Exploring a link between fatigue and intestinal injury during pelvic radiotherapy

Exploring the links among inflammation and gut microbiome with psychoneurological symptoms and gastrointestinal toxicities in gynecologic cancers: a systematic review

INTRODUCTION

Emerging evidence highlights the roles the gut microbiome and the immune system, integral parts of the gut-brain axis, play in developing various symptoms in cancer patients. The purpose of this systematic review was to describe the roles of inflammatory markers and the gut microbiome, as well as to describe their associations with psychoneurological symptoms and gastrointestinal toxicities in women with gynecologic cancers.

METHODS

A comprehensive literature search was conducted in PubMed, Embase, and Web of Science from January 2000 to February 2021. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were utilized to screen the found articles. The quality of the included studies was assessed using the Mixed Method Assessment Tool. In the included studies, various inflammatory markers and gut microbiome diversity and patterns were measured.

RESULTS

Sixteen studies met the eligibility criteria and were included in this systematic review. While there were discrepancies in the associations between various inflammatory markers and symptoms, most of the studies showed positive correlations between interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) and cancer-related psychoneurological symptoms and gastrointestinal toxicities in gynecologic cancer patients. Although there was no consensus in alpha diversity, studies showed significant dissimilarity in the microbial communities (beta diversity) in patients with gastrointestinal toxicities compared with patients without symptoms or healthy controls. Studies also reported inconsistent findings in the abundance of bacteria at different taxonomic levels. Radiation enteritis-derived microbiota could stimulate TNF-α and interleukin 1 beta (IL-1β) secretion.

CONCLUSIONS

Alteration of inflammatory markers, the gut microbiome, and their associations show emerging evidence in the development of psychoneurological symptoms and gastrointestinal toxicities in women with gynecologic cancers. More studies on the interactions between the immune system and the gut microbiome, two integral parts of the gut-brain axis, are required to shed light on the roles they play in symptom development.

A Preparatory Study for a Randomized Controlled Trial of Dietary Fiber Intake During Adult Pelvic Radiotherapy

Background: Patients undergoing pelvic radiotherapy are often advised to omit fiber-rich foods from their diet to reduce the adverse effects of treatment. Scientific evidence supporting this recommendation is lacking, and recent studies on animals and humans have suggested that there is a beneficial effect of dietary fiber for the alleviation of symptoms. Randomized controlled studies on dietary fiber intake during pelvic radiotherapy of sufficient size and duration are needed. As preparation for such a large-scale study, we evaluated the feasibility, compliance, participation rate, and logistics and report our findings here in this preparatory study. Methods: In this preparatory study of a fiber intervention trial, Swedish gynecological cancer patients scheduled for radiotherapy were recruited between January 2019 and August 2020. During the intervention, the participants filled out questionnaires and used an application. They also consumed a fiber supplement at first in powder form, later in capsules. Blood- and fecal samples were collected. The study is registered in clinicaltrials.gov (https://clinicaltrials.gov/ct2/show/NCT04534075?cond=fidura&draw=2&rank=1). Results: Among 136 approached patients, 57 started the study and the participation rate for primary outcomes was 63% (third blood sample) and 65% (third questionnaire). Barely half of the participants provided fecal samples. Providing concise and relevant information to the patients at the right time was crucial in getting them to participate and stay in the study. The most common reasons for declining participation or dropping out were the expected burden of radiotherapy or acute side effects. Tailoring the ambition level to each patient concerning the collection of data beyond the primary endpoints was an important strategy to keep the dropout rate at an acceptable level. Using capsules rather than psyllium in powder form made it much easier to document intake and to create a control group. During the course of the preparatory study, we improved the logistics and for the last 12 participants included, the participation rate was 100% for the earliest primary outcome. Conclusion: A variety of adjustments in this preparatory study resulted in an improved participation rate, which allowed us to set a final protocol and proceed with the main study.

