primary gastric cancer的用法和样例：
例句
- With the development of endoscopic techniques, more and more early gastric cancers can be treated endoscopically.
摘要随着内镜技术的不断进步，越来越多的早期胃癌可经内镜下治疗。 - We consider the mucosa and submucosa carcinoma without lymphatic metastasis as early gastric carcinoma.
作者认为，位于粘膜和粘膜下层的胃癌，只有无周围淋巴结转移者，才能称为早期胃癌。
