The effect of free and encapsulated cisplatin into long-circulating and pH-sensitive liposomes on IEC-6 cells during wound healing in the presence of host-microbiota

OBJECTIVES

To circumvent cisplatin (CDDP) toxic effects and improve the antitumoural effect, our research group developed long-circulating and pH-sensitive liposomes containing CDDP (SpHL-CDDP). This study aimed to evaluate whether SpHL-CDDP is associated with intestinal protection under in-vitro conditions in the presence of host-microbiota, compared with free CDDP.

METHODS

The cytotoxicity of CDDP and SpHL-CDDP were evaluated by colorimetric MTT and sulforhodamine B (SRB) assays. Epithelial proliferation was assessed by using an in-vitro wounding model in the presence of host-microbiota with intestinal epithelial cell line 6 (IEC-6) monolayers. Cytokines were determined by ELISA.

KEY FINDINGS

Reduced cytotoxicity of SpHL-CDDP in IEC-6 cells (minimum of 1.3-fold according to the IC50 values) was observed when compared with CDDP. The presence of microbiota or CDDP reduced the wound healing. The association of microbiota and SpHL-CDDP improved the wound healing and cell number in IEC-6 cells when compared with control. These beneficial results can be associated with increased IL-6 and IL-10 levels induced by SpHL-CDDP which were affected by the presence of microbiota.

CONCLUSIONS

These results indicate that the presence of microbiota associated with SpHL-CDDP provided less intestinal cellular damages compared with CDDP and constitutes a promising candidate for clinical use.

Potential Successes and Challenges of Targeted Cancer Therapies

The concept and realization of targeted anticancer therapy (TAT) have existed for at least two decades and continue to expand rapidly. It has become clear that there is no "magic bullet" to cure cancer and that even TATs are unlikely to be successful as single agents, necessitating combination with chemotherapy, radiotherapy, or even other targeting agents. The other promise that has not been fulfilled by TAT is that of reduced toxicity. It was thought that by targeting receptors on or within cells, rather than particular phases of the cell cycle, TATs would not be toxic. However, it turns out that the targets also exist on or within normal cells and that there is even cross-reactivity between receptors on nontarget tissues. All of this results in toxicity, the mechanism of which are the same as the mechanism of action of the drugs, making toxicity reduction or prevention very difficult. This leads to new toxicities with new targeted treatments. Nevertheless, all of the above should not detract from the obvious successes of targeted agents, which have turned several acutely fatal cancers into chronic diseases and rendered some hitherto untreatable cancers into treatable diseases.

Individual or combination treatments with lapatinib and paclitaxel cause potential bone loss and bone marrow adiposity in rats

Cancer treatments with cytotoxic drugs have been shown to cause bone loss. However, effects on bone are less clear for ErbB-targeting tyrosine kinase inhibitors or their combination use with cytotoxic drugs. This study examined the effects of individual or combination treatments with breast cancer drugs lapatinib (a dual ErbB1/ErbB2 inhibitor) and paclitaxel (a microtubule-stabilizing cytotoxic agent) on bone and bone marrow of rats. Wistar rats received lapatinib (240 mg/kg) daily, paclitaxel (12 mg/kg) weekly, or their combination for 4 weeks, and effects on bone/bone marrow were examined at the end of week 4. Microcomputed tomographical structural analyses showed a reduction in trabecular bone volume in tibia following the lapatinib, paclitaxel or their combination treatments ( P < 0.05). Histomorphometry analyses revealed marked increases in bone marrow adipocyte contents in all treatment groups. Reverse transcription polymerase chain reaction gene expression studies with bone samples and cell culture studies with isolated bone marrow stromal cells showed that the all treatment groups displayed significantly reduced levels of osterix expression and osteogenic differentiation potential but increased expression levels of adipogenesis transcription factor peroxisome proliferator-activated receptor γ. In addition, these treatments suppressed the expression of Wnt10b and/or increased expression of Wnt antagonists (secreted frizzled-related protein 1, Dickkopf-related protein 1 and/or sclerostin). Furthermore, all treatment groups showed increased numbers of bone-resorbing osteoclasts on trabecular bone surfaces, although only the lapatinib group displayed increased levels of osteoclastogenic signal (receptor activator of nuclear factor κΒ ligand/osteoclastogenesis inhibitor osteoprotegrin expression ratio) in the bones. Thus, inhibiting ErbB1 and ErbB2 by lapatinib or blocking cell division by paclitaxel or their combination causes significant trabecular bone loss and bone marrow adiposity involving a switch in osteogenesis/adipogenesis potential, altered expression of some major molecules of the Wnt/β-catenin signalling pathway, and increased recruitment of bone-resorbing osteoclasts.

Matrix metalloproteinase expression is altered in the small and large intestine following fractionated radiation in vivo

PURPOSE

Radiotherapy-induced gut toxicity (RIGT) is associated with significant diarrhoea, pain and rectal bleeding. Matrix metalloproteinases (MMPs) have been reported to be involved in chemotherapy-induced gut toxicity and RIGT following single-dose irradiation in vivo. We therefore proposed MMPs would be involved in the pathobiology of RIGT following fractionated irradiation.

METHODS

Dark Agouti rats were treated with fractionated radiation (3 × 2.5 Gy/week for 6 weeks). Rats were killed at 3, 6 and 15 weeks to represent acute and chronic toxicities. Sections of jejunum and colon were immunostained for MMP-1, MMP-2, MMP-9 and MMP-14. Relative mRNA expression in jejunum and colon was quantified by RT-PCR for MMP-1, MMP-2, MMP-9 and MMP-14. Western blotting was also conducted on jejunum and colon tissue collected at week 6 to determine protein levels of pro- and active MMP-2.

RESULTS

MMP-2 total protein levels, determined by western blotting, significantly increased in both the jejunum (p = 0.0359) and the colon (p = 0.0134) 6 weeks into the fractionated radiation schedule. MMP-1, MMP-2, and MMP-14 mRNA expression significantly increased in the jejunum. MMP-2 mRNA expression was also significantly increased in the colon. Immunostaining of MMP-2 was observed to be increased in both crypt enterocytes and the lamina propria.

CONCLUSIONS

MMP-2 plays a role in the pathobiology of gastrointestinal toxicities following fractionated irradiation. Whilst MMP-1 and MMP-14 mRNA expression was increased, this occurred only in the jejunum, suggesting MMPs are differentially involved in RIGT depending on the intestinal region. Further studies are needed to elucidate the role these mediators play in the development and potentiation of RIGT.

Fractionated abdominal irradiation induces intestinal microvascular changes in an in vivo model of radiotherapy-induced gut toxicity

PURPOSE

Radiotherapy-induced gut toxicity (RIGT) is associated with diarrhoea, pain and rectal bleeding and can occur as an acute or chronic toxicity. The microvasculature has been shown to be altered in the development of RIGT; however, the features are not yet characterized. We hypothesized that apoptosis of microvascular cells would occur early in the gastrointestinal tract following fractionated irradiation, followed by late microvascular changes, including sclerosis and telangiectasis.

METHODS

Female Dark Agouti rats were treated with a 6-week fractionated radiation schedule of 3 × 2.5 Gy doses per week localized to the abdomen. At 3, 6 and 15 weeks, the intestines were assessed for markers of acute and chronic injury including morphological changes, collagen deposition, apoptosis and proliferation.

RESULTS

Apoptosis of microvascular cells significantly increased at 6 and 15 weeks in the jejunum (p = 0.0026 and p = 0.0062, respectively) and at 6 and 15 weeks in the colon (p < 0.0001 and p = 0.0005, respectively) in rats receiving fractionated radiation to the abdomen. Histopathological changes of the colon microvasculature were also seen from week 3, including thickening of the lamina propria and dilated, thickened, telangiectatic vessels.

CONCLUSIONS

Findings of this study provide evidence of regional and timing-specific changes in the intestinal microvasculature in response to fractionated radiotherapy which may play a role in development of both acute and chronic RIGT.