Dietary Fiber and the Hippocampal Neurogenic Niche in a Model of Pelvic Radiotherapy

We sought to determine whether radiation to the colorectum had an impact on parameters of hippocampal neurogenesis and, if so, whether it could be modulated by a fiber-rich diet. Male C57BL/6J mice were fed a diet containing bioprocessed oat bran or a fiber-free diet, starting two weeks before colorectal irradiation with 4 fractions of 8 Gray or sham-irradiation. Diets were then continued for 1, 6 or 18 weeks, whereafter parameters of hippocampal neurogenesis were analyzed and correlated to serum cytokine levels. No statistically significant changes in neuronal markers or cell proliferation were found at one week post-irradiation. Six weeks post-irradiation there was a decreased cell proliferation in the subgranular zone that appeared slightly more pronounced in irradiated animals on a fiber-free diet and increased numbers of immature neurons per mm² dentate gyrus in the irradiated mice, with a statistically significant increase in mice on a fiber-rich diet. Microglial abundancy was similar between all groups. 18 weeks post-irradiation, a fiber-free diet had reduced the number of immature neurons, whereas irradiation resulted in an increase. Despite this, the population of mature neurons was stable. Analysis of serum cytokines revealed a negative correlation between MIP1-α and the number of immature neurons one week after irradiation, regardless of diet. Our findings show that pelvic radiotherapy has the potential to cause a long-lasting impact on hippocampal neurogenesis, and dietary interventions may modulate this impact. More in-depth studies on the relationship between irradiation-induced intestinal injury and brain health are warranted.

Association of Radiotherapy-Related Intestinal Injury and Cancer-related Fatigue: A Brief Review and Commentary

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.

Co-Occurrence of Symptoms and Gut Microbiota Composition Before Neoadjuvant Chemotherapy and Radiation Therapy for Rectal Cancer: A Proof of Concept

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.

Gut microbiota and fatigue in rectal cancer patients: a cross-sectional pilot study

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.

Changes in Gut Microbiome Associated With Co-Occurring Symptoms Development During Chemo-Radiation for Rectal Cancer: A Proof of Concept Study

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.

Fatigue after heart transplantation - a possible barrier to self-efficacy

Rationale

Recovery after heart transplantation is challenging and many heart recipients struggle with various transplant‐related symptoms, side‐effects of immunosuppressive medications and mental challenges. Fatigue has been reported to be one of the most common and distressing symptoms after heart transplantation and might therefore constitute a barrier to self‐efficacy, which acts as a moderator of self‐management.

Aim

To explore the prevalence of fatigue and its relationship to self‐efficacy among heart recipients 1–5 years after transplantation.

Research method

An explorative cross‐sectional design, including 79 heart recipients due for follow‐up 1–5 years after transplantation. Three different self‐assessment instruments were employed; The Multidimensional Fatigue Inventory‐19, Self‐efficacy for managing chronic disease 6‐Item Scale and The Postoperative Recovery Profile.

Ethical approval

The study was approved by the Regional Ethics Board of Lund (Dnr. 2014/670‐14/10) with supplementary approval from the Swedish Ethical Review Authority (Dnr. 2019‐02769).

Results

The reported levels of fatigue for the whole group were moderate in all dimensions of the Multidimensional Fatigue Inventory‐19, with highest ratings in the General Fatigue sub‐scale. Those most fatigued were the groups younger than 50 years; pretransplant treatment with Mechanical Circulatory Support; not recovered or had not returned to work. Self‐efficacy was associated with the sub‐dimensions Mental Fatigue (ρ = −0·.649) and Reduced Motivation (ρ = −0·617), which explained 40·1% of the variance when controlled for age and gender.

Study limitations

The small sample size constitutes a limitation.

Conclusions

The moderate levels of fatigue reported indicate that it is not a widespread problem. However, for those suffering from severe fatigue it is a troublesome symptom that affects the recovery process and their ability to return to work. Efforts should be made to identify those troubled by fatigue to enable sufficient self‐management support.

iTRAQ-Based Proteomic Profiling of Potential Biomarkers in Rat Serum for Uranium Tailing Suspension Intratracheal Instillation

Protection against low-dose ionizing radiation is of great significance. Uranium tailings are formed as a byproduct of uranium mining and a potential risk to organisms. In this study, we identified potential biomarkers associated with exposure to low-dose radiation from uranium tailings. We established a Wistar rat model of low dose rate irradiation by intratracheal instillation of a uranium tailing suspension. We observed pathological changes in the liver, lung, and kidney tissues of the rats. Using isobaric tags for relative and absolute quantification, we screened 17 common differentially expressed proteins in three dose groups. We chose alpha-1 antiproteinase (Serpina1), keratin 17 (Krt17), and aldehyde dehydrogenase (Aldh3a1) for further investigation. Our data showed that expression of Serpina1, Krt17, and Aldh3a1 had changed after the intratracheal instillation in rats, which may be potential biomarkers for uranium tailing low-dose irradiation. However, the underlying mechanisms require further investigation.

