567P - The differences between suspicious Lynch and sporadic dMMR colorectal cancers

Date 08 October 2016
Event ESMO 2016 Congress
Session Poster Display
Topics Colon and Rectal Cancer
Presenter Guochen Liu
Citation Annals of Oncology (2016) 27 (6): 149-206. 10.1093/annonc/mdw370
Authors G. Liu, W. Huang, R. Liu, Z. Pan, P. Ding
  • Colorectal Cancer, Cancer Centre Sun Yat-Sen University, 510060 - Guangzhou/CN



Few studies have systematically compared the difference between germline and sporadic dMMR colorectal cancers on clinical-pathological features, prognosis, lymphocytic reactions, somatic mutation frequencies and neoantigen burdens.


We retrospectively collected dMMR colorectal patients identified by postoperative immunohistochemistry screening. According to genetic test or clinical-pathological criterias, patients were then grouped as suspicious Lynch or sporadic dMMR. We compared the clinico-pathologic and prognostic differences between the two groups. By evaluating the four components of lymphocytic reaction {i.e., Crohn's-like reaction (CRO), immunoreactions in the invasive margin (IM), in the tumour stroma (TS) and cancer center (CC)} and counting CD3 + /CD4 + /CD8 + /Foxp3+ tumor-infiltrating lymphocytes, we investigated their immune response and lymphocyte subgroup differences. By whole exome sequencing and neoantigen detection pipeline, we contrasted their discrepancies on mutational frequencies and neoantigen burdens.


213 of the 381 dMMR pts were grouped: 94 sporadic dMMR and 119 suspicious Lynch. Sporadic dMMR patients were significantly older (P 


There were more somatic mutations and neoantigens in suspicious Lynch patients and causing their more intense immunoreactions, which might benefit their survival.

Clinical trial identification


Legal entity responsible for the study

Sun Yat-sen University Cancer Center


Nature Science Foundation of China (Grant number: 81101591).


All authors have declared no conflicts of interest.