Does sucralfate reduce early side effects of pelvic radiation? A double-blind randomized trial

Protective Role of Natural Compounds under Radiation-Induced Injury

In recent years, evidence has shown the potential therapeutic effects of different natural compounds for the prevention and treatment of radiotherapy-induced mucositis (RIOM). RIOM represents one of the most frequent side effects associated with anti-neoplastic treatments affecting patients' quality of life and treatment response due to radiation therapy discontinuation. The innate radio-protective ability of natural products obtained from plants is in part due to the numerous antioxidants possessed as a part of their normal secondary metabolic processes. However, oxygen presence is a key point for radiation efficacy on cancer cells. The aim of this review is to describe the most recent evidence on radiation-induced injury and the emerging protective role of natural compounds in preventing and treating this specific damage without compromising treatment efficacy.

Interventions to reduce acute and late adverse gastrointestinal effects of pelvic radiotherapy for primary pelvic cancers

BACKGROUND

An increasing number of people survive cancer but a significant proportion have gastrointestinal side effects as a result of radiotherapy (RT), which impairs their quality of life (QoL).

OBJECTIVES

To determine which prophylactic interventions reduce the incidence, severity or both of adverse gastrointestinal effects among adults receiving radiotherapy to treat primary pelvic cancers.

SEARCH METHODS

We conducted searches of CENTRAL, MEDLINE, and Embase in September 2016 and updated them on 2 November 2017. We also searched clinical trial registries.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of interventions to prevent adverse gastrointestinal effects of pelvic radiotherapy among adults receiving radiotherapy to treat primary pelvic cancers, including radiotherapy techniques, other aspects of radiotherapy delivery, pharmacological interventions and non-pharmacological interventions. Studies needed a sample size of 20 or more participants and needed to evaluate gastrointestinal toxicity outcomes. We excluded studies that evaluated dosimetric parameters only. We also excluded trials of interventions to treat acute gastrointestinal symptoms, trials of altered fractionation and dose escalation schedules, and trials of pre- versus postoperative radiotherapy regimens, to restrict the vast scope of the review.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology. We used the random-effects statistical model for all meta-analyses, and the GRADE system to rate the certainty of the evidence.

MAIN RESULTS

We included 92 RCTs involving more than 10,000 men and women undergoing pelvic radiotherapy. Trials involved 44 different interventions, including radiotherapy techniques (11 trials, 4 interventions/comparisons), other aspects of radiotherapy delivery (14 trials, 10 interventions), pharmacological interventions (38 trials, 16 interventions), and non-pharmacological interventions (29 trials, 13 interventions). Most studies (79/92) had design limitations. Thirteen studies had a low risk of bias, 50 studies had an unclear risk of bias and 29 studies had a high risk of bias. Main findings include the following:Radiotherapy techniques: Intensity-modulated radiotherapy (IMRT) versus 3D conformal RT (3DCRT) may reduce acute (risk ratio (RR) 0.48, 95% confidence interval (CI) 0.26 to 0.88; participants = 444; studies = 4; I2 = 77%; low-certainty evidence) and late gastrointestinal (GI) toxicity grade 2+ (RR 0.37, 95% CI 0.21 to 0.65; participants = 332; studies = 2; I2 = 0%; low-certainty evidence). Conformal RT (3DCRT or IMRT) versus conventional RT reduces acute GI toxicity grade 2+ (RR 0.57, 95% CI 0.40 to 0.82; participants = 307; studies = 2; I2 = 0%; high-certainty evidence) and probably leads to less late GI toxicity grade 2+ (RR 0.49, 95% CI 0.22 to 1.09; participants = 517; studies = 3; I2 = 44%; moderate-certainty evidence). When brachytherapy (BT) is used instead of external beam radiotherapy (EBRT) in early endometrial cancer, evidence indicates that it reduces acute GI toxicity (grade 2+) (RR 0.02, 95% CI 0.00 to 0.18; participants = 423; studies = 1; high-certainty evidence).Other aspects of radiotherapy delivery: There is probably little or no difference in acute GI toxicity grade 2+ with reduced radiation dose volume (RR 1.21, 95% CI 0.81 to 1.81; participants = 211; studies = 1; moderate-certainty evidence) and maybe no difference in late GI toxicity grade 2+ (RR 1.02, 95% CI 0.15 to 6.97; participants = 107; studies = 1; low-certainty evidence). Evening delivery of RT may reduce acute GI toxicity (diarrhoea) grade 2+ during RT compared with morning delivery of RT (RR 0.51, 95% CI 0.34 to 0.76; participants = 294; studies = 2; I2 = 0%; low-certainty evidence). There may be no difference in acute (RR 2.22, 95% CI 0.62 to 7.93, participants = 110; studies = 1) and late GI toxicity grade 2+ (RR 0.44, 95% CI 0.12 to 1.65; participants = 81; studies = 1) between a bladder volume preparation of 1080 mls and that of 540 mls (low-certainty evidence). Low-certainty evidence on balloon and hydrogel spacers suggests that these interventions for prostate cancer RT may make little or no difference to GI outcomes.Pharmacological interventions: Evidence for any beneficial effects of aminosalicylates, sucralfate, amifostine, corticosteroid enemas, bile acid sequestrants, famotidine and selenium is of a low or very low certainty. However, evidence on certain aminosalicylates (mesalazine, olsalazine), misoprostol suppositories, oral magnesium oxide and octreotide injections suggests that these agents may worsen GI symptoms, such as diarrhoea or rectal bleeding.Non-pharmacological interventions: Low-certainty evidence suggests that protein supplements (RR 0.23, 95% CI 0.07 to 0.74; participants = 74; studies = 1), dietary counselling (RR 0.04, 95% CI 0.00 to 0.60; participants = 74; studies = 1) and probiotics (RR 0.43, 95% CI 0.22 to 0.82; participants = 923; studies = 5; I2 = 91%) may reduce acute RT-related diarrhoea (grade 2+). Dietary counselling may also reduce diarrhoeal symptoms in the long term (at five years, RR 0.05, 95% CI 0.00 to 0.78; participants = 61; studies = 1). Low-certainty evidence from one study (108 participants) suggests that a high-fibre diet may have a beneficial effect on GI symptoms (mean difference (MD) 6.10, 95% CI 1.71 to 10.49) and quality of life (MD 20.50, 95% CI 9.97 to 31.03) at one year. High-certainty evidence indicates that glutamine supplements do not prevent RT-induced diarrhoea. Evidence on various other non-pharmacological interventions, such as green tea tablets, is lacking.Quality of life was rarely and inconsistently reported across included studies, and the available data were seldom adequate for meta-analysis.

