Hormonal therapy in chronic radiation colitis

Activation of G protein coupled estrogen receptor prevents chemotherapy-induced intestinal mucositis by inhibiting the DNA damage in crypt cell in an extracellular signal-regulated kinase 1- and 2- dependent manner

Chemotherapy-induced intestinal mucositis (CIM) is a common adverse reaction to antineoplastic treatment with few appropriate, specific interventions. We aimed to identify the role of the G protein coupled estrogen receptor (GPER) in CIM and its mechanism. Adult male C57BL/6 mice were intraperitoneally injected with 5-fluorouracil to establish the CIM model. The selective GPER agonist G-1 significantly inhibited weight loss and histological damage in CIM mice and restored mucosal barrier dysfunction, including improving the expression of ZO-1, increasing the number of goblet cells, and decreasing mucosal permeability. Moreover, G-1 treatment did not alter the antitumor effect of 5-fluorouracil. In the CIM model, G-1 therapy reduced the expression of proapoptotic protein and cyclin D1 and cyclin B1, reversed the changes in the number of TUNEL+ cells, Ki67+ and bromodeoxyuridine+ cells in crypts. The selective GPER antagonist G15 eliminated all of the above effects caused by G-1 on CIM, and application of G15 alone increased the severity of CIM. GPER was predominantly expressed in ileal crypts, and G-1 inhibited the DNA damage induced by 5-fluorouracil in vivo and vitro, as confirmed by the decrease in the number of γH2AX+ cells in the crypts and the comet assay results. Referring to the data from GEO dataset we verified GPER activation restored ERK1/2 activity in CIM and 5-fluorouracil-treated IEC-6 cells. Once the effects of G-1 on ERK1/2 activity were abolished with the ERK1/2 inhibitor PD0325901, the effects of G-1 on DNA damage both in vivo and in vitro were eliminated. Correspondingly, all of the manifestations of G-1 protection against CIM were inhibited by PD0325901, such as body weight and histological changes, the mucosal barrier, the apoptosis and proliferation of crypt cells. In conclusion, GPER activation prevents CIM by inhibiting crypt cell DNA damage in an ERK1/2-dependent manner, suggesting GPER might be a target preventing CIM.

Effects of Estrogen on the Gastrointestinal Tract

Estrogen is a kind of steroid compound that has extensive biologic activities. The effect of estrogen is pleiotropic, affecting multiple systems in the body. There is accumulating evidence that estrogen has important effects on the gastrointestinal tract. Longer exposure to estrogen may decrease the risk of gastric cancer. Use of the anti-estrogen drug tamoxifen might increase the risk of gastric adenocarcinoma. Estrogen receptor β may serve as a target for colorectal cancer prevention. In addition, estrogen has been reported to be closely related to the mucosal barrier, gastrointestinal function and intestinal inflammation. However, the role of estrogen in the gastrointestinal tract has not been systematically summarized. In this review, we aim to provide an overview of the role of estrogen in the gastrointestinal tract and evaluate it from various aspects, including estrogen receptors, the mucosal barrier, intestinal inflammation and gastrointestinal tract tumors, which may provide the basis for the development of therapeutic strategies to manage gastrointestinal diseases.

Radiofrequency ablation using BarRx for the endoscopic treatment of radiation proctopathy: a series of three cases

Radiation proctopathy is a complication of pelvic radiotherapy, which occurs in patients treated for carcinoma of the prostate, rectum, urinary bladder, cervix, uterus, and testes. If it presents within 6 weeks to 9 months after therapy, it is called acute radiation proctitis/proctopathy (ARP), and if it occurs 9 months to a year after treatment, it is classified as chronic radiation proctitis/proctopathy (CRP). CRP occurs in 5%–20% of patients receiving pelvic radiation, depending on the radiation dose and the presence or absence of chemotherapy. In many cases, CRP resolves spontaneously, but in some, it can lead to persistent rectal bleeding. Other symptoms of CRP include diarrhea, mucoid discharge, urgency, tenesmus, rectal pain, and fecal incontinence. Despite the availability of several therapies, many patients fail to respond, and continue to suffer in their quality of life. Radiofrequency ablation (RFA) is a newer endoscopic technique that uses radiofrequency energy to ablate tissue. This is an emerging way to treat radiation proctopathy and other mucosal telangiectasia. We present three cases of radiation proctopathy treated with RFA at our institute and review the literature on treatment modalities for CRP. We were also able to find 16 other cases of CRP that used RFA, and review their literature as well as literature on other treatment modalities.

