A randomized, prospective cross-over trial comparing methylene blue-directed biopsy and conventional random biopsy for detecting intestinal metaplasia and dysplasia in Barrett's esophagus

BACKGROUND AND STUDY AIMS

The value of methylene blue-directed biopsies (MBDB) in detecting specialized intestinal metaplasia and dysplasia in Barrett's esophagus remains unclear. The aim of this study was to compare the accuracy of MBDB with random biopsy in detecting intestinal metaplasia and dysplasia in patients with Barrett's esophagus.

PATIENTS AND METHODS

A prospective, randomized, cross-over trial was undertaken to compare MBDB with random biopsy in patients with Barrett's esophagus segments 3 cm or more in length without macroscopic evidence of dysplasia or cancer. Dysplasia was graded as: indefinite for dysplasia, low-grade dysplasia, high-grade dysplasia, or carcinoma, and was reported in a blinded fashion.

RESULTS

Fifty-seven patients were recruited, 44 of whom were male. A total of 1,269 biopsies were taken (MBDB-651, random biopsie-618). Analysis of the results by per-biopsy protocol showed that the MBDB technique diagnosed significantly more specialized intestinal metaplasia (75 %) compared to the random biopsy technique (68 %; P = 0.032). The sensitivity and specificity rates of MBDB for diagnosing specialized intestinal metaplasia were 91 % (95 % CI, 88 - 93 %) and 43 % (95 % CI, 36 - 51 %), respectively. The sensitivity and specificity rates of MBDB for diagnosing dysplasia or carcinoma were 49 % (95 % CI, 38 - 61 %) and 85 % (95 % CI, 82 - 88 %), respectively. There were no significant differences in the diagnosis of dysplasia and carcinoma - MBDB 12 %, random biopsy 10 %. The methylene blue staining pattern appeared to have an influence on the detection of specialized intestinal metaplasia and dysplasia/carcinoma. Dark blue staining was associated with increased detection of specialized intestinal metaplasia (P < 0.0001), and heterogeneous staining (P = 0.137) or no staining (P = 0.005) were associated with dysplasia and/or carcinoma detection. The MBDB technique prolonged the endoscopy examination by an average of 6 min.

CONCLUSION

The diagnostic accuracy of the MBDB technique was superior to that of the random biopsy technique for identifying specialized intestinal metaplasia, but not dysplasia or carcinoma. The intensity of methylene blue staining has an influence on the detection of specialized intestinal metaplasia and dysplasia or carcinoma, which may help in targeting the biopsies. Although MBDB prolongs the endoscopy procedure slightly, it is a safe and well-tolerated procedure. Further clinical studies on the MBDB technique exclusively in endoscopically normal dysplastic Barrett's esophagus are needed.

Photodynamic therapy (PDT) for oesophageal dysplasia and early carcinoma with mTHPC (m-tetrahydroxyphenyl chlorin): a preliminary study

Barrett's oesophagus is a premalignant condition in which stratified squamous type mucosa of the normal oesophagus is replaced by specialised intestinal type columnar mucosa. Oesophageal resection was previously considered to be the treatment of choice for high-grade dysplasia or superficial carcinoma arising in this columnar-lined mucosa. We treated four patients with Barrett's oesophagus and high-grade dysplasia, and one patient with superficial oesophageal carcinoma with photodynamic therapy (PDT) using an argon-pumped dye laser light (652 nm). PDT was also delivered using a xenon arc lamp (Paterson lamp, light 652 nm +/- 15 nm) in two patients with Barrett's oesophagus and high-grade dysplasia. mTHPC (m-tetrahydroxyphenyl chlorin) 0.15 mg/kg was used as a photosensitiser in all the patients. We have been able to demonstrate the elimination of columnar-lined oesophageal mucosa, reduction in the length of the Barrett's segment or downgrading of the dysplasia in all of the patients. There is no evidence of recurrence in the patient who had oesophageal carcinoma, at 27 months follow-up. We conclude that mTHPC is useful as a photosensitiser for PDT in the management of Barrett's oesophagus with high-grade dysplasia or superficial carcinoma and the Paterson lamp is a potential alternative light source for PDT.

An update in the palliative management of malignant dysphagia

BACKGROUND

Oesophageal cancer is generally associated with late presentation and poor prognosis. Therefore palliative surgery has been largely superseded by less invasive non-surgical techniques. Once palliation is indicated, the aims of the management should be: the maintenance of oral intake, minimizing hospital stay, relief of pain, elimination of reflux and regurgitation and the prevention of aspiration.

METHODS

This study was a review of all published English language data on the palliation of malignant dysphagia between 1994-1999. The Medline and Bids databases were searched and other references were derived from the material perused.

RESULTS AND CONCLUSIONS

Palliative treatment for oesophageal cancer should be individualized and relate to tumour stage, size and location, the patient's medical condition and his/her personal wishes. The palliative treatment largely includes self-expanding metal stents (SEMS), laser (including photodynamic therapy (PDT)) or a combination of the two to relieve symptoms, this may be employed with or without other treatments such as radiotherapy/chemotherapy (RT/CT) with the aim of reducing tumour bulk and possibly prolonging survival. A multi-disciplinary approach is vital in patients with advanced oesophageal cancer.

