Applicability of endoscopic submucosal dissection for undifferentiated early gastric cancer: Mixed histology of poorly differentiated adenocarcinoma and signet ring cell carcinoma is a worse predictive factor of nodal metastasis.
BACKGROUND
Endoscopic submucosal dissection (ESD) is not considered an appropriate treatment for undifferentiated early gastric cancer (UEGC) due to the higher risk of nodal metastases. We aimed to investigate predictive factors for nodal metastases in UEGCs, determine whether the tumor histology is an independent factor for it, and explore whether ESD is applicable for UEGC.


METHODS
We reviewed the medical records of 1837 patients who underwent curative gastrectomy for poorly differentiated adenocarcinoma, signet ring cell carcinoma, and a mixed type of both tumors between 2008 and 2012.


RESULTS
Nodal metastases were found in 208 (11.3%) patients. Multivariate analysis revealed that lymphovascular invasion and tumor histology were significantly associated with nodal metastases in mucosal cancers, the rates of which were higher in mixed type tumors (6.3%) than in the other two types (2.0-2.5%; p = 0.005). No nodal metastases were observed in poorly differentiated adenocarcinomas <2 cm and signet ring cell carcinomas <1 cm without lymphovascular invasion and confined to the mucosa.


CONCLUSIONS
Mixed type tumors should not be considered for endoscopic resection. ESD might be applicable for mucosal tumors with poorly differentiated adenocarcinoma <2 cm and signet ring cell carcinoma <1 cm without lymphovascular invasion.
Department of Surgery, Ulsan University College of Medicine, Asan Medical Center, Seoul, 05505, South Korea.
In Seob
IS
Lee
Department of Surgery, Seoul Medical Center, Seoul, 02053, South Korea.
Sol
S
Lee
Department of Pathology, Ulsan University College of Medicine, Asan Medical Center, Seoul, 05505, South Korea.
Young Soo
YS
Park
Department of Surgery, Ulsan University College of Medicine, Asan Medical Center, Seoul, 05505, South Korea.
Chung Sik
CS
Gong
Department of Surgery, Ulsan University College of Medicine, Asan Medical Center, Seoul, 05505, South Korea.
Jeong Hwan
JH
Yook
Department of Surgery, Ulsan University College of Medicine, Asan Medical Center, Seoul, 05505, South Korea. Electronic address: bskim@amc.seoul.kr.
Byung Sik
BS
Kim
D000230:Adenocarcinoma / Q000556:secondary* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018279:Carcinoma, Signet Ring Cell / Q000556:secondary* / Q000601:surgery; D000069916:Endoscopic Mucosal Resection / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D005743:Gastrectomy; D005773:Gastroscopy; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000473:pathology* / Q000601:surgery; D015996:Survival Rate; D055815:Young Adult
Lymph node metastasis; Mixed histology; Undifferentiated gastric cancer