Dacomitinib-induced diarrhoea is associated with altered gastrointestinal permeability and disruption in ileal histology in rats

Dacomitinib-an irreversible pan-ErbB tyrosine kinase inhibitor (TKI)-causes diarrhoea in 75% of patients. Dacomitinib-induced diarrhoea has not previously been investigated and the mechanisms remain poorly understood. The present study aimed to develop an in-vitro and in-vivo model of dacomitinib-induced diarrhoea to investigate underlying mechanisms. T84 cells were treated with 1-4 μM dacomitinib and resistance and viability were measured using transepithelial electrical resistance (TEER) and XTT assays. Rats were treated with 7.5 mg/kg dacomitinib daily via oral gavage for 7 or 21 days (n = 6/group). Weights, and diarrhoea incidence were recorded daily. Rats were administered FITC-dextran 2 hr before cull, and serum levels of FITC-dextran were measured and serum biochemistry analysis was conducted. Detailed histopathological analysis was conducted throughout the gastrointestinal tract. Gastrointestinal expression of ErbB1, ErbB2 and ErbB4 was analysed using RT-PCR. The ileum and the colon were analysed using multiplex for expression of various cytokines. T84 cells treated with dacomitinib showed no alteration in TEER or cell viability. Rats treated with dacomitinib developed severe diarrhoea, and had significantly lower weight gain. Further, dacomitinib treatment led to severe histopathological injury localised to the ileum. This damage coincided with increased levels of MCP1 in the ileum, and preferential expression of ErbB1 in this region compared to all other regions. This study showed dacomitinib induces severe ileal damage accompanied by increased MCP1 expression, and gastrointestinal permeability in rats. The histological changes were most pronounced in the ileum, which was also the region with the highest relative expression of ErbB1.

Combination chemotherapy with cyclophosphamide, epirubicin and 5-fluorouracil causes trabecular bone loss, bone marrow cell depletion and marrow adiposity in female rats

The introduction of anthracyclines to adjuvant chemotherapy has increased survival rates among breast cancer patients. Cyclophosphamide, epirubicin and 5-fluorouracil (CEF) combination therapy is now one of the preferred regimens for treating node-positive breast cancer due to better survival with less toxicity involved. Despite the increasing use of CEF, its potential in causing adverse skeletal effects remains unclear. Using a mature female rat model mimicking the clinical setting, this study examined the effects of CEF treatment on bone and bone marrow in long bones. Following six cycles of CEF treatment (weekly intravenous injections of cyclophosphamide at 10 mg/kg, epirubicin at 2.5 mg/kg and 5-flurouracil at 10 mg/kg), a significant reduction in trabecular bone volume was observed at the metaphysis, which was associated with a reduced serum level of bone formation marker alkaline phosphatase (ALP), increased trends of osteoclast density and osteoclast area at the metaphysis, as well as an increased size of osteoclasts being formed from the bone marrow cells ex vivo. Moreover, a severe reduction of bone marrow cellularity was observed following CEF treatment, which was accompanied by an increase in marrow adipose tissue volume. This increase in marrow adiposity was associated with an expansion in adipocyte size but not in marrow adipocyte density. Overall, this study indicates that six cycles of CEF chemotherapy may induce some bone loss and severe bone marrow damage. Mechanisms for CEF-induced bone/bone marrow pathologies and potential preventive strategies warrant further investigation.

Serum-derived bovine immunoglobulin in the alleviation of irinotecan-induced mucositis

166

Background: Gastrointestinal (GI) mucositis is associated with diarrhoea and intestinal barrier dysfunction caused by apoptosis, immune dysfunction, and microbiome alterations. Serum-derived bovine immunoglobulin (SBI) has been shown to ameliorate inflammation in colitis models, has been shown to improve HIV-induced enteropathy and nutritional status, and is being investigated in post-surgical recovery in oncology patients. We investigated in a rat model whether SBI was effective in alleviating symptoms of GI mucositis. Methods: Animals were gavaged with 250 or 500mg/kg of SBI twice daily, before intraperitoneal administration of 200mg/kg irinotecan on day 4, and for 6 days post-irinotecan. Animals were monitored for bodyweight and diarrhoea. Tissues were collected at necropsy 6, 48, 96 and 144 hours post-irinotecan. H&E-stained colon and jejunum were analysed for histological damage. Results: The overall incidence, severity and duration of diarrhoea, and clinical symptoms of mucositis, were decreased in irinotecan-treated animals that had received SBI. Animals receiving 500 mg SBI/kg also tended to lose less bodyweight than animals treated only with irinotecan (P>0.10). Animals receiving SBI had less pronounced irinotecan-induced changes in neutrophil levels (P≈0.02), and lower tissue damage scores than those receiving irinotecan alone (P<0.0001). Conclusions: Twice-daily oral gavage of SBI was well-tolerated, and reduced the incidence, severity and duration of irinotecan-induced mucositis. SBI was associated with less pronounced changes in inflammatory cell levels and intestinal tissue damage. Ongoing experiments aim to explore the mechanisms of SBI-associated gastrointestinal protection.

Impact of CINV in earlier cycles on CINV and chemotherapy regimen modification in subsequent cycles in Asia Pacific clinical practice

PURPOSE

We sought to describe the impact of chemotherapy-induced nausea and vomiting (CINV) in prior cycles on CINV and chemotherapy regimen modification in subsequent cycles.

METHODS

Eligible patients in this multinational prospective observational study were adults (≥18 years old) receiving their first single-day highly or moderately emetogenic chemotherapy (HEC or MEC). Multivariate logistic regression was used to assess the impact of CINV in prior cycles on CINV in subsequent cycles. Other independent variables included in the model were the cycle number, age, sex, and emetogenicity of regimen.

RESULTS

There were 598 evaluable patients in cycle 2 and 533 in cycle 3, half receiving HEC and half MEC. Patients who experienced complete response (no emesis or rescue antiemetics) in earlier cycles, relative to those with no complete response, had an adjusted odds ratio (OR) of 5.9 (95% confidence interval (CI), 4.14-8.50) for experiencing complete response in subsequent cycles. Prior CINV was a significant and consistent predictor of subsequent CINV for all CINV endpoints: for emesis, OR 12.7 (95% CI, 8.47-18.9), for clinically significant nausea, OR 7.9 (95% CI, 5.66-10.9), and for clinically significant nausea and/or vomiting, OR 7.2 (5.17-10.1). Modifications to chemotherapy were recorded for 26-29% of patients in cycles 2 and 3, with CINV as the major reason for the modification for 5-9% of these patients.

CONCLUSIONS

CINV in prior cycles was a strong and consistent predictor of CINV in subsequent cycles, while the incidence of chemotherapy regimen modification due to CINV was low in individual cycles.

Baseline patient characteristics, incidence of CINV, and physician perception of CINV incidence following moderately and highly emetogenic chemotherapy in Asia Pacific countries

PURPOSE

This paper describes the incidence of chemotherapy-induced nausea and vomiting (CINV) after highly or moderately emetogenic chemotherapy (HEC or MEC) for cancer in six Asia Pacific countries.

METHODS

Sequential adult patients naïve to chemotherapy and scheduled to receive at least two cycles of single-day HEC or MEC were enrolled in this prospective observational study. Patients completed the Multinational Association of Supportive Care in Cancer (MASCC) Antiemesis Tool on post-chemotherapy days 2 and 6 to record acute-phase (first 24 h) and delayed-phase (days 2-5) CINV.

RESULTS

There were 648 evaluable patients (318 HEC, 330 MEC) from Australia (n = 74), China (153), India (88), Singapore (57), South Korea (151), and Taiwan (125). Mean (SD) patient age was 56 (12) and 58% of patients were women; the most common primary cancers were breast (27%), lung (22%), and colon (20%). Overall in cycle 1, complete response (no emesis or rescue antiemetics) was recorded by 69% (95% confidence interval (CI), 66-73) of all evaluable patients, with country percentages ranging from 55 to 78% (p < 0.001). After HEC, no emesis was recorded by 75% and no nausea by 38% of patients. After MEC, 80% had no emesis and 50% no nausea. Acute-phase CINV was better controlled than delayed-phase CINV, and the control of nausea was the lowest of any CINV measure in all phases. In a CINV perception survey, physicians tended to overestimate emesis rate and underestimate nausea rate.

