Patient predictors of histopathologic response after photodynamic therapy of Barrett's esophagus with high-grade dysplasia or intramucosal carcinoma

Advancements in photodynamic therapy of esophageal cancer

The poor prognosis of patients with esophageal cancer leads to the constant search for new ways of treatment of this disease. One of the methods used in high-grade dysplasia, superficial invasive carcinoma, and sometimes palliative care is photodynamic therapy (PDT). This method has come a long way from the first experimental studies to registration in the treatment of esophageal cancer and is constantly being improved and refined. This review describes esophageal cancer, current treatment methods, the introduction to PDT, the photosensitizers (PSs) used in esophageal carcinoma PDT, PDT in squamous cell carcinoma (SCC) of the esophagus, and PDT in invasive adenocarcinoma of the esophagus. For this review, research and review articles from PubMed and Web of Science databases were used. The keywords used were "photodynamic therapy in esophageal cancer" in the years 2000-2020. The total number of papers returned was 1,000. After the review was divided into topic blocks and the searched publications were analyzed, 117 articles were selected.

Ablative therapies of the biliary tree

Cholangiocarcinoma, a malignancy of the epithelial cells in the intrahepatic or extrahepatic biliary tree, is often diagnosed at later stages. Median survival duration ranges from 3 to 9 months with a less than ten percent 5-year survival rate. Thus, often treatment strategies are aimed more towards palliation instead of cure. With the majority of patients presenting with unresectable disease at the time of diagnosis, surgical intervention is not feasible, making less invasive endoscopic therapies more suitable. Initially, biliary stents were utilized for biliary decompression to mitigate cholestatic symptoms and prevent cholangitis; however, this strategy did not prove to provide significant survival benefit. Therefore, efforts to treat the tumor burden itself in addition to maintaining biliary patency became a focus of innovation and research in the endoscopic field. This study has led to the advent of therapies such as photodynamic therapy, radiofrequency ablation, and intraluminal brachytherapy. These options combined with biliary stenting have shown to not only offer the benefit of biliary decompression, but also to potentially improve stent patency and survival. Further, there is an anti-tumor effect of each of these modalities, portending an additional benefit in this subset of patients. Despite numerous retrospective and prospective studies assessing these ablative therapies, there is still a paucity of appropriately powered randomized controlled trials, and further research has yet to be done in the field. This review details the current literature entailing endobiliary ablative strategies.

Endoscopic therapy for Barrett’s esophagus and early esophageal cancer: Where do we go from here?

Since Barrett’s esophagus is a precancerous condition, efforts have been made for its eradication by various ablative techniques. Initially, laser ablation was attempted in non-dysplastic Barrett’s esophagus and subsequently, endoscopic ablation using photodynamic therapy was used in Barrett’s patients with high-grade dysplasia who were poor surgical candidates. Since then, various ablative therapies have been developed with radiofrequency ablation having the best quality of evidence. Resection of dysplastic areas only without complete removal of entire Barrett’s segment is associated with high risk of developing metachronous neoplasia. Hence, the current standard of management for Barrett’s esophagus includes endoscopic mucosal resection of visible abnormalities followed by ablation to eradicate remaining Barrett’s epithelium. Although endoscopic therapy cannot address regional lymph node metastases, such nodal involvement is present in only 1% to 2% of patients with intramucosal adenocarcinoma in Barrett esophagus and therefore is useful in intramucosal cancers. Post ablation surveillance is recommended as recurrence of intestinal metaplasia and dysplasia have been reported. This review includes a discussion of the technique, efficacy and complication rate of currently available ablation techniques such as radiofrequency ablation, cryotherapy, argon plasma coagulation and photodynamic therapy as well as endoscopic mucosal resection. A brief discussion of the emerging technique, endoscopic submucosal dissection is also included.

Endoscopic Management of Pancreatobiliary Neoplasms

Endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) are the mainstays of interventional endoscopic practice. EUS occupies a central role in the diagnosis of pancreatobiliary neoplasms and offers a platform for a wide range of direct tumor therapies. Initial steps have demonstrated the feasibility of such applications in animal models and pilot studies. Larger clinical trials and incorporation of EUS-based therapies into cooperative cancer studies might demonstrate an impact in the clinical prognosis of patients with pancreatic cancer. ERCP plays an important role in elucidating indeterminate biliary strictures and in treating patients with malignant biliary obstruction who are symptomatic or have borderline-resectable or unresectable disease. ERCP-directed ablative therapies enable neoadjuvant and palliative intervention in patients with malignant biliary obstruction, in particular perihilar cholangiocarcinoma. Additional comparative, multicenter studies are needed to better understand the safety and efficacy of endobiliary brachytherapy, photodynamic therapy, and radiofrequency ablation in patients with pancreatobiliary malignancies.