Fear of graft rejection after heart transplantation - a nationwide cross-sectional cohort study

BACKGROUND

Cellular rejection is most common 3-6 months after heart transplantation while chronic rejection, that is, cardiac allograft vasculopathy and malignancy are the most common causes of death in heart-transplant recipients beyond the third year after transplantation. However, the heart transplantation recipient's perceived threat of graft rejection has never been explored.

AIM

The aim was to explore perceived threat of the risk of graft rejection and its relationship to psychological wellbeing, fatigue, health literacy, adherence and self-efficacy 1-5 years after heart transplantation.

METHODS

In a nationwide, cross-sectional study that constituted part of the Self-management after thoracic transplantation project, 79 heart recipients (68% men and 32% women with a mean age of 52.6 years) were investigated after one year (n=28), two years (n=17), three years (n=11), four years (n=17) and five years (n=6). The instruments used were: the Perceived Threat of the Risk of Graft Rejection, the Psychological General Well-being, Self-efficacy for Managing Chronic Disease, the Multidimensional Fatigue Inventory, the Newest Vital Sign and the Basel Assessment of Adherence to Immunosuppressive Medication Scale.

RESULTS

Twenty-eight per cent of the heart transplantation recipients perceived graft rejection as a serious threat. Intrusive anxiety was low and 37% perceived the threat of the risk of graft rejection as being beyond their control. Heart transplant recipients with high level of fatigue and low psychological well-being reported stronger intrusive anxiety and less control.

CONCLUSION

A perceived threat of the risk of graft rejection is present in the everyday lives of heart transplantation recipients and is strongly related to overall psychological well-being.

The Role of Gut Microbiome Perturbation in Fatigue Induced by Repeated Stress from Chemoradiotherapy: A Proof of Concept Study

OBJECTIVES

The objectives of this proof of concept study were to (a) examine the temporal changes in fatigue and diversity of the gut microbiome over the course of chemoradiotherapy (CRT) in adults with rectal cancers; (b) investigate whether there are differences in diversity of the gut microbiome between fatigued and nonfatigued participants at the middle and at the end of CRT; and (c) investigate whether there are differences in the relative abundance of fecal microbiota at the phylum and genus levels between fatigued and nonfatigued participants at the middle and at the end of CRT.

METHODS

Stool samples and symptom ratings were collected prior to the inception of CRT, at the middle (after 12-16 treatments) and at the end (after 24-28 treatments) of the CRT. Descriptive statistics and Mann-Whitney U test were computed for fatigue. Gut microbiome data were analyzed using the QIIME2 software.

RESULTS

Participants (N = 29) ranged in age from 37 to 80 years. The median fatigue score significantly changed at the end of CRT (median = 23.0) compared with the median score before the initiation of CRT for the total sample (median = 17.0; p ≤ 0.05). At the middle of CRT, the alpha diversity (abundance of Operational Taxonomic Units) was lower for fatigued participants (149.30 ± 53.1) than for nonfatigued participants (189.15 ± 44.18, t(23) = 2.08, p ≤ 0.05). At the middle of CRT, the alpha diversity (abundance of Operational Taxonomic Units) was lower for fatigued participants (149.30 ± 53.1) than for nonfatigued participants (189.15 ± 44.18, Proteobacteria, Firmicutes, and Bacteroidetes were the dominant phyla for fatigued participants, and Escherichia, Bacteroides, Faecalibacterium, and Oscillospira were the most abundant genera for fatigued participants.

CONCLUSION

CRT-associated perturbation of the gut microbiome composition may contribute to fatigue.

Exploring the Relationship between Diarrhea and Fatigue that can occur during Cancer Treatment: Using Structural Equation Modeling

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.

Fatigue 1–5 years after lung transplantation: A multicenter cross-sectional cohort study

The aim of this study was to investigate the prevalence of fatigue among lung recipients 1–5 years after transplantation (LuTx) and to explore its relationship to distressing symptoms such as dyspnea, sleep problems, pain, and decreased appetite, as well as psychological and transplant specific wellbeing. A cross-sectional, multicenter cohort study was conducted. A total of 117 lung recipients with a mean age of 54 years ( SD 13 years) who were due for their annual follow-up were included at 1 year ( n = 35), 2 years ( n = 28), 3 years ( n = 23), 4 years ( n = 20), and 5 years ( n = 11) after lung transplantation. Several instruments were used: the Multidimensional Fatigue Inventory, the Organ Transplant and Symptom Well-being Instrument (OTSWI), the Pain-O-Meter, and the Psychological General Well-Being Index. Overall 56% reported high or severe fatigue. The Psychological General Well-Being sum score makes the strongest contribution ( p < .0001) to explaining the variance in general fatigue (Beta –.628). The results of the study indicate that efforts both to identify fatigue and to test interventions are needed after LuTx.