Photodynamic therapy using 5-aminolaevulinic acid for oesophageal adenocarcinoma associated with Barrett's metaplasia

Photodynamic therapy (PDT) is a novel technique for local endoscopic treatment of gastrointestinal neoplasia. Current photosensitisers for PDT may cause prolonged skin phototoxicity. 5-Aminolaevulinic acid (ALA), a precursor of the photosensitiser protoporphyrin IX (PpIX), is more acceptable because of its short half-life and preferential accumulation in mucosa and mucosal tumour. We have treated 12 patients, median age 73 years (range 55-88) with oesophageal adenocarcinoma arising from Barrett's metaplasia (two carcinomas-in-situ, grade 0; 10 carcinomas, grade 1-11A based on endoluminal ultrasound in two and CT scanning in 10 patients). ALA (60 and 75 mg/kg body weight) was given orally in two or five equally divided doses. The PpIX distribution in stomach, normal oesophagus, Barrett's mucosa and carcinoma was measured by quantitative fluorescence photometry. PDT was performed using laser light (630 nm) delivered via a cylindrical diffuser 4-6 h after the first dose of ALA. The patients received one to four sessions of PDT. PpIX accumulation in the mucosa was two to three times that in the lamina propria. The differential distribution between carcinomatous and normal oesophageal mucosa was less marked (carcinoma:normal mucosa ratio = 1.4). Higher doses of ALA increased PpIX accumulation in all tissues but did not increase the differential PpIX distribution between tumour and normal oesophageal mucosa. After PDT using ALA (ALA/PDT), all mucosa showed superficial white necrotic changes and the histology confirmed fibrinoid necrosis. One patient with carcinoma-in-situ had the tumour eradicated after one treatment with no recurrence at 28 months. Another patient with a small T1 tumour required four ALA/PDT treatments, and died of other disease after 36 months. There was no evidence of recurrence. The tumour bulk in the other carcinomas was not significantly reduced. ALA/PDT has a potential for the eradication of small tumours but careful patient selection with endoluminal ultrasound is needed when using ALA/PDT to treat oesophageal cancer.

Enhancement of photodynamic therapy in gastric cancer cells by removal of iron

BACKGROUND

Aminolaevulinic acid (ALA) is an endogenous substrate in the haem biosynthetic pathway. Protoporphyrin IX (PPIX), the immediate haem precursor in the pathway, has photoexcitable properties. Exogenous ALA has been used previously as a precursor agent in photodynamic therapy (PDT). Its main advantage is a short half-life and hence reduced incidence of skin photosensitivity. ALA can be toxic, however, causing, for example, transient increases in liver enzyme concentrations when given systemically and this may be dose related.

AIM

To assess whether accumulation of PPLX and ultimately the efficacy of PDT could be improved by modulating both ends of the haem biosynthetic pathway.

METHODS

Gastric cancer cells (MKN 28) were incubated with ALA (0-1000 mumolar) and desferrioxamine (0-800 mumolar) for 24 hours before exposure to argon-pumped dye laser (630 nm) at different energy levels (0-40 J/cm2). Cell viability was assessed by use of the methyl-tetrazolium (MTT) assay four hours after exposure to light.

RESULTS

Total PPIX accumulation increased linearly with increasing extracellular concentrations of ALA up to 1 mmolar (r = 0.973, p < 0.005). Adding 200 molar of desferrioxamine trebled PPIX accumulation over the same period of incubation. Cell viability after exposure to light decreased with low doses (0-30 mumolar) of desferrioxamine (r = 0.976, p = 0.024). However, higher doses of desferrioxamine (more than 40 molar) seemed to confer a protective effect against PDT.

CONCLUSION

PDT using ALA can be improved by removal of available iron with desferrioxamine. The reason for the protective effect of desferrioxamine seen at higher doses is not clear.

Helicobacter pylori eradication--comparison of three drug regimens and symptomatic assessment in duodenitis and antral gastritis

Helicobacter pylori (Hp) eradication in peptic ulcer disease is associated with a greatly reduced recurrence rate. The optimal drug regimen for HP eradication remains uncertain. It is also unclear if eradication of Hp in duodenitis and antral gastritis improves symptoms. The aims of this study were to compare the efficacy of three drug regimens in the eradication of Hp and to assess if Hp eradication improved symptoms in patients with duodenitis and antral gastritis. Patients (n = 79) found to have duodenal ulcer, duodenitis and/or antral gastritis with a positive urease test (CLO) at endoscopy were allocated to one of the three regimens: A. omeprazole 20 mg b.d. and clarithromycin 500 mg t.d.s. for two weeks (n = 27), B. De-Nol 240 mg b.d. for four weeks, metronidazole 400 mg t.d.s. and amoxicillin 500 mg t.d.s. for one week (n = 26), and C. omeprazole 20 mg b.d. and amoxicillin 500 mg t.d.s. for two weeks (n = 26). In conclusion, traditional 'triple' therapy with bismuth and two antibiotics achieved the highest Hp eradication rate and was best tolerated. Recolonisation with Hp was uncommon after eradication. Dyspeptic symptoms improved with Hp eradication in duodenitis and antral gastritis.

Eradication of high-grade dysplasia in columnar-lined (Barrett's) oesophagus by photodynamic therapy with endogenously generated protoporphyrin IX

BACKGROUND

High-grade dysplasia in columnar-lined (Barrett's) oesophagus presents a difficult therapeutic dilemma. Choices for management are endoscopic surveillance to detect a cancer or oesophagectomy. One carries the risk of missing invasive cancer, the other carries worrying morbidity and mortality. We have used endoscopic photodynamic therapy to eradicate high-grade dysplasia.

METHODS

After the oral administration of 5-aminolaevulinic acid, the accumulation of the endogenously generated photosensitiser protoporphyrin IX was measured with quantitative fluorescence microscopy. Five patients with histologically confirmed high-grade dysplasia were treated with endoscopic photodynamic therapy with 630 nm laser light to activate the photosensitiser.

