Time patterns of changes in biomarkers, symptoms and histopathology during pelvic radiotherapy

Characterization of Early and Late Damage in a Mouse Model of Pelvic Radiation Disease

Pelvic radiation disease (PRD), a frequent side effect in patients with abdominal/pelvic cancers treated with radiotherapy, remains an unmet medical need. Currently available preclinical models have limited applications for the investigation of PRD pathogenesis and possible therapeutic strategies. In order to select the most effective irradiation protocol for PRD induction in mice, we evaluated the efficacy of three different locally and fractionated X-ray exposures. Using the selected protocol (10 Gy/day × 4 days), we assessed PRD through tissue (number and length of colon crypts) and molecular (expression of genes involved in oxidative stress, cell damage, inflammation, and stem cell markers) analyses at short (3 h or 3 days after X-ray) and long (38 days after X-rays) post-irradiation times. The results show that a primary damage response in term of apoptosis, inflammation, and surrogate markers of oxidative stress was found, thus determining a consequent impairment of cell crypts differentiation and proliferation as well as a local inflammation and a bacterial translocation to mesenteric lymph nodes after several weeks post-irradiation. Changes were also found in microbiota composition, particularly in the relative abundance of dominant phyla, related families, and in alpha diversity indices, as an indication of dysbiotic conditions induced by irradiation. Fecal markers of intestinal inflammation, measured during the experimental timeline, identified lactoferrin, along with elastase, as useful non-invasive tools to monitor disease progression. Thus, our preclinical model may be useful to develop new therapeutic strategies for PRD treatment.

An 8-week exercise study to improve cancer treatment related fatigue and QOL among African American breast cancer patients undergoing radiation treatment: A pilot randomized clinical trial

BACKGROUND

Cancer treatment related fatigue (CTRF) is one of the most debilitating side effects of adjuvant radiation therapy (RT). Several studies have found that physical activity (PA) may be an effective intervention to decrease fatigue and enhance QOL in cancer survivors. The primary objective of the PEDLAR study is to test the feasibility of an easily administered 8-week structured moderate-intensity PA intervention, delivered concurrently with RT, in reducing CTRF and improving health-related QOL among African-American breast cancer patients. This study is also designed to provide pilot data on the acceptability and adherence of PA interventions in African-American women with breast cancer.

METHODS

It is a prospective, 2-arm, 8-week feasibility trial. Participants are randomized to either a structured, moderate-intensity aerobic training exercise regimen concurrent with radiotherapy or a control group.

RESULTS

Participants in intervention group reported high satisfaction with exercise and adherence was >75% for exercise sessions.

CONCLUSIONS

African-American breast cancer patients in a moderate-intensity 75 min/wk aerobic exercise intervention had marginally lower fatigue at 8-wk follow-up compared to baseline. The control group participants had marginally higher fatigue at 8-wk follow-up compared to baseline. Participants in the intervention group reported slightly better quality of life at 8-wk follow-up compared to baseline (P = 0.06).

Gastrointestinal Toxicity of Pelvic Radiotherapy: Are We Letting Women Down?

For all cancers there are four areas of importance: prevention, early diagnosis, optimising therapy and living with and beyond. For women diagnosed with gynaecological cancers, progress in these first three areas has been immense. However, living with and beyond has largely been ignored as a significant issue. As a group, patients treated for gynaecological cancer are more often young and more often suffer the most difficult long-term issues. Despite the growing number of long-term survivors, little has been done to ensure appropriate assessment and treatment of side-effects of cancer therapies, especially when radiotherapy has been used. For many affected patients their symptoms become part of everyday life, 'normality' is adjusted and these changes are tolerated even when severely limiting activities. Data show that even expert clinicians frequently do not appreciate the true impact of these problems and the focus of treatment and of follow-up remains fixed on 5-year survival and cancer recurrence, respectively. Many clinicians are unaware of what experts can do for toxicity and do not know where to refer their patients. However, rapid identification of patients with significant symptoms can lead to earlier diagnosis of treatable pathologies and improvement in patients' quality of life. In addition, the underlying pathophysiology of radiation-induced damage is potentially amenable to disease-modifying therapies. This review focuses on the factors that contribute to patients developing pelvic radiation disease, what can be done to mitigate the toxicity of treatment and highlights the challenges that must be addressed to reduce the gastrointestinal toxicity of pelvic radiotherapy.