Oncologic Photodynamic Therapy: Basic Principles, Current Clinical Status and Future Directions

Photodynamic therapy (PDT) is a clinically approved cancer therapy, based on a photochemical reaction between a light activatable molecule or photosensitizer, light, and molecular oxygen. When these three harmless components are present together, reactive oxygen species are formed. These can directly damage cells and/or vasculature, and induce inflammatory and immune responses. PDT is a two-stage procedure, which starts with photosensitizer administration followed by a locally directed light exposure, with the aim of confined tumor destruction. Since its regulatory approval, over 30 years ago, PDT has been the subject of numerous studies and has proven to be an effective form of cancer therapy. This review provides an overview of the clinical trials conducted over the last 10 years, illustrating how PDT is applied in the clinic today. Furthermore, examples from ongoing clinical trials and the most recent preclinical studies are presented, to show the directions, in which PDT is headed, in the near and distant future. Despite the clinical success reported, PDT is still currently underutilized in the clinic. We also discuss the factors that hamper the exploration of this effective therapy and what should be changed to render it a more effective and more widely available option for patients.

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.

Epidemiology, Diagnosis, and Management of Esophageal Adenocarcinoma

Esophageal adenocarcinoma (EAC) is rapidly increasing in incidence in Western cultures. Barrett's esophagus is the presumed precursor lesion for this cancer. Several other risk factors for this cancer have been described, including chronic heartburn, tobacco use, white race, and obesity. Despite these known associations, most patients with EAC present with symptoms of dysphagia from late-stage tumors; only a small number of patients are identified by screening and surveillance programs. Diagnostic analysis of EAC usually commences with upper endoscopy followed by cross-sectional imaging. Endoscopic ultrasonography is useful to assess the local extent of disease as well as the involvement of regional lymph nodes. T1a EAC may be treated endoscopically, and some patients with T1b disease may also benefit from endoscopic therapy. Locally advanced disease is generally managed with esophagectomy, often accompanied by neoadjuvant chemoradiotherapy or chemotherapy. The prognosis is based on tumor stage; patients with T1a tumors have an excellent prognosis, whereas few patients with advanced disease have long-term survival.

Brief report: the length of newly diagnosed Barrett's esophagus may be decreasing

Few studies have examined the temporal trends of length in newly diagnosed Barrett's esophagus (BE) and arrived at conflicting results. The aim of this study was to identify whether there has been a change over time in the length of BE at the time of diagnosis. This is a retrospective, single-center, observational study from Houston, Texas on newly diagnosed BE between 2008 and 2013. All cases were defined by the presence of endoscopically visible BE and histologic confirmation of intestinalized columnar epithelium with goblet cells. The length of BE was measured using the Prague classification. We examined temporal changes in 1-year intervals in the length of BE at the time of diagnosis. Both the frequency and mean length of BE at diagnosis seemed to decrease over time from February 2008 to July 2013. The proportion of patients diagnosed with BE ≥3 cm per year declined during the study period, while the proportion of patients with BE ≥1 and <3 cm increased, and those with <1 cm remained stable. The mean age and the gender of patients diagnosed with BE ≥3 cm did not differ significantly by BE length or year of diagnosis. The mean length of newly diagnosed BE may be decreasing as a result of a decline in BE ≥3 cm. These observations cannot be explained by changes in age and gender.

