Inclusion Criteria:  Surgically treated T1-T4 adenocarcinoma with or without prior chemotherapy AND close (<2.5mm)/positive resection margin AND/OR N1 staging at lymphadenectomy ECOG performance status <2 Age > 18 Estimated life expectancy > 6 months Ability to provide written informed consent Cardiovascular comorbidities limiting life expectancy  Exclusion Criteria:  Metastatic disease Biliary tract or neuroendocrine neuroplasm History of malignancies except for non-melanoma cutaneous tumors