CONCLUSIONS

CINV remains a substantial problem, and country-specific information about CINV can be useful in developing strategies to improve outcomes for patients undergoing chemotherapy.

Antiemetic therapy in Asia Pacific countries for patients receiving moderately and highly emetogenic chemotherapy--a descriptive analysis of practice patterns, antiemetic quality of care, and use of antiemetic guidelines

PURPOSE

This paper reports prescribing patterns for prophylaxis of chemotherapy-induced nausea and vomiting (CINV) after highly or moderately emetogenic chemotherapy (HEC or MEC) for cancer in six Asia Pacific countries.

METHODS

In a prospective noninterventional study, 31 sites in Australia, China, India, Singapore, South Korea, and Taiwan recorded details of CINV prophylaxis for the acute phase (first 24 h) and delayed phase (days 2-5) after single-day HEC or MEC for adult patients. Additional information on CINV prophylactic medications was collected from 6-day patient diaries. Primary antiemetic therapies were defined as corticosteroids, the 5-hydroxytryptamine-3 receptor antagonists (5HT3-RAs), and neurokinin-1 receptor antagonists (NK1-RAs).

RESULTS

Evaluable patients in cycle 1 numbered 648 (318 [49%] HEC and 330 [51%] MEC) of mean (SD) age of 56 (12) years, including 58% women. For the acute phase after HEC, overall (and country range), 96% (91-100%) of patients received a 5HT3-RA, 87% (70-100%) a corticosteroid, and 43% (0-91%) an NK1-RA. CINV prophylaxis for the HEC delayed phase was more variable: including 22% (7-65%) 5HT3-RA, 52% (12-93%) corticosteroid, and 46% (0-88%) NK1-RA. For the MEC acute phase, 97% (87-100%) of patients received 5HT3-RA and 86% (73-97%) a corticosteroid. For the MEC delayed phase, 201 patients (61%) received a primary antiemetic, including 5HT3-RA (41%), corticosteroid (37%), and/or NK1-RA (4%).

CONCLUSIONS

The 5HT3-RAs were prescribed consistently in all countries, while prescribing of other antiemetic therapies was variable, and corticosteroids were under-prescribed for CINV prophylaxis, particularly in the delayed phase.

Rationale and design of the Pan Australasian chemotherapy-induced emesis burden of illness study

BACKGROUND

Preventing and managing chemotherapy-induced nausea and vomiting (CINV) remain important goals. The objective of the Pan Australasian chemotherapy-induced emesis burden of illness (PrACTICE) study was to describe the incidence of CINV after highly or moderately emetogenic chemotherapy (HEC or MEC) for cancer in current clinical practice in Australia and five Asian countries (China, India, Singapore, South Korea, and Taiwan).

STUDY DESIGN

This prospective, observational study of CINV was conducted at 31 sites in these six countries from August 2011 through September 2012 and enrolled male and female adult patients (≥18 years of age) naïve to HEC and MEC who were scheduled to receive at least two cycles of single-day chemotherapy. The primary effectiveness endpoint was complete response, defined as no vomiting or use of rescue therapy, during chemotherapy cycle 1 in the overall phase (0-120 h), acute phase (0-24 h), and delayed phase (>24-120 h). Study outcomes were analyzed descriptively. Primary outcomes, CINV incidence, and treatment patterns (chemotherapy, CINV prophylaxis, rescue medication prescription, and rescue medication use) were assessed by phase (overall, acute, delayed), by cycle (as appropriate), within and across countries, and by level of chemotherapy emetogenicity (HEC vs. MEC). The impact of CINV in cycle 1 on CINV in cycle 2 was analyzed for all patients with evaluable data for cycle 2. No site-specific analyses were performed. The remainder of this special series of papers reports on the results of this study.

Determining the mechanisms of lapatinib-induced diarrhoea using a rat model

INTRODUCTION

Diarrhoea caused by treatment with receptor tyrosine kinase inhibitors (TKI) targeting Epidermal Growth Factor Receptors (EGFR) is an important clinical toxicity in oncology that remains poorly understood. This study aimed to identify histological and molecular changes within the intestine following lapatinib to elucidate mechanisms of diarrhoea related to treatment with this dual EGFR TKI.

METHODS AND MATERIALS

Male albino Wistar rats were orally gavaged lapatinib at 100, 240 or 500 mg/kg daily for 4 weeks and assessed for indicators of gastrointestinal injury at the end of each week. Lapatinib in combination with weekly paclitaxel (9 mg/kg i.p.) was also assessed for cumulative injury. At each time point, blood was collected for biochemical analysis. Sections or jejunum and colon were also collected and underwent immunohistochemistry and RT-PCR to detect markers of EGFR pathway signalling, and morphometric analysis to assess changes in mucosal architecture.

RESULTS

Lapatinib (with or without paclitaxel co-treatment) caused dose-dependent changes in crypt length, mitotic rate and goblet cell morphology. Jejunal crypt expression of EGFR and ErbB2 were decreased, whilst no changes in Erk1/2 were observed. Markers of apoptosis (caspase-3) and proliferation (Ki-67) were only significantly altered in rats treated with both lapatinib and paclitaxel.

CONCLUSIONS

In our novel rat model of lapatinib-induced diarrhoea we have shown that changes in small intestinal morphometry and expression of EGFR are associated with diarrhoea. Further research is required to test intervention agents for the prevention of diarrhoea.

The prevention of oral mucositis in patients with blood cancers: current concepts and emerging landscapes

BACKGROUND

The prevention of oral mucositis (OM) in the management of hematological malignancies continues to represent an unmet clinical need. Addressing this issue has major clinical implications as OM can also greatly impair patient's quality of life.

OBJECTIVES

To review currently available measures and investigational agents to prevent OM in hematological patients.

METHODS

we searched for OM and related issues using Medline; the abstract books of the most important hematological and oncological meetings were also reviewed.

RESULTS/CONCLUSIONS

Many agents targeting different mechanisms of mucosal damage have been applied in order to prevent OM; most of them have failed or its efficacy has not been fully demonstrated. Palifermin is the first pharmaceutical/biological agent approved for the prevention of OM; its use is currently restricted to patients who have received radiotherapy-containing conditioning regimens prior to autologous hematopoietic stem cell transplantation. No clear benefit by this agent has been demonstrated outside of this specific setting and its application should be limited to clinical trials. Other interventions, such as other growth factors and non mitogenic measures are under investigation or in development and their application in the hematological setting is expected in the short term.

Biomarkers of chemotherapy-induced diarrhoea: a clinical study of intestinal microbiome alterations, inflammation and circulating matrix metalloproteinases

PURPOSE

A common side effect of chemotherapy treatment is diarrhoea. Unfortunately, the underlying mechanisms of chemotherapy-induced diarrhoea (CD) are poorly understood. We aimed to determine if faecal microbes of CD patients were displaced, if faecal calprotectin increased during CD and if there were alterations in circulating matrix metalloproteinases, nuclear factor kappa B (NF-κB), IL-1β and TNF.

PATIENTS AND METHODS

Twenty-six cancer patients receiving chemotherapy were enrolled and requested to provide stool samples and blood samples at various times during their chemotherapy cycle. Stool samples were analysed using conventional culture techniques and qRT-PCR. ELISA kits determined faecal calprotectin levels, levels of circulating matrix metalloproteinases and circulating NF-κB, IL-1β and TNF.

RESULTS

The majority of patients with CD showed decreases in Lactobacillus spp., Bifidobacterium spp., Bacteroides spp. and Enterococcus spp. Increases were observed in Escherichia coli and Staphylococcus spp. Methanogenic archaea were also quantified, with all patients except one showing a decrease. Faecal calprotectin levels were increased in 81.25 % of patients with CD. Circulating MMP-3 and MMP-9 significantly increased following chemotherapy. Circulating levels of NF-κB, IL-1β and TNF were increased following chemotherapy, although this did not reach significance.

