Endoscopic Raman spectroscopy enables objective diagnosis of dysplasia in Barrett's esophagus

BACKGROUND

Early detection and targeted endoscopic resection of Barrett's esophagus-associated high-grade dysplasia (HGD) can prevent progression to invasive esophageal malignancy. Raman spectroscopy, a highly sophisticated analytical technique, has been translated into an endoscopic tool to facilitate rapid, objective diagnosis of dysplasia in the esophagus.

OBJECTIVE

To evaluate the ability of endoscopic Raman spectroscopy (ERS) to objectively detect esophageal HGD and adenocarcinoma.

DESIGN

A total of 798 one-second spectra were measured from 673 ex vivo esophageal tissue samples, collected from patients with Barrett's esophagus by using a novel endoscopic Raman probe. Spectra were correlated with consensus histopathology. Multivariate analysis was used to evaluate the classification accuracy of ERS ex vivo.

SETTING

Probe measurements were conducted in the laboratory. Tissue specimens were collected from the operating theatre and endoscopy unit.

PATIENTS

Tissue from 62 patients was included in the study.

INTERVENTIONS

Endoscopic biopsy/resection or esophagectomy was performed where indicated clinically.

MAIN OUTCOME MEASUREMENT

Diagnostic performance of ERS for detection of HGD and esophageal adenocarcinoma.

RESULTS

ERS demonstrated a sensitivity of 86% and a specificity of 88% for detecting HGD and adenocarcinoma. The ability to grade dysplasia and differentiate intestinal metaplasia from nonintestinal metaplasia columnar-lined esophagus was also demonstrated. Diagnostic classification was based on objective measurement of the biochemical profile of different tissue types. The potential for combination ERS and narrow-band imaging was also demonstrated.

LIMITATIONS

Measurements were taken from ex vivo tissue.

CONCLUSION

ERS enables rapid, accurate, objective diagnosis of superficial esophageal disease (metaplasia, dysplasia, intramucosal cancer) in clinically applicable time scales.

Association between length of Barrett's esophagus and risk of high-grade dysplasia or adenocarcinoma in patients without dysplasia

BACKGROUND & AIMS

It is not clear whether length of Barrett's esophagus (BE) is a risk factor for high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC) in patients with nondysplastic BE. We studied the risk of progression to HGD or EAC in patients with nondysplastic BE, based on segment length.

METHODS

We analyzed data from a large cohort of patients participating in the BE Study-a multicenter outcomes project comprising 5 US tertiary care referral centers. Histologic changes were graded as low-grade dysplasia, HGD, or EAC. The study included patients with BE of documented length without dysplasia and at least 1 year of follow-up evaluation (n = 1175; 88% male), and excluded patients who developed HGD or EAC within 1 year of their BE diagnosis. The mean follow-up period was 5.5 y (6463 patient-years). The annual risk of HGD and EAC was plotted in 3-cm increments (≤3 cm, 4-6 cm, 7-9 cm, 10-12 cm, and ≥13 cm). We calculated the association between time to progression and length of BE.

RESULTS

The mean BE length was 3.6 cm; 44 patients developed HGD or EAC, with an annual incidence rate of 0.67%/y. Compared with nonprogressors, patients who developed HGD or EAC had longer BE segments (6.1 vs 3.5 cm; P < .001). Logistic regression analysis showed a 28% increase in risk of HGD or EAC for every 1-cm increase in BE length (P = .01). Patients with BE segment lengths of 3 cm or shorter took longer to develop HGD or EAC than those with lengths longer than 4 cm (6 vs 4 y; P = nonsignificant).

CONCLUSIONS

In patients with BE without dysplasia, length of BE was associated with progression to HGD or EAC. The results support the development of a risk stratification scheme for these patients based on length of BE segment.

Efficacy and durability of radiofrequency ablation for Barrett's Esophagus: systematic review and meta-analysis

BACKGROUND & AIMS

In patients with Barrett's esophagus (BE), radiofrequency ablation (RFA) safely and effectively eradicates dysplasia and intestinal metaplasia. We aimed to determine the efficacy and durability of RFA for patients with dysplastic and nondysplastic BE.

METHODS

We performed a systematic review and meta-analysis of studies identified in PubMed and EMBASE that reported the proportion of patients treated with RFA who had complete eradication of dysplasia (CE-D) and intestinal metaplasia (CE-IM), and the proportion of patients with recurrent IM after successful treatment. Pooled estimates of CE-D, CE-IM, IM recurrence, and adverse events were calculated.

RESULTS

We identified 18 studies of 3802 patients reporting efficacy and 6 studies of 540 patients reporting durability. Ten were prospective cohort studies, 9 were retrospective cohort studies, and 1 was a randomized trial. CE-IM was achieved in 78% of patients (95% confidence interval [CI], 70%-86%) and CE-D was achieved in 91% (95% CI, 87%-95%). After eradication, IM recurred in 13% (95% CI, 9%-18%). Progression to cancer occurred in 0.2% of patients during treatment and in 0.7% of those after CE-IM. Esophageal stricture was the most common adverse event and was reported in 5% of patients (95% CI, 3%-7%). Confidence in most summary estimates was limited by a high degree of heterogeneity, which did not appear to be caused by single outlier studies.

CONCLUSIONS

Treatment of BE with RFA results in CE-D and CE-IM in a high proportion of patients, with few recurrences of IM after treatment and a low rate of adverse events. Despite the large amount of study heterogeneity, these data provide additional information for patients and providers to make informed treatment decisions.

Persistence of nondysplastic Barrett's esophagus identifies patients at lower risk for esophageal adenocarcinoma: results from a large multicenter cohort

BACKGROUND & AIMS

Recent population-based studies have shown a low risk of esophageal adenocarcinoma (EAC) in patients with nondysplastic Barrett's esophagus (NDBE). We evaluated whether persistence of NDBE over multiple consecutive surveillance endoscopic examinations could be used in risk stratification of patients with Barrett's esophagus (BE).

METHODS

We performed a multicenter outcomes study of a large cohort of patients with BE. Based on the number of consecutive surveillance endoscopies showing NDBE, we identified 5 groups of patients. Patients in group 1 were found to have NDBE at their first esophagogastroduodenoscopy (EGD). Patients in group 2 were found to have NDBE on their first 2 consecutive EGDs. Similarly, patients in groups 3, 4, and 5 were found to have NDBE on 3, 4, and 5 consecutive surveillance EGDs. A logistic regression model was built to determine whether persistence of NDBE independently protected against development of cancer.

RESULTS

Of a total of 3515 patients with BE, 1401 patients met the inclusion criteria (93.3% white; 87.5% men; median age, 60 ±17 years). The median follow-up period was 5 ± 3.9 years (7846 patient-years). The annual risk of EAC in groups 1 to 5 was 0.32%, 0.27%, 0.16%, 0.2%, and 0.11%, respectively (P for trend = .03). After adjusting for age, sex, and length of BE, persistence of NDBE, based on multiple surveillance endoscopies, was associated with a gradually lower likelihood of progression to EAC.

CONCLUSIONS

Persistence of NDBE over several endoscopic examinations identifies patients who are at low risk for development of EAC. These findings support lengthening surveillance intervals or discontinuing surveillance of patients with persistent NDBE.