Clonal selection and persistence in dysplastic Barrett's esophagus and intramucosal cancers after failed radiofrequency ablation

Metachronous Squamous Cell Carcinoma of the Esophagus After Resolution of Previous Adenocarcinoma

Esophageal cancer is the sixth leading cause of cancer-related death worldwide. Metachronous malignancies refer to multiple independent primary cancers diagnosed at least 6 months apart. The incidence of metachronous esophageal cancers with different histologic subtypes is extremely rare. This case presents an unprecedented occurrence of esophageal adenocarcinoma, followed by metachronous squamous cell carcinoma.

Utility of ancillary studies in the diagnosis and risk assessment of Barrett's esophagus and dysplasia

Barrett's esophagus (BE) is a major risk factor for the development of esophageal adenocarcinoma (EAC). BE patients undergo periodic endoscopic surveillance with biopsies to detect dysplasia and EAC, but this strategy is imperfect owing to sampling error and inconsistencies in the diagnosis and grading of dysplasia, which may result in an inaccurate diagnosis or risk assessment for progression to EAC. The desire for more accurate diagnosis and better risk stratification has prompted the investigation and development of potential biomarkers that might assist pathologists and clinicians in the management of BE patients, allowing more aggressive endoscopic surveillance and treatment options to be targeted to high-risk individuals, while avoiding frequent surveillance or unnecessary interventions in those at lower risk. It is known that progression of BE to dysplasia and EAC is accompanied by a host of genetic alterations, and that exploration of these markers could be potentially useful to diagnose/grade dysplasia and/or to risk stratify BE patients. Several biomarkers have shown promise in identifying early neoplastic transformation and thus may be useful adjuncts to histologic evaluation. This review provides an overview of some of the currently available biomarkers and assays, including p53 immunostaining, Wide Area Transepithelial Sampling with Three-Dimensional Computer-Assisted Analysis (WATS^3D), TissueCypher, mutational load analysis (BarreGen), fluorescence in situ hybridization, and DNA content abnormalities as detected by DNA flow cytometry.

Persistent or recurrent Barrett's neoplasia after an endoscopic therapy session is associated with DNA content abnormality and can be detected by DNA flow cytometric analysis of paraffin-embedded tissue

Endoscopic therapy is currently the standard of care for the treatment of high-grade dysplasia (HGD) or intramucosal adenocarcinoma (IMC) in patients with Barrett's esophagus (BE). Visible lesions are treated with endoscopic mucosal resection (EMR), which is often coupled with radiofrequency ablation (RFA). However, endoscopic therapy may require multiple sessions (one session every 2-3 months) and does not always assure complete eradication of neoplasia. Furthermore, despite complete eradication, recurrences are not uncommon. This study assesses which potential risk factors can predict a poor response after endoscopic sessions. Forty-five BE patients who underwent at least one endoscopic session (EMR alone or ablation with or without preceding EMR) for the treatment of HGD/IMC, low-grade dysplasia (LGD), or indefinite for dysplasia (IND) were analyzed. DNA flow cytometry was performed on 82 formalin-fixed paraffin-embedded samples from the 45 patients, including 78 HGD/IMC, 2 LGD, and 2 IND. Eight non-dysplastic BE samples were used as controls. Three to four 60-micron thick sections were cut from each tissue block, and the area of HGD/IMC, LGD, or IND was manually dissected. Potential associations between clinicopathologic risk factors and persistent/recurrent HGD/IMC following each endoscopic session were examined using univariate and multivariate Cox models with frailty terms. Sixty (73%) of the 82 specimens showed abnormal DNA content (aneuploidy or elevated 4N fraction). These were all specimens with HGD/IMC (representing 77% of that group). Of these 60 HGD/IMC samples with abnormal DNA content, 42 (70%) were associated with subsequent development of persistent/recurrent HGD/IMC (n = 41) or esophageal adenocarcinoma (EAC; n = 1) within a mean follow-up time of 16 months (range: 1 month to 9.4 years). In contrast, only 6 (27%, all HGD/IMC) of the 22 remaining samples (all with normal DNA content) were associated with persistent/recurrent HGD/IMC. For outcome analysis per patient, 11 (24%) of the 45 patients developed persistent/recurrent HGD/IMC or EAC, despite multiple endoscopic sessions (mean: 3.6, range: 1-11). In a univariate Cox model, the presence of abnormal DNA content (hazard ratio [HR] = 3.8, p = 0.007), long BE segment ≥ 3 cm (HR = 3.4, p = 0.002), endoscopic nodularity (HR = 2.5, p = 0.042), and treatment with EMR alone (HR = 2.9, p = 0.006) were significantly associated with an increased risk for persistent/recurrent HGD/IMC or EAC. However, only abnormal DNA content (HR = 6.0, p = 0.003) and treatment with EMR alone (HR = 2.7, p = 0.047) remained as significant risk factors in a multivariate analysis. Age ≥ 60 years, gender, ethnicity, body mass index (BMI) ≥ 30 kg/m², presence of hiatal hernia, and positive EMR lateral margin for neoplasia were not significant risk factors for persistent/recurrent HGD/IMC or EAC (p > 0.05). Three-month, 6-month, 1-year, 3-year, and 6-year adjusted probabilities of persistent/recurrent HGD/IMC or EAC in the setting of abnormal DNA content were 31%, 56%, 67%, 79%, and 83%, respectively. The corresponding probabilities in the setting of normal DNA content were 10%, 21%, 28%, 38%, and 43%, respectively. In conclusion, in BE patients with baseline HGD/IMC, both DNA content abnormality and treatment with EMR alone were significantly associated with persistent/recurrent HGD/IMC or EAC following each endoscopic session. DNA content abnormality as detected by DNA flow cytometry identifies HGD/IMC patients at highest risk for persistent/recurrent HGD/IMC or EAC, and it also serves as a diagnostic marker of HGD/IMC with an estimated sensitivity of 77%. The diagnosis of HGD/IMC in the setting of abnormal DNA content may warrant alternative treatment strategies as well as long-term follow-up with shorter surveillance intervals.