CONCLUSIONS

We demonstrated that CD is associated with marked changes in intestinal microflora, methanogenic archaea, matrix metalloproteinase and serum levels of NF-κB, IL-1β and TNF. These changes may result in diminished bacterial functions within the gut, altering gut function and initiating intestinal damage, resulting in the onset of diarrhoea. More importantly, these changes may provide clinicians with a possible new target for biomarkers of toxicity.

Predictors of acute adverse events from rapid rituximab infusion

PURPOSE

This study aimed to identify the predictors of acute adverse events resulting from rapid rituximab infusion over 90 min.

METHOD

It was a retrospective cohort study using medical record review based on a convenience sampling from 2007 till May 2011 in both in-patient and ambulatory setting in Royal Adelaide Hospital.

RESULTS

There were a total of 294 patients who received 376 courses and 1,571 cycles of rapid rituximab infusion. Forty-three (14.6 %) patients experienced acute adverse events of hypotension being the most commonly occurring events followed by patients feeling hot and face-flushed. There were 11 predictors analysed, namely age, gender, diagnosis, stage of disease, presence of cardiac or lung morbidities, type of treatment, number of course and cycles, total white blood cells count, lymphocyte counts and lactate dehydrogenase using log generalised estimating equation for univariate and multivariate analysis. The findings successfully demonstrated that high lymphocyte counts were the independent predictor of acute adverse event from rapid rituximab infusion (p = 0.0009). Patient with high lymphocyte counts were 6.9382 times the odd to experience an adverse event as compared to those with normal lymphocyte counts.

CONCLUSION

There are no specific patient characteristics to preclude prescribing rapid rituximab infusion following a 90-min regimen for non-Hodgkin lymphoma except a potential for adverse events to occur when patients have abnormally high lymphocyte counts.

Systematic review of agents for the management of gastrointestinal mucositis in cancer patients

PURPOSE

The aim of this study was to review the available literature and define clinical practice guidelines for the use of agents for the prevention and treatment of gastrointestinal mucositis.

METHODS

A systematic review was conducted by the Mucositis Study Group of the Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO). The body of evidence for each intervention, in each cancer treatment setting, was assigned an evidence level. Based on the evidence level, one of the following three guideline determinations was possible: recommendation, suggestion, and no guideline possible.

RESULTS

A total of 251 clinical studies across 29 interventions were examined. Panel members were able to make one new evidence-based negative recommendation; two new evidence-based suggestions, and one evidence-based change from previous guidelines. Firstly, the panel recommends against the use of misoprostol suppositories for the prevention of acute radiation-induced proctitis. Secondly, the panel suggests probiotic treatment containing Lactobacillus spp., may be beneficial for prevention of chemotherapy and radiotherapy-induced diarrhea in patients with malignancies of the pelvic region. Thirdly, the panel suggests the use of hyperbaric oxygen as an effective means in treating radiation-induced proctitis. Finally, new evidence has emerged which is in conflict with our previous guideline surrounding the use of systemic glutamine, meaning that the panel is unable to form a guideline. No guideline was possible for any other agent, due to inadequate and/or conflicting evidence.

CONCLUSIONS

This updated review of the literature has allowed new recommendations and suggestions for clinical practice to be reached. This highlights the importance of regular updates.

Development of a rat model of oral small molecule receptor tyrosine kinase inhibitor-induced diarrhea

Orally administered small molecule receptor tyrosine kinase inhibitors (RTKIs) are increasingly common treatments for cancer, both alone and in combination with chemotherapy. However, their side effect profiles and the underlying mechanisms of such are not yet fully elucidated. Management of their most common dose limiting side effect, diarrhea, has been hampered by a lack of suitable animal models. We aimed to develop a clinically relevant rat model of RTKI-induced diarrhea that could be utilized for investigating supportive care interventions and pharmacokinetics. Albino Wistar rats were treated daily for 4 weeks with various concentrations of lapatinib to determine the optimal dose for development of diarrhea. This was then followed by an experiment with addition of paclitaxel once weekly for 4 weeks to observe effects of combination drug treatment on diarrhea. Data regarding animal tolerance to the treatment, organ weights, circulating lapatinib concentration and histopathology were collected weekly. Lapatinib caused diarrhea in rats that was dose-dependent. Diarrhea occurred without causing significant intestinal histopathology. Follow up experiments are currently underway to determine the exact pathogenesis and mechanisms of lapatinib-induced diarrhea and potential protective strategies.

Kinetics and regional specificity of irinotecan-induced gene expression in the gastrointestinal tract

Gastrointestinal toxicity remains a significant and dose-limiting complication of cancer treatment. While the pathophysiology is becoming clearer, considerable gaps in the knowledge remain surrounding the timing and site-specific gene changes which occur in response to insult. As such, this study aimed to assess gene expression profiles in a number of regions along the gastrointestinal tract following treatment with the chemotherapy agent, irinotecan, and correlate them with markers of cell death and tissue damage. Data analysis of microarray results found that genes involved in apoptosis, mitogen activated kinase (MAPK) signalling and inflammation were upregulated within 6h, while genes involved in cell proliferation, wound healing and blood vessel formation were upregulated at later time points up to 72 h. Cell death was significantly increased at 6 and 24h, and the stomach showed the lowest severity of overt tissue damage. Real time PCR of MAPK signalling pathway genes found that the jejunum and colon had significantly increased expression in a number of genes at 72 h, where as the stomach was unchanged. These results indicate that overall severity of tissue damage may be determined by precisely timed target gene responses specific to each region. Therapeutic targeting of key gene responses at the appropriate time point may prove to be effective for prevention of chemotherapy-induced gastrointestinal damage.

Irinotecan-induced mucositis manifesting as diarrhoea corresponds with an amended intestinal flora and mucin profile

Chemotherapy-induced diarrhoea is a major oncological problem, caused by the cytotoxic effects of cancer chemotherapy. Irinotecan is linked with severe mucositis and diarrhoea, the mechanisms of which remain poorly understood. Bacterial beta-glucuronidase is thought to be involved in the metabolism of irinotecan, implicating the intestinal flora. Intestinal mucins may also be implicated in the development of chemotherapy-induced diarrhoea. Rats were treated with 200 mg/kg of irinotecan and killed at 96, 120 and 144 h. The rats were monitored for diarrhoea. Pathology and immunohistochemical staining was performed. The samples were cultured and faecal DNA was analysed using real-time polymerase chain reaction. Severe diarrhoea was observed from 72 to 96 h. A decrease in body mass was also observed after treatment. Significant changes in goblet cell numbers (both complete and cavitated cells) were observed in the small and large intestines. Changes in MUC gene expression were observed in the small intestine only. Modifications were observed to the intestinal flora profile, especially Escherichia coli, and an increase in the expression of beta-glucuronidase was detected. In conclusion, irinotecan-induced diarrhoea may be caused by an increase in some beta-glucuronidase-producing bacteria, especially E. coli, exacerbating the toxicity of active metabolites. Accelerated mucous secretion and mucin release may also contribute to the delayed onset of diarrhoea.