FINDINGS

Protoporphyrin IX accumulated in the dysplastic epithelium rather than the adjacent stroma. Selective necrosis of the dysplastic epithelium in columnar-lined oesophagus occurred after light activation. High-grade dysplasia was eradicated in all patients and squamous regeneration occurred after acid suppression with a protonpump inhibitor. There were no complications or recurrence of dysplasia after 26-44 months' endoscopic and histological follow-up. In two cases we saw non-dysplastic Barrett's epithelium underneath regenerative squamous mucosa.

INTERPRETATION

High-grade dysplasia in columnar-lined oesophagus can be eradicated by endoscopic photodynamic therapy with endogenously generated PpIX. Remaining non-dysplastic Barrett's epithelium will require surveillance, but overall the technique has interrupted or delayed the worsening of the dysplasia through to carcinoma. This technique may prevent the need for surgical excision in these patients.

Mucosal ablation using photodynamic therapy for the treatment of dysplasia: an experimental study in the normal rat stomach

Surgery is the only effective treatment for dysplasia in the gastrointestinal tract with considerable associated morbidity and mortality and is difficult to justify without confirmed malignancy. Photodynamic therapy (PDT) produces localised necrosis, which can be limited to the mucosa. This study examined the mechanical properties of the normal rat stomach after PDT. The aim of this study was to measure the bursting pressure of PDT lesions in the stomach and to assess gastric emptying after producing circumferential mucosal necrosis at the pylorus by PDT. Two photosensitising agents were used--5-aminolaevulinic acid (ALA), and aluminium disulphonated phthalocyanine (A1S2Pc). Normal rats were sensitised and PDT lesions created in the stomach with red light. The bursting pressure was measured and compared with that in thermal control lesions. In further experiments, circumferential mucosal necrosis was produced at the pylorus, and animals observed for subsequent eating and weight gain. It was found that gastric bursting pressure was reduced after thermal injury, but not at any time after PDT (with A1S2Pc, but not ALA, adhesive omental reinforcement was required to maintain the gastric wall strength at one week). For the pyloric lesions, gastric emptying was permanently impaired using A1S2Pc, but with low dose ALA (20 mg/kg) had returned to normal by three days. With ALA, but not A1S2Pc, necrosis could be limited to the mucosa. In conclusion, using ALA, selective ablation of the gastric mucosa is possible, which does not reduce the strength of the stomach and only temporarily delays gastric emptying. PDT is a promising technique for the circumferential ablation of dysplastic mucosa.

Photodynamic therapy for villous adenomas of the colon and rectum

Endoscopic thermal laser therapy of colorectal villous adenomas is associated with a high recurrence rate due to incomplete tumor ablation, as treatment over carries a risk of perforation. Photodynamic therapy has been shown to be a promising in the treatment of small malignant tumors, and may be useful for benign adenomas. Eight patients with nine colosigmoid villous adenomas measuring 1-5 cm in length were treated with photodynamic therapy using either haematoporphyrin derivative or Photofrin as photosensitizer and multiple (4-16) applications of interstitial photoirradiation with red light (630 nm, 100 mW x 500 s per application). All but one adenoma had previously been incompletely treated with Nd-YAG laser therapy. Some skin sensitivity to light was seen in one patient. Seven adenomas were eradicated (follow-up 9-56 months, median = 12) as judged by follow-up endoscopy and biopsy. No local complications were seen. Substantial necrosis was produced in the other two adenomas, but they were not completely destroyed, probably due to inadequate light. PDT holds promise in the non-surgical management of villous adenomas, particularly after initial tumour debulking with the Nd-YAG laser.

The effect of antioxidant supplementation on a serum marker of free radical activity and abnormal serum biochemistry in alcoholic patients admitted for detoxification

Alcoholics admitted for detoxification were entered into a double blind placebo controlled trial of oral supplementation with an antioxidant cocktail (vitamin E, beta carotene, vitamin C and selenium) in order to determine the effect of this supplementation on the rate of resolution of a serum marker of free radical activity and abnormal serum biochemistry. The molar proportion of linoleic acid that was diene conjugated (a marker of free radical activity), was increased in the alcoholics 2.9% +/- 1.2 (mean +/- S.D.) compared to normal controls 1.3% +/- 0.6 (P < 0.0001) but fell at a similar rate during the first week of hospitalisation in supplemented and placebo-treated patients with a mean fall of 53.7% (+/- 16.4 S.D.) in the placebo group and 56.0% (+/- 23.7) (P = 0.32, NS) in the antioxidant supplemented group. Similarly, there was no difference in the rate of fall between serum aspartate transaminase (AST) concentration in the two groups: the placebo group falling by a mean of 68.9% (+/- 35.2) and the antioxidant supplemented group falling by 70.1% (+/- 10.0) (P = 0.41, NS) over the first 7 days of hospitalization. Alcoholics had low serum concentrations of vitamin E compared with controls (15.6 mg/l +/- 6.2 S.D.) which rose more in the supplemented group over the period of a week (7.7 mg/l +/- 4.4 to 21.6 mg/l +/- 5.1) (a mean rise of 180.5%) compared with the placebo group (8.6 mg/l +/- 6.8 to 9.6 mg/l +/- 5.7)--a mean rise of 11.6% (P = 0.006).(ABSTRACT TRUNCATED AT 250 WORDS)

Oral versus intravenous administration of 5-aminolaevulinic acid for photodynamic therapy