FAK alleviates radiation-induced rectal injury by decreasing apoptosis

Radiation-induced rectal injury is closely related with radiotherapy efficiency. Here, we investigated the effect of focal adhesion kinase (FAK) in radiation-induced rectal injury. Peripheral blood samples of patients with rectal cancer were collected prior to radiotherapy. Differentially expressed genes and copy number variations (CNVs) were analyzed by microarray analysis. The CTCAE v3.0 toxicity grades were used to assess acute rectal injury. The radiosensitivity of human intestinal epithelial crypt (HIEC) cells were assayed by colony formation, mitochondrial membrane potential, flow cytometry and western blotting. The rectums of C57BL/6 mice were X-irradiated locally with a single dose of 15 Gy. The effect of FAK on radiation-induced injury was investigated by hematoxylin-eosin (H&E) staining, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), immunohistochemistry (IHC) and quantitative real-time PCR (qRT-PCR). FAK mRNA level was inversely correlated with rectal injury severity in patient samples. A CNV amplification located on chromosome 8 was closely related with FAK. Further functional assays revealed increased levels of γH2AX expression and apoptosis-related proteins in FAK-silenced HIEC cells. The ratio of TUNEL, cl-caspase-3, cyto-c and bax/bcl-2 expression in the rectum mucosa treated with a FAK inhibitor increased significantly. These results demonstrated that FAK reduced radiation-induced rectal injury by decreasing apoptosis.

Nutritional strategies to prevent gastrointestinal toxicity during pelvic radiotherapy

Radiotherapy-induced damage to non-cancerous gastrointestinal mucosa has effects on secretory and absorptive functions and can interfere with normal gastrointestinal physiology. Nutrient absorption and digestion may be compromised. Dietary manipulation is an attractive option with sound rationale for intervention. The aim of this review was to synthesise published evidence for the use of elemental formulae, low or modified fat diets, fibre, lactose restriction and probiotics, prebiotics and synbiotics to protect the bowel from gastrointestinal side effects during long-course, radical pelvic radiotherapy. Thirty original studies (recruiting n 3197 patients) were identified comprising twenty-four randomised controlled trials, four cohort studies and two comparator trials. Endpoints varied and included symptom scales (Inflammatory Bowel Disease Questionnaire, Common Technology Criteria for Adverse Events, Radiation Therapy Oncology Group) and Bristol Stool Scale. Dietary and supplement interventions were employed with many studies using a combination of interventions. Evidence from RCT was weak for elemental, low or modified fat and low-lactose interventions and modestly positive for the manipulation of fibre during radiotherapy. Evidence for probiotics as prophylactic interventional agents was more promising with a number of trials reporting positive results but strength and strains of interventions vary, as do methodologies and endpoints making it difficult to arrive at firm conclusions with several studies lacking statistical power. This consolidated review concludes that there is insufficient high-grade evidence to recommend nutritional intervention during pelvic radiotherapy. Total replacement of diet with elemental formula could be effective in severe toxicity but this is unproven. Probiotics offer promise but cannot be introduced into clinical practice without rigorous safety analysis, not least in immunocompromised patients.

A systematic review of molecular responses to cancer therapy in normal human mucosa

OBJECTIVE

Cancer therapy-induced inflammation of oral and gastrointestinal mucosae affects patients nonuniformly. Preventive strategies are limited; no biomarker exists for pretreatment identification of patients likely to be severely affected. Animal models are preferred for studying molecular responses in mucosae during chemotherapy, but translation into clinical practice is difficult. We performed a systematic review to retrieve articles that described molecular changes in human mucosae during cancer therapy.

STUDY DESIGN

We searched MEDLINE and Ovid Embase searches for studies reported in the English language literature from January 1990 to November 2016 and studies referenced in selected articles, which analyzed mucosae from patients at risk of developing mucositis during cancer therapy. Two authors extracted data according to predefined data fields, including study quality indicators.

RESULTS

We identified 17 human studies on chemotherapy (n = 9) and radiotherapy (n = 8), but no studies on targeted therapy. Studies were heterogeneous with regard to patient cohorts, analysis methods, cancer treatments, biopsy timings, and correlations to clinical mucositis. Consequently, a meta-analysis was not feasible.