Treatment of hemorrhagic radiation-induced proctopathy with a 4% formalin application under perianal anesthetic infiltration

AIM: To evaluate the results of hemorrhagic radiation proctopathy treatment with a 4% formalin application.

METHODS: A prospective study was performed. Over a three-year period, 38 patients underwent 4% formalin application under perianal anesthetic infiltration for hemorrhagic radiation proctopathy. All patients included in the study were irradiated for prostate cancer. The patients ranged in age from 56-77 years (average 70 ± 5 years). All of the patients were referred for formalin therapy after noninvasive management had failed. Twenty-four (63.2%) patients underwent a single application, 10 (26.3%) patients underwent 2 applications, and 4 (10.5%) patients underwent 3 applications.

RESULTS: Two to 36 mo (average 12 ± 3 mo) following treatment, 34 patients were interviewed (four were lost to follow-up). Twenty (58.8%) subjects reported complete cure, 8 (23.5%) subjects reported significant improvement, and 6 (17.7%) subjects reported no change. One patient (who underwent a colostomy at a regional hospital with no specialized services available for previous bleeding episodes from radiation proctopathy) was cured, and the colostomy was closed. One patient (2.6%) developed rectal mucosal damage after the second application.

CONCLUSION: A 4-min application of 4% formalin for hemorrhagic radiation-induced proctopathy under perianal anesthetic infiltration in patients who have received external radial radiation therapy for prostate cancer is simple, reasonably safe, inexpensive, generally well tolerated, and effective.

Radiofrequency ablation for the treatment of radiation proctitis: a case report and review of literature

Radiation proctitis is a frequent complication of pelvic radiation for cancer. This condition can present acutely within several weeks of radiation, or chronically many months or years after radiation, leading to rectal bleeding and transfusion-dependent anemia. Various medical and endoscopic therapies have been described to treat this condition; however, some patients fail to respond to the current standard therapies. Here we present a case of refractory radiation proctitis, with suboptimal response to other therapies, treated successfully with a novel method, radiofrequency ablation.

Approaches to the prevention and management of radiation colitis

Radiation colitis refers to the characteristic changes in the mucosa of the colon and rectum secondary to pelvic radiation. Based on the interval from radiation to mucosal changes or symptoms, there are two well-defined forms of radiation colitis: acute, manifested by mucosal sloughing causing diarrhea, mucus discharge, and tenesmus; and chronic, characterized by obstructed defecation or ischemia of the mucosa due to obliterative endarteritis and resulting in mucosal telangiectasias, mucosal pallor, and friability causing rectal bleeding. Up to 25% of all patients receiving pelvic radiation develop mild symptoms, and 2% to 3% develop moderate to severe symptoms. Radiation colitis can be difficult to treat in some patients. There are several options for treating its symptoms. Argon plasma coagulation is the most common method of treating telangiectasias. Topical formaldehyde has also been used for distal telangiectasias. Obstructed defecation caused by radiation strictures (which are very fibrotic) usually can be treated successfully with stool softeners, colonic dilation, or steroid injection. Surgery should be avoided if possible because of its technical difficulty and the high incidence of postoperative complications such as anastomotic leak and fistula formation. New advances in radiation delivery techniques (eg, intensity-modulated radiation therapy) using specialized computer algorithms and medications such as amifostine may decrease the incidence of radiation colitis.

