Simultaneous gastric cancer and breast cancer metastases to the stomach with lymph node collision tumor: a case report.

BACKGROUND: While double primary cancers are common in breast cancer patients, co-existence of primary gastric cancer and gastric metastases of breast cancer is exceedingly rare. CASE PRESENTATION: A 51-year-old woman receiving chemotherapy for breast cancer presented with melena and presyncope. A circumferential thickening of the pylorus and small submucosal tumor-like lesions in the gastric fundus and corpus were confirmed on endoscopy. Immunohistochemistry of biopsies revealed that the former was composed of poorly differentiated gastric cancer cells, while the latter were breast cancer metastases. Distal gastrectomy was performed. Pathological evaluation of the resected specimen revealed gastric adenocarcinoma in the pyloric lesion and breast countless cancer metastases throughout the remainder of the stomach, with positive margins. One lymph node had evidence of both stomach cancer and breast cancer metastases, forming a collision tumor. Despite a successful surgery, the patient died 6 months later due to progression of breast cancer. CONCLUSION: We report a case of synchronous primary gastric adenocarcinoma and gastric metastases of breast cancer. Inter-disciplinary collaboration is crucial in determining the optimal treatment in double cancers.

Predictive factors for lymph node metastasis and defining a subgroup treatable for laparoscopic lymph node dissection after endoscopic submucosal dissection in poorly differentiated early gastric cancer.

AIM: To investigate the predictive factors of lymph node metastasis (LNM) in poorly differentiated early gastric cancer (EGC); to guide the individual application of a combination of endoscopic submucosal dissection (ESD) and laparoscopic lymph node dissection (LLND) in a suitable subgroup of patients with poorly differentiated EGC. METHODS: We retrospectively analyzed 138 patients with poorly differentiated EGC who underwent gastrectomy with lymphadenectomy between January 1990 and December 2015. The association between the clinicopathological factors and the presence of LNM was retrospectively analyzed by univariate and multivariate logistic regression analyses. Odds ratios (OR) with 95% confidence interval (95%CI) were calculated. We further examined the relationship between the positive number of the significant predictive factors and the LNM rate. RESULTS: The tumor diameter (OR = 13.438, 95%CI: 1.773-25.673, P = 0.029), lymphatic vessel involvement (LVI) (OR = 38.521, 95%CI: 1.975-68.212, P = 0.015) and depth of invasion (OR = 14.981, 95%CI: 1.617-52.844, P = 0.024) were found to be independent risk factors for LNM by multivariate analysis. For the 138 patients diagnosed with poorly differentiated EGC, 21 (15.2%) had LNM. For patients with one, two and three of the risk factors, the LNM rates were 7.7%, 47.6% and 64.3%, respectively. LNM was not found in 77 patients that did not have one or more of the three risk factors. CONCLUSION: ESD might be sufficient treatment for intramucosal poorly differentiated EGC if the tumor is less than or equal to 2 cm in size and when LVI is absent upon postoperative histological examination. ESD with LLND may lead to the elimination of unnecessary gastrectomy in poorly differentiated EGC.