Long-term outcomes of the randomized controlled trial comparing 5-aminolaevulinic acid and Photofrin photodynamic therapy for Barrett's oesophagus related neoplasia

OBJECTIVE

Photodynamic therapy (PDT) was used as therapy for early neoplasia associated with Barrett's oesophagus (BE). This is 5-year follow-up of patients enrolled into randomised controlled trial of 5-aminolaevulinic acid (ALA) vs. Photofrin PDT.

METHODS

Biopsies were taken from original Barrett's segment during endoscopic follow up using Seattle protocol. Endoscopic mucosal resection (EMR) ± radiofrequency ablation (RFA) was preferred therapy in patients who failed PDT and/or had recurrent neoplasia.

RESULTS

Fifty eight of 64 patients enrolled in the original trial were followed up including 31 patients treated with ALA PDT (17 patients with ≤6 cm, 14 patients with >6 cm segment of BE) and 27 treated with Photofrin PDT (14 patients with ≤6 cm, 13 patients with >6 cm BE). Initial success was achieved in 65% (20/31) ALA and 48% (13/27) Photofrin patients (p = .289). Thirty five percent patients (7/20) relapsed in ALA group and 54% (7/13) relapsed in Photofrin group (p = .472). At a median follow-up of 67 months, no significant difference was found in long-term complete reversal of intestinal metaplasia (CR-IM) and complete reversal of dysplasia (CR-D) between ALA and Photofrin groups (78% vs. 63%; p = .18; 90% vs. 76%; p = .26). Original length of BE did not alter long-term outcome. Four patients from each group progressed to invasive oesophageal adenocarcinoma. Initial success of ALA PDT was associated with significantly better likelihood of long-term remission (p = .03).

CONCLUSIONS

Initial response to PDT plays key role in long term outcome. RFA ± EMR have, however, become preferred minimally invasive ablative therapy for BE-related neoplasia due to poor efficacy of PDT.

Metaplasia: tissue injury adaptation and a precursor to the dysplasia-cancer sequence

Metaplasia is the replacement of one differentiated somatic cell type with another differentiated somatic cell type in the same tissue. Typically, metaplasia is triggered by environmental stimuli, which may act in concert with the deleterious effects of microorganisms and inflammation. The cell of origin for intestinal metaplasia in the oesophagus and stomach and for pancreatic acinar-ductal metaplasia has been posited through genetic mouse models and lineage tracing but has not been identified in other types of metaplasia, such as squamous metaplasia. A hallmark of metaplasia is a change in cellular identity, and this process can be regulated by transcription factors that initiate and/or maintain cellular identity, perhaps in concert with epigenetic reprogramming. Universally, metaplasia is a precursor to low-grade dysplasia, which can culminate in high-grade dysplasia and carcinoma. Improved clinical screening for and surveillance of metaplasia might lead to better prevention or early detection of dysplasia and cancer.