CONCLUSIONS

Few human studies described the molecular responses of the normal mucosa to cancer therapy. Studies were heterogeneous and had sparse correlations to clinical mucositis. We proposed a model for acquiring data on treatment- and disease-specific phenotypes and transcriptomes for predictive or preventive initiatives.

Probiotics for prevention of radiation-induced diarrhea: A meta-analysis of randomized controlled trials

Background

Radiotherapy is commonly used for abdominal or pelvic cancer, and patients receiving radiotherapy have a high risk developing to an acute radiation-induced diarrhea. Several previous studies have discussed the effect of probiotics on prevention of radiation-induced diarrhea, but the results are still inconsistent.

Objective

We performed a meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy of probiotic supplementation for prevention the radiation-induced diarrhea.

Methods

Relevant RCTs studies assessing the effect of probiotic supplementation on clinical outcomes compared with placebo were searched in PubMed, EMBASE, and the Cochrane Library databases (up to March 30 2016). Heterogeneity was assessed with I² and H², and publication bias was evaluated using sensitive analysis.

Results

Six trials, a total of 917 participants (490 participants received prophylactic probiotics and 427 participants received placebo), were included in this meta-analysis. Compared with placebo, probiotics were associated with a lower incidence of radiation-induced diarrhea (RR: 0.55; 95% CI: 0.34–0.88; P = 0.01; I²: 87%; 95% CI: 75%-94%; H²: 2.8; 95% CI: 2.0–4.0). However, there is no significant difference in the anti-diarrheal medication use (RR: 0.68; 95% CI: 0.40–1.14; P = 0.14) or bristol scale on stool form (RR: 0.64; 95% CI: 0.35–1.17; P = 0.14).

Conclusion

Probiotics may be beneficial to prevent radiation-induced diarrhea in patients who suffered from abdominal or pelvic cancers during radiotherapy period.

An exercise trial to reduce cancer related fatigue in African American breast cancer patients undergoing radiation therapy: Design, rationale, and methods

BACKGROUND

Cancer related fatigue (CRF) is a common and debilitating side-effect of radiotherapy in breast cancer patients. Physical activity interventions can attenuate CRF but evidence in African-American women with breast cancer is lacking.

METHODS/DESIGN

The "Pedlar" Study is a prospective, 8-week structured moderate-intensity exercise intervention, delivered concurrently with radiotherapy, to reduce CRF and improve health-related quality of life among African American breast cancer patients. Forty African American women with breast cancer scheduled to receive radiation therapy at MedStar Washington Hospital Center will be randomized to one of the two trial arms: 1) a facility-based aerobic exercise utilizing a portable stationary pedal exerciser; and 2) a control group. Intervention arm participants will exercise at the hospital either before or after their radiation treatment. Assessments will be conducted at baseline, 4, and 8 weeks. The outcome variables are CRF, biomarkers of inflammation, and health-related quality of life.

DISCUSSION

The Pedlar Study will provide preliminary evidence on whether a short-term moderate-intensity exercise intervention might be effective in reducing CRF in African American women undergoing radiotherapy for breast cancer, and whether this effect is mediated by inflammation.

The Efficacy of Probiotic (Lactobacillus rhamnosus GG) and 5-ASA (Aminosalicylic Acid) in the Treatment of Experimental Radiation Proctitis in Rats

The aims of the study are to demonstrate the effect of probiotic use on the healing of radiation proctitis (RP) and evaluate the efficiency of fecal biomarkers at follow-up of the treatment. Thirty-two male/female rats were randomly separated into four groups of eight rats. The first group (control) was not radiated. RP was created by 17.5 Gy single dose rectal irradiation. The second group (RP) was subjected to RP, but not treated. The third group (RP+ASA) was treated with 5-aminosalicylic acid (5-ASA) 250 mg/kg daily by gastric lavage for 14 days after the irradiation, and the forth group (RP+LGG) was treated with Lactobacillus GG (LGG) 25 × 100 million CFU daily. Feces samples were taken at the 7th and 14th day of the treatment for fecal biomarkers. Rectums of the rats were resected at the 14th day by laparotomy. Samples were evaluated both macroscopically and microscopically. RP was achieved both macroscopically and microscopically. Weight loss of RP group is statistically significant (p < 0.005) than other groups. The healing ratio of RP+ASA and RP+LGG groups was significantly better than the RP group (p < 0.005) both macroscopically and microscopically. But there was no significant difference between ASA and LGG groups. Biochemically, fecal calprotectin was found to be more effective than fecal myeloperoxidase and fecal lactoferrin to show the efficacy of treatment of radiation proctitis. The results of our study demonstrate that probiotic is as effective as 5-aminosalicylic in the treatment of radiation proctitis, and fecal calprotectin is a useful biomarker in determining the response to the treatment.