Relationship between dose of methotrexate, apoptosis, p53/p21 expression and intestinal crypt proliferation in the rat

Previous studies have shown that apoptosis is induced by cytotoxic chemotherapy and precedes hypoproliferation of intestinal crypt cells. However, the relationship between the degree of intestinal apoptosis and crypt cell hypoproliferation may not be directly related. The purpose of this study was to investigate the relationship between apoptosis and hypoproliferation with increasing doses of chemotherapy. Eleven groups of breast cancer-bearing DA rats were treated with two doses of methotrexate (MTX) i. m. at varying concentrations (0.5, 1.5, 2.5 and 5.0 mg/kg) or saline (control). Animals were killed at 6 or 24 h following treatment. The small and large intestines were examined for apoptosis, villous area (small intestine), crypt length and mitotic count per crypt. Immunohistochemical expression of p53 and p21(waf1/cip1) (p21) were examined quantitatively. Data were analysed using Peritz' F-test. Low dose MTX (0.5 mg/kg) did not change p53 expression at 6 h but induced a 15-fold increase in apoptosis in the crypts of the small intestine. This was associated with only a minor reduction in crypt cell proliferation. Higher doses of MTX increased p53 expression and caused a lower (7-fold) but more prolonged peak of apoptosis that was accompanied by reduced villous area, shortened crypts and a more profound reduction in crypt cell proliferation. Unlike the small intestine, apoptosis in the colon was 10-fold lower, proportional to the dose of MTX and did not induce overt damage. Expression of p21 did not change with any dose at either timepoint. We conclude that apoptosis is not always associated with crypt cell hypoproliferation and that the small intestine can recover after low dose MTX despite a heightened peak of apoptosis of crypt cells.

Gastrointestinal microflora and mucins may play a critical role in the development of 5-Fluorouracil-induced gastrointestinal mucositis

5-Fluorouracil (5-FU) is a commonly used chemotherapy agent in clinical oncology practice. Two of its major side effects are mucositis and diarrhoea. The structure of mucins offers mucosal protection, and allows maintenance of intestinal flora by providing attachment sites and preventing bacterial overgrowth and/or penetration. The aim of this study was to investigate changes in mucin secretion and microflora following treatment with 5-FU. Female DA rats were given a single 150 mg/ kg i.p. dose of 5-FU. Rats were killed at various time points after treatment. Control rats received no treatment. Jejunum, colon and faecal samples were collected. Standard microbiological culture techniques were used to identify bacteria, and real-time PCR was used to quantify bacteria in faecal samples. Goblet cells and cavitated goblet cells (having undergone mucus exocytosis) were also counted. Statistical analysis was carried out using Kruskal-Wallis test, a non-parametric method of testing equality of group medians. Following treatment with 5-FU, we showed decreases in Clostridium spp., Lactobacillus spp. and Streptococcus spp., and an increase in Escherichia spp. in the jejunum. In the colon, 5-FU caused decreases in Enterococcus spp., Lactobacillus spp. and Streptococcus spp. Real-time PCR of faecal samples showed decreasing trends in Lactobacillus spp. and Bacteroides spp., and an increasing trend in E. coli. Significant increases (P < 0.05) were seen in Clostridium spp. and Staphylococcus spp. at 24 h. Goblet cell numbers decreased significantly in the jejunum from 24-72 h, with a significant increase in the percentage of cavitated goblet cells. In conclusion, 5-FU treatment causes significant changes in intestinal flora and mucin secretion in rats. These changes could result in systemic effects and, in particular, may contribute to the development of chemotherapy-induced mucositis.

Velafermin improves gastrointestinal mucositis following irinotecan treatment in tumor-bearing DA rats

Mucositis is a common, costly and unpleasant side effect of cancer chemotherapy and radiotherapy. Velafermin (FGF-20) has shown the potential to reduce these side effects. Irinotecan is a chemotherapeutic agent which is commonly used in solid tumors, and causes GI mucositis manifested by severe diarrhea. Therefore the primary aim of this study was to investigate whether velafermin reduces the GI mucositis induced by irinotecan. The secondary aim was to test varying schedules of administration of velafermin. Groups of tumor-bearing DA rats (6 per group) were treated with varying doses (4, 8 or 16 mg/kg) of velafermin intraperitoneally either prior to, prior to and during, or after chemotherapy treatment. Rats received a single dose of 200 mg/kg irinotecan intraperitoneally. Rats were monitored closely for the incidence and severity of diarrhea and mortality before being killed 192 h following treatment. Mortality, diarrhea and histopathology were assessed throughout the gastrointestinal tract. Severe or moderate diarrhea occurred in approximately 40% of rats treated with irinotecan alone. This was associated with a 50% mortality rate 96 h following chemotherapy. Velafermin administered at 16 mg/kg prior to irinotecan improved gastrointestinal mucositis as measured by reduced diarrhea and mortality following irinotecan chemotherapy in the DA rat. Rats that received velafermin prior to, or prior to and during irinotecan treatment did develop severe or moderate diarrhea, however it occurred later, in fewer rats and was not associated with mortality. Other dosing regimens were not as effective. This has important implications for the use of velafermin in GI mucositis in humans, and should be further studied.

Gene expression analysis of multiple gastrointestinal regions reveals activation of common cell regulatory pathways following cytotoxic chemotherapy

Gastrointestinal mucositis involves many changes at the gene level, affecting epithelial/subepithelial interactions and leading to overt damage. The regional specificity and time course of these changes, and how they relate to subsequent mucositis development however remain unknown. The aim of this study was to determine the early time course of gene expression changes along the gastrointestinal tract of the DA rat following chemotherapy. Female DA rats were treated with a single dose of 200 mg/kg irinotecan to induce mucositis, and were killed at short intervals following treatment. Small sections of stomach, jejunum and colon were harvested for analysis of genetic profiles. RNA was hybridised to high density Affymetrix oligonucleotide microarrays. Data analysis was carried out with software package, TimeCourse, freely available through Bioconductor. As early as 1 hr following chemotherapy, expression of hundreds of genes was altered, including those for transcription factors, stress response proteins and protein turnover. These genes are involved in cell proliferation, differentiation and apoptosis along with other cellular processes. At early time points, there was a significant response involving the mitogen-activated protein kinase pathway, cell cycle regulation and cytokine receptor signalling. At later time points, changes to the complement cascade became prominent. We have shown that changes in gene expression following chemotherapy occur by 1 hr, and persist for at least 72 hr after treatment. Many of these changes are highly likely to be specifically related to the subsequent development of gastrointestinal mucositis.

A novel animal model to investigate fractionated radiotherapy-induced alimentary mucositis: the role of apoptosis, p53, nuclear factor-kappaB, COX-1, and COX-2

Radiation-induced mucositis is a common and serious side effect of radiotherapy. Molecular mechanisms of mucosal injury, however, are still poorly understood and extremely difficult to study in humans. A novel Dark Agouti rat model using fractionated radiotherapy to induce mucositis has been developed to investigate the occurrence of alimentary mucosal injury. Twenty-four Dark Agouti rats were randomly assigned to receive either fractionated radiotherapy or no radiotherapy. The irradiated rats received a fractionated course of abdominal radiotherapy at 45 Gy/18 fractions/6 weeks treating thrice weekly (i.e., at a radiation dose of 2.5 Gy per fraction). After each week of radiation, a group of irradiated rats was killed. Histomorphology and mucin distribution in the alimentary tract was investigated. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay was used to examine apoptosis in the colon and jejunum, and intestinal morphometry was used to assess villus length, crypt length, and mitotic crypt count. Immunohistochemistry of p53, nuclear factor-kappaB, cyclooxygenase (COX)-1, and COX-2 was also done. The fractionated radiotherapy course induced alimentary mucositis from week 1, with more severe injury seen in the small intestine. The hallmark appearance of apoptosis was present in the crypts of the small and large intestine. In the jejunum and colon, goblet cell disorganization and degeneration was obvious and crypt mitotic counts were severely depleted throughout the treatment. Expression of p53, nuclear factor-kappaB, COX-1, and COX-2 was increased in the irradiated intestinal sections. Fractionated radiation-induced alimentary mucositis has been effectively documented in the Dark Agouti rat for the first time. Further studies investigating the molecular mechanisms underlying radiation-induced mucositis are planned to ultimately achieve anti-mucotoxic-targeted therapies.

Establishment of a single-dose irinotecan model of gastrointestinal mucositis

BACKGROUND

Irinotecan is a common cytotoxic agent used in advanced colorectal cancers. However, a major clinical problem with this cytotoxic is that it causes gastrointestinal mucositis manifest by severe diarrhoea. To date there is no established single dose of irinotecan in rats to enable determination of changes occurring following administration. Therefore, the primary aim of this study was to determine a single dose of irinotecan that induced reproducible gastrointestinal mucositis in DA rats. The secondary aim was to determine if the presence of tumour altered the development of mucositis.