Post-ablation surveillance in Barrett's esophagus: A review of the literature

Barrett’s esophagus (BE) is a pre-malignant condition affecting up to 15% of patients with gastroesophageal reflux disease. Neoplastic Barrett’s mucosa is defined as harboring high grade dysplasia or intra-mucosal cancer, and carries a high risk of progression to esophageal adenocarcinoma. The rising incidence of Barrett’s lesions along with the high morbidity of surgical approaches has led to the development of numerous validated endoscopic techniques capable of eradicating neoplastic mucosa in a minimally invasive manner. While there has been widespread adoption of these techniques, less is known about optimal surveillance intervals in the post-therapy period. This is due in part to limitations in current surveillance methods, questions about durability of treatment response and the risk of subendothelial progression. As we are now able to achieve organ sparing eradication of superficial neoplasia in BE, we need to also then focus our attention on how best to manage these patients after eradication is achieved. Implementing optimal surveillance practices requires additional understanding of the biology of the disease, appreciation of the limits of current tools and treatments, and exploration of the role of adjunctive technologies. The aim of this article is to provide a comprehensive review of current literature surrounding post-ablation surveillance in neoplastic BE.

The Complex, Clonal, and Controversial Nature of Barrett's Esophagus

Barrett's esophagus (BO) is a preneoplastic condition described as the replacement of the stratified squamous epithelium of the distal esophagus with one that histologically presents as a diverse mixture of metaplastic glands resembling gastric or intestinal-type columnar epithelium. The clonal origins of BO are still unclear. More recently, we have begun to investigate the relationship between the various metaplastic gland phenotypes observed in BO, how they evolve, and the cancer risk they bestow. Studies have revealed that glands along the BO segment are clonal units containing a single stem cell clone that can give rise to all the differentiated epithelial cell types in glands. Clonal lineage tracing analysis has revealed that Barrett's glands are capable of bifurcation and this facilitates clonal expansion and competition. In fact, BO in some patients appears to consist of multiple, independently initiated clones that compete with each other for space and possibly resources. This chapter discusses the concepts of clonal competition and expansion in BO and sets out to query what we know about the role of gland diversity and phenotypic evolution within this complex columnar metaplasia.

Comparison of endoscopic treatment modalities for Barrett's neoplasia

BACKGROUND

There are few data comparing endoscopic treatment outcomes for Barrett's esophagus (BE).

OBJECTIVE

To compare treatment outcomes in BE patients treated with radiofrequency ablation (RFA), RFA after EMR, and porfimer sodium photodynamic therapy (Ps-PDT).

DESIGN

Retrospective, observational study.

SETTING

Single tertiary center between 2001 and 2013.

PATIENTS

A total of 342 BE patients treated with RFA (n = 119), EMR+RFA (n = 98), and Ps-PDT (n = 125).

MAIN OUTCOME MEASUREMENTS

Rates of complete remission of intestinal metaplasia (CRIM), BE recurrence, and adverse events.

RESULTS

Baseline BE high-grade dysplasia (HGD) and adenocarcinoma were more common in the Ps-PDT group (89%) compared with the EMR-RFA (70%) and RFA (37%) groups. At a median follow-up of 14.2 months, 173 patients (50.6%) achieved CRIM. CRIM was significantly more common in Ps-PDT patients compared with RFA (P < .001) and EMR-RFA (P < .001) patients on multivariable analysis. In patients who achieved CRIM, the rates of subsequent BE recurrence were relatively similar among the 3 groups. Although the rates of bleeding were similar, strictures were less common in RFA patients (2.4%) compared with EMR-RFA (13.3%, P = .001) and Ps-PDT (10.4%, P =.043) patients.

CONCLUSION

This study of endoscopic treatment for Barrett's dysplasia and neoplasia found that complete remission was achieved more often and more rapidly after Ps-PDT with similar disease recurrence rates compared with EMR or RFA. Adverse events were more common after EMR and Ps-PDT. Further studies are required to determine which ablation and resection techniques are ideally suited for each BE patient.