Research status of radiation induced gastroduodenal injury

With the development of modern radiotherapy techniques, such as three dimensional conformal radiotherapy, Gamma-knife treatment, and tomotherapy, patients who have abdominal tumors like liver cancer, pancreatic cancer, and colon cancer can live longer. The wide use of radiation therapy increases the incidence of gastroduodenal radioactive injury. This article reviews the pathogenesis and pathological characteristic of radiation induced gastroduodenal injury, factors influencing the injury, and the diagnosis and treatment of radiation induced gastroduodenal injury. Currently, there have been few studies on the mechanism of radiation induced gastroduodenal injury. The optimal timing of endoscopic examination after radiotherapy is still inconclusive. V25 for the stomach, V35 for the duodenum and aV55 Gy for the duodenum are predictive factors for gastroduodenal toxicity (>grade 2, CTCAE3.0). There has been no treatment standard for curing radiation induced gastroduodenitis. Traditional Chinese medicine has unique advantages in the prevention and control of radiation induced gastroduodenal injury.

Pelvic radiation therapy: Between delight and disaster

In the last few decades radiotherapy was established as one of the best and most widely used treatment modalities for certain tumours. Unfortunately that came with a price. As more people with cancer survive longer an ever increasing number of patients are living with the complications of radiotherapy and have become, in certain cases, difficult to manage. Pelvic radiation disease (PRD) can result from ionising radiation-induced damage to surrounding non-cancerous tissues resulting in disruption of normal physiological functions and symptoms such as diarrhoea, tenesmus, incontinence and rectal bleeding. The burden of PRD-related symptoms, which impact on a patient's quality of life, has been under appreciated and sub-optimally managed. This article serves to promote awareness of PRD and the vast potential there is to improve current service provision and research activities.

Gastrointestinal Safety Pharmacology in Drug Discovery and Development

Although the basic structure of the gastrointestinal tract (GIT) is similar across species, there are significant differences in the anatomy, physiology, and biochemistry between humans and laboratory animals, which should be taken into account when conducting a gastrointestinal (GI) assessment. Historically, the percentage of cases of drug attrition associated with GI-related adverse effects is small; however, this incidence has increased over the last few years. Drug-related GI effects are very diverse, usually functional in nature, and not limited to a single pharmacological class. The most common GI signs are nausea and vomiting, diarrhea, constipation, and gastric ulceration. Despite being generally not life-threatening, they can greatly affect patient compliance and quality of life. There is therefore a real need for improved and/or more extensive GI screening of candidate drugs in preclinical development, which may help to better predict clinical effects. Models to identify drug effects on GI function cover GI motility, nausea and emesis liability, secretory function (mainly gastric secretion), and absorption aspects. Both in vitro and in vivo assessments are described in this chapter. Drug-induced effects on GI function can be assessed in stand-alone safety pharmacology studies or as endpoints integrated into toxicology studies. In silico approaches are also being developed, such as the gut-on-a-chip model, but await further optimization and validation before routine use in drug development. GI injuries are still in their infancy with regard to biomarkers, probably due to their greater diversity. Nevertheless, several potential blood, stool, and breath biomarkers have been investigated. However, additional validation studies are necessary to assess the relevance of these biomarkers and their predictive value for GI injuries.

Systematic review: the role of the gut microbiota in chemotherapy- or radiation-induced gastrointestinal mucositis - current evidence and potential clinical applications

BACKGROUND

Gastrointestinal mucositis is defined as inflammation and/or ulcers of the gastrointestinal tract occurring as a complication of chemotherapy and radiation therapy, and affects about 50% of all cancer patients.

AIM

To assess the role of gut microbiota in the pathogenesis of gastrointestinal mucositis and the potential for manipulations of the microbiota to prevent and to treat mucositis.