Gene expression profiles among murine strains segregate with distinct differences in the progression of radiation-induced lung disease

Molecular mechanisms underlying development of acute pneumonitis and/or late fibrosis following thoracic irradiation remain poorly understood. Here, we hypothesize that heterogeneity in disease progression and phenotypic expression of radiation-induced lung disease (RILD) across murine strains presents an opportunity to better elucidate mechanisms driving tissue response toward pneumonitis and/or fibrosis. Distinct differences in disease progression were observed in age- and sex-matched CBA/J, C57L/J and C57BL/6J mice over 1 year after graded doses of whole-thorax lung irradiation (WTLI). Separately, comparison of gene expression profiles in lung tissue 24 h post-exposure demonstrated >5000 genes to be differentially expressed (P<0.01; >twofold change) between strains with early versus late onset of disease. An immediate divergence in early tissue response between radiation-sensitive and -resistant strains was observed. In pneumonitis-prone C57L/J mice, differentially expressed genes were enriched in proinflammatory pathways, whereas in fibrosis-prone C57BL/6J mice, genes were enriched in pathways involved in purine and pyrimidine synthesis, DNA replication and cell division. At 24 h post-WTLI, different patterns of cellular damage were observed at the ultrastructural level among strains but microscopic damage was not yet evident under light microscopy. These data point toward a fundamental difference in patterns of early pulmonary tissue response to WTLI, consistent with the macroscopic expression of injury manifesting weeks to months after exposure. Understanding the mechanisms underlying development of RILD might lead to more rational selection of therapeutic interventions to mitigate healthy tissue damage.

Summary: Rational mouse model selection is crucial for identifying new therapeutic targets and screening medical interventions in acute pneumonitis and/or late fibrosis following thoracic irradiation.

Citrulline as a biomarker of gastrointestinal toxicity in patients with rectal carcinoma treated with chemoradiation

BACKGROUND

Gastrointestinal toxicity is the principal toxicity of chemoradiation in the treatment of rectal carcinoma. The assessment of this toxicity still relies mostly on the symptoms reported by the patient.

METHODS

Plasma citrulline, serum neopterin and urinary neopterin were followed weekly in 49 patients with rectal carcinoma during chemoradiation.

RESULTS

Citrulline significantly (p<0.05) decreased while serum and urinary neopterin concentrations increased during therapy. Irradiated gut volume correlated significantly inversely with citrulline and positively with urinary neopterin. Statistically significant inverse correlations were also observed between urinary neopterin and plasma citrulline concentrations during the treatment. Urinary neopterin concentrations were significantly higher and citrulline concentrations were lower in patients who experienced grade ≥3 gastrointestinal toxicity.

CONCLUSIONS

Citrulline represents a promising biomarker of gastrointestinal toxicity. Moreover, the volume of irradiated gut correlated with urinary neopterin concentrations and an association was observed between gastrointestinal toxicity evidenced by lower citrulline concentrations and systemic immune activation reflected in increased concentrations of urinary neopterin.

Gut microbial dysbiosis may predict diarrhea and fatigue in patients undergoing pelvic cancer radiotherapy: a pilot study

Fatigue and diarrhea are the most frequent adverse effects of pelvic radiotherapy, while their etiologies are largely unknown. The aim of this study is to investigate the correlations between fatigue, diarrhea, and alterations in gut microbiota induced by pelvic radiotherapy. During the 5-week treatment of pelvic radiotherapy in 11 cancer patients, the general fatigue score significantly increased and was more prominent in the patients with diarrhea. The fatigue score was closely correlated with the decrease of serum citrulline (an indicator of the functional enterocyte mass) and the increases of systemic inflammatory proteins, including haptoglobin, orosomuoid, α1-antitrypsin and TNF-α. Serum level of lipopolysaccharide (LPS) was also elevated, especially in the patients with diarrhea indicating epithelial barrier breach and endotoxemia. Pyrosequencing analysis of 16S rRNA gene revealed that microbial diversity, richness, and the Firmicutes/Bacteroidetes ratio were significantly altered prior to radiotherapy in patients who later developed diarrhea. Pelvic radiotherapy induced further changes in fecal microbial ecology, some of which were specific to the patients with or without diarrhea. Our results indicate that gut microbial dysbiosis prior to radiation therapy may be exploited to predict development of diarrhea and to guide preventive treatment options. Radiation-induced dysbiosis may contribute to pelvic radiation disease, including mucositis, diarrhea, systemic inflammatory response, and pelvic radiotherapy-associated fatigue in cancer patients.

