Background and Aims

Endoscopic submucosal dissection (ESD) has become an important and minimally invasive treatment for early gastric cancer (EGC) with a negligible risk of metastasis not only for differentiated-type (D-type) cancer but also for undifferentiated-type (UD-type) cancer. We aimed to investigate the incidence and characteristics of metachronous cancer after ESD for UD-type cancer, which has not yet been elucidated.

Methods

In total, 175 patients who underwent ESD for UD-type EGC were enrolled. For comparison, 350 patients who underwent ESD for D-type EGC during the same period were randomly selected. These patients underwent a follow-up EGD annually. The median observation period was 6.0 years and 5.4 years, respectively.

Results

The annual incidence of metachronous cancer after ESD for UD-type and D-type cancer was .9% and 5.3%, respectively. Among the patients who underwent ESD for UD-type cancer, 30.9% of patients were uninfected with Helicobacter pylori, whereas all patients who underwent ESD for D-type cancer were infected with H pylori. All patients who developed metachronous cancer were infected with H pylori. UD-type metachronous cancer developed more frequently in patients after ESD for UD-type cancer than after ESD for D-type cancer, and the curative resection rate of ESD was significantly lower in these cases.

Conclusions

Metachronous cancers developed only in H pylori-infected patients in this cohort. Although metachronous cancer incidence was significantly less frequent in patients after ESD for UD-type cancer, the curative resection rate of ESD was significantly lower. Routine surveillance should be conducted more carefully after ESD for UD-type cancer, especially in H pylori-infected patients.

中文翻译：

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内镜黏膜下剥离术后异时癌发生率：未分化型和分化型早期胃癌的比较

背景和目标

内镜黏膜下剥离术 (ESD) 已成为早期胃癌 (EGC) 的重要微创治疗方法，其转移风险可忽略不计，不仅对于分化型 (D 型) 癌，而且对于未分化型 (UD 型)癌症。我们旨在调查 UD 型癌症 ESD 后异时性癌症的发生率和特征，这尚未阐明。

方法

总共招募了 175 名因 UD 型 EGC 接受 ESD 的患者。为了比较，随机选择了 350 名在同一时期因 D 型 EGC 接受 ESD 的患者。这些患者每年接受一次 EGD 随访。中位观察期分别为 6.0 年和 5.4 年。

结果

UD 型和 D 型癌症 ESD 后异时癌的年发病率分别为 0.9% 和 5.3%。在因UD型癌症接受ESD的患者中，30.9%的患者未感染幽门螺杆菌，而所有因D型癌症接受ESD的患者均感染了幽门螺杆菌。所有发生异时性癌症的患者均感染了幽门螺杆菌。UD 型异时癌在 ESD 后发生 UD 型癌的患者比 ESD 后 D 型癌患者更频繁，并且这些病例的 ESD 治愈性切除率显着降低。

结论

异时性癌症仅在该队列中感染幽门螺杆菌的患者中发生。尽管 UD 型癌症 ESD 后患者的异时性癌症发病率显着降低，但 ESD 的治愈性切除率显着降低。对于 UD 型癌症，尤其是H pylori感染患者，ESD 后应更仔细地进行常规监测。