what can i expect?

mom80yrs oldcolon cancer  june 062 pints of bloodsurgery july 06 infection delayed chemo 3 monthstried a lower dose of Xeloda for 6 months ... couldnt tank the side effectsnow on Irinotecan and erbitux  3 monthssept 07 Ct scanshowed 9 tumors 3 in the stomach area and 6 in the lungs cea has slowly risen to 145 they continue to want to treat her...what can i expect?is it worth putting her through chemo?    ...