A238 A RETROSPECTIVE ANALYSIS OF THE LONG-TERM OUTCOMES OF PATIENTS WITH T1B ESOPHAGEAL CANCER

Abstract Background Endoscopic mucosal resection is commonly performed for dysplasia/early adenocarcinoma within the setting of Barrett’s esophagus. Cancers that invade the submucosa (T1b) can be further subdivided into SM1, SM2, and SM3, depending on the depth of invasion into the submucosa. Invasive adenocarcinoma significantly increases the risk of lymph node metastasis, which is of critical importance if endoscopic treatment is the only therapy planned. Accurate prediction of lymph node status is therefore crucial in order to determine the appropriate method (surgery or endoscopic) of treatment for early lesions. Aims This study aims to assess the long-term outcomes of patients who have had treatment for a T1b esophageal adenocarcinoma and to determine the extent of lymph node involvement as assessed through surgical specimens or long term clinical/radiological follow up. Additionally, factors associated with lymph node metastasis will be evaluated. Methods A retrospective chart review of patients with T1b esophageal cancer between 01/05-05/17 was performed at 4 sites which deal with most of the esophageal cancers in British Columbia. Data collected includes demographics, procedure dates, indication, findings, imaging, characteristics of the cancer (depth and extent of penetration, size of lesion, differentiation, lymphovascular invasion), method of resection, and follow-up. Results 36 patients were found to have a T1b esophageal adenocarcinoma. 75% (27/36) of these patients received surgery to remove the cancer while 25% (9/36) received EMR. The overall rate of lymph node metastasis (LNM) for all patients was 13.8% (5/36). All of these patients went for surgery and had at least one high-risk factor (poorly differentiated, positive for lymphovascular invasion, >2cm). 56% (15/27) of patients that went for surgery received neoadjuvant therapy, including only 1 of the 5 patients with LNM. The average follow up was 777 days (range, 0 – 2660 days) for surgical patients and was 1210 days (range, 120 – 2880 days) for EMR patients. Conclusions 13.8% of patients have had evidence of lymph node involvement in this group with T1b esophageal adenocarcinoma. Patients with T1b esophageal adenocarcinoma that have low risk features (well differentiated, negative for lymphovascular invasion,