Improving the detection rate of early gastric cancer requires more than open access gastroscopy: a five year study

A survey of open-access endoscopy in primary health care centres: outcome of gastric carcinoma patients diagnosed by general practitioners compared with hospital-referred endoscopy

BACKGROUND

We examined open-access endoscopy service based on general practitioner endoscopists.

METHODS

We compared the survival of the gastric carcinoma patients originally diagnosed in health care centres by general practitioner endoscopists and hospital outpatient clinic by specialists.

RESULTS

A total of 159 gastric carcinoma cases diagnosed during 1996-2000 were included in to the present study. Of them, 58% (N = 92) and 42% (N = 67) were detected by general practitioners and specialists, respectively. We observed no difference in the mean age of patients (71.3 years versus 71.4 years, p = 0.97) and stage of tumours [15% (N = 14) versus 21% localised tumours (N = 14, p = 0.30)] between cases diagnosed by general practitioners and specialists. The number of patients who underwent radical extirpation were 14% (N = 13) and 19% (N = 13, p = 0.38), respectively. After a minimum follow-up of 3.5 years, 29 patients (18%) were alive. The mean survival time of hospital-diagnosed carcinoma patients was longer (23.6 months versus 18.7 months, p = 0.23). Eight patients had undergone hospital-referred gastroscopy less than 3 years before cancer diagnosis. In multivariate analysis, radical extirpation of carcinoma (odds ratio 0.11, 95% confidence interval 0.04-0.28) predicted survival; whereas age (odds ratio 1.03 per year, 95% confidence interval 0.99-1.07 per year), female sex (odds ratio 1.785, 95% confidence interval 0.71-4.81) and the open-access endoscopy based on general practitioner endoscopists (odds ratio 1.48, 95% confidence interval 0.60-3.65) predicted neither survival nor carcinoma-related death.

CONCLUSION

No significant difference was detected in the outcome of gastric cancer patients diagnosed in primary care centres by general practitioner endoscopists and in hospital outpatient clinic by specialists.

Dysphagia referrals to a district general hospital gastroenterology unit: hard to swallow

The aim of our study was to audit dysphagia referrals received by a specialist gastroenterology unit during an entire year. We used a prospective audit carried out over a 12-month period at the District General Hospital gastroenterology unit. The audit included 396 consecutive patients who were referred with swallowing difficulties. We found that 60 referrals (15.2%) were inaccurate and the patients had no swallowing problem. Of the 336 patients with genuine dysphagia, only 29 (8.6%) were new cancer cases. The large majority of subjects had benign disease mostly related to acid reflux. Weight loss was significantly associated with malignancy but also occurred in one third of patients with reflux alone. The temporal pattern of dysphagia was not significantly predictive of cancer. All the cancer patients were above the age of 50 years. Although patients were in general assessed rapidly after hospital referral, the productivity, in terms of early tumor diagnosis, was extremely low. We conclude that there is a substantial rate of inaccurate referrals of dysphagia patients. Most true cases of swallowing difficulty relate to benign disease. Even the devotion of considerable resources to the early diagnosis of esophago gastric malignancy in an attempt to conform with best practice guidelines results in a very low success rate in terms of the detection of potentially curable tumors.

Cost-benefit analysis of Helicobacter pylori screening

BACKGROUND

Helicobacter pylori screening may markedly reduce mortality and morbidity in the decades ahead.

AIMS

This study explores the costs and benefits of population-based H. pylori screening in terms of health care cost taking into account all relevant H. pylori-related diseases.

MATERIAL AND METHODS

The computer-based decision analysis compared two strategies: (1) screen for H. pylori and treat those individuals who test positive, and (2) do not screen for H. pylori, and test and treat H. pylori only if related clinical symptoms appear. The model estimated the discounted H. pylori-related accumulative health care costs from screening age to death in both strategies. The baseline case estimates cost-benefit for screenees aged 15-45 years. The main outcome measure is the incremental health care cost per case in the screening compared with the no-screening alternative. The probability estimates were obtained from the Finnish Vammala H. pylori screen and treat project, including 5288 subjects in the years 1996-1998, published studies, national statistics and hospitals' internal accounts.