METHODS

Search of the literature published in English using Medline, Scopus and the Cochrane Library, with main search terms 'intestinal microbiota', 'bacteremia', 'mucositis', 'chemotherapy-induced diarrhoea', 'chemotherapy-induced mucositis', 'radiotherapy-induced mucositis'.

RESULTS

The gut microbiota plays a major role in the maintenance of intestinal homoeostasis and integrity. Patients receiving cytotoxic and radiation therapy exhibit marked changes in intestinal microbiota, with most frequently, decrease in Bifidobacterium, Clostridium cluster XIVa, Faecalibacterium prausnitzii, and increase in Enterobacteriaceae and Bacteroides. These modifications may contribute to the development of mucositis, particularly diarrhoea and bacteraemia. The prevention of cancer therapy-induced mucositis by probiotics has been investigated in randomised clinical trials with some promising results. Three of six trials reported a significantly decreased incidence of diarrhoea. One trial reported a decrease in infectious complications.

CONCLUSIONS

The gut microbiota may play a major role in the pathogenesis of mucositis through the modification of intestinal barrier function, innate immunity and intestinal repair mechanisms. Better knowledge of these effects may lead to new therapeutic approaches and to the identification of predictive markers of mucositis.

A randomized double-blind controlled trial: impact of probiotics on diarrhea in patients treated with pelvic radiation

BACKGROUND & AIMS

Radical radiation therapy is commonly used for treatment of pelvic cancer. Up to 80% of patients receiving radiotherapy will develop acute radiation induced diarrhea. The primary aim of this randomized double blind controlled trial is to evaluate the effect of the probiotic Bifilact(®) on moderate and severe treatment-induced diarrhea during pelvic radiation.

METHODS

Patients with pelvic cancers were treated between 2006 and 2010 at L'Hôtel-Dieu de Québec, University Health Center. Some patients had surgery before pelvic radiotherapy and some received chemotherapy. A total of 246 Patients were randomized between a placebo and either of two regiments of double strain Bifilact(®) probiotics (Lactobacillus acidophilus LAC-361 and Bifidobacterium longum BB-536): a standard dose twice a day (1.3 billion CFU) or a high dose three times a day (10 billion CFU). Patients were trained to record their digestive symptoms daily with a standardized scale and they met a registered dietician and radiation oncologist every week during treatment. The main analysis compared time to first appearance of grade ≥2-3-4 diarrhea using Kaplan-Meier curves as measured by proportion of patients without moderate and severe diarrhea.

RESULTS

229 patients were analyzed. The difference between the groups for overall grade 2-3-4 diarrhea was not statistically significant (p = 0.13). However at 60 days, the proportion of patients without moderate and severe diarrhea in the standard dose group (35%) was more than twice as high as that of the placebo group (17%) with a hazard ratio of 0.69 (p = 0.04). In patients who had surgery, the standard probiotics dose group had a better proportion of patients without very severe diarrhea than the placebo group, respectively 97% and 74% (p = 0.03). In all groups, the average number of bowel movements per day during treatment was less than 3 soft stools (p = 0.80) and the median abdominal pain less than 1 based on the National Cancer Institute scale (p = 0.23).

CONCLUSION

Standard dose of Bifilact(®) may reduce radiation induced grade 2-3-4 diarrhea at the end of the treatment of patients with pelvic cancer. In patients operated on before RT, a standard dose of probiotics may reduce radiation induced grade 4 diarrhea. Nutritional interventions by a registered dietician seemed to reduce global digestive symptoms.

TRIAL REGISTRATION

clinicaltrials.gov. Identifier NCT01839721.

Systematic review: the efficacy of nutritional interventions to counteract acute gastrointestinal toxicity during therapeutic pelvic radiotherapy

BACKGROUND

Radiotherapy-induced damage to noncancerous gastrointestinal mucosa has effects on secretory and absorptive functions and can interfere with normal gastrointestinal physiology. Nutrient absorption and digestion may be compromised. Dietary manipulation is an attractive option for the prevention and management of symptoms.

AIM

To synthesise the evidence for the use of elemental formula low- or modified-fat diets, fibre, lactose restriction and probiotics, prebiotics and synbiotics to protect the gastrointestinal tract during pelvic radiotherapy.

METHODS

Four electronic databases were searched. Randomised controlled trials (RCT), controlled trials (CT) and case series in adult patients receiving radiotherapy for pelvic cancers employing nutritional interventions to reduce gastrointestinal toxicity were included. Methodological quality was assessed using a bespoke tool.

