Endoscopic Mucosal Resection Valuable for Cancer Diagnosis

Laird Harrison

January 27, 2022

Surgeons should perform endoscopic mucosal resection (EMR) for all visible lesions in the presence of neoplasia to make an accurate histopathologic diagnosis of early-stage esophageal cancer, said a physician presenting at the 2022 Gastrointestinal Cancers Symposium.

Vani Konda, MD, a gastroenterologist with Baylor Scott and White Center for Esophageal Diseases, Dallas, participated in an educational session on approaches for treating localized gastroesophageal cancer. In her presentation, she addressed the advantages and disadvantages of EMR and endoscopic submucosal dissection (ESD) for esophageal neoplasia for both diagnosis and treatment.

Esophageal neoplasia therapy includes tissue-acquiring (lesion removal and histopathologic samples) and non–tissue-acquiring therapies (which include radiofrequency ablation, cryotherapy and hybrid-argon plasma coagulation.

The optimal therapy may vary with the esophageal cancer, and the cancer may vary with geography. Worldwide, squamous cell carcinoma is predominant, while in Western countries, esophageal adenocarcinoma is most prevalent. The incidence and mortality of esophageal adenocarcinoma has been rising for several decades, Konda said.

Considering Risk Factors

Barrett's esophagus is a known risk factor for esophageal adenocarcinoma. It can be seen endoscopically as salmon-colored lining, and histologically as specialized intestinal metaplasia.

A lesion extending beyond the basement membrane into the lamina propria is an intramucosal carcinoma, or T1a lesion. A lesion extending beyond the muscularis mucosa into the submucosa is a submucosal carcinoma, or T1b tumor, Konda said.

"The difference between T1a and T1b is important in the selection of treatment approaches due to the risk of lymphoma metastasis," she said. She equated a T1a lesion with a 2% or smaller risk of lymphoma metastasis, and a T1b tumor with a 20% risk.

Endoscopic therapy is more reasonable for a T1a lesion, especially since the alternative, esophagectomy, may have a mortality rate of 2% or higher, she said, while for T1b tumors, surgical or systemic treatments are warranted.

A diagnosis of high-grade dysplasia by biopsy is associated with a 40% risk of prevalent cancer, mostly intramucosal carcinoma. On the other hand, submucosal carcinoma is rare in the absence of endoscopically visible lesions. "This risk of prevalent cancer, especially in visible lesions, is the reason that we should address all visible lesions with endoscopic resection, especially in the setting of dysplasia," Konda said.

EMR is more accurate than biopsies; diagnoses change up to half the time when EMR is done after a preresection biopsy, and there's a higher interobserver agreement among pathologists with EMR, she said.

The goal of therapy in Barrett's esophagus is total Barrett's eradication to treat not only the known neoplasia, but also the rest of the at-risk epithelium.

Piecemeal EMR for the entire Barrett's epithelium can bring about a 96% or greater neoplasia eradication rate. But the stricture rate may reach 37%, and bleeding and perforation are also common.

Combining endoscopic mucosal resection for visible lesions with ablation for the rest of the at-risk lining can achieve an eradication rate of 93% with a more favorable complication profile.

Weighing the Benefits of ESD

In contrast to EMR, ESD has been practiced more frequently in Asia. It provides an en bloc specimen.

A 2014 systematic review of 380 EMR procedures and 333 ESD procedures for Barret's associated neoplasia indicated that ESD takes longer. The recurrence rate was 0.7% for ESD versus 2.6% for EMR, but this difference fell just short of statistical significance (P = .06). Bleeding and perforation rates were similar, but stricture rates reached 22.3% with wide-field EMR, 3.4% with ESD and 0.7% with focal EMR.

In a 2016 head-to-head trial, researchers assigned 20 patients each to EMR or ESD. They found the procedure longer, but the en bloc resection was higher in ESD. Complete remission of the neoplasia was not statistically different between the two groups, with 15 of 16 patients achieving this goal with ESD and 16 of 17 with EMR. All the patients had complete remission after one retreatment of residual neoplasia. There were two severe adverse events in the ESD group, and none in the EMR group.

Weighing the pros and cons, Konda concluded that EMR is technically easier and adequate in most cases of Barrett's esophagus, while ESD may be preferred in select cases with concern for submucosal carcinoma or nonlifting lesions.

She advocated taking patient characteristics, disease characteristics, and available expertise into account.

Konda reported financial relationships with Ambu, Cernostics, Exact Sciences, Medtronic, and Lucid Sciences. The Gastrointestinal Cancers Symposium is sponsored by the American Gastroenterological Association, the American Society for Clinical Oncology, the American Society for Radiation Oncology, and the Society of Surgical Oncology.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.


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