Physiologic changes of the anorectum after pelvic radiotherapy for the treatment of prostate and bladder cancer

Evaluation of anorectal function using real-time tissue elastography before and after preoperative chemoradiotherapy

PURPOSE

This study aimed to clarify the relationship between changes in elasticity and anorectal function before and after chemoradiotherapy.

METHODS

This is a single-center prospective cohort study (Department of Surgical Oncology, The University of Tokyo). We established a technique to quantify internal anal sphincter hardness as elasticity using transanal ultrasonography with real-time tissue elastography. Twenty-seven patients with post-chemoradiotherapy rectal cancer during 2019-2022 were included. Real-time tissue elastography with transanal ultrasonography was performed before and after chemoradiotherapy to measure internal anal sphincter hardness as "elasticity" (hardest (0) to softest (255); decreased elasticity indicated sclerotic changes). The relationship between the increase or decrease in elasticity pre- and post-chemoradiotherapy and the maximum resting pressure, maximum squeeze pressure, and Wexner score were the outcome measures.

RESULTS

A decrease in elasticity was observed in 16/27 (59.3%) patients after chemoradiotherapy. Patients with and without elasticity decrease after chemoradiotherapy comprised the internal anal sphincter sclerosis and non-sclerosis groups, respectively. The maximum resting pressure post-chemoradiotherapy was significantly high in the internal anal sphincter sclerosis group (63.0 mmHg vs. 47.0 mmHg), and a majority had a worsening Wexner score (60.0% vs. 18.2%) compared with that of the non-sclerosis group. Decreasing elasticity (internal anal sphincter sclerosis) correlated with a higher maximum resting pressure (r = 0.36); no correlation was observed between the degree of elasticity change and maximum squeeze pressure.

CONCLUSION

Internal anal sphincter sclerosis due to chemoradiotherapy may correlate to anorectal dysfunction.

Anal and rectal function after intensity-modulated prostate radiotherapy with endorectal balloon

BACKGROUND AND PURPOSE

Late anorectal toxicity influences quality of life after external beam radiotherapy (EBRT) for prostate cancer. A daily inserted endorectal balloon (ERB) during EBRT aims to reduce anorectal toxicity. Our goal is to objectify anorectal function over time after prostate intensity-modulated radiotherapy (IMRT) with ERB.

MATERIAL AND METHODS

Sixty men, irradiated with IMRT and an ERB, underwent barostat measurements and anorectal manometry prior to EBRT and 6 months, one year and 2 years after radiotherapy. Primary outcome measures were rectal distensibility and rectal sensibility in response to stepwise isobaric distensions and anal pressures.

RESULTS

Forty-eight men completed all measurements. EBRT reduced maximal rectal capacity 2 years after EBRT (250 ± 10 mL vs. 211 ± 10 mL; p < 0.001), area under the pressure-volume curve (2878 ± 270 mL mmHg vs. 2521 ± 305 mL mmHg; p = 0.043) and rectal compliance (NS). Sensory pressure thresholds for first sense and first urge (both p < 0.01) increased. Anal maximum pressure diminished after IMRT (p = 0.006).

CONCLUSIONS

Rectal capacity and sensory function are increasingly affected over time after radiotherapy. There is an indication that these reductions are affected less with IMRT + ERB compared to conventional radiation techniques.

Non-surgical interventions for late rectal problems (proctopathy) of radiotherapy in people who have received radiotherapy to the pelvis

BACKGROUND

This is an update of a Cochrane review first published in 2002, and previously updated in 2007. Late radiation rectal problems (proctopathy) include bleeding, pain, faecal urgency, and incontinence and may develop after pelvic radiotherapy treatment for cancer.

OBJECTIVES

To assess the effectiveness and safety of non-surgical interventions for managing late radiation proctopathy.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 11, 2015); MEDLINE (Ovid); EMBASE (Ovid); CANCERCD; Science Citation Index; and CINAHL from inception to November 2015.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing non-surgical interventions for the management of late radiation proctopathy in people with cancer who have undergone pelvic radiotherapy for cancer. Primary outcomes considered were: episodes of bowel activity, bleeding, pain, tenesmus, urgency, and sphincter dysfunction.

DATA COLLECTION AND ANALYSIS

Study selection, 'Risk of bias' assessment, and data extraction were performed in duplicate, and any disagreements were resolved by involving a third review author.