AUTHORS' CONCLUSIONS

Conformal radiotherapy techniques are an improvement on older radiotherapy techniques. IMRT may be better than 3DCRT in terms of GI toxicity, but the evidence to support this is uncertain. There is no high-quality evidence to support the use of any other prophylactic intervention evaluated. However, evidence on some potential interventions shows that they probably have no role to play in reducing RT-related GI toxicity. More RCTs are needed for interventions with limited evidence suggesting potential benefits.

Chronic radiation proctitis: tricks to prevent and treat

OBJECTIVE

The purpose of this study was to give an overview of the measures used to prevent chronic radiation proctitis (CRP) and to provide an algorithm for the treatment of CRP.

METHODS

Medical literature databases including PubMed and Medline were screened and critically analyzed for relevance in the scope of our purpose.

RESULTS

CRP is a relatively frequent late side effect (5-20%) and mainly dependent on the dose and volume of irradiated rectum. Radiation treatment (RT) techniques to prevent CRP are constantly improving thanks to image-guided RT and intensity-modulated RT. Also, newer techniques like protons and new devices such as rectum spacers and balloons have been developed to spare rectal structures. Biopsies do not contribute to diagnosing CRP and should be avoided because of the risk of severe rectal wall damage, such as necrosis and fistulas. There is no consensus on the optimal treatment of CRP. A variety of possibilities is available and includes topical and oral agents, hyperbaric oxygen therapy, and endoscopic interventions.

CONCLUSIONS

CRP has a natural history of improving over time, even without treatment. This is important to take into account when considering these treatments: first be conservative (topical and oral agents) and be aware that invasive treatments can be very toxic.

Prevention of pelvic radiation disease

Pelvic cancers are among the most frequently diagnosed cancers worldwide. Treatment of patients requires a multidisciplinary approach that frequently includes radiotherapy. Gastrointestinal (GI) radiation-induced toxicity is a major complication and the transient or long-term problems, ranging from mild to very severe, arising in non-cancerous tissues resulting from radiation treatment to a tumor of pelvic origin, are actually called as pelvic radiation disease. The incidence of pelvic radiation disease changes according to the radiation technique, the length of follow up, the assessment method, the type and stage of cancer and several other variables. Notably, even with the most recent radiation techniques, i.e., intensity-modulated radiotherapy, the incidence of radiation-induced GI side effects is overall reduced but still not negligible. In addition, radiation-induced GI side effects can develop even after several decades; therefore, the improvement of patient life expectancy will unavoidably increase the risk of developing radiation-induced complications. Once developed, the management of pelvic radiation disease may be challenging. Therefore, the prevention of radiation-induced toxicity represents a reasonable way to avoid a dramatic drop of the quality of life of these patients. In the current manuscript we provide an updated and practical review on the best available evidences in the field of the prevention of pelvic radiation disease.