RESULTS

The incremental cost per case was 26 US dollars in the screening compared with the no-screening alternative. It was lowest in the group aged 45 years, where H. pylori screening showed cost savings per case.

CONCLUSIONS

H. pylori screening is more favourable in the older age cohorts. The estimated cost per screenee can be considered to be very acceptable if the current pathophysiological evidence on the potential effects of H. pylori eradication are confirmed in the future. However, there is uncertainty about the possible negative effect of eradicating H. pylori infection on gastro-esophageal reflux disease and esophageal adenocarcinoma. This could change the balance of benefits against risks of eradicating H. pylori infection.

Intraprocedural steps to enhance efficiency

This section focuses on intraprocedural steps that can improve endoscopic efficiency. Contributors to procedural efficiency and inefficiency are considered. The limitations to enhancing efficiency are presented. Strategies for incorporating contributors to efficiency including techniques, technologies, accessories, and attitudes are presented.

Empirical use of antisecretory drug therapy delays diagnosis of upper gastrointestinal adenocarcinoma but does not effect outcome

BACKGROUND

Upper gastrointestinal cancer carries a poor prognosis. Although the incidence of gastric adenocarcinoma is falling, oesophageal adenocarcinoma is increasing. This has been attributed to an increasing prevalence of gastro-oesophageal reflux disease, commonly treated empirically in primary care with antisecretory drugs. Treatment has been associated with delayed diagnosis but it is unclear if this influences prognosis.

AIMS

To ascertain the effect of antisecretory drugs on time to diagnosis, symptoms, tumour stage and outcome.

METHODS

A retrospective cohort study of primary care records for 747 patients diagnosed with upper gastrointestinal adenocarcinoma at South Tees NHS Trust between 1991 and 2001.

RESULTS

Mean time from the onset of symptoms to diagnosis was 30 weeks. Mean and median times at the primary care stage were longer than at the hospital stage for both oesophageal and gastric cancer (P < 0.0001). Patients with benign symptoms prescribed antisecretory drugs were referred later than those not on antisecretory drugs (P < 0.0001), as were patients with alarm symptoms (P = 0.0008). Prior use of antisecretory drugs delayed diagnosis by 17.6 weeks (mean) but had no effect on tumour stage at diagnosis or survival.

CONCLUSION

Prior antisecretory drug therapy was associated with delayed diagnosis of upper gastrointestinal adenocarcinoma irrespective of presenting symptoms. Concerns that delays might adversely affect tumour stage or long-term survival were not substantiated.

Biopsy assessment of drug efficacy in the gastrointestinal tract

When using biopsy pathology in clinical pharmacology to assess drug efficacy in the gastrointestinal tract, a number of questions must be answered: Is the biopsy necessary or more effective than macroscopic views by endoscopy? Can we extract maximal information from the specimen? Are there surrogate serum or other markers that give an overall measure of disease and/or improvement? Indeed, clinicopathological correlation is of paramount importance. If biopsy is to be used, it is important to utilize appropriate scoring systems. Many grading systems use continuous spectra, which are ordinal categorical variables and therefore a grading system of assigned 'numbers' which cannot be used in processes that require continuous variables such as linear regression. The use of grading vs a 'true' score with real numbers must be carefully considered, the site and number of biopsies must be precisely chosen and interobserver reproducibility of results evaluated before undertaking drug trials. Immunocytochemistry and in situ hybridization, however, can provide quantifiable molecular information related to mechanisms of drug action. The biopsy is of significant value as it is a true in vivo assessment if the above caveats are taken into account. However, further work is needed to determine sound histological criteria to assess the efficacy of drugs for use in gastrointestinal disease.

Open-access gastroscopy is associated with improved outcomes in gastric cancer

OBJECTIVE

To examine whether patients with gastric cancer diagnosed via open-access gastroscopy (OAG) differ in their outcomes compared with patients referred conventionally to outpatient clinics or as acute emergencies.

