[Endoscopic submucosal dissection in undifferentiated early gastric cancer: evaluation of the first cases and analysis of its application as an absolute indication in Peru].

Unlabelled: Endoscopic submucosal dissection (ESD) is the technique of choice in the management of early gastric cancer. Recently, it is also considered as an absolute indication in selected cases of early undifferentiated gastric cancer (U-EGC).

Objectives: In the present study, the first documented cases of ESD in patients with U-EGC are presented and analyzed.

Materials And Methods: Retrospective and multicenter study carried out from February 2018 to April 2024. Twelve cases were included with a final histopathological diagnosis of U-EGC after undergoing ESD under absolute indication. En bloc and curative resection rates, incidence of adverse events, and surgical outcomes in cases referred to surgery are described.

Results: The median age of the patients was 54.5 years, with a female predominance. All lesions were resected en bloc. There were no complications associated with ESD. The histopathological results revealed a predominance of the signet ring cell subtype. A 66.7% curative resection was achieved. Five patients were referred to surgery after ESD, without finding residual cancer or affected lymph nodes in the surgical specimens. There were no recurrences at a median follow-up of 7.5 months.

Conclusions: The findings suggest that DES is a safe and effective treatment for selected cases of U-EGC in Peru, achieving curative resection rates similar to those published in eastern studies.