Roles of three common VEGF polymorphisms in the risk of age-related macular degeneration

Associations between vascular endothelial growth factor (VEGF) polymorphisms (rs833061, rs1413711, and rs3025039) and risk of age-related macular degeneration (AMD) have been extensively studied, but the currently available results are contentious rather than conclusive. Therefore, we performed the present meta-analysis to further assess the associations. Literature search in PubMed, Embase, and Web of Science databases was conducted until April 2013. The strength of the associations between VEGF polymorphisms and AMD risk was estimated by pooled odds ratios (ORs) and 95% confidence intervals (CIs). Both models of fixed effects and random effects were performed to summarize the pooled ORs. All data were analyzed by Stata software 12.0. The meta-analysis results based on nine case-control studies with 2427 cases and 2037 controls showed that rs833061 had protective effects on AMD risk (TT vs. CT+CC: OR=0.58, 95% CI=0.41-0.81), whereas rs1413711 (TT vs. CT+CC: OR=1.46, 95% CI=1.10-1.93) and rs3025039 (TT vs. CC: OR=1.87, 95% CI=1.15-3.02; TT vs. CT+CC: OR=2.09, 95% CI=1.30-3.37) represented as risk factors for AMD. Subgroup analysis by ethnicity suggested significantly reduced risk in Caucasians (TT vs. CT+CC: OR=0.60, 95% CI=0.36-0.99; T vs. C: OR=0.89, 95% CI=0.78-1.00) and Asians (TT+CT vs. CC: OR=0.57, 95% CI=0.34-0.96; TT vs. CT+CC: OR=0.54, 95% CI=0.33-0.90) for rs833061, yet elevated risk in Caucasians (TT vs. CT+CC: OR=2.05, 95% CI=1.24-3.38) for rs1413711 and in Asians (TT vs. CC: OR=2.06, 95% CI=1.24-3.43; TT vs. CC: OR=2.34, 95% CI=1.42-3.89) for rs3025039. In stratified analysis by type of AMD, rs833061 was observed to decrease wet AMD risk, while rs1413711 and rs3025039 were found to increase the risk of wet AMD. Based on the currently available data, this meta-analysis suggests that the VEGF polymorphisms may be associated with risk of AMD, particularly wet AMD.

Incidence and predictors of adenocarcinoma following endoscopic ablation of Barrett's esophagus

BACKGROUND

The rate and risk factors of recurrent or metachronous adenocarcinoma following endoscopic ablation therapy in patients with Barrett's esophagus (BE) have not been specifically reported.

AIM

The aim of this study was to determine the incidence and predictors of adenocarcinoma after ablation therapy for BE high-grade dysplasia (HGD) or intramucosal carcinoma (IMC).

METHODS

This is a single center, retrospective review of prospectively collected data on consecutive cases of endoscopic ablation for BE. A total of 223 patients with BE (HGD or IMC) were treated by ablation between 1996 and 2011. Primary outcome measures were recurrence and new development of adenocarcinoma after ablation. Recurrence was defined as the presence of adenocarcinoma following the absence of adenocarcinoma in biopsy samples from two consecutive surveillance endoscopies. Logistic regression analysis was performed to assess predictors of adenocarcinoma after ablation.

RESULTS

One hundred and eighty-three patients were included in the final analysis, and 40 patients were excluded: 22 for palliative ablation, eight lost to follow-up, five for residual carcinoma and five for postoperative state. Median follow-up was 39 months. Recurrence or new development of adenocarcinoma was found in 20 patients (11 %) and the median time to recurrence/development of adenocarcinoma was 11.5 months. Independent predictors of recurrent or metachronous adenocarcinoma were hiatal hernia size ≥ 4 cm (odds ratio 3.649, P = 0.0233) and histology (HGD/adenocarcinoma) after first ablation (odds ratio 4.141, P = 0.0065).

CONCLUSIONS

Adenocarcinoma after endoscopic therapy for HGD or IMC in BE is associated with large hiatal hernia and histology status after initial ablation therapy.

Association between complement factor H Val62Ile polymorphism and age-related macular degeneration susceptibility: a meta-analysis

BACKGROUND

An increasing body of studies has assessed the contribution of Val62Ile polymorphism to age-related macular degeneration (AMD) risk, but the exact association still remains uncertain. This meta-analysis was undertaken in order to further characterize the potential association between Val62Ile polymorphism and AMD risk in four different ethnic populations.

METHODS

A meta-analysis was performed using data available from 16 case-control studies evaluating correlation between the Val62Ile polymorphism and AMD in Caucasian, Chinese, Japanese and South Korean populations. Data extraction and study quality assessment were performed in duplicate. Summary odds ratios (ORs) and 95% confidence intervals (CIs) of allele contrast and genotype contrast were estimated using the random-effects model. The Q-statistic test was used to identify heterogeneity, and the funnel plot was adopted to evaluate publication bias.