DESIGN AND SETTING

Prospective observational study in the gastroenterology and surgical units of a large district general hospital.

PARTICIPANTS

One hundred consecutive patients with gastric adenocarcinoma.

MAIN OUTCOME MEASURES

Data were collected prospectively and subdivided into two groups according to whether the patients were referred via the open-access route or the conventional route.

RESULTS

Diagnostic delay from onset of symptoms was shorter for patients referred via OAG compared with those referred conventionally. Stages of disease were significantly earlier in patients referred via OAG compared with patients referred conventionally. Potentially curative resection was significantly more likely following OAG than after conventional referral. Cumulative five-year survival for patients referred via OAG was 30% compared with 12% after conventional outpatient referral and 13% after acute referral. Multivariate analysis revealed three factors to be associated with survival: stage of disease, distant metastases and referral via the open-access route.

CONCLUSIONS

Gastric cancers presenting at OAG were diagnosed at an earlier stage than cancers diagnosed after conventional referral. This led to a higher proportion of potentially curative resections and better five-year survival.

Can a non-invasive strategy for managing young dyspeptics be safely implemented in Asia?

Dyspepsia is a common problem in the Asia-Pacific region, with a prevalence rate ranging from 10-20%. It constitutes 2-5% of consultations with primary-care physicians and forms a major part of the gastroenterologists' workload. Although upper gastrointestinal endoscopy (UGIE) is the investigation of choice, no serious disease is present in the majority of patients and various other ways have been suggested, mainly in the West, to reduce the demand on the finite resources of UGIE services. The alternative methods to UGIE have been based on non-invasive detection of Helicobacter pylori in patients with dyspepsia, as the organism has been shown to be associated with most peptic ulcers and even gastric cancer. A positive H. pylori test in a patient with dyspepsia may not necessarily indicate serious disease, but H. pylori eradication eliminates the propensity for developing peptic ulcers and perhaps even cancer (not proven). In high-risk populations, non-invasive screening for H. pylori can even be considered a 'cancer test', as it can help target investigations in a selected group of patients.

The effects of an awareness-raising program for patients and primary care physicians on the early detection of gastro-oesophageal cancer

OBJECTIVE

To test the efficacy of education by home letter, together with improved specialist/GP liaison, in promoting the detection of treatable gastro-oesophageal cancer in patients over 40.

DESIGN

Prospective non-randomized trial with matched control group.

PARTICIPANTS

37,500 individuals over 40, registered with 12 general practices, were sent yearly letters for 3 consecutive years, advising them to consult a doctor with 4 specific symptoms. A matched control population of 60,500 received no intervention.

MAIN OUTCOME MEASURES

Cancer cases were identified from cancer registry data, and the stage distribution and operability rates calculated from review of hospital case notes.

RESULTS

Twenty of 59 cancer patients in the study group (34%) and 42 of 125 in the control group (34%) underwent resections; 24% (14/59) of study group and 18% (23/125) of control patients had "curable" disease (odds ratio [OR]= 1.51 [95%CI 0.71-3.23], X(2) = 1.164, P = 0.28). In year 1 of the study, 11 of 20 (55%) study group patients underwent resection compared to P 10 of 38 (26%) control group patients (P = 0.045, Fisher's exact test, OR = 3.4 [95% CI 1.09-0.7]). In year 1, 8 of 20 study patients (40%) had "curable" disease compared to 10.5% (4/38) control patients (P = 0.0128 Fisher's exact test, OR = 5.67 [95% CI 1.44 - 22.3]). There was no difference in survival between the groups overall or on comparing each year of study.

CONCLUSION

This intervention caused a transient marked improvement in resection rate and curability, but the longer term impact on stage and resection rate was nonsignificant, and survival was not affected. Improving the detection of curable upper GI cancer is likely to require more complex and intensive interventions.