Genetic Insights in Barrett's Esophagus and Esophageal Adenocarcinoma

Beginning in the 1980s, an alarming rise in the incidence of esophageal adenocarcinoma (EA) led to screening of patients with reflux to detect Barrett's esophagus (BE) and surveillance of BE to detect early EA. This strategy, based on linear progression disease models, resulted in selective detection of BE that does not progress to EA over a lifetime (overdiagnosis) and missed BE that rapidly progresses to EA (underdiagnosis). Here we review the historical thought processes that resulted in this undesired outcome and the transformation in our understanding of genetic and evolutionary principles governing neoplastic progression that has come from application of modern genomic technologies to cancers and their precursors. This new synthesis provides improved strategies for prevention and early detection of EA by addressing the environmental and mutational processes that can determine "windows of opportunity" in time to detect rapidly progressing BE and distinguish it from slowly or nonprogressing BE.

Radiofrequency ablation for Barrett's-associated intramucosal carcinoma: a multi-center follow-up study

BACKGROUND

Radiofrequency ablation (RFA), with or without endoscopic mucosal resection (EMR), has been validated as a safe, effective and durable treatment option for dysplastic Barrett's esophagus. Its durability in eradicating Barrett's-associated intramucosal carcinoma (IMC), however, is unclear. We set out to assess the long-term safety and efficacy of RFA for IMC.

METHODS

Retrospective review of two tertiary care facility records for patients undergoing RFA, with or without EMR, for biopsy-proven IMC. Our primary outcome of interest was to quantify the rate of durable complete eradication for intestinal metaplasia and for IMC and associated dysplasia. A multi-variate regression analysis was performed to identify features which correlate with durable eradication of IMC/dysplasia. Our secondary outcome of interest was treatment-related complications.

RESULTS

36 patients (26 male; mean age 64 ± 12 years), with a mean Barrett's length of 3.5 ± 2.5 cm, underwent RFA for biopsy-proven IMC. EMR was performed in 31 (86%) prior to or during RFA. Complete eradication of IMC/dysplasia was achieved in 32/36 (89%) and patients required a mean of 1 ± 1 EMR and 2 ± 1 RFA sessions to achieve eradication. During a mean follow-up period of 24 ± 19 months, durable complete eradication of IMC/dysplasia was achieved in 29/36 (81%) patients. On multi-variate regression analysis, undergoing an EMR prior to RFA was associated with an increased likelihood of maintaining durable eradication of IMC/dysplasia (p = 0.03). Treatment-related complications included: bleeding (3%) and stricture formation (19%).

CONCLUSION

RFA is an effective and durable treatment option for Barrett's-associated IMC. Greater than 80% of patients will achieve and maintain complete eradication of IMC at a mean of 2 years follow-up.

Barrett oesophagus: lessons on its origins from the lesion itself

Barrett oesophagus develops when the lower oesophageal squamous epithelium is replaced with columnar epithelium, which shows both intestinal and gastric differentiation. No consensus has been reached on the origin of Barrett oesophagus. Theories include a direct origin from the oesophageal-stratified squamous epithelium, or by proximal migration of the gastric cardiac epithelium with subsequent intestinalization. Variations of this theory suggest the origin is a distinctive cell at the squamocolumnar junction, the oesophageal gland ducts, or circulating bone-marrow-derived cells. Much of the supporting evidence comes from experimental models and not from studies of Barrett mucosa. In this Perspectives article, we look at the Barrett lesion itself: at its phenotype, its complexity, its clonal architecture and its stem cell organization. We conclude that Barrett glands are unique structures, but share many similarities with gastric glands undergoing the process of intestinal metaplasia. We conclude that current evidence most strongly supports an origin from stem cells in the cardia.

Complete endoscopic mucosal resection is effective and durable treatment for Barrett's-associated neoplasia

BACKGROUND & AIMS

Barrett's esophagus (BE) with high-grade dysplasia (HGD) or intramucosal carcinoma (IMC) is treated by complete eradication of areas of BE by endoscopic mucosal resection (EMR). By using this approach, histologic analysis also can be performed. We investigated the effectiveness, safety, and durability of this approach, as well as its use in diagnosis after a single referral.

METHODS

We collected data from 107 patients who were referred to the Center for Endoscopic Research and Therapeutics at the University of Chicago for BE (mean length, 3.6 cm) with suspected HGD or IMC, from August 2003 through December 2012. All patients underwent EMR and were followed up through January 2014 (mean follow-up time, 40.6 mo). The primary outcome was treatment efficacy (complete eradication of BE and associated neoplasia); secondary outcomes included safety, durability, and accuracy of diagnosis.