MAIN RESULTS

We identified 1221 unique references and 16 studies including 993 participants that met our inclusion criteria. One study found through the last update was moved to the 'Studies awaiting classification' section. We did not pool outcomes for a meta-analysis due to variation in study characteristics and endpoints across included studies.Since radiation proctopathy is a condition with various symptoms or combinations of symptoms, the studies were heterogeneous in their intended effect. Some studies investigated treatments targeted at bleeding only (group 1), some investigated treatments targeted at a combination of anorectal symptoms, but not a single treatment (group 2). The third group focused on the treatment of the collection of symptoms referred to as pelvic radiation disease. In order to enable some comparison of this heterogeneous collection of studies, we describe the effects in these three groups separately.Nine studies assessed treatments for rectal bleeding and were unclear or at high risk of bias. The only treatments that made a significant difference on primary outcomes were argon plasma coagulation (APC) followed by oral sucralfate versus APC with placebo (endoscopic score 6 to 9 in favour of APC with placebo, risk ratio (RR) 2.26, 95% confidence interval (CI) 1.12 to 4.55; 1 study, 122 participants, low- to moderate-quality evidence); formalin dab treatment (4%) versus sucralfate steroid retention enema (symptom score after treatment graded by the Radiation Proctopathy System Assessments Scale (RPSAS) and sigmoidoscopic score in favour of formalin (P = 0.001, effect not quantified, 1 study, 102 participants, very low- to low-quality evidence), and colonic irrigation plus ciprofloxacin and metronidazole versus formalin application (4%) (bleeding (P = 0.007, effect not quantified), urgency (P = 0.0004, effect not quantified), and diarrhoea (P = 0.007, effect not quantified) in favour of colonic irrigation (1 study, 50 participants, low-quality evidence).Three studies, of unclear and high risk of bias, assessed treatments targeted at something very localised but not a single pathology. We identified no significant differences on our primary outcomes. We graded all studies as very low-quality evidence due to unclear risk of bias and very serious imprecision.Four studies, of unclear and high risk of bias, assessed treatments targeted at more than one symptom yet confined to the anorectal region. Studies that demonstrated an effect on symptoms included: gastroenterologist-led algorithm-based treatment versus usual care (detailed self help booklet) (significant difference in favour of gastroenterologist-led algorithm-based treatment on change in Inflammatory Bowel Disease Questionnaire-Bowel (IBDQ-B) score at six months, mean difference (MD) 5.47, 95% CI 1.14 to 9.81) and nurse-led algorithm-based treatment versus usual care (significant difference in favour of the nurse-led algorithm-based treatment on change in IBDQ-B score at six months, MD 4.12, 95% CI 0.04 to 8.19) (1 study, 218 participants, low-quality evidence); hyperbaric oxygen therapy (at 2.0 atmospheres absolute) versus placebo (improvement of Subjective, Objective, Management, Analytic - Late Effects of Normal Tissue (SOMA-LENT) score in favour of hyperbaric oxygen therapy (HBOT), P = 0.0019) (1 study, 150 participants, moderate-quality evidence, retinol palmitate versus placebo (improvement in RPSAS in favour of retinol palmitate, P = 0.01) (1 study, 19 participants, low-quality evidence) and integrated Chinese traditional plus Western medicine versus Western medicine (grade 0 to 1 radio-proctopathy after treatment in favour of integrated Chinese traditional medicine, RR 2.55, 95% CI 1.30 to 5.02) (1 study, 58 participants, low-quality evidence).The level of evidence for the majority of outcomes was downgraded using GRADE to low or very low, mainly due to imprecision and study limitations. 

AUTHORS' CONCLUSIONS

Although some interventions for late radiation proctopathy look promising (including rectal sucralfate, metronidazole added to an anti-inflammatory regimen, and hyperbaric oxygen therapy), single small studies provide limited evidence. Furthermore, outcomes important to people with cancer, including quality of life (QoL) and long-term effects, were not well recorded. The episodic and variable nature of late radiation proctopathy requires large multi-centre placebo-controlled trials (RCTs) to establish whether treatments are effective. Future studies should address the possibility of associated injury to other gastro-intestinal, urinary, or sexual organs, known as pelvic radiation disease. The interventions, as well as the outcome parameters, should be broader and include those important to people with cancer, such as QoL evaluations.

