Bone metastasis from early gastric cancer following non-curative endoscopic submucosal dissection

Abstract

A 67-year-old male underwent endoscopic submucosal dissection (ESD) to treat early gastric cancer (EGC) in 2001. The lesion (50 mm × 25 mm diameter) was histologically diagnosed as poorly differentiated adenocarcinoma, with an ulcer finding. Although the tumor was confined to the mucosa with no evidence of lymphovascular involvement, the ESD was regarded as a non-curative resection due to the histological type, tumor size, and existence of an ulcer finding (as indicated by the 2010 Japanese gastric cancer treatment guidelines, ver. 3). Despite strong recommendation for subsequent gastrectomy, the patient refused surgery. An alternative follow-up routine was designed, which included five years of biannual clinical examinations to detect and measure serum tumor markers and perform visual assessment of recurrence by endoscopy and computed tomography scan after which the examinations were performed annually. The patient’s condition remained stable for eight years, until a complaint of back pain in 2010 prompted further clinical investigation. Bone scintigraphy indicated increased uptake. Histological examination of biopsy specimens taken from the lumbar spine revealed adenocarcinoma resembling the carcinoma cells from the EGC that had been treated previously by ESD, and which was consistent with immunohistochemical findings of gastrointestinal tract cancer. Thus, the diagnosis of bone metastasis from EGC was made. The reported rates of EGC recurrence in surgically resected cases range 1.4%-3.4%, but among these bone metastasis is very rare. To our knowledge, this is the first reported case of bone metastasis from EGC following a non-curative ESD and occurring after an eight-year disease-free interval.

Keywords: Endoscopic submucosal dissection, Early gastric cancer, Non-curative resection, Bone metastasis, Late recurrence

Core tip: This case report provides the first description of an adult male with bone metastasis from early gastric cancer following an eight-year disease-free interval after endoscopic submucosal dissection (ESD). Although the original tumor was confined to the mucosa, with no evidence of lymphovascular involvement, the ESD was regarded as a non-curative resection based upon the tumor’s histological type and size, and existence of an ulcer finding. If any patient, who is otherwise fit, initially refuses surgery and requests a contraindicated ESD, efforts should be made to persuade the patient to undergo a gastrectomy with lymph-node dissection.