Endogenously synthesised protoporphyrin IX (PpIX) following the administration of 5-amino-laevulinic acid (ALA) is an effective photosensitiser for photodynamic therapy (PDT). Following intravenous administration, PpIX accumulates predominantly in mucosa of hollow viscera and on light exposure, mucosal ablation results with relative sparing of the submucosa and muscularis layers. Oral administration is effective with ALA in contrast to conventional exogenous photosensitisers such as haematoporphyrin derivative and phthalocyanines. Oral administration of ALA is also simpler, safer, cheaper and more acceptable to patients. We studied the porphyrin sensitisation kinetics profile in the stomach, colon and bladder in normal rats following enterally and parenterally administered ALA using microscopic fluorescence photometric studies of frozen tissue sections. Mucosal cells in all three organs exhibit higher fluorescence levels as compared with underlying smooth muscle following both intravenous and oral administration. Peak concentration were seen 4 h after sensitisation at the highest doses used (200 mg kg-1 i.v., 400 mg kg-1 oral), and slightly earlier with lower doses. The temporal kinetics of both routes of administration were similar although a higher oral dose was required to achieve the same tissue concentration of PpIX. The highest level of fluorescence was achieved in the gastric mucosa and in decreasing levels, colonic and bladder mucosa. A similar degree of mucosal selectivity was achieved in each organ with each route of administration but an oral dose in excess of 40 mg kg-1 was required to achieve measurable PpIX sensitisation. In a pilot clinical study, two patients with inoperable rectal adenocarcinomas were given 30 mg kg-1 and one patient with sigmoid colon carcinoma was given 60 mg kg-1 ALA orally. Serial biopsies of normal and tumour areas were taken over the subsequent 24 h. Fluorescence microscopy of these specimens showed maximum accumulation of PpIX 4 to 6 h after administration of 30 mg kg-1 ALA. There was greater PpIX accumulation in tumour than adjacent normal mucosa in two patients. Preferential PpIX accumulation in tumour was greater in the patient receiving 60 mg kg-1 ALA.

Photodynamic therapy of the normal rat stomach: a comparative study between di-sulphonated aluminium phthalocyanine and 5-aminolaevulinic acid

Dysplasia in the upper gastrointestinal tract carries a risk of invasive malignant change. Surgical excision of the affected organ is the only treatment available. Photodynamic therapy has been shown to be promising in the treatment of early and superficial tumours and may be useful for the ablation of dysplastic mucosa. Because of the diffuse nature of the disease, such treatment would necessarily involve destruction of large areas of mucosa and it is desirable to confine its effect to the mucosa in order that safe healing can take place. By means of photometric fluorescence microscopy, we have studied the pattern of photosensitisation in the normal rat stomach using di-sulphonated aluminium phthalocyanine (AlS2Pc) and 5-aminolaevulinic acid (ALA) as photosensitisizers. AlS2Pc resulted in a panmural photosensitisation of the gastric wall with the highest level encountered in the submucosa. The mucosa and muscularis propria were sensitised to equal extent. Following light exposure, a full thickness damage resulted. ALA is a natural porphyrin precursor and exogenous administration gave rise to accumulation of protoporphyrin IX (PPIX) in the cells. The resultant pattern of photosensitisation was predominantly mucosal and its photodynamic effect was essentially confined to the mucosa. ALA produced a selective photosensitisation of the gastric mucosa for its photodynamic ablation with sparing the underlying tissue layers.

Prospective quality-of-life analysis after palliative photoablation for the treatment of malignant dysphagia

Forty patients were treated for the relief of malignant dysphagia by using laser photoablation. Their quality of life was assessed before the start of treatment and at monthly intervals until death. Two methods were used, a physician's assessment (QL index) and a patient's self-assessment, the linear analogue self-assessment (LASA). There was significant correlation between assessments done at different times by different physicians (QL index rs, 0.786; P less than 0.001; LASA rs, 0.865; P less than 0.001). The correlation coefficient of the QL index and the LASA score with the patient's dysphagia grade was 0.459 and 0.336, respectively. The patient's swallowing ability, QL index, and LASA all were improved significantly at some time after laser therapy. The mean survival was 16 weeks with 58% of patients dying at home, 28% in the hospital, and 18% in a hospice. It was concluded that laser photoablation improves the overall quality of life in patients with malignant dysphagia.

Enteral feeding as sole treatment for Crohn's disease: controlled trial of whole protein v amino acid based feed and a case study of dietary challenge

A controlled trial was performed to compare enteral feeding with either an amino acid based feed or a whole protein feed as sole treatment for active Crohn's disease. Twenty four patients were studied (nine with ileal, 11 with ileocolonic, and four with colonic disease). Both feeds proved effective; nine of 13 patients randomised to receive the amino acid based feed were in clinical remission within three weeks as defined by a simple activity index compared with eight of 11 treated with the whole protein feed. Patients in clinical remission were then crossed over onto the other feed. None of the six patients who were changed to the whole protein feed relapsed over the subsequent three week period compared with three of seven patients who were changed to the amino acid based feed. In responders the median serum C reactive protein concentration fell from 21 mg/l (range 9-82) on entry to 6 mg/l (range 3-19) at six weeks. Seven patients relapsed within eight months of starting solid food (mean 3.7 months), while nine were still in remission (follow up period 3-9 months, median six months). Detailed studies of staged reintroduction of food and permitted food additives were carried out over a four year period in a patient with extensive stricturing small bowel Crohn's disease who had been brought into remission by open treatment with enteral feeding. Carrageenan, other permitted emulsifiers, bread, meat, potatoes, oranges, refined sugar, dairy produce, flour, and rice were all reintroduced without any objective ill effect, but green vegetables provoked a clinical and biochemical relapse within one week of introduction. Remission was rapidly achieved by switching back to the enteral feed but reintroduction of the low residue diet that had been previously tolerated produced a brisk relapse. Clinical and biochemical remission was again achieved by a return to the enteral feed but relapse again occurred with reintroduction of the low residue diet. These studies confirm the therapeutic effect of enteral feeding in Crohn's disease. This effect does not seem to be due to avoidance of whole protein, but the very low residue of chemically defined enteral feeds may be important, particularly in patients with intestinal strictures.