Management of radiation-induced rectal bleeding

Pelvic radiation disease is one of the major complication after radiotherapy for pelvic cancers. The most commonly reported symptom is rectal bleeding which affects patients' quality of life. Therapeutic strategies for rectal bleeding are generally ignored and include medical, endoscopic, and hyperbaric oxygen treatments. Most cases of radiation-induced bleeding are mild and self-limiting, and treatment is normally not indicated. In cases of clinically significant bleeding (i.e. anaemia), medical therapies, including stool softeners, sucralfate enemas, and metronidazole, should be considered as first-line treatment options. In cases of failure, endoscopic therapy, mainly represented by argon plasma coagulation and hyperbaric oxygen treatments, are valid and complementary second-line treatment strategies. Although current treatment options are not always supported by high-quality studies, patients should be reassured that treatment options exist and success is achieved in most cases if the patient is referred to a dedicated centre.

Management of intestinal complications in patients with pelvic radiation disease

Gastrointestinal toxicity after radiotherapy for pelvic cancer is a major complication-the most commonly reported symptoms include rectal bleeding, diarrhea, and fecal incontinence, which substantially impair patients' quality of life. Management of these symptoms can be a challenge, although available treatment strategies generally are ignored or underused. Radiation-induced symptoms have multiple mechanisms of pathogenesis; the first step for the correct management is to identify the mechanism that is causing the symptoms. Optimal management requires close liaisons among physicians, gastroenterologists with specialist interests, radiotherapists, oncologists, dieticians, nurses, and surgeons. Patients should be reassured that treatment options (medical, endoscopic, and surgical) exist and are in most cases successful if patients are referred to experts in pelvic radiation disease. However, although new therapeutic approaches are not yet always supported by high-quality trials, research projects are underway to improve management of patients. Clinicians should focus on using proven treatments correctly and avoiding misuse.

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.

Multicenter, phase 3 trial comparing selenium supplementation with observation in gynecologic radiation oncology

PURPOSE

We assessed whether adjuvant supplementation with selenium improves the selenium status and reduces side effects of patients treated by radiotherapy (RT) for cervical and uterine cancer.

METHODS AND MATERIALS

Whole-blood selenium concentrations were measured in patients with cervical cancer (n = 11) and uterine cancer (n = 70) after surgical treatment, during RT, at the end of RT, and 6 weeks after RT. Patients with initial selenium concentrations of less than 84μg/L were randomized before RT either to receive 500 μg of selenium (in the form of sodium selenite [selenase, biosyn Arzneimittel GmbH, Fellbach, Germany]) by mouth on the days of RT and 300 μg of selenium on the days without RT or to receive no supplement during RT. The primary endpoint of this multicenter Phase 3 study was to assess the efficiency of selenium supplementation during RT; the secondary endpoint was to decrease radiation-induced diarrhea and other RT-dependent side effects.

RESULTS

A total of 81 patients were randomized. We enrolled 39 in the selenium group (SG) and 42 in the control group (CG). Selenium levels did not differ between the SG and CG upon study initiation but were significantly higher in the SG at the end of RT. The actuarial incidence of diarrhea of Grade 2 or higher according to Common Toxicity Criteria (version 2) in the SG was 20.5% compared with 44.5% in the CG (p = 0.04). Other blood parameters, Eastern Cooperative Oncology Group performance status, and self-reported quality of life were not different between the groups.

CONCLUSIONS

Selenium supplementation during RT is effective in improving blood selenium status in selenium-deficient cervical and uterine cancer patients and reduces the number of episodes and severity of RT-induced diarrhea.

Radiation damage to the gastrointestinal tract: mechanisms, diagnosis, and management

PURPOSE OF REVIEW

To summarize current knowledge about gastrointestinal radiation toxicity, with emphasis on mechanisms and clinical diagnosis and management.

RECENT FINDINGS

While there has been only modest change in cancer incidence and cancer mortality rates during the past 30 years, the number of cancer survivors has more than doubled. Moreover, the recognition of uncomplicated cancer cure as the ultimate goal in oncology has intensified efforts to prevent, diagnose, and manage side effects of radiation therapy. These efforts have been facilitated by recent insight into the underlying pathophysiology.

