The current state of diagnosis and treatment for early gastric cancer

Abstract

The prognosis for gastric cancer depends on its stage; so, detection in the early stage of disease is important, when complete and curative removal is possible. Accurate diagnosis can be facilitated by a sound understanding of the basic findings of white light endoscopy of early gastric cancer, and diagnosis can be refined further by the combined use of other imaging modalities such as image-enhanced endoscopy including chromoendoscopy and endoscopic ultrasonography. Minimally invasive endoscopic treatment has come to be the preferred therapeutic approach for early gastric cancer. In addition to conventional endoscopic mucosal resection, a new technique known as endoscopic submucosal dissection (ESD) has spread rapidly worldwide. Indeed, strategies for ESD have been established, devices developed, its indications expanded, and its safety and long-term results extensively reported. Some unique combination therapies involving endoscopy and surgical treatment have also been reported. It is anticipated that the number of patients undergoing endoscopic therapy will continue to increase, and the ongoing developments in endoscopic treatment are expected not only to improve gastric cancer prognosis but also to maintain good quality of life after treatment.

Figure 1

Macroscopic classification of early gastric cancer. (Type 0: superficial, flat tumor with or without minimal elevation or depression).

Figure 2

Macroscopic classification of early gastric cancer: (a) type 0-I (protruded type); (b) type 0-IIa (superficial and elevated type); (c) type 0-IIb (flat type); (d) type 0-IIc (superficial and depressed type); (e) type-III (excavated type).

Figure 3

(a) A differentiated type 0-IIa lesion on the anterior wall of the middle gastric body. Magnifying endoscopy (ME) with narrow band imaging (NBI) shows (b) a clear demarcation line (arrows) at the border of the lesion with noncancerous mucosa to the left and cancerous mucosa to the right and (c) an irregular microvascular pattern plus the absence of a microsurface pattern in the cancerous mucosa.

Figure 4

(a) An undifferentiated type 0-IIc lesion on the lesser curvature of the lower gastric body. (b) Magnifying endoscopy with narrow band imaging shows only a regular microvascular pattern plus a regular microsurface pattern in the cancerous mucosa with no identifiable demarcation line. (c) Multiple biopsies were taken from the mucosa surrounding the lesion to determine the horizontal extent of the cancer. (d) Marking dots were placed outside the scars of negative biopsies, and ESD was performed. (e) Histopathologically, the cancer extends to height of the glandular neck within the lamina propria mucosae and is covered with normal crypt epithelium.

Figure 5

Procedure of endoscopic submucosal dissection. (a) Type 0-IIa lesion on the lesser curvature of the middle gastric body. (b) Chromoendoscopy with indigo carmine dye spraying. (c) Marking around the lesion. (d) Making small initial incision with a needle knife. (e) Mucosal cutting with an insulation-tipped diathermic knife-2 (IT knife-2). (f) Circumferential incision of the mucosa. (g) Additional submucosal injection of diluted epinephrine and indigo carmine. (h) Dissection of the submucosal layer with an IT knife-2. (i) The mucosal defect after resection of the lesion.