New treatments for fecal incontinence: update for the gastroenterologist

Fecal incontinence is one of the most emotionally devastating of all nonfatal conditions. Many patients do not respond satisfactorily to conservative measures, and there is a need for new and effective strategies when medical therapy fails. The development of sacral nerve stimulation and other forms of neuromodulation and the injection of biologically compatible substances into the anal sphincter complex have brought renewed enthusiasm for using these novel treatments in this underserved population. Because injectable bulking agents such as dextranomer in stabilized hyaluronic acid can be administered in an outpatient setting, this procedure is being marketed to both gastroenterologists and surgeons. This article reviews both sacral nerve stimulation and dextranomer bulking agents and compares their strengths and potential limitations in patients with fecal incontinence.

Pathophysiology of late anorectal dysfunction following external beam radiotherapy for prostate cancer

BACKGROUND

Patients treated with external beam radiotherapy (EBRT) may suffer from long-term anorectal adverse effects. The purpose of the present study was to assess long-term functional and structural anorectal changes in patients previously treated with EBRT for prostate cancer and to suggest the mechanism behind the development of the adverse effects.

MATERIAL AND METHODS

Our previously proposed RT-induced anorectal dysfunction (RT-ARD) score, developed with the intention to survey anorectal dysfunction was used to identify patients with and without anorectal symptoms. Among 309 patients surveyed with the questionnaire, we chose 23 patients with the highest RT-ARD score and 19 patients with the lowest RT-ARD score. They were investigated by multimodal rectal sensory stimulation, standard anal physiological tests. Changes of the rectal mucosa were assessed by flexible sigmoidoscopy and graded by the Vienna Rectoscopy Score (VRS).

RESULTS

The mean follow-up time was 3.8 (range, 2.8; 8.6) years in patients with high RT-ARD and 3.8 (range, 2.6; 5.9) in patients with low RT-ARD. Endoscopic evaluation revealed higher VRS scores in patients with high RT-ARD compared to patients with low RT-ARD (p = 0.002). Patients with high RT-ARD had increased rectal sensory response to distension manifested both as volume (p = 0.006) and cross-sectional area (p = 0.04), and they had reduced maximum anal resting pressure assessed by anal manometri (p = 0.02).

CONCLUSIONS

Long-term anorectal symptoms correlate to changes in anorectal biomechanical properties and rectal mucosal injury. Our data suggests that RT-induced long-term anorectal dysfunction is multifactorial caused by injury of the rectal mucosa and the internal anal sphincter combined with increased rectal sensitivity and reduced rectal functional capacity.

Systematic review: anal and rectal changes after radiotherapy for prostate cancer

PURPOSE

Pelvic radiotherapy may lead to changes of anorectal function resulting in incontinence-related complaints. The aim of this study was to systematically review objective findings of late anorectal physiology and mucosal appearance after irradiation for prostate cancer.

METHODS

MEDLINE, EMBASE, and the Cochrane library were searched. Original articles in which anal function, rectal function, or rectal mucosa were examined ≥3 months after EBRT for prostate cancer were included.

RESULTS

Twenty-one studies were included with low to moderate quality. Anal resting pressures significantly decreased in 6 of the 9 studies including 277 patients. Changes of squeeze pressure and rectoanal inhibitory reflex were less uniform. Rectal distensibility was significantly impaired after EBRT in 7 of 9 studies (277 patients). In 4 of 9 studies on anal and in 5 of 9 on rectal function, disturbances were associated with urgency, frequent bowel movements or fecal incontinence. Mucosal changes as assessed by the Vienna Rectoscopy Score revealed telangiectasias in 73 %, congestion in 33 %, and ulceration in 4 % of patients in 8 studies including 346 patients, but no strictures or necrosis. Three studies reported mucosal improvement during follow-up. Telangiectasias, particularly multiple, were associated with rectal bleeding. Not all bowel complaints (30 %) were related to radiotherapy.

CONCLUSIONS

Low to moderate quality evidence indicates that EBRT reduces anal resting pressure, decreases rectal distensibility, and frequently induces telangiectasias of rectal mucosa. Objective changes may be associated with fecal incontinence, urgency, frequent bowel movements, and rectal bleeding, but these symptoms are not always related to radiation damage.