Comparison of distribution and photodynamic effects of di- and tetra-sulphonated aluminium phthalocyanines in normal rat colon

We have previously reported photodynamic therapy of normal rat colon using aluminium sulphonated phthalocyanine (AISPc). In that study, the AISPc used was a mixture of phthalocyanines of different degrees of sulphonation. Phthalocyanines of defined degrees of sulphonation have recently become available and we compared the distribution of the di- and tetra-sulphonates (AIS2Pc and AIS4Pc) in rat colon and colon wall structures employing both chemical extraction and fluorescence photometry using a charge coupled device imaging system. Also, the photodynamic effects produced by these components in rat colon were compared at various times after photosensitization. After intravenous photosensitizer administration using equimolar doses, the concentration of AIS2Pc in colon fell off more rapidly with time than AIS4Pc. Differences were noted in the microscopic distribution of these compounds, with the di-sulphonate exhibiting peak fluorescence in colon wall structures by 1 h after photosensitization, while mucosal fluorescence with the tetra-sulphonate peaked at 5 h. Fluorescence was also lost from the colon wall much more slowly with the tetra-sulphonate, which tended to be retained in the submucosa. Maximum photosensitizing capability was seen at 1 h with AIS2Pc and no lesions could be produced with photodynamic therapy at 1 week, with up to 5.65 mumol/kg. With AIS4Pc (5.65 mumol/kg), while no lesions could be produced with light treatment at 1 h, photodynamic therapy at 1 week produced lesions only slightly smaller than those produced with treatment at 48 h (the time of maximum effect), and significant photosensitization was present at 2 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

Palliative laser therapy for tumours of the gastrointestinal tract

The argon ion and Nd: YAG lasers were used initially in the mid 1970s to produce haemostasis in acutely bleeding peptic ulcers. With the evolution of treatment techniques, the main area of use of the Nd: YAG laser has now become the palliation of upper and lower GI malignancies. Thermal ablation of tumours may be achieved endoscopically by non-contact laser application at high power, or in the contact mode using artificial sapphire probes at much lower energy levels. Still lower powers can be employed therapeutically using interstitial hyperthermia, and this is best applied endoscopically to exophytic tumour nodules in the gut lumen or to tumours localized ultrasonically in solid organs, such as the liver or pancreas. PDT involves destruction of previously photosensitized tumours by the cytotoxic action of singlet oxygen released on exposure of the neoplastic tissue to light of an appropriate wavelength. Although the theory is attractive, the available experimental and clinical information suggests that treatment should, for the present, be confined to small or early malignancies whose depth of invasion can be verified by endoscopic ultrasound or other imaging techniques. PDT carries the biological advantage of healing by regeneration with preservation of connective tissue stroma, while the Nd: YAG laser causes destruction by thermal coagulation or vaporization and subsequent healing by fibrosis. Laser therapy of GI tumours expands the range of therapeutic endoscopic procedures in a relatively safe and readily repeatable manner which achieves high patient tolerance. By reducing morbidity, mortality and time spent in hospital, it offers significant advantages in the palliative treatment of conditions previously managed by conventional surgery, and also offers opportunities for treatment of previously inoperable disorders. Developments in laser technology and diagnostic imaging techniques are likely to promote laser therapy in the future as a primary treatment modality.

Selective necrosis in dimethylhydrazine-induced rat colon tumors using phthalocyanine photodynamic therapy

Photodynamic therapy is a relatively new method for the local destruction of tumors based on the administration of a photosensitizing agent that is retained in tumors and then activated to produce cytotoxic agents following irradiation with light. The selective retention of photosensitizers by dimethylhydrazine-induced colonic tumors over adjacent normal tissue is small (2:1, tumor to normal), making the possibility of producing selective tumor necrosis with total sparing of normal tissue difficult. Colonic cancers and adjacent normal colon were treated with the same light doses from an argon-pumped dye laser 48 h after intravenous injection of 0.5 or 5 mg/kg of the photosensitizer, aluminum-sulfonated phthalocyanine. There was little difference between the amount of necrosis in the tumor and the adjacent normal colon if the injected dose of photosensitizer was 5 mg/kg. However, at the lower dose of 0.5 mg/g, up to 2 mm of necrosis could be produced in the tumor without damaging the normal colon. In vivo fluorescence measurements showed that the photosensitizer was photodegraded during irradiation. This was confirmed by in vitro fluorescence scans of the normal colon after irradiation; the fluorescence from the photosensitizer was lowest at the point of irradiation. It is postulated that at low dosage, selective necrosis can occur because the photosensitizer is photodegraded in the normal colon before a threshold photodynamic dose is reached, whereas in tumor containing twice as much photosensitizer, a photodynamic threshold dose can be achieved and necrosis produced.

Prospective randomised trial of laser therapy only and laser therapy followed by endoscopic intubation for the palliation of malignant dysphagia

Forty six consecutive patients admitted for the relief of malignant dysphagia were prospectively randomised to receive laser therapy only or initial laser therapy followed by endoscopic intubation. Twenty patients were treated in each group with six exclusions. The patients' swallowing ability was assessed before and during the remainder of their life on a 0-4 scale with 0 being normal swallowing and 4 total dysphagia. The patient's quality of life was measured at the same times, using a physician's assessment (QL index) and the patient's own assessment using a linear analogue self assessment (LASA). There was a significant correlation between all the QL index and the LASA scores collected (n = 126; rs = 0.594, p less than 0.001). The mean monthly dysphagia grade correlated with the QL index (rs = 0.433, p less than 0.001) and the LASA (rs = 0.272, p less than 0.002). There was no significant difference in the dysphagia grade before or after treatment in either group. Dysphagia fluctuated more in those treated with the laser only, however, than in those with a tube inserted. There was also no significant difference in the quality of life measured between the two groups of patients. The complication rate (laser only 10%, laser/intubation 40%, p less than 0.05) was significantly higher in intubated patients. The recurrent dysphagia rate (laser only 25%, laser/intubation 45%, NS) was higher in patients treated with intubation, but they required fewer endoscopic procedures. Overall both procedures were effective in relieving dysphagia and in maintaining quality of life. There was no procedure related mortality in either group.