Audit of a nurse endoscopist based one stop dyspepsia clinic

As a response to the UK Health Department's "two week cancer wait" initiative a one stop dyspepsia clinic based on a nurse endoscopist was introduced, and the first 100 cases attending this clinic have been audited. After referral on a purpose designed form, patients were assessed by a gastroenterologist and then investigated at the same visit--where possible and appropriate--by endoscopy or ultrasound scan. All endoscopies were performed by a trained nurse specialist. Of the 100 patients, 84 were gastroscoped the same day and 11 had an ultrasound scan. Inappropriate tests were avoided in 16% of referrals. The commonest endoscopic diagnoses were minor oesophageal or gastroduodenal inflammation (64% of gastroscopies). Only six oesophageal or gastric cancers were found--all at an advanced stage--and three further malignancies were diagnosed. Only a minority (12%) of the patients with "alarm symptoms" had cancer. The waiting time for an appointment rose progressively during the first six months of the clinic. The system was popular with patients as most of them (70%) were dealt with at a single hospital attendance. Basing the endoscopy practice on a trained nurse specialist not only facilitated the creation of the service by maximising the use of scarce resources, but also improved communication and overall management of patients.

Gastric cancer: diagnosis, risk factors, treatment and life issues

Gastric cancer is the sixth most common malignancy in the UK. It is responsible for over 9000 deaths annually in the UK. Distal gastric cancer has a decreasing incidence, but proximal gastric cancer continues to increase. Gastroscopy remains the gold standards for accurate diagnosis. Early diagnosis is essential, but symptoms and signs are often mistaken for other less serious diseases. Major surgery is the only proven treatment, but 5-year survival rates postoperatively are only 34%, and many people will continue to suffer side-effects of the surgery. Open access gastroscopy and health promotion may be the best chance of detecting this disease early enough so that it is treated successfully.

In vivo near-infrared Raman spectroscopy: demonstration of feasibility during clinical gastrointestinal endoscopy

Raman spectroscopy (RS) has potential for disease classification within the gastrointestinal tract (GI). A near-infrared (NIR) fiber-optic RS system has been developed previously. This study reports the first in vivo Raman spectra of human gastrointestinal tissues measured during routine clinical endoscopy. This was achieved by using this system with a fiber-optic probe that was passed through the endoscope instrument channel and placed in contact with the tissue surface. Spectra could be obtained with good signal-to-noise ratio in 5 s. The effects on the spectra of varying the pressure of the probe tip on the tissue and of the probe-tissue angle were determined and shown to be insignificant. The limited set of spectra from normal and diseased tissues revealed only subtle differences. Therefore, powerful spectral-sorting algorithms, successfully implemented in prior ex vivo studies, are required to realize the full diagnostic potential of RS for tissue classification in the GI.

In vivo near-infrared Raman spectroscopy: demonstration of feasibility during clinical gastrointestinal endoscopy

Raman spectroscopy (RS) has potential for disease classification within the gastrointestinal tract (GI). A near-infrared (NIR) fiber-optic RS system has been developed previously. This study reports the first in vivo Raman spectra of human gastrointestinal tissues measured during routine clinical endoscopy. This was achieved by using this system with a fiber-optic probe that was passed through the endoscope instrument channel and placed in contact with the tissue surface. Spectra could be obtained with good signal-to-noise ratio in 5 s. The effects on the spectra of varying the pressure of the probe tip on the tissue and of the probe-tissue angle were determined and shown to be insignificant. The limited set of spectra from normal and diseased tissues revealed only subtle differences. Therefore, powerful spectral-sorting algorithms, successfully implemented in prior ex vivo studies, are required to realize the full diagnostic potential of RS for tissue classification in the GI.

Detection of upper gastrointestinal cancer in patients taking antisecretory therapy prior to gastroscopy

BACKGROUND

The incidence of early gastric cancer has not increased despite better access to endoscopic facilities for general practitioners. Many patients receive a course of symptomatic treatment while waiting for gastroscopy.

AIMS

To ascertain the effect of antisecretory therapy on the diagnostic process and findings for patients with upper gastrointestinal cancer.

