What adjuvant chemotherapy would you recommend in a elderly patient with resected stage III colon cancer with MMR deficiency with MLH1 promoter hypermethlation?  

This is a great question and actually a quite common situation we see in the clinic. Majority of the dMMR colorectal cancer is actually due to MLH1 promotor hypermethylation (about 75% of all dMMR colorectal cancer) while a small portion of dMMR colorectal cancer is due to Lynch syndrome. These pati...

One could also argue, that in an elderly frail patient with a low absolute benefit of adjuvant chemotherapy and its attendant side effects consider surveillance and if there is systemic recurrence (25%) palliate with immune therapy. 

Great answers. We also have a study that allows any chemo duration for stage 3 and if ctDNA is positive, could get PD1.

Approximately 60% of the stage III dMMR colon cancer patients are cured after surgical resection and at most, only 10–15% benefit from oxaliplatin-based adjuvant treatment (André et al., PMID 26527776, Tougeron et al., PMID 26839356). There is considerable prognostic heterogeneity depen...