SUMMARY

The risk of injury to the intestine is dose limiting during abdominal and pelvic radiation therapy. Delayed bowel toxicity is difficult to manage and adversely impacts the quality of life of cancer survivors. More than 200,000 patients per year receive abdominal or pelvic radiation therapy, and the estimated number of cancer survivors with postradiation intestinal dysfunction is 1.5-2 million. Worthwhile progress towards reducing toxicity of radiation therapy has been made by dose-sculpting treatment techniques. Approaches derived from an improved understanding of the pathophysiology of bowel injury, however, will result in further advances. This article discusses the mechanisms of radiation-induced bowel toxicity and reviews current principles in diagnosis and management.

Sucralfate protects intestinal epithelial cells from radiation-induced apoptosis in rats

Radiotherapy for malignant pelvic disease is often followed by acute radiation colitis (ARC). It has been reported that sucralfate treatment has a protective effect against ARC, though the mechanisms of action are unknown. The effects of sucralfate on X-ray radiation-induced apoptosis was studied at 4 Gy in the colonic crypt cells of rats. Sucralfate enemas given prior to radiation resulted in the following: (1) reduction in number of apoptotic colonic crypt cells; (2) reduction in number of caspase-3 positive cells; (3) decreases in p53 accumulation and p21 expression; (4) decreases of Bax/Bcl-2 ratio. The protective effects of sucralfate against ARC may be partially due to the suppression of radiation-induced apoptosis by way of p53 in the colon and the protection of the colonic epithelial stem cell region.

Sucralfate does not ameliorate acute radiation proctitis: randomised study and meta-analysis

AIMS

During pelvic radiotherapy, many patients develop radiation-induced gastrointestinal symptoms, which may interfere with treatment. Prophylaxis during radiotherapy should ideally prevent acute reaction and the development of delayed injury. Sucralfate, an aluminium sucrose octasulphate, has been used for acute and delayed radiation side-effects. However, conflicting results have been published. We report here a prospective, randomised, placebo-controlled study of prophylactic sucralfate during pelvic radiotherapy. In addition, a meta-analysis of available data from the literature has been carried out.

MATERIALS AND METHODS

Fifty-one patients with localised pelvic tumours scheduled for curative conformal pelvic radiotherapy (total dose 64-70 Gy over 6.5-7 weeks in 2 Gy daily fractions) were included. Peroral sucralfate 2 g three times daily, or identically appearing placebo tablets, was given during the course of radiotherapy. Symptom registration, endoscopy and biopsies were carried out immediately before radiotherapy, 2 weeks and 6 weeks into the treatment course, and 2 weeks after completing radiotherapy. Mucosal cup forceps biopsies were obtained through a rigid proctoscope. Graded endoscopic appearance and quantitative histology were registered.

RESULTS

On the basis of previously published negative reports, an unplanned interim analysis of 44 evaluable patients showed significantly increased diarrhoea in the sucralfate group and the trial was stopped. No difference was seen in other symptoms, endoscopic appearance or histology. A meta-analysis comprising five published studies showed no statistically significant beneficial effect of sucralfate on acute symptoms.

CONCLUSION

Sucralfate cannot be recommended for prophylaxis of acute radiation proctopathy and may even worsen the symptoms.

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.

Acute and long-term toxicity following radiotherapy alone or in combination with chemotherapy for locally advanced cervical cancer

Randomised studies in locally advanced cervical cancer patients showed that cisplatin should be given concurrently with radiotherapy, because of a better long-term survival compared to radiotherapy alone. This increases the relevance of treatment related toxicity. This review summarises the acute and long-term toxicity of radiotherapy given with or without chemotherapy for cervical cancer. Acute toxicity (all grades) of radiotherapy is reported in 61% of the patients in the rectosigmoid, in 27% as urological, in 27% as skin and in 20% as gynaecological toxicity. Moderate and severe morbidity consists of 5% to 7% gastrointestinal and 1% to 4% genitourinary toxicity. Adding chemotherapy to radiotherapy increases acute haematological toxicity to 5% to 37% of the patients and nausea and vomiting in 12% to 14%. Late effects of radiotherapy include gastrointestinal, urological, female reproductive tract, skeletal and vascular toxicity, secondary malignancies and quality of life issues. For at least 20 years after treatment, new side effects may develop. Gastrointestinal toxicity usually occurs in the first 2 years after treatment in about 10% of the patients. The incidence of moderate and severe urological toxicity can increase up to 10% and rises over time. Gynaecological toxicity usually occurs shortly after treatment while skeletal and vascular toxicity can occur years to decades later. Thus far, no increase in late toxicity has been observed after the addition of cisplatin to radiotherapy. Finally, methods to prevent or decrease late toxicity and therapeutical options are discussed. However, most randomised studies still have a limited follow-up period.