Recent advances in the management of radiation colitis

Radiation colitis, an insidious, progressive disease of increasing frequency, develops 6 mo to 5 years after regional radiotherapy for malignancy, owing to the deleterious effects of the latter on the colon and the small intestine. When dealing with radiation colitis and its complications, the most conservative modality should be employed because the areas of intestinal injury do not tend to heal. Acute radiation colitis is mostly self-limited, and usually, only supportive management is required. Chronic radiation colitis, a poorly predictable progressive disease, is considered as a precancerous lesion; radiation-associated malignancy has a tendency to be diagnosed at an advanced stage and to bear a dismal prognosis. Therefore, management of chronic radiation colitis remains a major challenge owing to the progressive evolution of the disease, including development of fibrosis, endarteritis, edema, fragility, perforation, partial obstruction, and cancer. Patients are commonly managed conservatively. Surgical intervention is difficult to perform because of the extension of fibrosis and alterations in the gut and mesentery, and should be reserved for intestinal obstruction, perforation, fistulas, and severe bleeding. Owing to the difficulty in managing the complications of acute and chronic radiation colitis, particular attention should be focused onto the prevention strategies. Uncovering the fibrosis mechanisms and the molecular events underlying radiation bowel disease could lead to the introduction of new therapeutic and/or preventive approaches. A variety of novel, mostly experimental, agents have been used mainly as a prophylaxis, and improvements have been made in radiotherapy delivery, including techniques to reduce the amount of exposed intestine in the radiation field, as a critical strategy for prevention.

[Nonsurgical treatment of chronic radiation-induced hemorrhagic proctitis]

The incidence of radiation-induced chronic hemorrhagic proctitis is less than 10 to 20%. The onset of this proctitis is delayed relative to the radiation therapy and generally develops from 6 to 24 months later. There are numerous predisposing factors, the most important of which is the radiation therapy dose: risk increases exponentially above 40-45 Gy. Its pathophysiology involves progressive obliterating endarteritis and transmural interstitial fibrosis, which induce chronic ischemia that is irreversible and progressive during the years after radiation therapy. Its diagnosis depends most often on the combination of clinical history and typical endoscopic appearance (congestive mucosa and/or telangiectases). Topical administrative of sucralfate or corticosteroids as well as argon plasma coagulation, with formalin treatment if necessary, provides relief for most patients.

Radiation proctopathy in the treatment of prostate cancer

PURPOSE

To compile and review data on radiation proctopathy in the treatment of prostate cancer with respect to epidemiology, clinical manifestations, pathogenesis, risk factors, and treatment.

METHODS

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

RESULTS

Rectal toxicity as a complication of radiotherapy has received attention over the past decade, especially with the advent of dose-escalation in prostate cancer treatment. A number of clinical criteria help to define acute and chronic radiation proctopathy, but lack of a unified grading scale makes comparing studies difficult. A variety of risk factors, related to either radiation delivery or patient, are the subject of intense study. Also, a variety of treatment options, including medical therapy, endoscopic treatments, and surgery have shown varied results, but a lack of large randomized trials evaluating their efficacy prevents forming concrete recommendations.

CONCLUSION

Radiation proctopathy should be an important consideration for the clinician in the treatment of prostate cancer especially with dose escalation. With further study of possible risk factors, the advent of a standardized grading scale, and more randomized trials to evaluate treatments, patients and physicians will be better armed to make appropriate management decisions.

Estradiol treatment ameliorates acetic acid-induced gastric and colonic injuries in rats

To evaluate the role of estrogen treatment on the healing of acetic acid-induced gastric or colonic injury, rats were given 17beta estradiol benzoate (0.001, 0.1, and 10 mg/kg) or vehicle for 7 days (following the induction of ulcer) or 4 days (following the induction of colitis) until they were decapitated. Food intake and fecal output were decreased by estradiol treatment but gastric emptying rate was not changed. Estradiol (10 mg/kg) reduced gastric ulcer index and colonic damage score compared to vehicle-treated groups. SEM and light microscopy demonstrated a significant reduction in the severity of ulcers and colitis by estradiol treatment. Gastric microscopic score was not changed by estradiol treatment, whereas in the colonic tissue score was significantly reduced. Elevated gastric MPO levels were reduced in gastric but not in colonic tissues as compared with corresponding vehicle groups. In conclusion, exogenous estradiol treatment at pharmacological doses improves the healing of both gastric and colonic injury induced by acetic acid in rats.