RESULTS

Twenty-two original studies (2446 patients) were identified. Study quality was highly variable with only 37% scoring ≥10 points (maximum 17: bespoke scale). Few studies assessed compliance with the intervention. End-points varied and included symptom scales (IBDQ, CTC, Bristol Stool and RTOG). Evidence from RCTs was weak for elemental, low- or modified-fat, fibre and low-lactose interventions with 1/4, 3/4, 1/2, 0/1 trials respectively reporting favourable outcomes. Evidence for probiotics as prophylactic interventions was more promising (4/5 favourable), but dose, strains and methodologies varied.

CONCLUSIONS

There is insufficient high-grade evidence to recommend nutritional intervention during pelvic radiotherapy. Total replacement of diet with elemental formula may be appropriate in severe toxicity. Probiotics offer promise, but cannot be introduced into clinical practice without rigorous safety analysis, not least in immunocompromised patients. The methodological quality of nutritional intervention studies needs to be improved.

Clinical trial: Efficacy of a low or modified fat diet for the prevention of gastrointestinal toxicity in patients receiving radiotherapy treatment for pelvic malignancies

BACKGROUND

Inflammatory responses to pelvic radiotherapy can result in severe changes to normal gastrointestinal function with potentially severe long-term effects. Reduced or modified fat diets may confer benefit.

METHODS

This randomised controlled trial recruited patients with gynaecological, urological or lower gastrointestinal malignancy due to receive radical radiotherapy. Patients were randomised to a low fat (20% total energy from long chain triglycerides), modified fat (20% from long chain triglycerides and 20% from medium chain triglycerides) or normal fat diet (40% total energy from long chain triglycerides). The primary outcome was a difference in change in Inflammatory Bowel Disease Questionnaire--Bowel (IBDQ-B) score, from the start to end of radiotherapy.

RESULTS

A total of 117 patients with pelvic tumours (48% urological; 32% gastrointestinal; 20% gynaecological), with mean (SD) age: 65 (11.0) years, male:female ratio: 79:38, were randomised. The mean (SE) fall in paired IBDQ-B score was -7.3 (0.9) points, indicating a worsening toxicity. Differences between groups were not significant: P = 0.914 (low versus modified fat), P = 0.793 (low versus normal fat) and P = 0.890 (modified versus normal fat). The difference in fat intake between low and normal fat groups was 29.5 g [1109 kJ (265 kcal)] amounting to 11% (of total energy intake) compared to the planned 20% differential. Full compliance with fat prescription was only 9% in the normal fat group compared to 93% in the low fat group.

CONCLUSIONS

A low or modified fat diet during pelvic radiotherapy did not improve gastrointestinal symptom scores compared to a normal fat intake. An inadequate differential in fat intake between the groups may have confounded the results.

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.

Biomarkers of regimen-related mucosal injury

Regimen-related mucosal toxicity is extremely common following cytotoxic chemotherapy and radiotherapy. The alimentary mucosa is particularly susceptible to injury and dysfunction, leading to a constellation of adverse side effects. Currently there is no "one fit" biomarker of such injury. A number of biomarkers have been investigated in the context of gastrointestinal diseases, which may prove useful in the oncology arena. Two of significant potential include citrulline and calprotectin, however more work is required to define the most appropriate settings for their use. Identification of a biomarker that is easily obtained, measured, and accurately indicates mucosal damage, would allow for improved patient diagnosis of toxicities and prompt appropriate intervention. In this review, we highlight the effectiveness of currently examined biomarkers and discuss future avenues for research in this exciting area.

"Pelvic radiation disease": new understanding and new solutions for a new disease in the era of cancer survivorship

BACKGROUND

Cancer therapies increasingly achieve cure, but result in chronic moderate or severe gastrointestinal side effects in millions of patients worldwide. Paradoxically, modern therapies threaten to increase the burden of chronic gastrointestinal toxicity, not reduce it.

AIM

To define pelvic radiation disease.

METHODS

A reinterpretation of published data.