METHODS

A consecutive case study survey of the primary care records of 133 patients who had died of upper gastrointestinal cancer during 1995-97 in the South Tees health district in the north-east of England (population 300 000).

RESULTS

From the 133 patients identified, 116 had died from adenocarcinoma of the oesophagus (31) or stomach (85). Failure to reach the diagnosis of cancer at the index gastroscopy was associated with prior acid suppression therapy. Only one of 54 patients on no treatment or antacids alone was erroneously diagnosed as suffering from benign disease, whereas 22 of 62 patients treated with acid suppression were diagnosed as suffering from benign disease but at varying times later turned out to have adenocarcinoma. Twenty of 45 patients taking a proton pump inhibitor had a delayed diagnosis compared with two of 17 taking an H(2) receptor antagonist. The commonest lesion seen at index gastroscopy in those in whom the diagnosis was initially missed was gastric ulcer. Healing occurred in six patients taking a proton pump inhibitor, despite their later diagnosis of malignancy.

CONCLUSIONS

The treatment of dyspeptic symptoms with acid suppression prior to gastroscopy masks and delays the detection of gastric and oesophageal adenocarcinoma on endoscopy in one third of patients.

A pilot study of the safety and effects of the matrix metalloproteinase inhibitor marimastat in gastric cancer

The aim of this study was to evaluate the safety and tolerability of 4 weeks administration of marimastat, and to seek evidence of biological activity as observed by changes in the endoscopic appearance of the gastric tumours. 35 patients with advanced, inoperable gastric or gastro-oesophageal tumours were recruited. The dose of marimastat was reduced from the starting dose of 50 mg twice daily (6 patients) to 25 mg once daily (29 patients). 31 completed the 28 day study period. Marimastat was generally well tolerated, with the principal treatment-related toxicity being pain and stiffness of the musculoskeletal system. These symptoms occurred more frequently at the higher-dose, and increased to involve a total of 13 patients (37%) with longer-term treatment. The events were usually rapidly reversible on drug discontinuation. 3 patients receiving prolonged treatment experienced more severe symptoms, with the development of skin thickening and contractures in the hands. At endoscopy, 10 patients showed an increased fibrotic cover of the tumour, 8 had decreased haemorrhagic appearance, and in at least 2 cases where comparative tumour histology was assessable, there was evidence of increased stromal fibrotic tissue.

Treatment of Helicobacter pylori infection to reduce gastric cancer incidence: uncertain benefits of a community based programme in Australia

Helicobacter pylori is a cause of gastric adenocarcinoma, but the role of H. pylori eradication in reducing cancer risk is unknown. We sought to estimate the benefits of a screening and treatment programme for H. pylori infection, aimed at reducing the incidence of gastric cancer in Australia. The impact of this programme on cancer incidence was evaluated in sensitivity analyses utilizing Western Australian Cancer Registry data and published data on the epidemiology of H. pylori and gastric cancer. The impact of variation in parameters used in the sensitivity analyses was substantial, ranging from a 38% reduction in lifetime risk of gastric cancer in a best-case to 3% in a worst-case scenario. In an intermediate-case scenario there is a 23% reduction in lifetime risk, but in real terms this reflects a fall in cumulative incidence from 0.7 to 0.5% for males or 0.3 to 0.2% for females. The projected cumulative lifetime incidence of gastric cancer in H. pylori-infected males is 2.2% and 0.9% for females; this contrasts with 0.4 and 0.2%, respectively, for those never infected. According to an intermediate-case scenario, to prevent one gastric cancer, screening with or without subsequent treatment would be required in 617 men or 1639 women. Furthermore, this programme may be less effective in reducing cancer incidence than would be achieved naturally over the next 15 years, providing the current annual decline in gastric cancer incidence continues. In conclusion, the benefits of a community based programme of H. pylori eradication in terms of cancer risk reduction remain unclear, related largely to uncertainties in the parameters used to calculate these benefits. In Australia, any benefits obtained are likely to be, at best, modest.