Topic: Feverfew?

Hi, my relative is 3 years post resection but recently has experienced elevated CA19-9 and questionable shadow/soft tissue appearance on scan around the portal vein. 

He does not want to do chemo/radiation and is going back on Vit C IV (which he had done post surgery. 

I have been exploring other alternative approaches - one of which is feverfew which has been shown to promote apoptosis on cc cells.

Does anyone have any experience with this?