RESULTS

The lack of interest in patients with pelvic radiation disease is startling. Symptoms after radiotherapy are only a manifestation of new onset gastrointestinal physiological deficits induced by the radiotherapy. With proper diagnosis and treatment of these deficit(s), the symptoms are curable. Science suggests that much radiotherapy-induced gastrointestinal morbidity is preventable. Once the true nature of radiation injury is understood, straightforward solutions emerge and inaccurate dogmas can be discarded. Imprecise language is a fundamental barrier to progress in complex disorders.

CONCLUSIONS

Radiation-induced gastrointestinal toxicity is bedeviled by inappropriate terminology, causing confusion, and myth which legitimizes inappropriate clinical behavior. We must address honestly the uncomfortable reality that doctors, sometimes do harm. Not to do so in an era where survivorship is a reality, will deny millions often with severe symptoms from "pelvic radiation disease", the care which will help them.

Faecal calprotectin and lactoferrin values during irradiation of prostate cancer correlate with chronic radiation proctitis: results of a prospective study

OBJECTIVE

Acute proctitis and chronic radiation proctitis are relevant complications of pelvic radiation. The purpose of this study was to investigate two markers of gut inflammation during and after irradiation for prostate cancer to evaluate a correlation between acute and chronic proctitis.

MATERIAL AND METHODS

Two patient groups were analysed. In group 1, stool samples from 20 patients were collected before therapy, every week during therapy, at the end of therapy, and 13 and 27 months after therapy. Group 2 comprised 47 patients who had undergone irradiation 40 months earlier. Toxicity was determined by common toxicity criteria (CTC) and the LENT soma scale. Calprotectin and lactoferrin values were determined by ELISA.

RESULTS

In group 1, acute values for both faecal markers were significantly correlated with chronic proctitis symptoms and all patients with chronic toxicity had acute proctitis symptoms with elevated faecal values. In group 2, where stool samples were solely collected 40 months after irradiation, the Pearson square test showed both a significant correlation between calprotectin and lactoferrin values and toxicity after 40 months.

CONCLUSIONS

Within a group of 19 patients followed for two years after irradiation for prostate cancer, and 47 patients tested 40 months after irradiation, increased faecal values of calprotectin and lactoferrin were significantly correlated with the occurrence of chronic proctitis. This observation should be confirmed in an expanded study.

Predicting late effects of pelvic radiotherapy: is there a better approach?

PURPOSE

Significant chronic symptoms following pelvic radiotherapy occur more frequently than commonly realized. Predictive factors for the development of late symptoms are poorly defined. Moderate sustained acute (cumulative) toxicity might predict severe late effects better than peak reaction.

METHODS AND MATERIALS

To determine prospectively whether peak or cumulative gastrointestinal (GI) acute symptoms better predict late symptoms in patients receiving pelvic radiotherapy. Symptom scores were measured weekly from the start of radiotherapy, and at 1 year using the Modified Inflammatory Bowel Disease Questionnaire-Bowel subset. The possible prognostic impact of patient-related factors was explored.

RESULTS

Three hundred and eight patients were recruited. 100 were excluded due to lack of follow-up data at one year resulting from death, too ill, stoma, relapsed, non-response or withdrawal. A further 15 were excluded for incomplete data, leaving 193 patients with evaluable data. Of these, 28 had GI, 101 urological, and 64 gynecological cancers. Patients' median age was 65 years (range, 23-82), and they were treated with median 60 Gy dose for a median of 6 weeks. Univariate analysis revealed a significant association between cumulative acute symptom scores and scores at 1 year (p < 0.001), which was dose-independent (p < 0.001). Acute peak and 1-year scores were not associated (p = 0.431). The correlation coefficient between cumulative acute symptoms and symptoms at 1 year was 0.367 and for peak acute symptoms was weaker at 0.057. Patients with an abnormal body mass index and current smokers were more likely to experience worse symptoms at 1 year.

CONCLUSION

Cumulative acute symptoms are more predictive of late symptoms than peak acute changes in score. This association is independent of the radiotherapy dose delivered and is suggestive of a consequential late effect.