Guidance on the management of diarrhoea during cancer chemotherapy

Diarrhoea induced by chemotherapy in cancer patients is common, causes notable morbidity and mortality, and is managed inconsistently. Previous management guidelines were based on poor evidence and neglect physiological causes of chemotherapy-induced diarrhoea. In the absence of level 1 evidence from randomised controlled trials, we developed practical guidance for clinicians based on a literature review by a multidisciplinary team of clinical oncologists, dietitians, gastroenterologists, medical oncologists, nurses, pharmacist, and a surgeon. Education of patients and their carers about the risks associated with, and management of, chemotherapy-induced diarrhoea is the foundation for optimum treatment of toxic effects. Adequate--and, if necessary, repeated--assessment, appropriate use of loperamide, and knowledge of fluid resuscitation requirements of affected patients is the second crucial step. Use of octreotide and seeking specialist advice early for patients who do not respond to treatment will reduce morbidity and mortality. In view of the burden of chemotherapy-induced diarrhoea, appropriate multidisciplinary research to assess meaningful endpoints is urgently required.

Living through pelvic radiotherapy:A mixed method study of self-care activities and distressful symptoms

PURPOSE

To explore patients' experience of their illness when undergoing pelvic radiotherapy by describing the presence and severity of distressful symptoms and to explore initiated self-care activities in response to illness and symptoms.

METHODS

A mixed-method study was performed which included a core qualitative dataset and a supplementary quantitative dataset. Twenty-nine women undergoing five weeks of radiotherapy were prospectively interviewed during five weeks of treatment in order to capture experiences, distressful symptoms and quality of life during treatment. Grounded theory formed collection and analysis of the qualitative dataset and statistics were used to analyze the quantitative dataset.

RESULTS

A maintained self-identity was concluded as being central during the trajectory of treatment. Initiated self-care activities served to alleviate physical, emotional, and social suffering; helping the respondents keep their integrity and sense of self. Previous life experiences influenced the process of being able to maintain self-identity. The gastrointestinal symptoms and pain caused most distress.

CONCLUSIONS

In order to be able to maintain self-identity patients endure treatment by focusing on symptoms, on getting cured and on their self-image. Several distressful symptoms implied social limitations and a sense that the body would not take the strain. The result of this study can help health care professionals to gain a better understanding of the struggle to endure pelvic radiotherapy. Further, health care professionals should be more proactive in alleviating their patients' distressful symptoms. The results imply that previous life experiences should precede initiated interventions because these life experiences affect the patients' self-care activities.

Biomarkers of normal tissue toxicity after pelvic radiotherapy

PURPOSE OF REVIEW

To review the evidence for candidate biomarkers of gastrointestinal toxicity following pelvic radiotherapy to highlight recent findings of potential interest to those involved in the treatment of pelvic malignancies or the management of gastrointestinal consequences of cancer treatments.

RECENT FINDINGS

Multiple serum and faecal biomarkers have been studied for use in the detection of gastrointestinal toxicity following pelvic radiotherapy. There is no single biomarker that has been shown to be useful and studies have been hampered by the lack of a 'gold standard' test to confirm the presence of toxicity. Given the complex effects of pelvic radiotherapy on the gastrointestinal tract, it is likely that a panel of biomarkers would be necessary in clinical practice.

SUMMARY

Biomarkers for gastrointestinal toxicity have a potential role in determining the outcomes of current and evolving radiotherapy techniques, identifying those patients at risk of greater degrees of toxicity to facilitate individualized treatment and determining whether symptoms that develop following treatment are related to the previous radiotherapy. Outcome measurement of pelvic radiotherapy has been plagued by inaccurate terminology and crude outcome measures. An accurate and acceptable biomarker or panel of biomarkers has the potential to revolutionize cancer management from treatment planning to posttreatment care. Several candidate biomarkers show promising results, but further robust research is required to clearly identify reliable biomarkers that can be translated into clinical practice.