is radiotherapy necessary for colorectal cancer?

My mom has been diagnosed with stage IIIC Colorectal cancer with a tumor ~14cm from the anal verge, and has had the colon resection surgery.  Now we are deciding on the rest of the treatment plan.  Her oncologist is recommending both chemotherapy and radiation, and is uncertain which to do first.  However, we're worried that since this may actually be colon, not rectal cancer due to the location, radiation isn't necessary and may be harmful (some of the side effects are terrible and sometimes become permanent).   On one hand, with such an advanced cancer one should take all steps to prevent local recurrence.  But on the other, in this case, will radiation decrease the chance enough to warrant the potential side effects? Anyone have any experience with a borderline case like this?  

[jdwithhcv]

I had a diagnosis very similar to your mother's - Stage IIIC rectal cancer, very close to the anal verge.  I had radiation and chemo before my first surgery.  Radiation was very difficult and I have some lasting damage and scarring, however I am cancer free for over five years now.  I would not recommend radiation lightly, but if her medical team deems it necessary I think she should follow their advice.

Best of luck to your mother.

jd