Systematic review for non-surgical interventions for the management of late radiation proctitis

Chronic radiation proctitis produces a range of clinical symptoms for which there is currently no recommended standard management. The aim of this review was to identify the various non-surgical treatment options for the management of late chronic radiation proctitis and evaluate the evidence for their efficacy. Synonyms for radiation therapy and for the spectrum of lower gastrointestinal radiation toxicity were combined in an extensive search strategy and applied to a range of databases. The included studies were those that involved interventions for the non-surgical management of late radiation proctitis. Sixty-three studies were identified that met the inclusion criteria, including six randomised controlled trials that described the effects of anti-inflammatory agents in combination, rectal steroids alone, rectal sucralfate, short chain fatty acid enemas and different types of thermal therapy. However, these studies could not be compared. If the management of late radiation proctitis is to become evidence based, then, in view of its episodic and variable nature, placebo controlled studies need to be conducted to clarify which therapeutic options should be recommended. From the current data, although certain interventions look promising and may be effective, one small or modest sized study, even if well-conducted, is insufficient to implement changes in practice. In order to increase recruitment to trials, a national register of cases with established late radiation toxicity would facilitate multi-centre trials with specific entry criteria, formal baseline and therapeutic assessments providing standardised outcome data.

Non surgical interventions for late radiation proctitis in patients who have received radical radiotherapy to the pelvis

BACKGROUND

Chronic radiation proctitis (inflammation of the rectum) may develop after the completion of pelvic radiotherapy. Presently there is no recommended standard management.

OBJECTIVES

To assess the effects of various non-surgical treatment options for the management of late chronic radiation proctitis.

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register, issue 1, 2001, MEDLINE 1966 to 2001, EMBASE 1980 to 2001, CANCERCD 1980 to 2001, Science Citation Index 1991 to 2001, CINAHL 1982 to 2001, as well as sources of grey literature. We also hand searched relevant textbooks and contacted experts in the field.

SELECTION CRITERIA

Studies (preferentially randomised controlled trials) of interventions for the non-surgical management of late radiation proctitis in patients who have undergone pelvic radiotherapy as part of their cancer treatment.

DATA COLLECTION AND ANALYSIS

The inclusion criteria were independently applied by two of the reviewers (AD and EJM) and where there was disagreement this was resolved by involving a third reviewer to form a consensus.

MAIN RESULTS

Six randomised controlled trials were included. None of the trials compared anti-inflammatories with placebo. However rectal sucralfate showed greater clinical improvement for proctitis than anti-inflammatories (odds ratio 14.00, 95% confidence interval 1.46 to 134.26; n=1 study), though no difference was seen for endoscopic improvement (odds ratio 2.74, 95% confidence interval 0.64 to 11.76, n=1 study). The addition of metronidazole to the anti-inflammatory regime also appeared to improve the response rate, as measured by the reduction in rectal bleeding, diarrhoea, erythema and ulceration (n=1 study). Similarly rectal hydrocortisone appeared to be more effective than rectal betamethasone for clinical improvement although no difference was seen in endoscopic improvement (n=1 study). Short chain fatty acid enemas did not appear to be effective compared to placebo (n=2 studies). In the comparison of the heater probe and bipolar electrocautery (n=1 study), there was no discernible difference for severe bleeding after one year, but the heater probe demonstrated a greater increase in the haematocrit and reduced transfusion requirements.

REVIEWER'S CONCLUSIONS

Late radiation complications are a relatively rare manifestation, with many potential carers and poor diagnostic criteria. Although certain interventions look promising and may be effective (such as rectal sucralfate, adding metronidazole to the anti-inflammatory regime and heater probes), single small studies (even if well conducted) provide insufficient evidence. The episodic and variable nature of late radiation proctitis also requires placebo controlled studies to establish whether particular treatments are effective. Regional or centralised registers of radiation toxicity should be established so that interventions can be administered in the setting of multi-centre trials with specific entry criteria, formal baseline and therapeutic assessments providing standardised outcome data including quality of life evaluations.