Short-term effects of neoadjuvant chemoradiotherapy on internal anal sphincter function: a human in vitro study

BACKGROUND

Neoadjuvant chemoradiotherapy is recommended in the treatment of locally advanced rectal cancer. Studies have suggested that chemoradiotherapy adversely affects anorectal function. However, the functional implication and the underlying neuromyogenic changes involved in radiation-induced damage are poorly understood.

OBJECTIVE

This study evaluated the functional changes following chemoradiotherapy on the internal anal sphincter.

DESIGN AND PATIENTS

This article describes an in vitro study on the internal anal sphincter collected from patients undergoing abdominoperineal resection or proctectomy. Five patients were treated by surgery alone (control group), and 6 received preoperative chemoradiotherapy (treatment group). Sphincter strips were mounted in organ bath, and the responses to electrical field stimulation and drugs were monitored.

SETTINGS

The study was performed at the University of Oxford.

MAIN OUTCOME MEASURES

The end points of this study were to investigate whether chemoradiotherapy has any significant effects on internal anal sphincter function and, subsequently, to establish the type of injury induced.

RESULTS

Chemoradiotherapy strips developed similar tone, but significantly lower spontaneous activity (p = 0.001) than controls. Electrical field stimulation induced relaxation, followed by contraction. At 50 Hz, electrical field stimulation produced 25.6 ± 4.9% (mean ± SE) of maximum relaxation followed by a contraction of 5.5 ± 0.9% of basal tone in chemoradiotherapy strips i9n comparison with 47.0 ± 6.2% (p = 0.009) and 17.7 ± 4.0% (p = 0.007) in controls. Relaxation was significantly attenuated by N-nitro-L-arginine. Significant differences were found in responses to carbachol (p = 0.018) and phenylephrine (p = 0.022), but not to sodium nitroprusside.

LIMITATIONS

This work was limited by the relatively small number of patients enrolled, because of the difficulty of finding human tissue for laboratory studies, and the lack of long-term results.

CONCLUSIONS

Chemoradiotherapy significantly impairs internal anal sphincter function and intrinsic nerves seem more susceptible than smooth muscle. The exclusion of anal canal from the radiation field is recommended, when oncologically safe.

Differences in radiation dosimetry and anorectal function testing imply that anorectal symptoms may arise from different anatomic substrates

PURPOSE

To explore the influence of functional changes and dosimetric parameters on specific incontinence-related anorectal complaints after prostate external beam radiotherapy and to estimate dose-effect relations for the anal wall and rectal wall.

METHODS AND MATERIALS

Sixty patients, irradiated for localized prostate cancer, underwent anorectal manometry and barostat measurements to evaluate anal pressures, rectal capacity, and rectal sensory functions. In addition, 30 untreated men were analyzed as a control group. In 36 irradiated patients, the anal wall and rectal wall were retrospectively delineated on planning computed tomography scans, and dosimetric parameters were retrieved from the treatment plans. Functional and dosimetric parameters were compared between patients with and without complaints, focusing on urgency, incontinence, and frequency.

RESULTS

After external beam radiotherapy, reduced anal pressures and tolerated rectal volumes were observed, irrespective of complaints. Patients with urgency and/or incontinence showed significantly lower anal resting pressures (mean 38 and 39 vs. 49 and 50 mm Hg) and lower tolerated rectal pressures (mean 28 and 28 vs. 33 and 34 mm Hg), compared to patients without these complaints. In patients with frequency, almost all rectal parameters were reduced. Several dosimetric parameters to the anal wall and rectal wall were predictive for urgency (e.g., anal D(mean)>38 Gy), whereas some anal wall parameters correlated to incontinence and no dose-effect relation for frequency was found.

CONCLUSIONS

Anorectal function deteriorates after external beam radiotherapy. Different incontinence-related complaints show specific anorectal dysfunctions, suggesting different anatomic and pathophysiologic substrates: urgency and incontinence seem to originate from both anal wall and rectal wall, whereas frequency seems associated with rectal wall dysfunction. Also, dose-effect relations differed between these complaints. This implies that anal wall and rectal wall should be considered separate organs in radiotherapy planning.

Fecal incontinence affecting quality of life and social functioning among long-term gynecological cancer survivors

INTRODUCTION

Fecal incontinence is a symptom reported by cancer survivors after pelvic radiotherapy and is recognized to be one of the most troubling symptom-induced sources of distress to patients.

