Dormant stomach cancer help

My mum has stomach cancer and had surgery to remove it,but surgeon who performed the surgery said he couldn't get all of it out and some is laying dormant but he couldn't get to it and remove it.Am looking to hear from someone or know of someone who has same type of cancer and can offer help and advice as to what treatments that can help get the dormant cancer out,or know of any specialists places that deal with this type of cancer that can help,so have you or someone you know had same dormant cancer and have successfully had it removed if so please let me know ASAP your help and advice would be very much appreciated as am trying everything I can to find treatments that can help my mum.many thanks Ricky