RESULTS

Sixteen studies involving a total of 11,400 subjects based on the search criteria were included in the meta-analysis. In overall populations, the Val62Ile polymorphism seemed to be associated with AMD (ORAA vs. GG=0.40, 95% CI=0.28-0.59; ORAA+GA vs. GG=0.72, 95% CI=0.64-0.80; ORAA vs. GC+GG=0.50, 95% CI=0.36-0.70; ORA vs. G=0.68, 95% CI=0.58-0.78; ORGA vs. GG=0.71, 95% CI=0.65-0.77). Similarly, subgroup analysis also revealed that this polymorphism was related to AMD in all ethnicities.

CONCLUSIONS

This meta-analysis suggested that Val62Ile polymorphism was associated with susceptibility to AMD.

Association between variant Y402H in age-related macular degeneration (AMD) susceptibility gene CFH and treatment response of AMD: a meta-analysis

Purpose

To investigate the association between polymorphism rs1061170 (T1277C, Y402H) in age-related macular degeneration (AMD) susceptibility gene Complement Factor H (CFH) and treatment response of neovascular AMD.

Methods

We performed a literature-based meta-analysis including 10 published association studies involving 1,510 patients. Treatments included anti-VEGF (bevacizumab and ranibizumab) or photodynamic therapy. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using fixed- and random-effects models. Q-statistic test was used to assess heterogeneity.

Results

Polymorphism rs1061170 showed a significant summary OR of 1.68 (95% CI, 1.09 to 2.60; P = 0.020; CC versus TT; random-effects) for treatment response of neovascular AMD with heterogeneity of 0.09. In subgroup analysis, rs1061170 was more likely to be a predictor of response to anti-VEGF therapy (P = 0.011). However, heterozygous TC genotype was not associated with altered treatment response (OR = 1.18, 95% CI, 0.95 to 1.47; P = 0.145; fixed-effects). Influence analysis indicated the robustness of our findings.

Conclusions

rs1061170 might be associated with treatment response of neovascular AMD, especially for the anti-VEGF agents. It might be the first meta-analytically confirmed genetic marker predictive for AMD treatment response though a further validation in larger studies is needed.

Length of Barrett's segment predicts success of extensive endomucosal resection for eradication of Barrett's esophagus with early neoplasia

BACKGROUND

Although the efficacy and safety of extensive endomucosal resection (EMR) in eradicating Barrett's esophagus (BE) harbouring early neoplasia have been established, factors predicting efficacy remains unclear.

AIM

To determine the complete eradication rate of Barrett's esophagus with high-grade intraepithelial neoplasia (HGIN) or intramucosal carcinoma (IMC), safety, and factors predicting complete eradication by EMR.

METHODS

Patients with histological confirmation of Barrett's HGIN/IMC were prospectively identified. EMR was performed using Duette multiband ligator or cap technique by a single operator (NEM).

RESULTS

99 patients (81 males) with median age 67 years [interquartile range (IQR) 60-77 years] and median Barrett's length 4 cm (IQR 2-6 cm) were included. Of 628 index EMRs [mean 6.3, median 5 (IQR 3-8)], 23% showed IMC, 58.5% showed HGIN, and 16% showed low-grade dysplasia only. A median of 8 EMR resections per patient (IQR 6-16, 1,064 resections in 89 patients) resulted in complete eradication of BE harboring neoplasia in 49.4% and eradication of HGIN/IMC in 81% (BE <5 cm subgroup: 65% complete eradication and 91% HGIN eradication) at median follow-up of 18 months (range 6-27 months). On univariate analysis, focal dysplasia (P = 0.003) and Barrett's length <5 cm (P = 0.001) were predictors of complete BE eradication. Barrett's length <5 cm was the only significant predictor [odds ratio (OR) 3.4, standard error (SE) 0.11, P = 0.0006] on multiple logistic regression analysis. Strictures developed in 27% and major bleeding in 2% with no procedure-related perforations or mortality.

CONCLUSIONS

Extensive EMR for removal of BE with early neoplasia is safe. Outcomes for complete BE eradication are modest at 49.4% and eradication of high-grade dysplasia at 81%. Barrett's length <5 cm is the only significant predictor of complete response.

Endoscopic radiofrequency ablation combined with endoscopic resection for early neoplasia in Barrett's esophagus longer than 10 cm

BACKGROUND

Radiofrequency ablation (RFA) is safe and effective for eradicating Barrett's esophagus (BE) and BE-associated early neoplasia. Most RFA studies have limited the baseline length of BE (<10 cm), and therefore little is known about RFA for longer BE.