OBJECTIVE

To investigate how fecal incontinence, patient-reported as emptying of all stools into clothing without forewarning, impact self-assessed quality of life from a social, psychological, sexual, and functional aspect among gynecological cancer survivors treated with pelvic radiotherapy.

METHODS

We identified a cohort of 789 eligible women in the Stockholm and Gothenburg areas treated with pelvic radiotherapy alone or as combined treatment of gynecological cancer. From the Swedish Population Registry, we identified 478 control women. Data were collected using a study-specific, validated, postal questionnaire including questions covering symptoms from the pelvic region, demographics, social functioning, psychological, and quality-of-life issues.

RESULTS

Participation was 78% for cancer survivors and 72% for control women. The fecal incontinence symptom emptying of all stools into clothing without forewarning was reported by 70 cancer survivors (12%), with lowered quality of life in 74% of the 70 cancer survivors. This symptom kept the survivors from going to parties (relative risk [RR], 11.8; 95% confidence interval [CI], 6.6-21.1), kept the survivors from traveling (RR, 9.3; 95% CI, 5.3-16.5), affected their work ability (RR, 7.9; 95% CI, 3.8-16.4), hindered their sexual life (RR, 9.2; 95% CI, 4.8-17.6), and changed them as persons (RR, 4.9; 95% CI, 2.9-8.1). The prevalence of the symptom emptying of all stools into clothing without forewarning among control women was 3 (1%) of 344.

CONCLUSIONS

Among gynecological cancer survivors having undergone pelvic radiotherapy alone or as part of a combined treatment, fecal incontinence is associated with social, psychological, sexual, and functional consequences.

[Normal tissue tolerance to external beam radiation therapy: anal canal]

The anal canal is regarded as an organ at risk more often in pelvis radiation, but also in brachytherapy. Acute or chronic complications depend on its different components and are different from the anal margin or the rectum. The toxicity scale can be the NCI CT C version 3, completed by the tardive toxicity SOMALENT scale. The mean dose and maximal dose are recognized as predictors of complications. The maximum recommended dose despite the paucity of literature is 55 Gy.

The short-term effect of neoadjuvant chemoradiation on anorectal function in low and midrectal cancer: analysis using preoperative manometric data

PURPOSE

The purpose of this study was to evaluate the short-term preoperative effects of neoadjuvant chemoradiation on anorectal function, excluding the bias of postoperative impairment.

METHODS

We analyzed 80 patients on whom preoperative anorectal manometry data were available for both prechemoradiation and postchemoradiation. Patients were divided into 2 groups according to the tumor location; lower rectum (n = 52) and mid rectum (n = 28). The paired t test was used to compare prechemoradiation and postchemoradiation parameters including the mean resting pressure, maximum squeeze pressure, percentage asymmetry of the resting and squeeze sphincter, length of the high-pressure zone, rectal sensory threshold, and rectal compliance.

RESULTS

In patients with a lower rectal cancer, there were significant differences in the percentage asymmetry of the squeeze sphincter (27.81 +/- 6.46 vs 25.38 +/- 5.93%, P < .01), length of the high-pressure zone (2.14 +/- 0.74 vs 2.33 +/- 0.72 cm, P = .05), and rectal compliance (1.14 +/- 0.41 vs 1.02 +/- 0.40 mL/mmHg, P = .04). In patients with midrectal cancer, only the mean resting pressure increased significantly (45.08 +/- 18.57 vs 52.83 +/- 17.87 mmHg, P < .01). Clinical symptom evaluation demonstrated a significant decrease in the number of defecations and the frequency of tenesmus.

CONCLUSION

Neoadjuvant chemoradiation did not impair overall short-term sphincter function significantly, regardless of the location of the primary tumor. Although there was a decrease in rectal compliance, it seemed that the tumor-downsizing effect compensated the expected worsening of anorectal function in the early postchemoradiation period.

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.

Radiation-induced sequelae affecting the continence organ: incidence, pathogenesis, and treatment

INTRODUCTION

Incontinence is a late complication that causes symptoms years after radiation treatment and is difficult to deal with; it poses a particular challenge for care-providing physicians.

