Radical resection with or without adjuvant chemotherapy is a common option for stage II and III colorectal cancer. Few reports exist regarding gastric tumorigenesis, including gastric cancer, gastric intraepithelial neoplasia, and gastric stromal tumor, in patients who received this protocol as the standard treatment for colorectal cancer. We present two cases of gastric tumorigenesis in patients with colorectal cancer following radical resection combined with adjuvant chemotherapy. Both patients underwent gastrectomy and D2 lymphadenectomy for their gastric tumors; neither patient developed recurrence up to 2 years after treatment. These cases indicate that patients should be monitored closely for gastric tumorigenesis after treatment for colorectal cancer. Early detection and active surgical treatment can provide satisfactory results for colorectal cancer followed by gastric tumorigenesis. Long-term follow-up and regular examinations, especially gastroscopy, are necessary to detect gastric tumorigenesis after colorectal cancer. The focus on monitoring colorectal cancer alone in colorectal cancer patients should be changed to include a broader range of cancers in addition to precancers and other tumors, such as gastric stromal tumor.
Keywords: Colorectal cancer; gastrectomy; gastric cancer; gastric intraepithelial neoplasia; gastric tumorigenesis; gastrointestinal stromal tumor.