Preoperative radiotherapy and extracellular matrix remodeling in rectal mucosa and tumour matrix metalloproteinases and plasminogen components

BACKGROUND. Preoperative radiotherapy reduces recurrence but increases postoperative morbidity. The aim of this study was to explore the effect of radiotherapy in rectal mucosa and rectal tumour extracellular matrix (ECM) by studying enzymes and growth factors involved in ECM remodeling. MATERIALS AND METHODS. Twenty patients with short-term preoperative radiotherapy and 12 control patients without radiotherapy were studied. Biopsies from rectal mucosa and tumour were collected prior to radiotherapy and at surgery. Tissue MMP-1, -2, -9, TIMP-1, uPA, PAI-1, TGF-beta1 and calprotectin were determined by ELISA. Biopsies from irradiated and non-irradiated peritoneal areas were also analysed. RESULTS. Radiotherapy increased the tissue levels of MMP-2 and PAI-1 in both the rectal mucosa and tumours while calprotectin and uPA showed an increase only in the mucosa after irradiation. The increase of calprotectin was due to an influx of inflammatory cells as revealed by immunohistochemistry. Prior to irradiation, the tumour tissues had increased levels of MMP-1, -2, -9, total TGF-beta1, uPA, PAI-1 and calprotectin compared to mucosa, while TIMP-1 and the active TGF-beta1 fraction showed no statistical difference. CONCLUSIONS. This study indicates a radiation-induced effect on selected ECM remodeling proteases. This reaction may be responsible for early and late morbidity. Interference of this response might reduce these consequences.

Faecal DNA and calprotectin as biomarkers of acute intestinal toxicity in patients undergoing pelvic radiotherapy

BACKGROUND

Acute intestinal toxicity is a frequent complication that may lead to interruption of treatment in patients undergoing pelvic radiotherapy. Reliable, non-invasive biological markers to evidence their severity are not yet available.

AIM

To test faecal DNA and calprotectin as potential biomarkers of intestinal toxicity caused by pelvic radiotherapy.

METHODS

Patients were categorized according to the location of the cancer as nonrectal (n = 25) and rectal (n = 27). Four stool samples were collected at weeks w0, w3, w5 (end of radiotherapy) and w7. Faecal DNA was determined by quantitative PCR and calprotectin by ELISA. Intestinal toxicity was scored according to the Common Toxicity Criteria.

RESULTS

In the nonrectal group, acute diarrhoea toxicity was present in 80% of patients, faecal DNA increased 10-fold during radiotherapy (1.5 x 10(3) copies/mg dry weight, 9.5 x 10(2)-8.8 x 10(3) at w0, median and interquartile range vs. 1.3 x 10(4), 1.9 x 10(3)-3.9 x 10(4) at w5, P < 0.01), but was not recovered at w7 (3.4 x 10(3), 1.5 x 10(3)-4.1 x 10(4)) and calprotectin doubled during treatment at w3 and w5. No significant changes in faecal markers were found in the rectal group.

CONCLUSION

Faecal excretion of human DNA and calprotectin increased during pelvic radiotherapy treatment, and may be a good objective biomarker of intestinal damage in nonrectal cancer patients.

Can biological markers act as non-invasive, sensitive indicators of radiation-induced effects in the gastrointestinal mucosa?

BACKGROUND

Reliable, non-invasive biological markers of the severity of radiotherapy-induced damage to the gastrointestinal tract are not available. Clinicians continue to use symptom scores as surrogate indicators of toxicity.

AIM

To determine whether levels of potential biochemical markers of mucosal toxicity change during pelvic radiotherapy.

METHODS

Fifty-nine patients (30:29 males:females) with mixed pelvic malignancies, receiving 45-70 Gy were recruited. At baseline and weeks 4 or 5 of radiotherapy, blood samples for citrulline, C-reactive protein, eosinophil cationic protein and stool samples for faecal calprotectin were obtained. Symptoms were measured using the Inflammatory Bowel Disease Questionnaire - Bowel Subset, Radiation Therapy Oncology Group and Vaizey Incontinence Questionnaires. Paired t-tests of change in marker values were calculated.

RESULTS

Citrulline (P = 0.02) and faecal calprotectin (P = 0.01) values changed significantly between baseline and 4/5 weeks. Inflammatory Bowel Disease Questionnaire - Bowel Subset fell significantly (mean fall = 10 points, s.d.: 8.9). Changes in markers did not correlate with symptoms.

CONCLUSIONS

Some biochemical markers of mucosal toxicity change significantly during treatment. Further studies must investigate the timing of changes of these biochemical markers, their relationship to gastrointestinal physiological change and the radiotherapy dose delivered to the gastrointestinal tract and whether changes in markers acutely can predict the degree of long-term gastrointestinal dysfunction.