REVIEW

This review looks at our current knowledge of the incidence, symptoms, and treatment of fecal incontinence induced by radiation treatment. An approximate estimation based on retrospective data suggests an incidence of fecal incontinence of up to one-third of patients. The mechanism that causes incontinence are changes in anal resting tone, squeeze pressure, and rectal volume or rectal compliance. The other associated aspects of incontinence include such further disorders as proctitis, colitis, and other disturbances involving the lower digestive tract. The therapeutic options mainly comprise the treatment of associated aspects, such as proctitis or diarrhea.

CONCLUSION

Surgical treatment should be the absolute exception. If the creation of a stoma is being considered, a resective procedure offering freedom from symptoms seems to be the more advantageous option.

Radiation therapy-induced mucositis: Relationships between fractionated radiation, NF-κB, COX-1, and COX-2

Radiation therapy is one of the three major treatment modalities used in eradicating malignant tumours. When ionising radiation is used to treat abdominal tumours, severe side effects largely due to mucosal damage in the alimentary tract are common, particularly when it is combined with chemotherapy. Radiation-induced mucositis may not only limit the therapeutic doses of combined treatment but also adversely affect the quality of life of the patient. Treatment strategies to treat and prevent radiation-induced mucositis have been reviewed and published in the Clinical Practice Guidelines, 2004. However evidence supporting an effective treatment approach is tenuous, probably because the mechanistic evolution of radiation-induced mucositis is poorly understood. Several animal models have been used to examine the various effects of radiation but no single animal model has been able to effectively capture the effects of radiation on the alimentary tract at the molecular level before symptoms begin. This review will outline the events which occur following radiation exposure; from chromosomal aberrations in the mucosal cells leading to apoptotic and mitotic death, to the evolution of mucositis involving changes in gene activations and signaling. A better understanding of the mechanisms of radiation therapy-induced mucositis is necessary as it will allow for future pharmaceutical interventions to alleviate if not eliminate the debilitating side effects.

Improving the morbidity of anorectal injury from pelvic radiotherapy

OBJECTIVE

Radiation anorectal injury due to pelvic radiotherapy for non intestinal cancer is a significant cause of morbidity which may limit the treatment dose required. Conservative treatment options are of limited value and surgery is reserved only for the most severe complications. This review addresses radioprotection of the anorectum and aims to increase awareness amongst surgeons of the strategies that have been in practice in order to minimize the side-effects of radiotherapy while preserving its therapeutic efficacy.

METHODS

This review is based on a literature search (Medline and NLM PubMed) with manual cross-referencing of all articles related to anorectal radiation injury.

RESULTS

Optimization of radiation dose, the use of radioprotective agents and improvement in radiation delivery are the main areas of development. There are few data on the potential of altered fractionation schedules in reducing anorectal injury. A few phase I and II studies suggest that the pharmacological agents amifostine and misoprostol could be beneficial in limiting radiation damage but larger phase III studies are awaited.

CONCLUSION

The introduction of 3-dimensional conformal radiation therapy and intensity modulated radiation therapy has been the most significant advance in reducing radiation morbidity.

Preoperative chemoradiation for rectal cancer causes prolonged pudendal nerve terminal motor latency

PURPOSE

A worsened anorectal function after chemoradiation for high-risk rectal cancer is often attributed to radiation damage of the anorectum and pelvic floor. Its impact on pudendal nerve function is unclear. This prospective study evaluated the short-term effect of preoperative combined chemoradiation on anorectal physiologic and pudendal nerve function.

METHODS

Sixty-six patients (39 men, 27 women) with localized resectable (T3, T4, or N1) rectal cancer were included in the study. All patients received 45 Gy (1.8 Gy/day in 25 fractions) over five weeks, plus 5-fluorouracil (350 mg/m2/day) and leucovorin (20 mg/m2/day) concurrently on days 1 to 5 and 29 to 33. Patients who had rectal cancer with a distal margin within 6 cm of the anal verge had the anus included in the field of radiotherapy (Group A, n = 26). Patients who had rectal cancer with a distal margin 6 to 12 cm from the anal verge had shielding of the anus during radiotherapy (Group B, n = 40). The Wexner continence score, anorectal manometry and pudendal nerve terminal motor latency were assessed at baseline and four weeks after completion of chemoradiation.