Photodynamic therapy for colorectal cancer: a quantitative pilot study

Ten patients with colorectal cancers unsuitable for operation were treated with endoscopic photodynamic therapy (PDT). The patients were assessed before treatment, and at 1 week and 1 month after treatment by colonoscopy with biopsy and endoluminal ultrasound examination. The depth of tumour was measured and the effect of PDT was quantified by measuring the reduction in tumour depth. All patients were sensitized with 2.5 mg kg-1 of haematoporphyrin derivative, 48 h before phototherapy. A standard treatment protocol of light exposure was used. Up to four parts of the tumour were treated with 50J of red light (630 nm) from a tuneable dye laser, through a flexible optical fibre passed through the colonoscope and inserted into the tumour. Two patients with small lesions are tumour-free 20 and 28 months after PDT. One treatment of an advanced tumour was complicated by a haemodynamically significant secondary haemorrhage. PDT may be most suitable for the treatment of small tumours or for small areas of persistent tumour where the bulk has been removed by alternative techniques.

A prospective randomised controlled trial of tamoxifen and cyproterone acetate in pancreatic carcinoma

In a prospective controlled clinical trial, 108 patients with pancreatic adenocarcinoma were randomly allocated to receive tamoxifen 20 mg b.d., cyproteron acetate 100 mg t.d.s. or no active treatment. The median survival of those receiving tamoxifen was longer than either of the other two groups (5.25 compared to 4.25 and 3 months, respectively) but this difference did not achieve statistical significance. Cox regression analysis of 12 clinical and biochemical features showed that, for the entire group of patients, survival was significantly longer in younger patients, those undergoing surgical bypass and those with better initial performance status. However, even when adjustment was made to allow for the distribution of these prognostic variables within the three groups, the difference in survival still did not achieve statistical significance. No side-effects attributable to treatment was observed.

Palliative laser therapy for inoperable rectal cancer--does it work? A prospective study of quality of life

Endoscopic neodymium yttrium aluminium garnet (Nd YAG) laser therapy, is a new and simple method for the palliative treatment of inoperable colorectal cancer. To date the authors have treated 70 patients and the value of this method was assessed prospectively in 14 patients. Quality of life was measured before, during, and after treatment. The quality of life (QL) index, a physician's assessment and a linear analogue self-assessment (LASA) were used. A close correlation was found between the two assessment methods (r = 0.79). Overall there was a significant improvement from the mean pretreatment score and the best score achieved posttreatment (QL: P = 0.002; LASA: P = 0.002). Patients with diarrhea, rectal bleeding, mucus discharge, or pain secondary to tumor bulk, will benefit most from this treatment. Malignant cachexia, pain secondary to sacral plexus involvement, tumor encroachment on the anal canal and/or sphincter dysfunction resulting from tumor invasion should be viewed as relative contraindications to laser therapy. The authors conclude that in selected patients endoscopic laser therapy can provide effective palliation in patients with malignant tumors of the rectum and descending colon.

Laser therapy in the management of benign and malignant tumours in the colon and rectum

Since 1983 the Neodymium-YAG laser has been used endoscopically to treat 93 patients with inoperable colorectal carcinoma and 18 patients with benign sessile adenomas. In an additional 11 patients with colorectal cancer, photodynamic therapy (PDT) has been applied using an argon-pumped dye laser. Objective and subjective measurements of quality of life have shown the beneficial effects of the Nd-YAG laser in the relief of symptoms, and four patients have apparently been rendered disease free. Benign tumours also respond to Nd-YAG ablation but close histological supervision is necessary to detect malignant transformation at an early stage. Although PDT may offer a potential for cure in small inoperable tumours, it seems likely that Nd-YAG laser treatment will remain the laser option of choice for advanced bulky tumours.

Photodynamic therapy for colorectal disease

Photodynamic therapy (PDT) involves the parenteral administration of a photosensitising agent with some selectivity for malignant tissue. When activated by light, usually from a laser, local tissue destruction occurs. The amount of tissue destruction is dependent on the concentration of the photosensitising agent in the tissue and the light energy delivered. By careful manipulation of laser energy and photosensitiser dosage true selective destruction of malignant tissue can be produced in experimental colon cancers with total sparing of normal colon although under these conditions, the extent of necrosis in the tumour is only 2-3 mm from the light source. In addition, PDT has been shown not to reduce the mechanical strength of the colon even if full thickness necrosis is produced in normal areas. In contrast, thermal full thickness laser damage of the colon considerably weakens the colonic wall and may cause perforation. Light microscopy with specific collagen stains and electron microscopy have shown that the submucosal collagen layer is preserved following PDT, but is destroyed by thermal laser therapy. An initial clinical trial of PDT has been performed in ten patients with inoperable tumours because of advanced metastatic disease or severe medical problems. PDT has been shown to be safe and some small colorectal cancers can be totally eradicated.