METHODS

Eighty-eight rats were divided into two groups, 44 received tumours and 44 remained tumour naïve. These were randomized to receive a single dose of irinotecan at 150, 200, 250 or 300 mg/kg. Two control groups of rats received either no treatment or 2 doses of 150 mg/kg irinotecan, shown previously to induce reproducible gastrointestinal mucositis. Rats were monitored closely for incidence and severity of diarrhoea, and mortality, before being killed 48 and 144 h following treatment.

RESULTS

Rats administered 250 and 300 mg/kg of irinotecan all developed diarrhoea, and this was associated with high mortality rates (up to 100%). Necropsies revealed that many of these rats had duodenal perforations and fatty lysis consistent with peritonitis. The lower doses of 150 and 200 mg/kg irinotecan also caused diarrhoea, but were not associated with high mortality rates. Histopathological examination confirmed small and large intestinal damage in all rats that received irinotecan, regardless of dose. Tumour-bearing rats had worse diarrhoea and higher mortality compared to tumour-naïve rats.

CONCLUSIONS

We find that a single dose of 200 mg/kg irinotecan causes reproducible gastrointestinal mucositis as measured by levels of diarrhoea, and small and large intestinal histology. Importantly this dose has a low mortality. The response to irinotecan is more pronounced in tumour-bearing rats.

Characterisation of mucosal changes in the alimentary tract following administration of irinotecan: implications for the pathobiology of mucositis

PURPOSE

The pathobiology of alimentary tract (AT) mucositis is complex and there is limited information about the events which lead to the mucosal damage that occurs during cancer treatment. Various transcription factors and proinflammatory cytokines are thought to play important roles in pathogenesis of mucositis. The aim of this study was to determine the expression of nuclear factor-kappaB (NF-kappaB), tumor necrosis factor (TNF) and interleukins-1beta (IL-1beta) and -6 (IL-6) in the AT following the administration of the chemotherapeutic agent irinotecan.

METHODS

Eighty-one female dark Agouti rats were assigned to either control or experimental groups according to a specific time point. Following administration of irinotecan, rats were monitored for the development of diarrhoea. The rats were killed at times ranging from 30 min to 72 h after administration of irinotecan. Oral mucosa, jejunum and colon were collected and standard immunohistochemical techniques were used to identify NF-kappaB, TNF, IL-1beta and IL-6 within the tissues. Sections were also stained with haematoxylin and eosin for histological examination.

RESULTS

Irinotecan caused mild to moderate diarrhoea in a proportion of the rats that received the drug. Altered histological features of all tissues from rats administered irinotecan were observed which included epithelial atrophy in the oral mucosa, reduction of villus height and crypt length in the jejunum and a reduction in crypt length in the colon. Tissue staining for NF-kappaB, TNF and IL-1beta and IL-6 peaked at between 2 and 12 h in the tissues examined.

CONCLUSIONS

This is the first study to demonstrate histological and immunohistochemical evidence of changes occurring concurrently in different sites of the AT following chemotherapy. The results of the study provide further evidence for the role of NF-kappaB and associated pro-inflammatory cytokines in the pathobiology of AT mucositis. The presence of these factors in tissues from different sites of the AT also suggests that there may be a common pathway along the entire AT causing mucositis following irinotecan administration.

VSL#3 probiotic treatment reduces chemotherapy-induced diarrhea and weight loss

BACKGROUND

One of the most common toxicities of cancer treatment is diarrhea. Probiotics have been shown effective at preventing diarrhea in inflammatory bowel disease and may prove useful in the oncology setting.

AIM

The primary aim of this study was to investigate the probiotic mixture, VSL#3, for amelioration of chemotherapy-induced diarrhea (CID).

METHODS

This experiment was carried out in a clinically relevant model of CID. VSL#3 was administered to female DA rats in one of three schedules. Irinotecan was used to induce mucositis and diarrhea, with rats monitored for seven days to record incidence of weight-loss and diarrhea. At study completion, intestines were collected to investigate histological and proliferative changes, apoptosis levels and mucin composition.

RESULTS

VSL#3 reduced weight loss following irinotecan when administered before and after chemotherapy. Moderate and severe diarrhea was also prevented in these rats. This was associated with a significant increase in crypt proliferation combined with an inhibition of apoptosis in both the small and large intestines. VSL#3 also prevented irinotecan-induced increases in goblet cells within jejunal crypts.

CONCLUSIONS

VSL#3 is effective at preventing severe diarrhea following chemotherapy with irinotecan and therefore has potential to be used clinically by cancer patients.

Chemotherapy-induced mucositis: the role of gastrointestinal microflora and mucins in the luminal environment

Collectively, mucositis refers to the damage caused to the mucous membranes of the body following cytotoxic cancer therapy. Diarrhea is one such manifestation of mucositis and is a common side effect of chemotherapy that remains poorly understood. It affects the entire gastrointestinal tract. The exact number of patients affected by diarrhea as a result of treatment is uncertain, although it is believed that approximately 10% of patients with advanced cancer will be affected. Despite advances in the understanding of oral and small intestinal mucositis over recent years, large intestinal mucositis, including diarrhea, has not been well defined, and the underlying mechanisms of the condition have yet to be established. The majority of the literature concerning diarrhea is based on clinical observations, with little basic research. However, from the research conducted, it is likely that the intestinal microflora play a role in the development of chemotherapy-induced diarrhea. This review will examine in detail what is known about the mechanisms of chemotherapy-induced diarrhea and will explore the potentially important relationship among intestinal microflora, the luminal environment, and the subsequent development of chemotherapy-induced diarrhea.

The role of pro-inflammatory cytokines in cancer treatment-induced alimentary tract mucositis: pathobiology, animal models and cytotoxic drugs

Alimentary tract (AT) mucositis can be a major problem for patients undergoing cancer treatment. It has significant clinical and economic consequences and is a major factor that can compromise the provision of optimal treatment for patients. The pathobiology of AT mucositis is complex and the exact mechanisms that underlie its development still need to be fully elucidated. Current opinion considers that there is a prominent interplay between all of the compartments of the mucosa involving, at a molecular level, the activation of transcription factors, particularly nuclear factor-kappaB, and the subsequent upregulation of pro-inflammatory cytokines and inflammatory mediators. The purpose of this review is to examine the literature relating to what is currently known about the pathobiology of AT mucositis, particularly with respect to the involvement of pro-inflammatory cytokines, as well as currently used animal models and the role of specific cytotoxic chemotherapy agents in the development of AT mucositis.

Role of p53 in irinotecan-induced intestinal cell death and mucosal damage

Irinotecan treatment of colorectal cancers results in high-grade intestinal mucositis in a large proportion of patients. The mechanisms behind irinotecan-induced mucosal injury, however, have yet to be fully explained. The aim of this study was to investigate the role of the p53 protein in the onset of intestinal damage following irinotecan treatment in two different settings. IEC-6 and FHs 74 intestinal cell lines were treated with irinotecan with and without a temporary p53 inhibitor, pifithrin-alpha, and examined for changes in proliferation and survival along with expression of p53 and related proteins. Forty tumour-bearing rats also underwent irinotecan treatment with and without pifithrin-alpha, and the effects on intestinal morphology, gene expression, apoptosis and other toxicities were assessed. Irinotecan caused a dose-dependent reduction in cell viability that was not prevented by pifithrin-alpha in either cell line. Rats responded to irinotecan with diarrhoea, weight loss, histopathological changes to the small and large intestine, increased crypt apoptosis, and a mild inflammatory response. Pifithrin-alpha reduced severity and duration of intestinal apoptosis; however, it did not significantly affect other parameters including p53 expression. Temporary inhibition of p53 activation does not markedly prevent intestinal cell death or mucositis following irinotecan treatment. Irinotecan may act through upregulation of proapoptotic proteins Bax and Bak to induce cell death.

