guided by the NIH SSM, CRS consortium members have worked to define symptom phenotypes, enhance understanding of the biologic mechanisms that can contribute to symptom phenotypes, and develop tailored interventions to improve symptom management. Dissemination of the CRS consortium efforts involve publications and presentations. Clinical Implications: Nurse scientists interested in symptom science and biobehavorial research face many challenges on how to initiate and sustain independent programs of research. Through the formation of a CRS consortium, oncology nurse scientists can work together to address identified issues in symptom measurement and management.

Abstract

Purpose: To investigate whether there are differences in diversity, taxonomic composition, and predicted functional pathways of the gut microbiome between Island Hispanic Puerto Ricans (HPR) and mainland non-Hispanic whites (NHW) measured before and at the end of chemo-radiation (CRT) for Rectal Cancer. Methods: Fifty-six stool samples of newly diagnosed rectal cancer patients (25 HPR and 31 NHW) were amplicon-sequenced during chemo-radiotherapy. 16S rRNA gene data was analyzed using QIIME2, phyloseq, and LEfSe. Results: We observed similar within-sample alpha diversity for HPR and NHW participants during CRT. However, at the end of CRT, several taxa were present at significantly different abundances across both groups. Taxa enriched in the gut of HPR compared to NHW included Muribaculaceae, Prevotella 2 and 7, Gemella, Bacillales Family XI, Catenibacterium, Sutterella, Pasteurellales, and Pasteurellaceae genera, whereas over-represented taxa in NHW participants were Turicibacter and Eubacteriaceae. Significant differences in predicted HPR microbiota functions included pathways for synthesis of L-methionine and degradation of phenylethylamine and phenylacetate. Conclusion: In this pilot study, taxonomic analyses and functional predictions of the gut microbiomes suggest greater inflammatory potential in gut microbial functions among HPR rectal cancer patients undergoing CRT compared to that of NHW participants.

Abstract

Cancer treatment-associated gut microbial perturbation/dysbiosis has been implicated in the pathobiology of sleep disturbance; however, evidence is scarce. Eighteen newly diagnosed rectal cancer patients (ages 52–81 years; 10 males) completed a sleep disturbance questionnaire and provided stool samples for 16s RNA gene sequencing during chemo-radiotherapy. Descriptive statistics, Wilcoxon test and regression analyses were computed. Regression analyses showed the Shannon's diversity index to be a significant factor associated with sleep disturbance. This preliminary work suggests that the biological “gut–brain axis” mechanism may be associated with symptoms of sleep disturbance.

Abstract

Objective: To examine the relationship of the symptoms of diarrhea and fatigue by testing a model that included multiple dimensions of the cancer-related-symptom experience. Methods: A secondary data analysis was conducted on data from the self-reports of 102 cancer patients co-experiencing diarrhea and fatigue during treatment at a comprehensive cancer center in the Southeastern United States. Structural equational modeling was employed to examine the relationship between the 2variables. Fatigue and diarrhea were assessed using items from the Cancer Symptom Scale. Results: The structural model results showed that (a) the model fit was adequate (b) diarrhea explained 7% of the variance in fatigue, and (c) the structural or path coefficient between diarrhea and fatigue was significant (0.267; p<0.05). Diarrhea had the strongest effect on fatigue interference (0.251). Conclusion: Diarrhea is a potential contributing factor to the symptom of fatigue and a potential target for interventions to prevent and ameliorate fatigue.