Endoscopic application of lasers in gastrointestinal disease

Laser therapy in gastrointestinal disease offers ever-increasing possibilities for therapeutic endoscopy with the prospect of reducing hospitalization, morbidity and mortality in many conditions traditionally treated by conventional surgery, as well as the opportunity to provide worthwhile palliation for previously inoperable disorders.

Massive pneumoperitoneum following laser therapy of inoperable oesophageal carcinoma

Two cases of large pneumoperitoneum are described following palliative laser therapy for inoperable oesophageal carcinoma. In both cases there was no constitutional upset and no perforation demonstrated on contrast examination of the oesophagus. The pneumoperitoneum is considered to be due to high pressure CO2, used to keep the tip of the laser clean, passing through the tumour and tracking into the peritoneum. The condition requires only conservative treatment.

Local control of rectal cancer with the Nd-YAG laser

Three patients with locally recurrent rectal cancer were treated using the Neodymium YAG laser to palliate the symptoms of tenesmus, discharge and bleeding. All were considered unfit for further surgical excision. The local tumour was completely removed following repeated laser therapy over a period of 4, 6 and 11 months, respectively. These patients remain well without evidence of local or systemic disease 26, 33 and 42 months after laser treatment. Laser therapy for palliation of local disease may be rewarded by prolonged local control and possible cure.

Photodynamic therapy in the normal rat colon with phthalocyanine sensitisation

Photodynamic therapy (PDT) involves the interaction of light with an administered photosensitising agent to produce cellular destruction. It has promising potential for the local and endoscopic treatment of gastrointestinal cancer. There is however little data on the response of normal intestine to PDT. We have investigated the use of a new photosensitiser chloro aluminum sulphonated phthalocyanine (AlSPc) for colonic PDT. The peak concentration of AlSPc in the colon measured by alkali extraction occurred 1 h after i.v. injection. The cellular uptake demonstrated by laser fluorescence microscopy was greater in the mucosa than in the muscle. AlSPc was activated in the tissues by light from an argon ion pumped dye laser at 675 nm. The laser power was set at 100 mW and the fibre placed touching the mucosa. In control animals no macroscopic damage was seen. Temperature measurement using a microthermocouple array showed no temperature rise during light exposure. The energy (fluence), dose of sensitiser and time from sensitisation to phototherapy were altered and the area of necrosis measured. The geometry of the colon made theoretical analysis of the correlation between laser energy and size of lesion difficult. However, following direct measurement of the relative light intensity (fluence rate) in the colon we were able to confirm that there was a threshold fluence for colonic necrosis. The area of photodynamic damage seen 72 h after phototherapy fell with the fall in tissue concentration of AlSPc from 1 h to 1 month after i.v. injection. However, maximum tissue necrosis occurred when treatment was performed immediately after i.v. injection. In this situation, intense vascular spasm was seen and any light transmitted through the colon which fell on the small bowel mesentery caused a lethal ischaemic necrosis. The initial histological changes after PDT were vascular, followed by full thickness necrosis at 72 h. Healing by regeneration was complete by 2-3 weeks. Despite full thickness necrosis there was no reduction in the colonic bursting pressure at any time. Colon treated by hyperthermia had a reduced bursting pressure. Specific collagen stains showed that PDT did not alter the submucosal collagen architecture whereas hyperthermia did.

Palliative laser therapy for malignant dysphagia

Seventy six patients with dysphagia caused by malignant tumours of the oesophagus or gastric cardia have been treated using the Neodymium Yttrium Aluminium Garnet (NdYag) laser. The laser was set to deliver 80-100 watts of power for 0.5-1 second pulses. To obtain improvement, patients on average needed four treatment sessions with a mean energy per treatment of 3586 joules. Follow up endoscopy and laser treatment was at four week intervals, unless the clinical or endoscopic results indicated otherwise. The immediate result was to allow 32% of patients to swallow anything they liked, a further 54% were able to take most solids and 9% were improved, or maintained on liquids only. The mortality of laser recanalisation and associated treatment was 5%. The improvement in swallowing was maintained until death in all but 15% of these patients, some of the 15% needed intubation to allow adequate swallowing. Endoscopic, or surgical intubation was required immediately in five patients after an initial laser course failed to provide improvement. The mean survival of the whole group was 19 weeks (range one to 112 weeks).

Oesophagogastric tumour in old age: palliative treatment by endoscopic laser photocoagulation

The results of palliative treatment, with laser photocoagulation used alone, of oesophagogastric tumours in 23 patients mean age 81.9 (range 75-93) years are reviewed. Most were frail including five with metastatic disease, seven with cardiovascular disease and five with cerebrovascular disease. Dysphagia was the presenting symptom in 21 patients, two presented with an acute haematemesis. Improvement in swallowing was achieved in 19 (90.5%). Hospital stay was minimal, and 93.3% deaths were in the community. The only complication was perforated oesophagus in 1 patient, treated successfully by conservative management. We suggest laser photocoagulation as the palliative treatment of choice for dysphagia due to oesophagogastric tumour in the frail elderly patient even when the malignancy is at an advanced stage. The major benefit of the technique is the ability to maintain patients comfortably in the community rather than committing them to terminal care in a hospital environment.

Alcohol enhances vitamin C excretion in the urine

Urinary ascorbic acid excretion was measured on four consecutive days in 9 normal male volunteers for 4 hr before and after drinking nothing (control), 0.58 g alcohol/kg body wt as whisky or lager or water (11./70 kg body wt). The normal reduction in ascorbic acid excretion under control conditions was abolished by drinking water. Alcohol in either form produced a 47% increase in urinary ascorbic acid excretion. A similar ascorbiuresis in chronic alcoholics would be an additional factor in the causation of vitamin C deficiency in these patients.