RESULTS

The median Wexner score deteriorated significantly (P < 0.0001) from 0 to 2.5 for both Groups A (range, 0-8) and B (range, 0-14). The maximum resting anal pressures were unchanged after chemoradiation. The maximum squeeze anal pressures were reduced (mean = 166.5-157.5 mmHg) after chemoradiation. This change was similar in both Groups A and B. Eighteen patients (Group A = 7, Group B = 11) developed prolonged pudendal nerve terminal motor latency after chemoradiation. These 18 patients similarly had a worsened median Wexner continence score (range, 0-3) and maximum squeeze anal pressures (mean = 165.5-144 mmHg). The results obtained were independent of tumor response to chemoradiation.

CONCLUSIONS

Preoperative chemoradiation for rectal cancer carries a significant risk of pudendal neuropathy, which might contribute to the incidence of fecal incontinence after restorative proctectomy for rectal cancer.

Faecal incontinence: A late side-effect of pelvic radiotherapy

AIMS

Despite advances in pelvic radiotherapy, damage to normal tissue can lead to chronic gastrointestinal problems. The frequency with which this affects quality of life is controversial. Faecal incontinence is not widely perceived to be a major issue after pelvic radiotherapy. The aim of this paper is to review the frequency and mechanisms for the development of faecal incontinence after pelvic radiotherapy, and to review treatment options for faecally incontinent patients.

MATERIALS AND METHODS

A search of original literature was carried out using MEDLINE and EMBASE databases from 1966 to 2005.

RESULTS

The reliability of the published data is poor because patients frequently fail to admit to faecal incontinence, and because prospective studies are lacking that assess faecal incontinence as a specific end point using adequate, validated and reproducible methodology. The published rates of late new-onset faecal incontinence after pelvic radiation are between 3% and 53%. Patients treated for prostate rather than gynaecological, bladder, rectal or anal cancer may have a lower rate. Only 8-56% of affected patients state that faecal incontinence reduces their quality of life. Studies examining the physiological changes occurring after radiotherapy are generally not adequately controlled or powered, assessment of ano-rectal function is rarely comprehensive and loss of patients to follow-up frequently makes it difficult to extrapolate results to a wider population. Where there is agreement over the physiological changes that occur after radiotherapy, it is not clear at what threshold these changes cause symptoms. No prospective studies of any non-surgical treatment for faecal incontinence after radiotherapy have been published. Surgery other than colostomy probably carries a high risk of complications in this group of patients, but few data have been published.

CONCLUSIONS

Now that improvements in outcome from combination treatments, including radiotherapy for pelvic cancer, are being achieved, it is time that serious attention is paid to determining how frequently significant gastrointestinal toxicity arises, and how best to optimise the quality of life of long-term survivors.

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.

Formalin application in the treatment of chronic radiation-induced hemorrhagic proctitis--an effective but not risk-free procedure: a prospective study of 33 patients

PURPOSE

This prospective study evaluated the efficacy and safety of local formalin application in chronic refractory radiation-induced hemorrhagic proctitis.

METHODS

All patients were treated under anesthesia by direct application of 4 percent formalin to the affected rectal areas.

RESULTS

The study included 33 patients (17 women) and was conducted between January 1994 and December 2001. There were 11 anal cancers (33 percent), 11 prostate cancers, 9 cervical or endometrial cancers, 1 bladder cancer, and 1 rectal cancer. The mean number of daily rectal bleeds was 2.7 (range, 0.5-15). Nineteen patients (58 percent) were blood transfusion dependent. Twenty-three patients had only one formalin application and 10 patients required a second application because of the persistent bleeding. The treatment was effective in 23 cases (70 percent): 13 patients had complete cessation of bleeding and 10 patients had only minor bleeding. Six anal or rectal strictures occurred: 4 patients had been treated for anal cancer (36 percent) and 2 patients had been treated for other cancers (9 percent). None of the strictures was malignant. Anal incontinence worsened in 5 patients of the 11 who had been treated for anal cancer (45 percent) and occurred in 4 of the 22 other patients (18 percent).

CONCLUSION

Formalin application is an effective treatment for chronic radiation-induced hemorrhagic proctitis. However, local morbidity is not negligible. This result may be related to the high proportion of anal cancers in the series. In our opinion, therefore, formalin application should be reserved for severe hemorrhagic proctitis refractory to medical treatment and should be thoroughly discussed in cases of anorectal radiation-induced stricture, prior anal incontinence, or treated anal cancer.