OBJECTIVE

To assess the safety and efficacy of RFA with or without prior endoscopic resection (ER) for BE ≥ 10 cm containing neoplasia.

DESIGN

Prospective trial.

SETTING

Two tertiary-care centers.

PATIENTS

This study involved consecutive patients with BE ≥ 10 cm with early neoplasia.

INTERVENTION

Focal ER for visible abnormalities, followed by a maximum of 2 circumferential and 3 focal RFA procedures every 2 to 3 months until complete remission.

MAIN OUTCOME MEASUREMENTS

Complete remission, defined as endoscopic resolution of BE and no intestinal metaplasia (CR-IM) or neoplasia (CR-neoplasia) in biopsy specimens.

RESULTS

Of the 26 patients included, 18 underwent ER for visible abnormalities before RFA. The ER specimens showed early cancer in 11, high-grade intraepithelial neoplasia (HGIN) in 6, and low-grade intraepithelial neoplasia (LGIN) in 1. The worst residual histology, before RFA and after any ER, was HGIN in 16 patients and LGIN in 10 patients. CR-neoplasia and CR-IM were achieved in 83% (95% confidence interval [CI], 63%-95%) and 79% (95% CI, 58%-93%), respectively. None of the patients had fatal or severe complications and 15% (95% CI, 4%-35%) had moderate complications. During a mean (± standard deviation) follow-up of 29 (± 9.1) months, no neoplasia recurred.

LIMITATIONS

Tertiary-care center, short follow-up.

CONCLUSION

ER for visible abnormalities, followed by RFA of residual BE is a safe and effective treatment for BE ≥ 10 cm containing neoplasia, with a low chance of recurrence of neoplasia or BE during follow-up.

Photodynamic therapy

Photodynamic therapy (PDT) is a photochemical process that uses a photosensitizer drug activated by laser light to produce mucosal ablation. Porfimer sodium PDT has proved long-term efficacy and durability in the treatment of Barrett's esophagus and high-grade dysplasia and early esophageal adenocarcinoma. Its use has been limited by serious side effects including prolonged cutaneous photosensitivity and stricture formation. Other photosensitizers with a better safety profile have been used mostly in Europe with limited experience. The future of PDT lies on a better understanding of dosimetry, tissue properties, and host genetic factors.

Secular trends in patients diagnosed with Barrett's esophagus

BACKGROUND

It is not known whether there have been recent changes in demographic or clinical characteristics among patients newly diagnosed with Barrett's esophagus (BE), which could be a result of changes in disease epidemiology or of screening or surveillance effects, and could have clinical implications.

AIMS

The aim of this study was to determine whether there has been a shift in age at diagnosis of BE over the past decade. Secondary aims were to determine whether there has been a shift in patient body mass index (BMI) or BE segment length.

METHODS

An endoscopic database at a tertiary medical center was used to identify all esophagogastroduodenoscopies (EGDs) performed between 1997 and 2007. The cohort was restricted to patients newly diagnosed with BE. Pathology records were reviewed to confirm biopsy findings of intestinal metaplasia (IM).

RESULTS

BE was diagnosed in 378 subjects between 1997 and 2007. Mean age at diagnosis of BE was 60.7 +/- 14.1 years, with mean BMI of 27.4 +/- 5.2 kg/m(2) and mean BE segment length of 4.7 +/- 3.7 cm. Between 1997 and 2007 there was no significant change in mean age at diagnosis, BMI, BE segment length or in proportion of men versus women newly diagnosed.

CONCLUSIONS

Despite an increase in volume of EGDs performed in an open-access endoscopy unit between 1997 and 2007, there was no appreciable shift in age at diagnosis of BE. BMI and BE segment length among newly diagnosed patients also remained stable over this time period.

History, molecular mechanisms, and endoscopic treatment of Barrett's esophagus

This report is an adjunct to the American Gastroenterological Association Institute's medical position statement and technical review on the management of Barrett's esophagus, which will be published in the near future. Those documents will consider a number of broad questions on the diagnosis, clinical features, and management of patients with Barrett's esophagus, and the reader is referred to the technical review for an in-depth discussion of those topics. In this report, we review historical, molecular, and endoscopic therapeutic aspects of Barrett's esophagus that are of interest to clinicians and researchers.