Chemotherapy-induced diarrhea is associated with changes in the luminal environment in the DA rat

The microflora of the gastrointestinal tract (GIT) are a complex ecosystem, performing a number of beneficial functions. Irinotecan causes both early and late diarrhea, the latter possibly caused, in part, by changes in the microflora of the GIT. Female DA rats were given atropine subcutaneously, prior to a single 200 mg/kg intraperitoneal dose of irinotecan. Animals were monitored for diarrhea and killed at 30 and 60 mins, 2, 6, 12, 24, 48, and 72 hrs after chemotherapy administration. Control rats received no treatment. Fecal samples and stomach, jejunum, and colon samples were collected and stored at -70 degrees C until required. Standard microbiological culture techniques were used to grow and isolate the flora. Biochemical tests were used to identify the bacteria. The level of growth was noted for relative comparison between time points and graded accordingly. Early diarrhea was observed in the rats from 2-6 hrs after treatment, after which time the diarrhea resolved. Late onset diarrhea was apparent 72 hrs after treatment. Changes were seen in the flora of the stomach, jejunum, colon and feces. The majority of microflora changes were seen 6, 12, and 24 hrs after treatment, with a relative increase or decrease in the presence of bacteria in comparison with control rats. In some rats bacteria were not observed at all time points, and different bacteria not seen in control animals were identified in rats treated with irinotecan. These changes were observed up to 72 hrs after treatment. In conclusion, irinotecan treatment causes changes in the flora of the stomach, jejunum, colon, and feces of rats and is associated with the development of diarrhea. These changes in flora may have systemic effects and in particular may contribute to the development of chemotherapy-induced mucositis.

Mucosal injury from targeted anti-cancer therapy

BACKGROUND

With the increased use of so-called targeted anti-cancer therapies, there has been a change in toxicities that patients are experiencing. As most targeted therapies are given in conjunction with more traditional chemotherapeutic agents, toxicities of these combination therapies are also evolving. Whilst we increasingly understand the mechanisms underlying the toxicities of chemotherapy and radiotherapy, the addition of targeted treatments requires a new understanding of both toxicity and interacting mechanisms.

AIMS

The aims of this review (which formed the basis of an invited plenary lecture at the 2006 Annual conference of the Multinational Association of Supportive Care in Cancer) were to define targeted anti-cancer therapy, to describe its known impact on the mucosa, either alone, or in combination with chemotherapy with or without radiotherapy, and finally to provide an outline for future directions in research into mucosal injury from targeted anti-cancer therapies.

METHODOLOGY

Two separate literature reviews were conducted. The combined reviews produced 700 papers of which approximately 70 were included in the review.

RESULTS

As with mucosal injury (or mucositis) in general, the studies are hampered by a lack of mucosal injury as primary endpoint, and the variable definitions and levels of reporting. The depth to which mucosal injury was studied was also inadequate. However, it is clear that the key to understanding toxicity is to understand the mechanism of action of the drug, from which it should be possible to predict the toxicities that will occur.

CONCLUSIONS

With the increasing use of targeted anti-cancer therapies, mucosal injury, particularly in its manifestations of diarrhoea, and mouth ulcers, is becoming even more prominent. More publications of basic and clinical research in this area is required.

Irinotecan changes gene expression in the small intestine of the rat with breast cancer

PURPOSE

The aetiology of mucositis is complex involving change in gene expression, altered apoptosis and interaction between epithelial and subepithelial compartments. This is the first investigation using microarray to assess chemotherapy-induced changes in the gut. The aims of this study were to identify genes that are altered by irinotecan, to determine how these genes contribute to apoptosis and to identify any potential gene families and pathways that are important for mucositis development.

METHODS

Tumour-bearing female dark Agouti rats were administered twice with 150 mg/kg of irinotecan and killed 6 h after the final dose. Jejunal tissue was harvested and RNA was isolated. cDNA was synthesised and purified, prior to hybridisation and microarray analysis. A 5-K oligo clone set was used to investigate gene expression. Results from the microarray were quantified using RT-PCR.

RESULTS

Many genes were significantly up- or down-regulated by irinotecan. In particular, multiple genes implicated in the mitogen-activated protein kinase (MAPK) signalling pathway were differentially regulated following treatment. These included interleukin 1 receptor, caspases, protein kinase C and dual-specificity phosphatase 6. RT-PCR was used to confirm effects of irinotecan on caspase-1 expression in jejunal tissue and was significantly increased 6 h after treatment with irinotecan.

CONCLUSIONS

This study has identified MAP kinase signalling as being involved with irinotecan-induced intestinal damage and confirms previous findings with radiation-induced oral mucosal damage, which also implicated this pathway. Microarrays are emerging as a valuable tool in mucositis research by linking such findings. The common pathway of chemotherapy- and radiotherapy-induced damage, which utilises the caspase-cascade, may be a useful target to prevent apoptosis following cancer treatment.

Cancer chemotherapy-induced diarrhoea and constipation: mechanisms of damage and prevention strategies

BACKGROUND

Diarrhoea and constipation are common toxicities of chemotherapy, and both are poorly understood. They are manifestations of alimentary mucositis, a condition which affects the entire gastrointestinal tract.

DISCUSSION

The absolute percentage of patients that have diarrhoea or constipation as a result of their treatment has yet to be fully defined, although general estimates place 10% of patients with advanced cancer as being afflicted. Although there has been some major progress in recent years with understanding the mechanisms of oral and small intestinal mucositis, diarrhoea and constipation have received very little attention. Although diarrhoea is a well-recognised side-effect of both chemotherapy and radiotherapy, very little research has been conducted on the mechanisms behind diarrhoea or its treatment. Much of the information in the published literature is based on clinical observations with very little basic science existing. Constipation is not as well recognised and very little is known about its mechanisms.

OBJECTIVES

This review will examine in detail the potentially complex pathogenesis of post-chemotherapy diarrhoea in both animal models and the clinical setting. Furthermore, it will explore what is known about chemotherapy-induced constipation. It will then outline an evidence-based pathway for the investigation and treatment of post-chemotherapy diarrhoea and constipation.

Intestinal mucositis: the role of the Bcl-2 family, p53 and caspases in chemotherapy-induced damage

Intestinal mucositis occurs as a consequence of cytotoxic treatment through multiple mechanisms including induction of crypt cell death (apoptosis) and cytostasis. The molecular control of these actions throughout the gastrointestinal tract has yet to be fully elucidated; however, they are known to involve p53, the Bcl-2 family and caspases. This review will provide an overview of current research as well as identify areas where gaps in knowledge exist.

Nuclear factor kappaB (NFkappaB) and cyclooxygenase-2 (Cox-2) expression in the irradiated colorectum is associated with subsequent histopathological changes

PURPOSE

Recent studies have proposed that mucositis development is the same throughout the gastrointestinal tract (GIT), as it is formed from one structure embryologically. Radiation-induced oral mucositis studies have outlined the key involvement of nuclear factor kappaB (NFkappaB) and cyclooxygenase-2 (Cox-2) in its pathobiology. The purpose of this study was therefore to investigate the expression of NFkappaB and Cox-2 in the irradiated colorectum and to correlate these with the associated histopathologic changes.

METHODS AND MATERIALS

Colorectal tissues from 28 colorectal cancer patients treated with preoperative radiotherapy were analyzed for histopathologic changes using a variety of tissue staining methods. The expression of NFkappaB and Cox-2 in these tissues was investigated using immunohistochemistry. Changes in expression of these proteins were then correlated with the histopathologic changes.

RESULTS

Radiation therapy caused injury to the normal colorectal tissue surrounding tumor site, particularly around the blood vessels. These changes were reflected in changes in NFkappaB and Cox-2 expression.

CONCLUSIONS

We conclude that different regions of the GIT, the colorectum, and oral cavity have similar underlying mechanisms of radiation-induced mucositis. Understanding these mechanisms will allow new approaches to be developed to specifically target steps in the evolution of alimentary mucositis.