RESULTS

BE was eradicated completely by EMR in 80.4% (86 of 107) of patients based on intention-to-treat analysis, and in 98.8% (79 of 80) of patients based on per-protocol analysis. The diagnosis was changed for 25% of patients after EMR, including 4 cases that initially were diagnosed as HGD by biopsy analysis and subsequently were found to have evidence of submucosal invasion when EMR specimens were assessed. Strictures and symptomatic dysphagia developed in 41.1% and 37.3% of patients, respectively, with an average of 2.3 dilations required. Perforations occurred in 2 patients after EMR and in 1 patient after dilation. HGD and IMC recurred in 1 patient each; both were treated successfully with EMR. Based on pathology analysis of the most recently collected specimens, 71.6% of patients (53 of 74) were in complete remission from intestinal metaplasia and 100% were in complete remission from HGD (74 of 74) or cancer (74 of 74).

CONCLUSIONS

For patients with BE with HGD or neoplasia, complete EMR is an effective and durable treatment and is a relatively safe technique. Specimens collected by EMR also can be analyzed histologically to aid in diagnosis. The common complication of EMR is esophageal stricture, which can be addressed with endoscopic dilation.

Prediction of response to endoscopic therapy of Barrett's dysplasia by using genetic biomarkers

BACKGROUND

Endoscopic therapy for the treatment of high-grade dysplasia (HGD) and intramucosal cancer (IMC) in Barrett's esophagus (BE) may not always result in complete remission of dysplasia (CRD).

OBJECTIVE

To determine whether genetic alterations in the Barrett's mucosa can predict response to endoscopic therapy.

DESIGN

Retrospective cohort study.

SETTING

Tertiary-care institution.

PATIENTS

Selected patients who underwent endoscopic therapy for BE containing HGD/IMC between 2003 and 2010.

INTERVENTIONS

Endoscopic therapy combining mucosal resection and different ablation modalities was performed based on patient characteristics, endoscopic findings, and technique evolution. Fluorescence in situ hybridization was used to evaluate genetic alterations on baseline endoscopic cytology brushings by using probes directed to loci 8q24 (MYC), 9p21 (CDKN2A; alias P16), 17q12 (ERBB2; alias Her-2/neu), and 20q13.2 (ZNF217).

MAIN OUTCOME MEASUREMENTS

Genetic biomarkers predicting achievement of CRD after endoscopic therapy.

RESULTS

A total of 181 patients were included (145 men; 66 ± 10 years of age). There were 130 patients (72%) who responded to endoscopic therapy with CRD. Multiple gains detected by fluorescence in situ hybridization was found to be a negative predictor (hazard ratio 0.57; 95% confidence interval, 0.40-0.82) after adjusting for potential clinical confounders. Similar results were found when analyses were restricted to patients (n = 66) undergoing radiofrequency ablation (hazard ratio 0.58; 95% confidence interval, 0.31-1.09).

LIMITATIONS

Retrospective study, heterogeneity of treatment modalities.

CONCLUSION

Patients with multiple gains detected by brush cytology specimens may have a lower response rate to endoscopic therapy. The presence of multiple gains can be an adjunct to standard histology in prognosticating BE patients with HGD/IMC undergoing endoscopic therapy.

Ablative therapy for esophageal dysplasia and early malignancy: focus on RFA

Ablative therapies have been utilized with increasing frequency for the treatment of Barrett's esophagus with and without dysplasia. Multiple modalities are available for topical ablation of the esophagus, but radiofrequency ablation (RFA) remains the most commonly used. There have been significant advances in technique since the introduction of RFA. The aim of this paper is to review the indications, techniques, outcomes, and most common complications following esophageal ablation with RFA.

Radiofrequency ablation for Barrett's esophagus

PURPOSE OF REVIEW

Several studies published in the last year that have provided evidence on the efficacy, durability and safety of radiofrequency ablation (RFA) in Barrett's esophagus are highlighted in this review.

RECENT FINDINGS

RFA is well tolerated and efficacious in most but not all Barrett's esophagus patients with dysplasia and esophageal adenocarcinoma (EAC). Recent reports have described highly variable rates of disease recurrence. Disease progression may occur during initial therapy or after complete eradication in a small, difficult to identify subset of patients. Studies are underway to help determine the predictors of response and recurrence. Modifications in technique and target populations have been described in the last year as well.

SUMMARY

Endoscopic mucosal resection and RFA are the cornerstones in the management of dysplasia and early EAC in Barrett's esophagus patients today. Despite the encouraging data on the effectiveness and safety of RFA, recurrence and progression of disease remain an issue in a subset of patients who are treated.