Advances in gastrointestinal endoscopy and laser therapy; the way ahead

Modern flexible fibreoptics enable gastroenterologists to visualise and treat many lesions and conditions in the upper gastrointestinal tract and colon. Therapeutic endoscopy is forming a larger proportion of many unit's workload and the newer techniques to stop or prevent rebleeding are the subject of much research and development. Developments in the fields of operative endoscopy, small intestinal endoscopy, and endoscopic ultrasound are also progressing rapidly. The place of video-endoscopy is still to be established but potentially has several advantages over fibreoptic endoscopy. Laser therapy has been well established as a means of treating gastrointestinal haemorrhage from peptic ulcers, and has potential use in the treatment of angiomatous lesions. It is increasingly being used both for palliation and 'cure' of malignancy and neoplasia in the gastrointestinal tract. The use of such lasers depends upon thermal damage, but newer types of non-thermal laser therapy, using pulsed lasers, or dye lasers with prior tumour sensitisation are rapidly going to be applied to the treatment of gastrointestinal disease.

Is there a place in the United Kingdom for intensive antacid treatment for chronic peptic ulceration?

Sixty nine patients with chronic duodenal or juxtapyloric ulceration were studied in a prospective double blind randomised trial to compare the efficacy of antacid and placebo at high (30 ml seven times daily) and low (10 ml as required) doses. After four weeks ulcers had healed in 12 out of 18 patients (67%) receiving "low dose" antacid compared with in six out of 17 patients (35%) receiving low dose placebo; ulcers had also healed in six out of 19 patients (32%) receiving "high dose" antacid compared with in two out of 15 patients (13%) receiving high dose placebo. Overall, the effect of antacid was superior to that of placebo in healing ulcers (p less than 0.05) and the effect of low dose treatment was superior to that of high dose treatment (p less than 0.01). There were no significant differences between antacid and placebo at eight weeks. Antacid was better than placebo in relieving pain, but the difference was not significant. Poor compliance and high incidence of diarrhoea made high dose antacid an impractical treatment. Low dose antacid was associated with a significantly better rate of healing than high dose antacid and was far better tolerated. This low dosage of antacid should be considered to be an active treatment in trials of ulcer healing.

Acute pancreatitis and Cushing's syndrome

A case of acute necrotizing pancreatitis in a 53-year-old man with an ectopic adrenocorticotrophin (ACTH) producing bronchial carcinoma is described. The aetiology of acute pancreatitis in relation to steroid therapy and malignancy is discussed and it is suggested that excess endogenous steroid production may also cause acute pancreatitis.

Injection sclerotherapy for oesophageal varices in the elderly

Thirty-seven patients admitted consecutively to the Gastroenterology Unit with haemorrhage from oesophageal varices were treated by injection sclerotherapy. The patients were subdivided according to age at presentation (below 65, over 65 years). The mortality and morbidity of the two groups, over the period of follow-up (mean 5.1 months) were compared. The risk of rebleeding was higher in the elderly (0.23 overall) than in the young (0.11 overall) and was reflected in the higher mortality, four of 14 elderly patients and four of 23 younger patients. A further three elderly patients succumbed to intercurrent illness during the same period. In three of the surviving elderly, complete resolution of varices was noted. Complications of sclerotherapy occurred in eight out of 51 injections in the elderly and six out of 97 in the young but were usually well tolerated. This study suggests that injection sclerotherapy is useful in the treatment of bleeding oesophageal varices in the elderly and suggests recommendations for improved survival.

Benign mesenchymoma of the stomach

Benign mesenchymoma is a mixed tumour of mesenchymal derivatives composed of a mixture of two or more mesenchymal elements in addition to fibrous tissue. Two cases of this tumour of the stomach are reported. As far as can be ascertained, there has been no previous report of gastric mesenchymoma.

Extensive gastrointestinal damage following a saline emetic

A 27-year old female received about 1 kg of salt in about 600 ml of water as an emetic after a self-poisoning attempt. Vomiting did not occur and massive necrosis of gastric, duodenal, and jejunal mucosa resulted in a severe and prolonged illness which required 31 weeks of continuous hospital care and 31 laparotomies over a period of 16 months. The dangers of salt emesis are emphasized.

Coeliac disease presenting as acute bleeding disorders

Two young women presented with acute bleeding disorders and were subsequently found to have coeliac disease.

Hepatocellular carcinoma in primary biliary cirrhosis: report of four cases

Of 98 patients dying with primary biliary cirrhosis only four developed hepatocellular carcinoma. It is suggested that the development of hepatocellular carcinoma is uncommon in this type of chronic liver disease because of its known female preponderance, and the fact that cirrhosis develops late in the course of the illness.

Hepatocellular carcinoma in Great Britain: influence of age, sex, HBsAg status, and aetiology of underlying cirrhosis

An analysis of 294 patients who died with cirrhosis showed that 24% had developed hepatocellular carcinoma. Haemochromatosis and HBsAg positive chronic active hepatitis were high risk groups (36% and 42% respectively) and the frequency was lowest in primary biliary cirrhosis and HBsAg negative chronic active hepatitis (3% and 11% respectively). Those with hepatocellular carcinoma showed a striking male preponderance (11:1) and further analysis has shown that the proportion developing this tumour in each group was closely related to the proportion of males in that group (r=0.97). Age was the only other significant factor, malignant change occurring more commonly in those over the age of 50 years than those below (30% and 7% respectively, P less than 0.005). The indluence of HBsAg was largely accounted for by the known predisposition of males to carry HBsAg. The group of patients who had developed this tumour without cirrhosis were younger (mean age 39 years) and had a lower male to female ratio of 1.1:1 and the place of contraceptive-related tumour within this group is dicussed.