Palifermin reduces diarrhea and increases survival following irinotecan treatment in tumor-bearing DA rats

Mucositis is a common side effect of cancer chemotherapy for which there is currently no treatment. Irinotecan is a commonly used effective chemotherapeutic agent, causing severe gastrointestinal mucositis and diarrhea. Previous research suggests that palifermin is potentially antimucotoxic. The primary aim of this study was to determine whether palifermin was effective in ameliorating irinotecan-induced gastrointestinal mucositis. We also determined the protective effects of single large and multiple small doses of palifermin. Tumor-bearing DA rats were treated with a single large (10 mg/kg) dose of palifermin 3 days prior to, or multiple small (3 mg/kg day for 3 days) doses of palifermin or vehicle control prior to, receiving 2 doses of 150 mg/kg irinotecan. Animals were killed at 6, 24, 48, 72, 96, 120, or 144 hr after treatment. The primary endpoints were diarrhea and mortality. Gastrointestinal morphometry, histopathology and apoptosis were assessed. Tumor weights and mitoses were measured to ensure palifermin did not promote tumor growth. Data were analyzed using Peritz' F-test, Student's t-test and Tukey-Kramer multiple comparison test. Animals pretreated with palifermin tolerated irinotecan treatment better than control animals with less severe diarrhea (5% in animals receiving 10 mg/kg palifermin, 11% in animals receiving 3 x 3 mg/kg palifermin and 28% in animals receiving irinotecan only) and reduced mortality (2% in animals receiving 10 mg/kg palifermin, 11% in animals receiving 3 x 3 mg/kg palifermin and 28% in animals receiving irinotecan only). Small and large intestinal weights were maintained. Intestinal morphometry was not maintained in palifermin-pretreated rats despite being increased prior to irinotecan treatment. Palifermin pretreatment did not prevent apoptosis that peaked at 6 hr in the jejunum or colon, but prevented apoptosis at 96 hr in the small intestine. Palifermin pretreatment in both treatment regimens significantly reduces diarrhea and mortality following irinotecan administration without adversely affecting tumor growth. This positive response warrants further investigation, particularly in humans.

Gastrointestinal mucositis

OBJECTIVE

To review the management of radiotherapy- and chemotherapy-induced gastrointestinal mucositis.

DATA SOURCE

Articles and research studies.

CONCLUSION

Gastrointestinal damage is becoming a common dose-limiting toxicity. However, there is only limited research into the mechanism and possible treatment of this toxicity.

IMPLICATIONS FOR NURSING PRACTICE

It is important to document the frequency and severity of gastrointestinal mucositis, and to alleviate symptoms wherever possible.

Novel therapies

OBJECTIVE

To highlight selected research directed to new drug and device technologies to manage mucositis in cancer patients and to illustrate potential impact of successful therapies.

DATA SOURCES

Published research articles and abstracts, clinical experience.

CONCLUSION

Advances in molecular modeling of mucosal injury in cancer patients have created new opportunities for therapy. Research is analyzing the impact of single-agent interventions; varying degrees of efficacy are being reported. Once optimal dosing strategies for single-agent management are defined, the opportunity for multi-agent therapies will emerge.

IMPLICATIONS FOR NURSING PRACTICE

The oncology nurse plays a pivotal role in assessing and managing mucositis in cancer patients.

Gastrointestinal mucositis: a new biological model

The history of research into gastrointestinal mucositis (GIM), and how the future directions are informed by the progress made in the study of oral mucositis (OM) are discussed. It is proposed that OM and GIM should both be considered to be elements of alimentary mucositis (AM), which covers mucosal damage through the entire alimentary tract, with regional differences being due to the specialized needs of each area.

Irinotecan causes severe small intestinal damage, as well as colonic damage, in the rat with implanted breast cancer

BACKGROUND AND AIMS

Irinotecan (CPT-11) is a chemotherapeutic drug for cancer that causes severe diarrhea by an uncertain mechanism. The aim of the present study was to investigate the time-course of apoptosis and whole intestinal damage after irinotecan to further elucidate the mechanism behind the diarrhea.

METHODS

Groups of breast cancer-bearing dark agouti (DA) rats were treated with 100, 150 or 200 mg/kg doses of irinotecan or vehicle control daily for two days, and killed at 6, 24, 72 or 96 h after treatment. Apoptosis and morphometry were examined in both the small and large intestines. Histopathology and goblet cell numbers were recorded. Data were analyzed using the Peritz' F-test.

RESULTS

Irinotecan increased apoptosis and caused villous atrophy and crypt hypoplasia in the small intestine, and increased apoptosis, crypt hypoplasia, crypt dilation and mucus secretion in the large intestine. Irinotecan at 100 and 150 mg/kg caused crypt hypoplasia at 6 and 24 h, with rebound hyperplasia at 72 and 96 h. At 200 mg/kg, irinotecan caused a more pronounced crypt hypoplasia earlier and all animals died by 96 h. Apoptosis peaked at 6 h and remained elevated over the remainder of the time-points. This was not dose-dependent. Irinotecan at all doses altered colonic, but not jejunal, goblet cells. Irinotecan increased colonic mucus secretion.

CONCLUSIONS

We conclude that irinotecan causes diarrhea by inducing apoptosis and hypoproliferation in both the small and large intestines, and causes colonic damage with changes in goblet cells and mucin secretion.

Effect of interleukin-11 on ameliorating intestinal damage after methotrexate treatment of breast cancer in rats

Gastrointestinal mucositis after cancer chemotherapy is an increasing problem that is essentially untreatable once established, although it gradually remits. The aim of this study was to investigate the time-course and effect of interleukin-11 (IL-11) on apoptosis and intestinal morphometry as measures of mucositis. Female DA rats were implanted subcutaneously with syngeneic breast cancer and treated with methotrexate (MTX). Intestinal morphometry was used to assess villus area, crypt length, and mitotic count per crypt. Apoptosis was assessed by TUNEL assay in the tumor and jejunum. Tumor proliferation was assessed by mitotic count. The time-course study showed that MTX increased apoptosis by 28-fold in the crypts of the small intestine and by 3-fold in the tumor, and peaked at 6 hr after chemotherapy. IL-11 (100 microg/kg/twice daily subcutaneously) maintained intestinal weight, and reduced the severity of mucositis, as measured by villus area, crypt length, and mitotic count per crypt. IL-11 at higher doses (200 microg and 400 microg/kg/twice daily subcutaneously), did not further improve villus area, crypt length, and mitotic count per crypt. IL-11 did not affect tumor apoptosis or proliferation. We conclude that IL-11 attenuated mucositis by maintaining intestinal weight and morphometry. IL-11 did not prevent apoptosis, but rather induced compensatory crypt cell proliferation.

The effect of keratinocyte growth factor on tumour growth and small intestinal mucositis after chemotherapy in the rat with breast cancer

PURPOSE

Mucositis from cancer chemotherapy is a common problem for which there is no definitive treatment. It produces significant morbidity and occasional mortality. Prevention and successful treatment could significantly enhance the quality of life of patients, and improve survival; however any potential preventative agent must not enhance tumour growth. The aims of this study were to assess the effect of keratinocyte growth factor (KGF) on breast tumour growth, and in preventing small intestinal mucositis induced by methotrexate (MTX).

METHODS

Tumour-bearing rats received KGF or saline for 5 days prior to either MTX or saline treatment, and were killed 24 h after the last MTX injection. The weights of the tumour, small and large intestines, and liver were recorded. Apoptosis was assessed by TUNEL assay in the tumour and jejunum. Intestinal morphometry was used to assess villus area, crypt length and mitotic crypt count. Tumour proliferation was assessed by mitotic count.

RESULTS

KGF increased the weight of the small intestine prior to chemotherapy but the weight was not maintained after chemotherapy. KGF synergized with MTX to increase apoptosis in both intestinal crypts and the breast cancer. KGF also reduced tumour size.

CONCLUSIONS

We conclude that KGF had a modest effect on intestinal growth prior to chemotherapy. It did not protect the gut from mucositis, nor did it worsen morphometry. It reduced tumour size.